RU2827290C2 - Agricultural sampling system and related methods - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: computer-controlled automated sampling system, and corresponding methods of collecting, processing and analyzing agricultural samples for the presence of various chemical properties, such as nutrients available to plants. System includes a sample preparation subsystem which receives soil samples collected by the sample collection subsystem and produces a suspension (for example, a mixture of soil, vegetation and/or organic fertilizers and water) and a chemical analysis subsystem which processes the prepared suspension samples for quantitative evaluation of several analytes and/or chemical properties of the sample. Preparation system may contain a suspension recirculation loop connected to devices intended for mixing, measuring and adjusting the ratio of water and solid substances in the suspension.

EFFECT: sampling system enables to process and analyze a plurality of samples for different analytes or chemical properties in a simultaneous parallel or partially parallel mode; preferably, the system can process soil samples "as they are collected" without drying and grinding.

18 cl, 70 dwg

Description

Links to related applications

This application is a continuation of U.S. Application No. 17/326,050, filed May 20, 2021, and claims priority to U.S. Provisional Application Nos. 63/191,186, 63/191,189, 63/191,195, 63/191,199, and 63/191,204, filed May 20, 2021. All of the foregoing applications are hereby incorporated by reference in their entirety.

Field of technology to which the invention relates

The present invention relates generally to the collection and analysis of agricultural samples and, more particularly, to a fully automated system for performing the collection of soil and other agriculturally related samples and the analysis of chemical properties.

State of the art

Periodic soil testing is an important aspect of agriculture. The results of the tests provide valuable information about the chemical composition of the soil, such as the nutrients available to plants and other important properties (e.g. levels of nitrogen, magnesium, phosphorus, potassium, pH, etc.), so that various amendments can be made to the soil to maximize the quality and quantity of the crop.

In some existing soil sampling processes, collected soil samples are dried, ground, watered, and then filtered to produce a soil suspension suitable for analysis. An extractant is added to the suspension to extract plant-available nutrients. The suspension is then filtered to produce a clear solution or supernatant, which is mixed with a chemical reagent for further analysis.

Improvements in soil, vegetation and organic matter research are desirable.

Disclosure of the essence of the invention

The present invention provides an automated computer-controlled sampling system and corresponding methods for collecting, processing and analyzing agricultural samples, such as, in one embodiment of the invention, inter alia, soil samples, for various chemical properties, such as plant-available nutrients. The sampling system allows for processing and analyzing multiple samples for various analytes (e.g., plant-available nutrients) and/or chemical properties (e.g., pH) simultaneously in parallel or partially in parallel, as well as in a relatively continuous and rapid sequence. Preferably, the system can process soil samples or other types of agricultural samples in an "as-collected" state without the complex drying and grinding steps of the previous processes described above.

The present system generally includes a sample preparation subsystem that receives soil samples or other types of agricultural samples and produces an agricultural slurry (e.g., a mixture of soil, vegetation, and/or organic fertilizers, and water), and a chemical analysis subsystem that receives and processes the prepared slurry samples from the sample preparation subsystem to quantify analytes and/or chemical properties of the sample. Agricultural samples may be collected automatically by the sample collection subsystem or by other means, including manual sampling. The described chemical analysis subsystem may be used to analyze an agricultural slurry that may consist of soil, vegetation, organic fertilizers, milk, or other types of samples.

In one embodiment of the invention, the sample preparation system generally includes a mixing device that mixes a collected raw soil sample in an "as collected" state (e.g., not dried and not crushed) with a diluent, such as water, to form a sample slurry. The unfiltered slurry is then coarsely filtered by a coarse filter unit to remove larger-than-desired solid particles, which may include foreign debris in the sample and/or hardened accumulations of solids of the agricultural sample that are not completely broken down by the mixing device. The filtered slurry (filtrate) is then fed to a closed slurry recirculation loop configured to circulate the slurry to determine the ratio of water to solids in the slurry. As further described herein, the various components that form integral parts of the loop are configured to circulate the slurry in the closed loop, suppress pressure surges, measure the density of the slurry, and measure the density of the solids component of the slurry. The operation of some or all of the system and loop components may be controlled by a programmable system controller. The system measures the actual water to solids ratio and compares this measurement to the desired target water to soil ratio required for subsequent chemical analysis of the slurry to quantify the level or concentration of the analyte of interest (e.g., soil nutrients or other parameter). The system is configured to add water to the closed loop to achieve the target water to soil ratio.

Once the desired water to soil ratio is achieved, the slurry is extracted from the slurry recirculation loop and filtered through a fine filter unit which is an integral component of the slurry recirculation channel. The extracted and filtered slurry is then processed by the chemical analysis subsystem which quantifies the concentration or level of the analyte(s) of interest. The chemical analysis subsystem performs the general functions of adding/mixing the extractant to the slurry, separating the clear supernatant from the slurry, adding/mixing the color changing reagent to the supernatant and finally determining or analyzing for analyte detection and/or chemical properties, such as colorimetric analysis or other analytical methods.

Although sampling systems (e.g., sampling, preparation, and processing) may be described herein with respect to processing soil samples, which is one category of use of the disclosed embodiments, it should be understood that the same systems, including devices and processes, may also be used to process other types of agricultural samples, including, but not limited to, vegetation, forage, organic fertilizers, food, milk, or other types of samples. Thus, the embodiments of the invention disclosed herein should be considered in a broad sense as an agricultural sampling system. Accordingly, the present invention is clearly not limited to use only in processing and analyzing soil samples for chemical properties of interest.

Brief description of the drawings

The present invention will be better understood from the detailed description and the accompanying drawings, in which like elements are designated by like reference numerals.

Fig. 1 is a block diagram of an agricultural sample analysis system in accordance with the present invention, showing high-level functional features of each subsystem of the sample analysis system;

Fig. 2 is a schematic system diagram of a central processing unit (CPU) based on a programmable processor or system controller for controlling the systems and devices disclosed in this document;

Fig. 3 is a basic schematic diagram of the first embodiment of the system for analyzing agricultural samples;

Fig. 4 is a basic schematic diagram of the second embodiment of the agricultural sample analysis system, which includes a closed suspension recirculation loop;

Fig. 5 is a perspective view of a first embodiment of a suspension density meter used in the systems shown in Fig. 3 or 4;

Fig. 6 shows its first side view;

Fig. 7 shows its second side view;

Fig. 8 shows its first end view;

Fig. 9 shows its second end view;

Fig. 10 shows its view from above;

Fig. 11 shows its view from below;

Fig. 12 shows its first view in longitudinal section;

Fig. 13 shows its second view in longitudinal section;

Fig. 14 shows its perspective view in longitudinal section;

Fig. 15 is a first perspective view of a second embodiment of a suspension density meter used in the systems shown in Fig. 3 or 4;

Fig. 16 shows its second view in perspective;

Fig. 17 shows its third perspective view with the peripheral board of the control system disconnected;

Fig. 18 shows its longitudinal sectional view;

Fig. 19A is a section of the oscillating tube of a density meter illustrating the accumulation of iron particles in the suspension on the inside of the tube caused by the magnetic field of a permanent magnet attached to the tube;

Fig. 19B shows the first embodiment of a magnetic insulation element attached to an oscillatory tube;

Fig. 19C shows a second embodiment of a magnetic insulation element attached to an oscillatory tube;

Fig. 19D shows a third embodiment of a magnetic insulation element attached to an oscillatory tube;

Fig. 19E shows a fourth embodiment of a magnetic insulation element attached to an oscillatory tube;

in Fig. 19F - possible directed oscillatory movements of the oscillatory tube;

in Fig. 19G - an oscillatory tube installed in a vertical position;

Fig. 20 is a first perspective view of a first embodiment of a fine filter unit;

Fig. 21 shows its second view in perspective;

Fig. 22 shows its view from below;

Fig. 23 shows its view from above;

Fig. 24 shows its longitudinal side view in section;

Fig. 25 is a first perspective view of a second embodiment of a fine filter unit;

Fig. 26 shows its second view in perspective;

Fig. 27 shows its end view;

Fig. 28 shows its view from above;

Fig. 29 shows its side view in section;

Fig. 30 is a schematic diagram of a pumpless system for mixing a soil suspension using compressed air;

Fig. 31 is a first graph showing the dependence of the amount of diluent (for example, water) added to the suspension on the density of the suspension;

Fig. 32 shows the second such graph;

Fig. 33 is the third such graph;

Fig. 34 is a schematic diagram of the equipment and a block diagram of an alternative embodiment of a system for preparing an agricultural suspension in accordance with a system for analyzing agricultural samples;

Fig. 35 is a block diagram of a system for analyzing agricultural samples, including the suspension preparation system shown in Fig. 34;

Fig. 36 is a perspective view from above of the coarse filter block of the agricultural suspension preparation system;

Fig. 37 shows its disassembled view;

Fig. 38 shows its perspective view from below;

Fig. 39 shows its first side view;

Fig. 40 shows its second side view;

Fig. 41 shows its longitudinal sectional view;

in Fig. 42 - an enlarged fragment indicated in Fig. 41;

Fig. 43 is a cross-sectional view of a coarse filter block;

Fig. 44 is a perspective view from above of the accumulator of the agricultural suspension preparation system;

Fig. 45 shows its perspective view from below;

Fig. 46 shows its perspective view from above in a disassembled state;

Fig. 47 shows its perspective view from below in a disassembled state;

Fig. 48 shows its longitudinal sectional view;

Fig. 49 - view from the inlet end of the accumulator;

Fig. 50 shows its cross-sectional view;

Fig. 51 is a perspective view from above of the mixing device of the agricultural suspension preparation system;

Fig. 52 shows its view from above;

Fig. 53 shows its view from below;

Fig. 54 shows its left view;

Fig. 55 shows its view from the right;

Fig. 56 shows its front view;

Fig. 57 shows its rear view;

Fig. 58 shows its side view in longitudinal section;

Fig. 59 shows its front view in longitudinal section;

Fig. 60 is a cross-sectional view of it from above, showing the drive gear;

Fig. 61 is a cross-sectional view from below showing the blade assembly;

Fig. 62 is a perspective view of it from above in an exploded state, showing the separated engine and parts of the drive gear;

Fig. 63 is a perspective view of the lower section of the mixing device;

Fig. 64 is a cross-sectional view of a pneumatic double-diaphragm (PDM) pump of an agricultural suspension preparation system, showing the pump in a first operating pumping state;

Fig. 65 is a cross-sectional view showing the pump in the second operating pumping state;

Fig. 66 is a first perspective view of one of the pump heads, showing the inside and the attached inlet and outlet shut-off valves;

Fig. 67 is its second perspective view, showing the opposite outer side;

Fig. 68 is a perspective view showing the inlet valve in a disassembled state;

Fig. 69 is a plan view of the inside of the unit consisting of the pump head and valve; and

Fig. 70 shows its longitudinal section.

All drawings are not necessarily drawn to scale. Components identified and represented in one figure but not identified in other figures are the same unless specifically stated otherwise. In this document, a reference to a whole figure number that appears in several figures with the same whole number but with different letter symbols is to be construed as a general reference to all of those figures unless specifically stated otherwise.

Implementation of the invention

The features and advantages of the invention are illustrated and described herein with reference to embodiments of the invention ("examples"). This description of embodiments of the invention is intended to be read in conjunction with the accompanying drawings, which should be considered as part of the entire description. Accordingly, the invention is clearly not to be limited to such embodiments of the invention illustrating some possible non-limiting combination of features that may occur separately or in other combinations of features.

In the description of the embodiments of the invention disclosed herein, any reference to direction or orientation is for convenience of description only and is not intended to limit the scope of the present invention in any way. Relative terms such as "lower", "upper", "horizontal", "vertical", "above", "under", "upper", "lower", "top" and "bottom", as well as derivatives thereof (e.g., "horizontally", "downwardly", "upwardly", etc.) are to be understood in terms of the orientation as described or the orientation shown in the drawings discussed. These relative terms are used for convenience of description only and do not require that the device be constructed or operated in any particular orientation. Terms such as "attached", "fastened", "connected", "linked", "interconnected" and the like refer to such a mutual arrangement in which the structures are fixed or attached to each other either directly or indirectly through intermediate structures, as well as to both movable and rigid fastening or mutual arrangement, unless expressly stated otherwise.

Any ranges specified herein are used as a shorthand notation to describe each value that falls within the range. Any value within the range may be selected as the extreme value of the range. In addition, all references cited herein are incorporated by reference in their entirety. In the event of a conflict between definitions in the present specification and those in a cited reference, the present specification controls.

Fig. 1 is a schematic block diagram of a system 3000 for collecting agricultural samples in accordance with the present invention. The subsystems described herein collectively provide for the complete processing and chemical analysis of agricultural samples collected from an agricultural field, sample preparation, and final chemical analysis. In one embodiment of the invention, the system 3000 can be mounted on a motorized sampling vehicle configured to move around an agricultural field to collect and process soil samples from various zones of the field. This allows for an accurate mapping of the complete nutrient distribution and chemical composition of the field to quickly and conveniently determine the necessary soil amendments and application rates needed for each zone based on a quantitative assessment of plant-available nutrients and/or chemical properties of the sample. The system 3000 advantageously allows for the processing and chemical analysis of multiple samples simultaneously for the presence of various chemical components or properties, such as, for example, but not limited to, plant-available nutrients. In one embodiment of the invention, the sampling system may be a soil sampling system configured to determine nutrient levels in various parts of an agricultural field for growing crops. However, the sampling system may be used for various other types of agricultural samples, as described earlier in this document.

The agricultural sampling system 3000 typically includes a sample collection subsystem 3001, a sample preparation subsystem 3002, and a chemical analysis subsystem 3003. The sample collection subsystem 3001 and the motorized sampling vehicle are fully described in U.S. Patent Application Publication No. 2018/0124992A1. In the case of soil sampling, the sample collection subsystem 3001 typically performs the function of retrieving and collecting soil samples from a field. The samples may be in the form of soil plugs or cores. The collected cores are transferred to a storage chamber or vessel for further processing by the sample preparation subsystem 3002. Other sampling systems are described in U.S. Patent Application Nos. 62/983,237, filed February 28, 2020; 63/017,789, filed April 30, 2020; 63/017840 of 30 April 2020; 63/018120 of 30 April 2020; 63/018153 of 30 April 2020; 63/191147 of 20 May 2021; 63/191159 of 20 May 2021; 63/191166 of 20 May 2021; 63/191172 of 20 May 2021; 17/326050 of 20 May 2021; 63/191186 of 20 May 2021; 63/191189 of 20 May 2021; 63/191195 of 20 May 2021; 63/191199 of 20 May 2021; 63/191204 of 20 May 2021; 17/343434 of 09 June 2021; 63/208865 of 09 June 2021; 17/343536 of 09 June 2021; 63/213319 of 22 June 2021; 63/260772 of 31 August 2021; 63/260776 of 31 August 2021; 63/260777 of 31 August 2021; 63/245278 of 17 September 2021; 63/264059 of 15 November 2021; 63/264062, dated November 15, 2021; 63/264065, dated November 15, 2021; 63/268418, dated February 23, 2022; 63/268419, dated February 23, 2022; 63/268990, dated March 8, 2022; and in PCT Application Nos. PCT/IB2021/051076, dated February 10, 2021; PCT/IB2021/051077, dated February 10, 2021; PCT/IB2021/052872, dated April 7, 2021; PCT/IB2021/052874, dated April 7, 2021; PCT/IB2021/052875 dated April 07, 2021; PCT/IB2021/052876 dated April 07, 2021.

The sample preparation subsystem 3002 typically performs the functions of receiving solids or cores of agricultural samples into a mixing device, adding a predetermined amount or volume of filtered water, mixing the soil and water mixture to form a sample slurry, coarsely cleaning the slurry, and feeding the filtered slurry into a mixing device that is part of a closed slurry recirculation loop and flow path that recirculates the slurry in the loop, measuring the actual water to soil ratio in the slurry, and diluting the slurry with water to achieve a target water to soil ratio.

The chemical analysis subsystem 3003 typically performs the functions of pumping or extracting a slurry from a slurry recirculation loop through a fine filter, adding an extractant, mixing the extractant and slurry to extract analytes of interest (e.g., plant available nutrients, etc.), processing the extractant-slurry mixture to produce a clear liquid or supernatant, removing or transferring the supernatant, introducing a reagent and holding the supernatant-reagent mixture for a period of time to allow for a complete chemical reaction with the reagent, and measuring parameters of the analyte, such as by absorbance using a colorimetric assay or other analytical method.

The sample preparation and chemical analysis subsystems 3002, 3003 and their equipment or components will now be described in more detail.

As noted in this document, the agricultural sampling system, subsystems, and associated processes/methods disclosed in this document may be used to process and analyze soil, vegetation/plants, organic fertilizers, feed, milk, or other parameters of interest related to agriculture. In particular, embodiments of the chemical analysis portion of the system (chemical analysis subsystem 3003) described in this document may be used to test a variety of chemical parameters and analytes (e.g., nutrients/chemicals of interest) in areas other than soil and plant/vegetation sampling. Some non-limiting examples (including soil and plants) are provided below.

Soil Analysis: Nitrate, Nitrite, Total Nitrogen, Ammonium, Phosphate, Orthophosphate, Polyphosphate, Total Phosphate, Potassium, Magnesium, Calcium, Sodium, Cation Exchange Capacity, pH, Percent Cation Saturation, Sulfur, Zinc, Manganese, Iron, Copper, Boron, Soluble Salts, Organic Matter, Excess Lime, Active Carbon, Aluminum, Amino Sugar Nitrate, Ammonia Nitrogen, Chloride, Carbon to Nitrogen Ratio, Electrical Conductivity, Molybdenum, Texture (Sand, Silt, Clay), Soil Cyst Nematode Egg Count, Mineralizable Nitrogen, and Soil Pore Space.

Plants/vegetation: Nitrogen, nitrate, phosphorus, potassium, magnesium, calcium, sodium, percent cation saturation, sulfur, zinc, manganese, iron, copper, boron, ammoniacal nitrogen, carbon, chloride, cobalt, molybdenum, selenium, total nitrogen and live plant parasitic nematodes.

Organic Fertilizers: Moisture/Total Solids, Total Nitrogen, Organic Nitrogen, Phosphate, Potassium, Sulfur, Calcium, Magnesium, Sodium, Iron, Manganese, Copper, Zinc, pH, Total Carbon, Soluble Salts, Carbon to Nitrogen Ratio, Ammonia Nitrogen, Nitrate Nitrogen, Chloride, Organic Matter, Ash, Conductivity, Kjeldahl Nitrogen, E. Coli, Faecal Coliforms, Salmonella, Total Kjeldahl Nitrogen, Total Phosphate, Potassium, Nitrate Nitrogen, Water Soluble Nitrogen, Water Insoluble Nitrogen, Ammonia Nitrogen, Humic Acid, pH, Total Organic Carbon, Bulk Density (packed), Moisture, Sulfur, Calcium, Boron, Cobalt, Copper, Iron, Manganese, Arsenic, Chloride, Lead, Selenium, Cadmium, Chromium, Mercury, Nickel, sodium, molybdenum and zinc.

Feed: Alanine, Histidine, Proline, Arginine, Isoleucine, Serine, Aspartic Acid, Leucine, Threonine, Cystine, Lysine, Tryptophan, Glutamic Acid, Methionine, Tyrosine, Glycine, Phenylalanine, Valine (requires crude protein), White Arsenic, Lead, Cadmium, Arsenic, Mercury.

Vitamin E (beta-tocopherol), vitamin E (alpha-tocopherol), vitamin E (delta-tocopherol), vitamin E (gamma-tocopherol), vitamin E (total), moisture, crude protein, calcium, phosphorus, ADF, ash, total digestible nutrients, energy (digestible and metabolizable), net energy (gain, lactation, maintenance), sulphur, calcium, magnesium, sodium, manganese, zinc, potassium, phosphorus, iron, copper (not applicable to premix), saturated fat, monounsaturated fat, omega-3 fatty acids, polyunsaturated fat, trans fatty acids, omega-6 fatty acids (requires crude or acidified fat), glucose, fructose, sucrose, maltose, lactose, aflatoxin (B1, B2, G1, G2), DON, fumonisin, ochratoxin, T2 toxin, zearalenone, vitamin B2, B3, B5, B6, B7, B9 and B12, calories, chloride, crude fiber, lignin, neutral detergent fiber, non-protein nitrogen, selenium, total iodine, total starch, vitamin A, vitamin D3 and free fatty acids.

Forage: Moisture, Crude Protein, Acid Detergent Fiber (ADF), NDF, Total Digestible Nutrients, Net Energy (Gain, Lactation, Maintenance), Relative Feed Value, Nitrate, Sulfur, Copper, Sodium, Magnesium, Potassium, Zinc, Iron, Calcium, Manganese, Sodium, Phosphorus, Chloride, Dietary Fiber, Lignin, Molybdenum, Hydrogen Cyanide, and Selenium USP.

Milk: Milk fat, true protein, somatic cell count, lactose, other solids, total solids, added water, milk urea nitrogen, acidity, pH, antibiotic and microbial tests.

Although the description below is for soil testing, any extraction, analysis or measurement system can be used with any of the above materials.

Control system

Fig. 2 is a system diagram showing a control or processing system 2800 that includes a programmable processor-based central processing unit (CPU) or system controller 2820, as referred to herein. The system controller 2820 may include one or more processors, a non-volatile tangible computer-readable medium, programmable input/output peripherals, and all other necessary electronic accessories typically associated with a full-featured processor-based controller. The control system 2800, including the controller 2820, is operatively and communicatively coupled to the various soil sample processing and analysis systems and devices described herein via appropriate communication channels to control the operation of these systems and devices in a fully integrated and sequential manner.

As shown in Fig. 2, the control system 2800, including the programmable controller 2820, according to one embodiment of the invention can be installed on a fixed support at any location or, conversely, on a movable self-propelled or towed machine (for example, a vehicle, a tractor, a combine harvester, etc.), which can include an agricultural implement (for example, a seeder, a cultivator, a plow, a sprayer, a spreader, an irrigation tool, etc.). In one example, the machine performs the operations of a tractor or a vehicle that is coupled with an implement for agricultural operations. In other embodiments of the invention, the controller can be part of a fixed station or structure.

The control system 2800, installed on or outside the movable machine, generally includes a controller 2820, a non-volatile tangible computer or machine-readable medium, such as a memory 2805, and a network interface 2815. The computer-accessible and machine-readable medium may include any suitable volatile memory and non-volatile memory or devices operatively and communicatively connected to the processor(s). Any suitable combination and types of volatile or non-volatile memory may be used, including, by way of example and without limitation, random access memory (RAM) and its various types, read-only memory (ROM) and its various types, hard drives, solid-state drives, flash memory or other suitable storage devices and devices that can be written to and/or read by a processor operatively connected to the medium. Volatile memory and nonvolatile memory can be used to store program instructions or software. In one embodiment of the invention, a computer-readable nonvolatile medium (e.g., memory 2805) contains executable computer program instructions that, when executed by the system controller 2820, the system performs the operations or methods of the present invention, including measuring properties and testing soil and vegetation samples. Although in the example embodiment of the invention the nonvolatile storage medium (e.g., memory 2805) is shown as a single medium, it should be understood that this term includes a single medium or several media (e.g., a centralized or distributed database and/or corresponding cache memory and servers) that store one or more sets of control logic or instructions. It should also be considered that the term "machine-readable nonvolatile medium" includes any medium that can store, encode or carry a set of instructions that are intended to be executed by a machine and that cause the machine to perform any one or more methods of the present invention. The term "machine-readable non-volatile medium" should accordingly also be understood to include, but not be limited to, solid-state storage devices, optical and magnetic media, and carrier wave signals.

Network interface 2815 interfaces with agricultural (e.g., soil or other) sample processing and analysis systems (and associated devices) described elsewhere (generally designated 2803 in Fig. 2) and other systems or devices, which may include, but are not limited to, device 2840 having its own controllers and devices.

The programmable controller 2820 may include one or more microprocessors, processors, a system on a chip (integrated circuit), one or more microcontrollers, or a combination thereof. The processing system includes a processing logic circuit 2826 for executing software instructions of one or more programs, and a communication module or unit 2828 (e.g., a transmitter, a transceiver) for transmitting and receiving messages from the network interface 2815 and/or the agricultural sample processing and analysis system 2803, which includes the sample preparation subsystem 3002 and the components described in this document, which also include components of the slurry recirculation closed loop 8002. The communication unit 2828 may be integrated into the control system 2800 (e.g., into the controller 2820) or separated from the programmable processing system.

The programmable logic circuit 2826 of the control system 2800, which controls the operation of the system controller 2820, including one or more processors, can process messages received from the communication unit 2828 or the network interface 2815, including agricultural data (for example, test data, test results, GPS data, liquid injection data, flow rate, etc.), as well as data from systems and devices 6803 for processing and analyzing soil samples. The memory 2805 of the control system 2800 is configured to store pre-programmed variables or set values/base values, store collected data and computer instructions or programs intended to be executed (e.g., software 2806) used to control the operation of the controller 2820. The memory 2805 can store, for example, software components such as test software for analyzing soil and vegetation samples for performing the operations of the present invention, or any other software application or module, images 2808 (e.g., captured images of agricultural crops), warnings, maps, etc. The system 2800 can also include an audio input/output subsystem (not shown), which can include a microphone and a speaker, for example, for receiving and sending voice commands or for user authentication or authorization (e.g., biometric).

The system controller 2820 communicates bidirectionally with the memory 2805 via the communication channel 2830, the network interface 2815 via the communication channel 2832, the display device 2830 and, optionally, the second display device 2825 via the communication channels 2834, 2835 and the input/output ports 2829 via the communication channels 2836. As shown in the figures, the system controller 2820 can also interact with the soil sample processing and analysis systems 2803 via wired/wireless communication channels 5752 either via the network interface 2815 and/or directly.

Display devices 2825 and 2830 can provide visual user interfaces for a user or an operator. Display devices can include display controllers. In one embodiment of the invention, display device 2825 is a portable tablet device or a computing device with a touch screen that displays data (for example, soil test results, vegetation test results, liquid application data, captured images, a localized view map layer, high-resolution field maps with liquid application data, seeding or harvesting data or other agricultural variables or parameters, yield maps, alerts, etc.) and data generated by a software application for analyzing agricultural data, and receives input data from a user or operator for an exploded image of a field area, monitoring and controlling operations in the field. Operations can include configuring a machine or equipment, creating data reports, controlling a machine or equipment including sensors and controllers, and storing the generated data. The display device 2830 may be a display (e.g., a display provided by an original equipment manufacturer (OEM)) that displays images and data for a localized map layer, liquid application data, seeding or harvesting data, yield data, for controlling a machine (e.g., a seeder, tractor, combine, sprayer, etc.), for adjusting the machine and monitoring the machine or equipment (e.g., a seeder, combine, sprayer, etc.) connected to the machine with sensors and controllers located on the machine or equipment.

Modifications to the agricultural sample suspension processing system

The following sections describe various features of the above-mentioned agricultural sample analysis systems and related devices previously described herein that process and analyze/measure a prepared agricultural sample suspension for analytes of interest (e.g., soil nutrients such as nitrogen, phosphorus, potassium, etc., vegetation, organic fertilizers, etc.). In particular, these modifications relate to the sample preparation subsystem 3002 and the chemical analysis subsystem 3003 of the agricultural (e.g., soil or other) sampling system 3000 shown in FIG. 1. To provide a broad context for the discussion of the alternative devices and equipment below, FIG. 3 is a high-level system block diagram summarizing the process flow of the agricultural sample analysis system. This embodiment of the invention illustrates the measurement of the density of a suspension in a static mode, as described further herein. In FIG. 4 shows essentially the same thing, but with the addition of a slurry recirculation loop between the fine cleaning station and the mixing chamber to prepare samples for dynamic continuous slurry density measurement.

As shown in Fig. 3 and 4, the systems 7000 for analyzing agricultural samples in the flow direction include an agricultural sample preparation subsystem 7001, a density measurement subsystem 7002, a fine purification subsystem 7003, an analyte extraction subsystem 7004, an ultrafine purification subsystem 7005, and an analyte measurement subsystem 7006. The soil sample preparation subsystem 7001 is that part of the system where the sample suspension is initially obtained. Accordingly, the subsystem 7001 may comprise the mixing device 8010 described herein, which includes a mixing chamber where water is added to a mass of an agricultural sample (e.g., soil or other agricultural solids) to prepare a slurry, and a coarse filter (e.g., filter unit 8020) described herein that removes large or larger than a certain size particles (e.g., small stones, rocks, trash, hardened clumps of agricultural waste, etc.) from the prepared soil slurry. In addition, the coarse filter may be sized to pass slurry particles of a desired maximum size to ensure uniform flow and slurry density for mass/density measurement used in the process as described further herein. The prepared and coarsely filtered suspension can be fed from the mixing device to the density measuring subsystem 7002 by pumping with a suspension pump 7081 or, alternatively, pneumatically by pressurizing the flow channel between the mixing device 8010 and the filter unit 8020 by means of compressed air supplied via a fluid connection to a compressed air source 7082 (shown in dotted lines in Fig. 3).

The analyte extraction subsystem 7004 and the measurement subsystem 7006 may comprise the agricultural sampling system 3000 shown in Fig. 1. The ultrafine purification subsystem 7005 may comprise the fine purification filter unit 8080 described herein (see, for example, Figs. 34-35), including any of its variations further described herein.

It should be noted that the arrangement of the devices and equipment shown in Fig. 3-4 (e.g. pumps, valves, etc.) can be changed and they can be moved in the systems without affecting the operation of the device. In addition, additional devices and equipment can be added, such as valves, pumps, other flow measuring devices, sensors (e.g. pressure, temperature, etc.) that control the flow of liquid/slurry and transmit additional operating information to the system controller, which can control the operation of the systems shown. Accordingly, the systems are not limited to only the configuration and devices/equipment shown.

Digital devices for measuring the density of suspensions

The density measuring subsystem 7002 comprises a digital device 7010 for measuring the density of a suspension for obtaining the density of a mixed suspension of an agricultural sample prepared in the sample preparation chamber shown in Fig. 3-4 (for example, in the mixing chamber 8013 of the mixing device 8010 shown in Fig. 34). In one embodiment of the invention, the density measuring device 7010 can be a digital oscillating density meter with a U-shaped tube of any of the embodiments of the invention shown in Fig. 5-19, and can be used to measure the density of a sample suspension, which can be a soil suspension in one non-limiting example, which will be used below for convenience. It should be understood that, however, any type of agricultural sample suspension can be used in the same system, including soil, vegetation, organic fertilizers, etc. The density of the suspension is used to determine the required amount of diluent (e.g. water) that needs to be added to the soil sample to achieve the required water to soil ratio for chemical analysis of the analyte, as described further herein. The U-shaped vibrating tube 7011 is excited by a frequency converter or driver 7012 to vibrate the tube at its characteristic natural frequency. In various embodiments of the invention, the driver 7012 can be an electromagnetic inductor, a piezoelectric actuator/element or a mechanical pulse generator that is capable of generating a user-controlled and programmed excitation frequency. A corresponding sensor is provided, such as a receiver or sensing element 7013, which is configured to detect and obtain a measurement of the vibrations of the vibrating tube when excited. The sensor can be an electromagnetic, inductive, piezoelectric receiver/element, optical or other commercially available sensor capable of detecting and measuring the frequency response of the vibrating tube 7011 when excited. The pulsating or oscillating motion of the excited oscillatory tube 7011 is detected by a sensor 7013, which measures the amplitude of the frequency response of the tube, which is highest at the natural oscillation/resonance frequency or secondary harmonic when the tube is empty. Alternatively, the phase difference between the excitation frequency and the excitation frequency can be used to narrow down to the natural frequency.

During operation, when the excitation changes, the oscillation frequency of the oscillating tube 7011 can change depending on the density of the suspension, either when the oscillating tube is filled without flow for measuring the density in a static mode in one embodiment of the invention, or in the presence of flow through the U-shaped tube with, preferably, a continuous and constant flow rate for continuous measurement of the density in another embodiment of the invention. The digital density measuring device converts the measured oscillation frequency into a density measurement using a digital controller, which is programmed to compare the basic natural frequency of the empty tube with the frequency of the tube filled with the suspension.

The frequency drive and the sensor 7012, 7013 are functionally and communicatively connected to an electronic control circuit comprising a processor or controller 7016-2 of a microprocessor density meter mounted on a printed circuit board 7016 of a control supported by a base 7014. The controller 7016-2 is configured to supply a pulsed excitation frequency to the oscillatory tube 7011 using the drive 7012 and to measure the resulting change in the resonant frequency and phase of the excited oscillatory tube. The digital device 7010 of the density measurement converts the measured oscillation frequency into a density measurement using a controller that is pre-programmed and configured using the current software or commands for performing the measurement and determining the density. The controller 7016-2 can be equipped and configured with all the usual auxiliary devices and devices, as well as any of the controllers previously described in this document, necessary for obtaining a fully functional programmable electronic controller. Accordingly, for the sake of brevity, these parts of the 7016-2 density meter controller will not be described in more detail.

Fig. 5-14 shows a density measuring device 7010 having an oscillating tube according to a first embodiment of the invention. The density measuring device 7010 also includes a base 7014, several supports 7015, a tube mounting block 7017, a connection manifold 7018, at least one or a pair of permanent magnets 7025, an electronic control board 7016 and an interface module 7016-1 for communication and electrical connection, configured both with the possibility of supplying electrical power to the board and providing a communication interface for connection to the system controller 2820. The base 7014 allows the density measuring device to be mounted on a flat horizontal support surface, a vertical support surface or a support surface located at any angle. Accordingly, any suitable orientation of the base for mounting can be used if necessary. The orientation of the base installation can be determined by the expected direction of oscillation of the oscillating tube 7011, taking into account the force of gravity acting on the oscillating tube filled with a suspension. It is generally preferred to mount all of the suspension channels in the oscillating tube in such a way as to provide the highest possible percentage of horizontal channels so that any settling of solids occurs perpendicular to the flow rather than parallel to it. In one embodiment of the invention, the base 7014 may be substantially flat and, as shown, may have a rectangular shape; however, bases of other, polygonal and non-polygonal shapes may be used. Alternatively, the base may include several mounting holes 7019 to facilitate fastening the base to a supporting surface using various fasteners (not shown). The base 7014 defines a longitudinal centerline CA of the density measuring device 7010, which is aligned with the length of the oscillating tube 7011 (as shown, parallel to the parallel branches of the tube). In other words, the length of the oscillating tube runs along the centerline CA. In one embodiment of the invention, as shown, the centerline CA and the flow channels within the oscillating tube 7011 may be horizontal, so that any sedimentation that occurs occurs perpendicular to the flow passing through the channel, and not in line with the flow. In other embodiments of the invention, at least a majority of the flow channels within the oscillating tube may be oriented horizontally.

The supports 7015 may have an elongated shape and separate the control board 7016 from the base 7014 so that the oscillating tube 7011 can occupy the space 7015-1 created between them. Any suitable number of supports can be used for this purpose. The space is preferably large enough to provide clearance for placing the oscillating tube 7011 and other accessories, such as the frequency driver 7012 and the sensor 7013. The flat control board 7016, as shown, can preferably be oriented parallel to the base 7014.

The frequency drive 7012 and the sensor 7013 may be rigidly mounted on the printed circuit board 7016 in one embodiment of the invention, as variously shown in Figs. 5-14. In other possible embodiments of the invention, as shown in Figs. 15-18, the drive and the sensor may be rigidly mounted on separate vertical supports 7031 attached to the base 7014. In each case, the drive and the sensor are mounted near and in close proximity to the permanent magnets 7025, but do not contact the permanent magnets. The permanent magnets 7025 generate a static magnetic field (magnetic flux lines) that interacts with the drive 7012 and the sensor 7013 to excite the oscillatory tube 7011 and measure the frequency of its oscillations during excitation.

The tube mounting block 7017 is designed to rigidly mount the oscillating tube 7011 thereon in a cantilever manner. The oscillating tube 7011 in one embodiment of the invention, as shown, may have a straight U-shaped configuration in which all sections lie in the same horizontal plane. The straight inlet end section 7011-1 and the straight outlet end section 7011-2 of the oscillating tube 7011 are mounted on the block 7017 and rigidly supported by it (see, for example, Fig. 14) to allow the tube to oscillate similarly to a tuning fork when excited electronically/electromagnetically. The mounting block 7017 includes a pair of through holes 7017-1, into which the end sections 7011-1, 7011-2 of the oscillating tube completely pass. In one embodiment of the invention, the holes 7017-1 may be parallel. The section 7011-3 of the U-shaped bend of the oscillating tube opposite the inlet and outlet end sections, and the adjacent sections of the tube located between the U-shaped bend and the fastening block 7017, do not have a support and are capable of freely oscillating in response to the excitation frequency supplied by the drive 7012.

The inlet end portion 7011-1 and the outlet end portion 7011-2 of the oscillating tube 7011 pass through the tube fastening block 7017 and protrude beyond it, and each of them enters a corresponding open through hole 7018-1 of the connecting manifold 7018, associated with the formation of an inlet 7020 for the slurry and an outlet 7021 for the slurry of the connecting manifold 7018 (see the arrows of the direction of the flow of the slurry in Fig. 14). The through holes 7018-1 can have any suitable configuration for hermetically holding the end portions 7011-1, 7011-2 of the oscillating tube 7011. To ensure a hermetically sealed connection between the oscillating tube and the connecting manifold 7018, suitable liquid seals such as O-rings, elastomeric sealants, etc. can be used. The connecting manifold 7018 is adjacent to the fastening block 7017 to provide through connecting holes for the inlet end portion 70111 and/or the outlet end portion 7011-12 to fully support the end portions of the oscillating tube 7011. In another possible embodiment, the connecting manifold 7018 can be located at a distance, but preferably in relative proximity to the fastening block 7017.

The mounting block 7017, the connecting manifold 7018 and the base 7014 may preferably be made of a suitable metal (e.g., aluminum, steel, etc.) of sufficient mass and thickness to act as vibration dampers so that the excitation of the oscillating tube that the density measuring device 7010 measures indicates only the frequency response of the filled oscillating tube 7011 without interference from any corresponding parasitic resonances that might otherwise be caused in the base or in the mounting block and the connecting manifold.

In the first embodiment of the oscillating tube shown in Fig. 5-14, the oscillating tube 7011 may have a conventional U-shaped form, as shown and previously described in this document. The tube may be oriented parallel to the flat upper surface of the base 7014. In one non-limiting embodiment of the invention, the oscillating tube 7011 may be made of a non-metallic material. Suitable materials include glass, such as borosilicate glass. However, in other possible embodiments of the invention, metal tubes may be used. Permanent magnets 7025 are fixedly and rigidly mounted on the oscillating tube 7011, for example, as shown, on opposite sides of the U-shaped tube near the section 7011-3 of the U-shaped bend. The U-shaped bend section is the farthest from the cantilever portion of the oscillating tube adjacent to the mounting block 7017 and thus experiences the greatest displacement/deflection when excited by the driver 7012, which makes the change in the vibration frequency of the tube easily detectable by the digital measuring controller 7016-2. This creates the greatest sensitivity for measuring the deviation in frequency of the slurry-filled oscillating tube 7011 compared to the natural frequency of the tube when it is empty; the deviation or difference in frequency is used by the controller 7016-2 to measure the density of the slurry.

Although laboratory digital density meters with oscillating tubes are available, they are not entirely suitable for measuring soil suspensions or other agricultural materials, which, unlike other liquid media, may contain varying amounts of iron (Fe). Iron in a soil suspension creates a problem that interferes with an accurate measurement of the density of the soil suspension, since the iron particles in the suspension are attracted to the permanent magnets used in the density measuring device 7010. This causes the iron particles to accumulate in the areas of the tube closest to the permanent magnets, thereby distorting the density measurement results and adversely affecting the resonant frequency of the oscillating tube when it is filled with a soil suspension and excited by the driver 7012. Fig. 19A shows such an undesirable situation with iron particles accumulated in the oscillating tube.

In order to solve the above-mentioned problem when handling suspensions containing iron particles, embodiments of the density measuring device 7010 according to the present invention can be modified to include various magnetic insulation elements or elements configured to magnetically isolate the permanent magnets from the oscillating tube 7011 and the iron-containing suspension located therein. In the embodiment of the invention shown in Figs. 5-14, each of the permanent magnets 7025 can be mounted on the oscillating tube 7011 by means of a magnetic insulation element comprising a non-magnetic support insulator 7024 (also shown schematically in Figs. 19B and 19C). The support insulator projects transversely outward from the sides of the oscillating tube in opposite directions and perpendicular to the longitudinal centerline CA of the density measuring device 7010. The support insulators 7024 have suitable dimensions or lengths for placing the permanent magnets at a sufficient distance from the oscillating tube 7011 to prevent the creation of a static magnetic field of sufficient strength inside the tube to attract and accumulate iron particles present in the soil suspension, for the reasons discussed above. The magnetic field can be such that its strength is weakened to such an extent that it allows the particles to move under the action of the flow without settling on the inside of the oscillating tube. As shown in Fig. 19B, the magnetic flux lines (dashed) that circulate and pass from the north (N) pole of the permanent magnet 7025 to the south (S) pole do not reach the oscillating tube 7011. The magnetic support insulators 7024 make it possible to avoid the problem of iron accumulation shown in Fig. 19A, caused by directly attaching the permanent magnets 7025 to the oscillating tube 7011.

In one embodiment of the invention, in which the oscillating tube 7011 is made of a non-metallic and non-magnetic material (for example, glass or plastic), the support insulators 7024 can be made as a single unit with the tube in the form of a monolithic structural part. In other embodiments of the invention, the support insulators on which the permanent magnets are mounted can be separate discrete elements that are rigidly connected to the oscillating tube 7011, for example, by means of glue, clamps or other suitable mechanical connection methods. Where a metal oscillating tube is used, the support insulators 7024 are made of a non-metallic material (for example, plastic or glass) and are attached or glued to the oscillating tube by suitable means (for example, glues, clamps, brackets, etc.).

Other possible devices for attaching the permanent magnets 7025 to the oscillating tube 7011 and the magnetic insulation elements that shield or direct the magnetic flux lines generated by the magnets away from the tube can be used. For example, Fig. 19D shows an assembly with a permanent magnet that contains a magnetic insulation element that contains a metallic magnetic shielding element 7030 placed between the permanent magnet and the oscillating tube to direct the magnetic flux lines (dashed line) away from the oscillating tube. In the illustrated embodiment of the invention, the shielding element 7030 is made in the form of a flat metal plate. Fig. 19E shows a U-shaped or cup-shaped shielding element 7030 that functions in the same way as the element shown in Fig. 19D. It is possible to use a metallic magnetic shielding element of any suitable shape, as long as the magnetic flux lines are redirected in such a way that they do not reach and penetrate the oscillating tube 7011.

In Fig. 19F it is shown that the excitations of the oscillating tube 7011 by means of the arrangement of the frequency drive and the sensor 7012, 7013 can be directed in the most rigid direction (for example, left/right, as shown by the arrows of the tube oscillation movement) or in the least rigid and most flexible direction (for example, up/down) for a horizontally oriented tube. This will significantly affect the natural frequency of the oscillating tube, which forms the reference point with which the excited tube filled with a suspension is compared to determine the density (mass) of the suspension. A more rigid direction of excitation/movement of the tube from side to side will have a higher natural frequency, while a more flexible direction up and down will have a lower natural frequency. Either orientation or different angular orientations of the oscillating tube can be used. Additionally, in some embodiments of the invention, it may be advantageous for the tube to be significantly stiffer in the direction of gravity (i.e., vertically) than in the direction of loading/excitation (i.e., horizontally, as indicated by the tube oscillatory motion arrows), as shown in Fig. 19G, to help reduce system noise that may affect the accuracy of the density measurement.

The density measuring device 7010 operates to obtain measurements of the density of the soil suspension in a conventional manner known in the art for such U-tube density meters. The results of the density measurements of the suspension are transmitted to a control system 2800 (programmable controller 2820) operatively connected to the density measuring device 7010 (see, for example, the density measuring subsystem 7002 shown in Fig. 3, 4 or 35). The controller uses the measurement results to automatically determine the amount of water (diluent) that must be added to the suspension to achieve a programmed target ratio of water to soil or other agricultural sample material, depending on the type of material to be collected and analyzed.

An example of a method/process for preparing a suspension of an agricultural sample will now be described using a density measurement of the suspension using a density measuring device 7010 (density meter) and a pre-programmed closed-loop control circuit implemented by a controller 2820 of a control system 2800 using appropriate software commands/control logic. In this example, for convenience of description, soil will be used as a sample, but this is not limiting, and the example can be used for other agricultural sample materials (e.g., plants, organic fertilizers, etc.). Considering an arbitrary amount of soil in the collected sample and an associated arbitrary moisture content in the soil based on environmental conditions in the agricultural field and the type of soil, the soil suspension will be diluted to achieve stable density values, thereby ensuring repeatability of the analysis results.

31-33 are curves showing the relationship between the amount of diluent (e.g., water) added to the slurry and the density of the slurry, which is used by the controller 2820 to determine the amount of diluent needed to achieve a programmed target water to soil ratio. The target water to soil ratio may be pre-programmed into the controller as a target slurry density, which can be directly equated to this ratio since the density of the diluent used is a known fixed factor. With a known density of the diluent used (e.g., water having a density of 0.998 g/ml), also pre-programmed into the controller, as more and more diluent is added to the slurry in the system, the density of the slurry mixture will eventually approach the density of the diluent, but can never change in the opposite direction and become less dense than this value. The relationship and curve shown in Fig. 33 are thus generated by the controller 2820 and are used to achieve the target slurry density (water to soil ratio). The dilution amount (Y axis) is the total volume added to achieve the dilution. As different amounts of soil, soil moisture, and water (diluent) are added to produce the original slurry mixture, the slope of this curve may change, but the overall shape will remain the same.

As shown in Fig. 3-4, the collected sample of raw soil and a known amount of water are initially mixed in the mixing device 100 for the first time, as indicated, to prepare a slurry. After the soil slurry has been mixed and homogenized in the mixer, the density meter records the first density measurement and transmits it to the controller 2820. Point 7090A on the curve in Fig. 31 indicates the first density measurement taken.

In order to more accurately determine the relationship between the amount of diluent and the density of the slurry in real time, in a next step, the controller 2820 measures and adds a known amount of water (for example, 20 ml) to the mixing device 100 through a operatively connected water supply control valve 7091, and the resulting density of the slurry is measured for a second time. Point 7090B on the curve in Fig. 32 indicates the second density measurement performed. Then, the controller can generate a linear relationship between the two taken points 7090A and 7090B of the density of the slurry (represented by a solid line on the curve between these two points). For a given pre-programmed target density of the slurry (the ratio of soil and water), the target density can then be entered into this ratio, and the output data calculated by the controller 2820 represents a first estimate of the total amount of diluent (for example, water) needed to achieve the target density.

The controller 2820 performs the following measurements and adds the calculated amount of additional diluent (e.g., water) needed to achieve the target slurry density to the slurry mixture, which is mixed with the slurry using the mixing device 100. The resulting slurry density is measured a third time. Point 7090C on the curve in Fig. 33 indicates the third measurement taken, which continues to add data points to the linear relationship (see the longer solid line on the curve). Once the controller has at least three measurements of the slurry density and corresponding points on the slurry density curve, the controller can perform a polynomial regression of the data, providing a more accurate curve fit. Based on the pre-programmed target density and using it, the controller 2820 then calculates the required total amount of the required diluent based on the updated curves and adds this amount to the slurry to achieve the target slurry density. This process can be repeated to improve the accuracy of the regression model or until the actual density is close enough to the target density.

Fig. 15-18 shows an alternative, second embodiment of a cantilever U-shaped oscillating tube 7032 for use with a density measuring device 7010, which differs from the straight U-shaped oscillating tube 7011 previously described herein. In this embodiment of the invention, the oscillating tube 7032 has a curved U-shape, wherein the primary U-shaped bend 7032-3 by 180 degrees passes back over the straight inlet end section 7032-1 and the outlet end section 7032-2 of the oscillating tube, attached to the tube fastening block 7017 and the connecting manifold 7018. This is created by adding two additional 180-degree secondary U-shaped bends 7032-4 between the straight end sections 7032-1, 7032-2 and the primary U-shaped section 7032-3. As shown, one secondary U-shaped curved section 7032-4 is located on the inlet branch for the suspension of the oscillating tube upstream of the primary U-shaped curve 7032-3, and the other is on the outlet branch for the suspension of the oscillating tube downstream of the primary U-shaped curve. In this embodiment of the curved oscillating tube, support insulators 7024 are located on the secondary U-shaped curved sections and project laterally outward in opposite lateral directions for holding the permanent magnets 7025 at a distance from the oscillating tube. The frequency driver and the sensors 7012, 7013 are supported on the base 7014 by separate vertical supports 7031 near the permanent magnets for exciting the oscillating tube 7032, as previously described in this document.

In the curved oscillating tube 7032, the flow of the suspension follows the path indicated by the flow direction arrows in Fig. 17. The flow of the suspension moves twice in a first direction parallel to the centerline CA and also twice in the opposite direction parallel to the centerline CA by means of the primary and/or secondary U-shaped curved sections 7032-3 and 7032-4. The primary U-shaped curved section 7032-3 is oriented horizontally while the secondary U-shaped curved sections 7032-4 are oriented vertically. As shown, in this design, the centerline CA and most of the flow channels within the oscillating tube 7032 can remain horizontal so that any sedimentation that occurs occurs perpendicular to the flow through the channel and not in line with the flow.

Unlike the first U-shaped oscillating tube 7011 shown in Fig. 5 described first above, the structure of the curved oscillating tube 7032 with a triple bend is advantageous in that the vibration displacement is reflected between the left and right sides of the tube (for example, the vertical bends 7032-4 move towards each other and then away from each other when the tube oscillates). Due to this, during the oscillation, equal and opposite forces always act, balancing each other, and thus external effects on the mass, rigidity or damping of the base and other components do not affect the vibration. The previous design of the oscillator with a straight U-shaped tube would easily transmit vibration to the base, since the oscillation was not balanced, and thus the entire system vibrated slightly. Since the entire system vibrates, any external influences on the mass, stiffness or damping of the entire system would artificially change the natural frequency, which would negatively affect the accuracy to some extent. However, a straight U-tube oscillator may be acceptable in cases where there are no excessive external influences.

The rest of the arrangement and components of the density measuring device 7010 are substantially the same as in the embodiment of the invention using the oscillating tube 7011, and the description thereof will not be repeated here for the sake of brevity.

In some embodiments of the invention, instead of separate units, a single device may be provided that combines the above-mentioned functions of both the frequency transmitter or driver 7012 and the receiver or sensor 7013. As one non-limiting example, such a device may be an ultrasonic transducer. For a combined single device 7012/7013 with one driver-sensor, the device may be activated to excite the oscillating tube 7011, stopped for several oscillations of the oscillating tube, and then reactivated to measure the resulting frequency response of the tube oscillations. In the combined design, only one permanent magnet 7025 is required, located near the driver/sensor.

Fine filter

The fine filter unit of the fine filter subsystem 7003 shown in Figs. 3 and 4 will now be described in more detail. During testing, the inventors have found that "fine" filtration (e.g., 0.010 inches/0.254 mm) immediately at the outlet of the mixing device can, in some situations, negatively and significantly impact the ability to obtain a proper water to soil ratio (e.g., 3:1) for all types of soils that may be encountered, sampled, and tested. Accordingly, it is useful to understand and measure the suspension density of the mixed raw soil sample exiting the mixing device 100 before performing fine filtering. Accordingly, preferred, but non-limiting, embodiments of the disclosed agricultural sample analysis systems 7000 include both a coarse filter 146 located upstream of the density measuring device 7010 and a fine filter 7050 or 7060 located downstream of the density measuring device, each of which is described in more detail below. Two different examples of configuration of an agricultural sample analysis system incorporating this two-stage filtration of the suspension are disclosed; further discussed in this document is one example with recirculation of the suspension from the fine filter unit back to the mixing device 100, shown in Fig. 4, and one example without recirculation, shown in Fig. 3.

In the agricultural sample analysis system, a first coarse filter 146 having a large mesh (e.g., allowing particles with a maximum size of about 0.04-0.08 inches/1-2 mm to pass in one possible implementation) is used to initially sift and filter out large stones, rocks, and aggregates from the suspension to avoid clogging the flow channel (pipeline) upstream of the microfluidic processing disk 4000, while allowing accurate density measurement in the density measurement device 7010. In one embodiment of the invention, the coarse filter 146 can be integrated into the mixing device 100, as described earlier in this document, or can be a separate unit located downstream. This coarse filtration is followed by fine filtration in fine filter units 7050 or 7060 having a fine mesh (e.g., allowing particles with a maximum size of less than 0.04 in./1 mm, such as about 0.010 in./0.25 mm, in one possible implementation) to pass through the agricultural sample suspension to be processed and analyzed downstream in the chamber (e.g., through microfluidic flow networks and microfluidic processing disk components) without causing flow obstruction/clogging. Examples of such networks with a microfluidic processing disk are disclosed in International Publication No. WO2020/012369. In the case of soil, these extremely fine particles passed through the fine filter unit make up a large portion of the nutrient content of the soil, so it is acceptable to use the finely filtered suspension for final chemical analysis in the system. It should be noted that the fine cleaning stage and the filter units 7050, 7060 are suitable and applicable to suspensions consisting of other agricultural materials from which a sample is taken (e.g. vegetation, organic fertilizers, etc.), and thus their application is not limited to soil suspensions only.

Fig. 21-24 shows a first embodiment of a fine filter unit 7050 suitable for use with any of the soil slurry preparation and analysis systems shown in Fig. 3 or 4. The fine filter unit 7050 is specifically designed for use with the slurry recirculation system shown in Fig. 4 (which includes a closed recirculation loop 7059), between the fine filter unit 7050 (or 7060) and the mixing device 100, as shown.

The filter unit 7050 has a longitudinal axis LA, an inlet 7051 for the pre-filtered suspension, an outlet 7052 for the pre-filtered suspension, several outlets 7053 for the filtrate (after filtration), an internal chamber 7057 for the pre-filtered suspension, an internal chamber 7054 for the filtrate and one or more filter elements, such as screens 7055, located between the chambers. In one embodiment of the invention, the screens 7055 can have an arcuate shape and can be located in the upper part of the chamber 7057 for the suspension, as best shown in Fig. 24. Any number of screens can be provided. A pair of ring seals 7056 provide a hermetically sealed attachment of the inlet and outlet pipes 7051, 7052 to the main body of the filter unit to ensure the initial placement of the filter screen 7055 inside the filter unit before securing the inlet and outlet pipes to the body. The main body may be rectangular, cylindrical or other in shape. The pipes may be disconnected from the central main body of the filter to provide access to the interior of the filter unit and to allow the initial installation or periodic replacement of the screens. Threaded fasteners 7058 or other suitable connecting means may be used to connect the inlet and outlet pipes to the opposite ends of the main body. The inlet and outlet connections 7051, 7052 for the slurry may have any suitable configuration so that a tube connector of any suitable type can be inserted into the bottom to provide a connection of the tube 7088 for the slurry of the system with the filter 7050. One non-limiting example of a tube connector that could be used is a John Guest plastic semi-cartridge connector, which is commercially available. Other tube connectors can be used. Any suitable non-metallic (for example, plastic) or metal materials can be used to manufacture the filter unit 7050, including the screens 7055. In one embodiment of the invention, the main body of the filter unit can be plastic, and the screens 7055 can be metal, such as a mesh screen that forms the mesh cells.

In operation and in describing the path of the suspension through the fine filter unit 7050 in accordance with Fig. 4, the unfiltered suspension flows sequentially (from top to bottom in the flow) from the coarse filter 146 through the density measuring device 7010 and enters the fine filter unit through the inlet pipe 7051. The suspension flows axially and linearly through the chamber 7057 for pre-filtered suspension and then exits the filter through the outlet pipe 7052 back to the mixing device 100 (see, for example, the "sample preparation chamber" in Fig. 4). A pump 7080 for recirculating the suspension can be provided, which controls the recirculation flow in the closed recirculation loop 7059 and returns the suspension, which has not yet undergone fine filtration, back to the mixing device. Any suitable type of suspension pump can be used. In some embodiments of the invention, the recirculation pump may be omitted if the main pump 7081 for the suspension provides sufficient power to move the flow of the suspension throughout the closed recirculation loop 7059. The system continuously recirculates the coarsely filtered suspension back to the main mixing chamber of the mixer for a certain period of time. This recirculation can help to more quickly obtain a homogeneous suspension mixture for analysis than when using only a mixer, due to the continuous recirculation of the suspension through the mixer and the coarse filter in the closed recirculation loop 7059. During the density measurement, water is automatically dosed and added to the mixing device 100 using the previously described control system 2800 (including a programmable controller 2820), based on the suspension density control system measured by the density measuring device 7010, which is operatively connected to the controller to achieve a programmed water to soil ratio. Due to such continuous recirculation of the suspension, it is better mixed.

After obtaining a coarsely filtered homogeneous suspension having the desired water to soil ratio, a small portion of the recirculating suspension flow can be diverted and recovered from the fine filter unit 7050 for initial processing in the analyte extraction subsystem 7004 and subsequent chemical analysis (see, for example, Fig. 4). The recovered suspension passes through the filter screens 7055 and enters the filtrate chamber 7054, and then out through the filtrate outlets 7053 into the analyte extraction subsystem. The flow of the recovered suspension can be controlled by appropriate control valves 7070, the position of which can be changed as needed between open with full flow, closed with no flow and partially open with throttled flow. The 7070 valves can be controlled manually or automatically by the 2820 controller to open at the appropriate time once a uniform suspension having the desired water to soil ratio is achieved or according to a preset program. Additional valves can also be used to open the water supply for backwashing the filter during the cleaning cycle in preparation for the next sample.

Although two filtrate outlets 7053 are shown in Figs. 20, 23 and 24, in other embodiments of the invention there may be more than two filtrate outlets or fewer (i.e., one outlet). Each filtrate outlet 7053 is in fluid communication with and supplies a finely purified suspension (filtrate) to a separate dedicated soil sample suspension processing and analysis unit or system described in International Publication No. WO2020/012369; each unit is isolated from the others and is configured to quantify the concentration of various analytes of interest (e.g., plant nutrients such as nitrogen, phosphorus, potassium, etc.) in parallel.

It should be noted that the term "pre-filtered" used above means that the soil suspension has not yet been filtered by the fine filter unit 7050 described. However, the suspension may have been pre-filtered or screened upstream, for example, in the coarse filter 146 shown in Fig. 3-4. Accordingly, the suspension may be filtered before entering the fine filter unit 7050 located downstream.

The fine filter unit 7050 is configured to prevent soil or other particles that cause clogging or otherwise clog the extremely small diameter microfluidic channels/pipes and components of the microfluidic processing disk, such as valves, pumps and chambers formed within the processing sectors for analyzing the microfluidic processing disk described in International Publication No. WO2020/012369, from entering the suspension. Accordingly, the filter screens 7055 of the fine filter unit 7050 are sized to allow the passage of soil particles that are compatible with the microfluidic processing disk and are smaller in size than those screened by the upstream coarse filter 146 associated with the mixing device. The filter screens 7055 have a plurality of openings, each of which is configured to remove particles larger than a predetermined size from the suspension to obtain a filtrate. The screens 7055 in one embodiment of the invention may be made of a metal mesh similar to a grid that forms the mesh cells for filtering the suspension.

Accordingly, in one preferred embodiment of the invention, the first coarse filter 146 of the system is configured to pass a suspension having a first maximum particle size, and the second fine filter unit 7050 is configured to pass a suspension having a second maximum particle size smaller than the first maximum particle size. In addition, the ultrafine filter subsystem 7005, which comprises a third ultrafine filter 5757 (which may be integrated into or associated with the microfluidic processing disk 4000, or may be associated with the soil sampling system 3000), configured to pass a suspension whose third maximum particle size is smaller than the first and second maximum particle sizes. As previously described in this document, the ultrafine filter 5757 is a microporous filter that can replace a centrifuge and is configured to obtain a clear filtrate from the soil suspension and the extractant mixture, which serves as a supernatant for chemical analysis. Accordingly, the performance of the ultrafine filter 5757 is superior to both the coarse and fine filters in terms of the smallest maximum particle size that can be passed. As a non-limiting example, typical pore sizes that can be used for the ultrafine filter 5757 are approximately 0.05 to 1.00 μm inclusive. It should be noted that the above terms "first," "second," and "third" are used to designate the filter units that the suspension encounters as it sequentially flows in the direction of flow as it passes through the systems shown in Figs. 3-4. Accordingly, the maximum particle size of the suspension continuously decreases as the suspension sequentially passes through each filter unit.

In normal filter operation, all flow is directed through the screen and anything that does not pass through the screen is retained on the screen and accumulates. This requires that the screen be either drained or backwashed after a period of time to keep it clean and able to function as intended. This is a problem if a large amount of solids needs to be filtered as it will result in a very short period of time for which the filter will operate before cleaning is required. For this reason, the new 7050, 7060 fine screen filter units have been developed which operate on the principle of extracting a small amount of soil slurry for testing from the main slurry recirculation channel as described above, rather than intercepting the entire slurry flow for fine cleaning. As an advantage, this allows the filter to remain clean for a much longer period of time as only a small portion of the slurry flow is extracted which passes through the screen perpendicular to the main direction of slurry flow through the filter unit. In addition, the main flow path of the suspension, which is preferably directed parallel to the plane occupied by the mesh 7055, continuously cleans the filter meshes 7055 (see, for example, Fig. 24) due to the shearing action of the flow to prevent the accumulation of particles on the meshes. It should also be noted that the fine filter units 7050 and 7060 advantageously allow avoiding internal zones with low pressure or flow, where solid particles can accumulate. It is also desirable to avoid such an orientation of the inner surface of the filter, in which solid particles will accumulate under the action of gravity. Accordingly, embodiments of the fine filter units 7050, 7060 can preferably be oriented in such a way that the filter meshes 7055, 7065 are respectively located above the main flow and the junction where the flow of the suspension is diverted for chemical analysis, and, preferably, in the transverse direction to the main path of passage of the suspension through the filter housings (see, for example, Figs. 24 and 29).

In Fig. 25-29 a second embodiment of the fine filter unit 7060 mentioned above is shown. The fine filter unit 7060 comprises several replaceable, if necessary, mesh filter assemblies or units 7068. In this embodiment of the invention, in contrast to the fine filter unit 7050, the mesh filter units can be removed and replaced without disturbing the end connections for feeding liquid to the tubes of the system, which greatly facilitates the periodic replacement of the screens over time. As described earlier in this document, the filter unit 7050 has screens 7055 installed inside, which can be accessed by removing the inlet and outlet pipes 7051, 7052 for the suspension. In some embodiments of the invention, the mesh filter units 7068 can be made disposable, so that used clogged mesh blocks are replaced with new mesh blocks, if necessary.

The fine filter unit 7060 has an axially elongated main body which has a longitudinal axis LA, an inlet 7061 for the pre-filtered suspension, an outlet 7062 for recirculating the pre-filtered suspension, several outlets 7063 for the filtrate (after filtration), an internal chamber 7067 for the main pre-filtered suspension, fluidly communicated with the inlet and outlet, and several mesh filter units 7068, each of which contains a filter element, such as a mesh 7065, located between the chamber 7067 and one outlet 7063 for the filtrate. The inlet 7061 and outlets 7062 may preferably be located at opposite ends of the fine filter unit housing at each end of the chamber 7067, allowing the main slurry chamber to form a slurry distribution manifold in fluid communication with each filtrate outlet 7063. In some embodiments, the screens 7065 may be convexly curved and dome-shaped (best shown in Fig. 29). The main chamber 7067 for the suspension extends in the axial direction between the inlet and outlet 7061, 7062 under the screen blocks 7068. The fine filter block 7060, although having a convex shape, can be used in the shown orientation such that the portions of the screens 7065 facing the suspension in the main chamber 7067 for the suspension can be considered to be substantially horizontally oriented and parallel to the longitudinal axis LA and the axial flow of the suspension passing through the screens of the main chamber for the suspension. The flow through the screens is then directed upwards (transversely to the longitudinal axis LA and the axial flow of the suspension in the chamber) when the fine filter block 7060 is used in the preferred horizontal position. This combines two advantages at once: (1) the screens 7065 are washed and cleaned as the slurry passes the screens in the slurry chamber 7067, which prevents the accumulation of slurry particles on the screens until the filtrate is recovered, and (2) the effect of gravity on the accumulation of particles on the screens is neutralized because the slurry enters the screens from below so that the particles are retained below the screens until the filtrate is recovered.

The fine filter block 7060 is extended in the axial direction such that the filter blocks 7068, as shown, can be arranged in a single longitudinal group or row so that the main chamber 7067 for the suspension is rectilinear to avoid the creation of an internal stagnation region and low pressure zones in the flow path of the suspension where particles in the suspension can accumulate.

An annular seal 7066, which in one embodiment of the invention may be elastomeric washers, may be built directly into each mesh filter unit 7068 as part of an assembly for hermetically sealing the mesh unit to the main body of the filter unit. In one embodiment of the invention, the mesh unit 7068 may have a cup-shaped configuration (best shown in Fig. 29) with a convexly curved dome-shaped mesh 7065 protruding outward/downward from one side of the seal 7066 into the main chamber 7067 for the slurry. Each mesh unit 7068 is received in a mating, upwardly open receptacle 7069 formed in the main body of the filter unit 7060, which is in fluid communication with the main chamber 7067 for the slurry of the filter unit. The screen retainer 7064 may be removably connected to the main body of the filter unit and at least partially located in each receiver for holding each screen unit, as best shown in Fig. 29. The main body may be rectangular, cylindrical or other shape. In one embodiment of the invention, the filtrate outlets 7063 may form an integral structural part of the screen retainers 7064, and in some embodiments of the invention, as shown, may end with a conventional tubular nipple for easy connection to the system piping. Other types of end connections may be used. The filtrate outlets 7063 completely pass through the retainers from top to bottom (Fig. 29). In some embodiments of the invention, the retainers 7064 may have a generally stepped cylindrical configuration. Threaded fasteners 7058 or other suitable connecting means may be used to removably connect the retainers 7064 to the main body of the filter unit. The fasteners 7064 hold the mesh filter units 7068 in the receivers 7069. Any suitable non-metallic (for example, plastic) or metallic materials can be used to manufacture the filter unit 7060, which includes the meshes 7065. In one embodiment of the invention, the main body of the filter unit can be plastic, and the meshes 7065 can be metal.

Similarly to the filter unit 7050 and the screens 7055, the screen units 7068 have screens 7065, each of which is designed to remove particles exceeding a predetermined size from the suspension to obtain a filtrate. Thus, the filter screens 7065 have a plurality of openings, each of which is designed to pass a suspension having a predetermined maximum particle size. The screens 7065 in one embodiment of the invention can be made of a metal mesh similar to a grid that forms the mesh cells for filtering the suspension. In other embodiments of the screens 7065 or 7055, polymeric meshes can be used. In other possible embodiments of the invention, filter materials of a different type can be used to perform the required sifting of the suspension.

An example of a process for replacing mesh filter units 7068 includes removing threaded fasteners 7058, removing retainers 7064 from each receiver 7069 perpendicular to the longitudinal axis LA of the main body of the filter unit, removing mesh filter units in the perpendicular direction, installing new mesh filter units perpendicular to the longitudinal axis LA in each receiver, installing retainers in the receivers and installing fasteners in place.

An overview of one non-limiting method for preparing an agricultural sample suspension using suspension recirculation and double filtration generally includes the following steps: mixing an agricultural sample with water in a mixing device to prepare a suspension; filtering the suspension a first time; measuring the density of the suspension; recirculating the suspension back to the mixing device; and extracting a portion of the recirculated suspension through a secondary fine filter to obtain a final filtrate. The first filtration of the suspension passes a suspension containing particles having a first maximum particle size, and the second filtration of the suspension passes a suspension containing particles having a second maximum particle size smaller than the first maximum particle size. The final filtrate is then passed to any of the agricultural sample analysis systems described herein, which are configured to further process and measure the analyte in the suspension.

It should be noted that both fine filter units 7050 and 7060 can be used in the agricultural sample analysis system shown in Fig. 3 without recirculation of the suspension, if the corresponding outlet pipes are simply closed with a plug or by closing a valve connected to the outlet pipe. Alternatively, the suspension can be disposed of as waste after passing through the fine filter. In this case, the filtrate would have to be extracted from the suspension during its passage through the filter.

Instead of the pump recirculation system shown in Fig. 4, Fig. 30 shows a schematic diagram showing an alternative equipment arrangement and method for recirculating the coarsely filtered slurry through the fine filters 7050 or 7060, using compressed air instead. The two mixing chambers are in fluid communication with the inlet and outlet of the fine filter unit 7050 or 7060, as shown in the flow path diagram, which may be the pipeline 7086 shown in the figure. At least one of the mixing chambers may be equipped with a mixing device 100A for initially preparing the water and soil slurry. The other mixing chamber may be an additional mixing device 100B or, alternatively, simply an empty high-pressure vessel. Four valves 7085A, 7085B, 7085C and 7085D for suspension are located between the fine filter unit and each of the chambers, as shown in the figure, for regulating the flow of suspension during mixing. During operation, if the suspension is first prepared in the mixing device 100A (sample preparation chamber No. 1), the valves 7085B and 7085C are open, and the valves 7085A and 7085D are closed. The mixing device 100A is under air pressure from the compressed air source 7086 with a valve, which forces the suspension to pass through the density measuring device 7010 and the fine filter unit 7050 or 7060 to the mixing device 100B. Then the valves 7085B and 7085C are closed, and the valves 7085A and 7085D are opened. Then, pressure is created in the mixing device 100B, causing the suspension to flow in the reverse direction through the fine filter unit 7050 or 7060 and the density measuring device 7010 back into the mixing device 100A. The sequential cycle is repeated several times to continue mixing the suspension. The valves and compressed air sources can be operatively connected to the system controller 2820 and can operate under its control, and the system controller 2820 can be programmed so that the said reverse flow occurs very quickly. The density of the suspension can be measured continuously each time the suspension passes through the density meter. After the required thorough mixing of the suspension, the filtrate outlets from the fine filter units are opened so that the filtered suspension is directed to the extraction subsystem 7004, shown in Fig. 4, for processing and chemical analysis. In some embodiments of the invention, a single source of compressed air can be used for all mixing chambers instead of separate sources. In another embodiment of the invention, the second chamber could be mounted directly above the first sample preparation chamber with a valve between them. Instead of pressurizing the second chamber, the suspension could flow back into the first chamber by gravity.

Determining the dimensions of the channel for the flow of suspension in the system

The internal diameter (ID) of the slurry flow channel, such as the slurry tubes 7088 shown in Figs. 3-4, is critical to the proper operation of the agricultural sample analysis systems 7000 without clogging the tube. When moving a slurry with large particles through a small tube, the likelihood of clogging increases. In a near-laminar flow, the velocity at the wall is close to zero, which exacerbates the problem. For small tubes, this becomes significant due to the high frictional forces on the slurry. If these frictional forces become too significant, the particles fall out of the flow and accumulate in the tube, causing the flow to stop. In addition, large particles can collide with other large particles in the small tube and cause clogging and flow to stop. However, having very large tubes is problematic because it is difficult to provide sufficient flow to keep the particles in suspension and prevent soil particles from settling.

The inventors have determined that the inner diameter of the tube 7088 and the channels for the suspension should be such that the inner diameter of the cross-section is at least twice the largest size of the particles in the suspension. That is, for example, if the coarse filter 146 or the fine filters 7050 or 7060 are filtering out particles larger than 2 mm in size (for example, in diameter), then the diameter of the tube should be at least 4 mm. And vice versa, the inner diameter of the tubes and channels should be such that the inner diameter of the cross-section is no more than ten times the largest size of the particles (for example, diameter). That is, for example, if the particles larger than 2 mm are filtered out, then the inner diameter of the tube should be no more than 20 mm in diameter. Accordingly, the preferred inner diameter of the tube 7088 for the suspension has a critical range between at least twice the largest particle size/diameter and no more than ten times the largest particle size/diameter.

In some embodiments of the invention, the tube material used may preferably be flexible and made of a fluoropolymer, such as, but not limited to, FEP (fluorinated ethylene propylene) in one non-limiting example. Other fluoropolymers such as PTFE (polytetrafluoroethylene), ETFE (ethylene tetrafluoroethylene) and PFA (perfluoroalkoxy polymer resin). The dynamic coefficient of friction (DCF) associated with these fluoropolymers also affects the preferred range of internal diameter of the tubes discussed above, since the tube material creates frictional resistance to the flow of the slurry. FEP, PTFE, ETFE and PFA have a DCF value in the range of about 0.02-0.4 inclusive, measured in accordance with the ASTM D1894 test protocol. Accordingly, the tube material used for the slurry tube 7088, associated with the above-mentioned range of critical tube internal diameters, preferably also has a DCT in the range of about 0.02-0.4 inclusive, in particular 0.08-0.3, associated with FEP in some embodiments of the invention. Tests conducted by the inventors confirmed that the use of FEP tubes falling within the range of the critical tube internal diameter allows avoiding the problems with blocking the flow of the slurry noted above. In other possible embodiments of the invention, a nylon tube can be used.

Agricultural sample suspension preparation system with modified suspension recirculation

Fig. 34-70 illustrate various features of a modified agricultural slurry preparation system 8000 of the agricultural sample analysis system 7000 and various components thereof. The system 8000 is one non-limiting embodiment of the sample preparation subsystem 3002 shown in Fig. 1. The system 8000 is configured to prepare an aqueous slurry containing agricultural sample material (e.g., solids) and having a desired target ratio of water in the slurry to solids suitable for further chemical analysis and quantitative determination of analyte levels in the sample (e.g., plant nutrients or others). In one embodiment of the invention, the system may include a closed slurry recirculation loop 8002 that includes a density measurement device capable of measuring the density of the prepared slurry. The recirculation loop may be isolated from other portions of the slurry system to form a closed slurry conduit or loop used in conjunction with agricultural slurry density measurement, as described further herein. The loop allows the slurry to recirculate in a closed recirculation system while water (diluent) is gradually added to achieve a target water to solids (agricultural) ratio. In one embodiment of the invention, the agricultural sample material may be soil that makes up the solid portion of the water-based slurry or the particulate portion; however, any of the other agricultural materials or solids previously described herein may be used with the slurry preparation system 8000.

Fig. 34 shows a simplified schematic diagram of the equipment of the 8000 agricultural suspension preparation system, shown in the corresponding high-level block diagram in Fig. 35.

As shown in Fig. 34-35, the system 8000 for preparing an agricultural slurry typically includes a mixing device 8010, a coarse filter unit 8020, and a closed slurry recirculation loop 8002 that are in fluid communication and interaction. The mixing device 8010 may be in fluid communication with the slurry recirculation loop 8002 through flow passages 8001. In one embodiment of the invention, the slurry may be supplied by gravity, compressed air, or it may be pumped from the mixing device into the recirculation loop. In one non-limiting design, gravity is used to avoid pump costs and maintenance. Other embodiments of the invention may be gravity-based with auxiliary compressed air.

The flow channels 8001 can be formed by tubes, hoses and/or pipelines individually or in combination of a suitable size (i.e. length and diameter) and material, for example, from metallic and/or non-metallic materials (for example, plastic, rubber, etc.). If necessary, a combination of these materials and sizes can also be used. The flow channels 8001 can be flexible, semi-rigid and/or rigid in design. In one embodiment of the invention, plastic tubes can be used, at least for some of the channels. The coarse filter unit 8020 can be connected to the recirculation circuit 8002 and the mixing device 8010 via the channels 8001 and can be located in the flow path between the recirculation circuit 8002 and the mixing device 8010.

The inventors have found that separating the function of preparing the initial volume of agricultural suspension using the mixing device 8010 from the function of maintaining the suspension in a mixed homogeneous state for measuring the density of the suspension leads to a more accurate determination of the density. Accordingly, as further described in this document, the suspension recirculation circuit 8002 comprises a separate special mixing device 8030 for this purpose.

Mixing device for suspension

The mixing device 8010, which is used to prepare the initial agricultural suspension by mixing the collected solid agricultural substances with water, typically comprises a sealed hollow body forming a mixing chamber 8013, a sample inlet 8011, a water inlet 8012 and a rotating paddle mechanism 8014 configured to mix the materials of the agricultural sample and water added to the mixing chamber 8013. The agricultural sample, consisting of bulk or raw collected agricultural material (for example, soil, organic fertilizers, vegetation or other agricultural materials), can be added to the mixing device 8004 through the sample inlet 8011. Water can be added through the water inlet 8012.

The vane mechanism 8014 typically comprises a vane assembly 8015 and a drive assembly, such as an electric motor 8016, coupled to an impeller or drive shaft 8017 of the vane assembly. One or more sets of impellers or vanes 8016 located at a distance from each other can be mounted on the drive shaft 8017, which can rotate at a constant predetermined speed or at variable speeds by means of the operation of the motor 8016. For this purpose, any suitable commercially available electric motor with a constant or variable speed can be used.

In one embodiment of the invention, compressed air from an available compressed air source 8005 can be used to feed unfiltered slurry from the mixing device 8010 to the coarse filter unit 8020 through the channel 8001. The shut-off valve 8003 in the channel 8001 for discharging the slurry from the mixing device 8010 can be closed. The compressed air supply line 8006 can be connected to the channel 8001 between the shut-off valve and the filter unit 8020. In other possible embodiments of the invention, the slurry can be pumped from the mixing device 8010 to the filter unit 8020.

Coarse filter block

In Fig. 36-43, additional images of the coarse filter unit 8020 are shown separately and in more detail. The coarse filter unit 8020 is configured to remove unwanted large particles that may remain in the suspension of the agricultural sample after the suspension is prepared in the mixing device 8010. Such large particles may include hardened accumulations or pieces of solid agricultural substances or foreign debris/objects collected together with the agricultural sample. For soil samples, such large-sized particles may be small field stones or pebbles, foreign objects in the soil (e.g., parts of agricultural equipment, tools, fasteners) or solid particles of plant residues.

The coarse filter screen 8021 installed inside the filter unit 8020 has a mesh size or openings selected in such a way as to prevent larger than required or oversized particles from passing through the screen, while allowing the desired smaller solid particles suspended in the agricultural slurry to pass into the slurry recirculation circuit 8002 for further processing, as further described in this document. Accordingly, the size of the openings or openings is selected in such a way as to prevent particles of a predetermined size from passing through the screen 8021, which may adversely affect the components or equipment (e.g., pumps, valves, etc.) described in this document and located downstream. Conversely, the openings of the screen are selected in such a way as to allow particles of a predetermined maximum size to pass through. In one non-limiting embodiment of the invention, for example, the opening or mesh size of the filter mesh 8021 can be about 1/16 inch (0.063 inches) for a soil-based suspension. Particles of the suspension larger than this size will not pass through the filter mesh. Other mesh opening sizes can be used for soil suspension or other types of agricultural suspensions. The filter mesh 8021 is elongated and in one embodiment of the invention can be arcuately curved from one side to the other side to more easily pass and remove accumulated debris.

In one embodiment of the invention, the coarse filter unit 8020 may have a substantially Y-shaped housing that includes an inlet 8022 for unfiltered slurry, an outlet 8023 for filtered slurry (filtrate), and an outlet 8024 for waste. The filter unit 8020 in some embodiments of the invention may be made of plastic; however, in other embodiments of the invention, a metal housing may be used. In one embodiment of the invention, the inlet 8022 for slurry may comprise an elastically deformable segmented pipe coupling 8022a that comprises several radially deformable elongated fingers 8022b with longitudinal slits 8022c separating the fingers along the circumference (designated in Fig. 36). The pipe coupling 8022a allows the tube/hose 8001 (flow channel) to be inserted inside the coupling, rather than from the outside, so that the end of the tube/hose enters the slurry inlet 8022 of the filter unit 8020. This advantageously eliminates any small holes, gaps or protruding edges in the connecting device where solid particles or debris of the unfiltered slurry could accumulate and cause clogging. Thus, the flow channel of the unfiltered slurry leading to the filter unit is not blocked from the inside, which also avoids flow disturbance. A standard tightening clamp 8022d for a hose (see, for example, Fig. 39) can be used to squeeze the fingers 8022b inward and secure the tube/hose 8001 on the pipe coupling 8022a. In other embodiments of the invention, other types of connecting elements for pipes and hoses can be used.

In one embodiment of the invention, the outlets 8024 for the filtrate and waste may be provided with threads for attaching the valves 8003 directly to the housing of the coarse filter unit 8020. However, other types of end connection devices may be used.

The filter mesh 8021 is located between the inlet 8022 for the suspension and the outlet 8023 for the filtrate, as best shown in Fig. 42. In one embodiment of the invention, the mesh 8021 can be elongated and arcuately curved from one side to the other side. The mesh 8021 can be installed in the central part of the Y-shaped housing, dividing the interior of the filter unit into an upper cavity 8028a (above the concave side of the mesh) and a lower cavity 8028b (under the convex side of the mesh). The filter unit 8020 is intended for use in a position in which the upper cavity is inclined downwards relative to the horizontal reference plane H passing through the filter housing (see, for example, Fig. 41). In other embodiments of the invention, other positions can be used.

As shown in Fig. 41 and 42, the lower cavity 8028b in some embodiments of the invention may have an inclined truncated-conical shape, forming a converging cone that narrows downwards in the direction from the filter screen 8021 to the outlet 8023 for the filtrate (filtered suspension). This directs and concentrates the filtered suspension leaving the filter unit 8020, while providing a large upper part of the lower cavity adjacent to the filter screen for filtering the maximum amount of suspension with a minimum pressure drop of the liquid.

The filter unit 8020 of the rough cleaning in some embodiments of the invention may also include a transparent cover 8027 to provide a visual inspection of the filter mesh 8021 for accumulation of debris removed from the slurry flow. Other embodiments of the invention may have an opaque cover. Each of the outlets 8023, 8024 for filtrate and waste, as well as the inlet 8022 for unfiltered slurry of the filter unit are closed/sealable for fluid isolation from other components of the slurry preparation system by means of special valves 8003 associated with each of the outlets and the inlet. In some embodiments of the invention, one or more of these valves 8003 of the filter unit may be directly connected to the housing of the filter unit. In one embodiment of the invention, pneumatic pinch valves with elastically deformable membranes or bladders (sometimes called sleeves) can be used, which are ideally suited for processing suspensions with entrained/suspended particles. Valves 8003, related to the pinch type of valves, include an opening 8003a for supplying compressed air to create pressure in the valve, which compresses the bladder to close the valve. Releasing the air pressure returns the bladder to the original open elastically biased state due to the ability of the bladder to restore shape. Such pinch valves are commercially available, and their principle of operation is known to those skilled in the art without further elaboration. However, other types of commercially available valves suitable for this application can be used. All valves 8003 discussed in this document can be switched between at least a fully closed position (no-flow state) and a fully open position (flow state). If necessary, some valves 8003 can be operated in a throttled (i.e., partially open) position. It should be noted that not every valve 8003 may be labeled in Figs. 34 and 35 for brevity and to minimize confusion in the drawings showing the valves.

The coarse filter unit 8020 may have a self-cleaning structure. As shown in Fig. 42, large particles (for example, agricultural solids or trash) captured or suspended in the slurry mixture from the mixing device 8010, which are too large to pass through the openings in the filter screen 8021, move in a linear trajectory along the concave upper surface of the screen 8021 to the waste outlet 8024. Smaller solids or particles in suspension passing through the screen are forced downwardly through the screen from the upper cavity 8028a to the lower cavity 8028b of the filter unit 8020 in a direction transverse to the flow path of the slurry in the upper cavity between the slurry inlet 8022 and the waste outlet 8024. It should be noted that the term "across" or "transverse" in this context does not necessarily mean perpendicular, but may also include some angular orientations relative to the control line or trajectory. The filtered suspension (filtrate) continues to flow into the suspension recirculation circuit 8002. This self-cleaning device successfully reduces clogging of the filter screen 8021, thereby allowing the filter unit to continue operating without frequent shutdowns of the unit for backwashing/cleaning of the screen.

The filter unit 8020 of the rough cleaning may also comprise a bubbling system used both for active filtering of the suspension and for periodic backwashing to clean the upper surface of the filter mesh 8021 from the debris settled on it, which is sifted out of the suspension passing through the mesh. The bubbling system comprises an inlet pipe 8025 for compressed air ("bubbler") and an inlet pipe 8026 for water under pressure. In one embodiment of the invention, a push-fit coupling may be used to connect the tube 8026b for supplying water under pressure to the inlet pipe 8026 for water, which may comprise a thread. A similar device may be used to connect the air tube to the inlet pipe 8025 for compressed air. However, other types of fittings may also be used.

Both the air inlet 8025 and the water outlet 8026 are located on the housing of the filter unit 8020 for supplying compressed air and cleaning water to the lower cavity 8028b of the filter unit 8020 under the convex lower surface of the filter screen 8021, as best shown in Fig. 42. The bubbling system combines air and water in the lower cavity 8028b to produce a stream of aerated water under pressure for both normal operation of the filter unit and for cleaning the screen. In some implementations, the lower cavity may first be filled with water before compressed air is supplied to operate the bubbler. During a normal slurry filtration operation or a backwash screen cleaning cycle, the stream of aerated water under pressure in the lower cavity 8028b flows upward through the filter screen to actively remove debris, which is washed away into the waste. During normal filtration, a stream of aerated water flows continuously to prevent accumulations or deposits from forming on the surface of the screen that could block the openings of the screen. As a benefit, the action of the pressurized "bubbler" provides greater force to agitate and dislodge larger debris or solids trapped in the suspension than water alone. In the case of soil suspensions, these suspensions may contain debris in the form of heavier pebbles or stones (or other foreign metallic or non-metallic objects) that are not easily removed and would otherwise frequently clog the screen. The stream of aerated water flushes the debris through the waste outlet 8024. The bubbling system also advantageously minimizes the water consumption for periodic cleaning of the coarse filter unit 8020 when the filter unit 8020 is not in use or between uses.

During the periodic cleaning operation of the screen for maintenance, the outlet 8023 for the filtrate is closed by closing the valve 8003 associated with it. The inlet 8022 for the slurry can be isolated by closing the inlet valve 8003 between the mixing device 8010 and the filter unit 8020. It should be noted that, as an alternative, the valve 8003 can remain open during the cleaning of the upstream mixing chamber with clean water and the subsequent discharge of this water through the filter into the waste. Therefore, the filter is often not isolated from the mixing during the cleaning process. The outlet 8025 for the waste is opened by opening the valve 8003 associated with it. This ensures the isolation of the filter unit 8021 from the mixing device 8010 and the slurry recirculation circuit 8002. After completion of the filter backwash/cleaning operation, waste outlet 8025 is closed and sealed by closing its associated valve 8003, and conversely, the valves associated with the slurry inlet and outlet are reopened to resume normal operation.

Since the coarse filter unit 8020 has a self-cleaning design and the bubbling system operates during the normal filtration process of the suspension, a small portion of the unfiltered suspension may be wasted in order to keep the filter mesh relatively free of debris and blockages. In order to minimize the amount of lost suspension, several measures are provided in the design of the filter unit. First, the inlet and outlet 8022, 8023 for the suspension, as well as the outlet 8024 for waste are oriented relative to each other so as to minimize the loss of suspension during the filtration process. In one non-limiting embodiment of the invention, the centerlines 8022L, 8023L of the inlet 8022 for the unfiltered suspension and the outlet 8023 for the filtrate, respectively, can be oriented parallel to each other. This allows the slurry to be introduced into and removed from the filter unit 8020 in a similar orientation (best shown in Fig. 42) to take advantage of the fact that unfiltered slurry will most easily continue to flow in the same direction in which it is introduced into the filter unit. However, the centerline of the waste outlet 8024L is oriented transversely to the centerlines of the slurry inlet and outlet. This results in less slurry passing through the waste path than through the filter screen 8021 due to the dynamic force of the incoming slurry into the filter unit 8020. The filter screen 8021 is also oriented transversely to the centerline 8022L of the slurry inlet 8022 so that the incoming slurry flow is directed at the upper surface of the screen 8021. This will result in the slurry passing through the screen downwards rather than at an angle or laterally towards the waste outlet. Finally, the lower cavity 8028B is larger in size than the upper cavity 8028a of the filter unit 8020 to provide less flow resistance. A narrower upper cavity creates more resistance, so that the flow of suspension tends to flow downwards through the filter mesh 8021.

It should be noted that if the expected amount of waste in the unfiltered agricultural slurry to be processed is small, then, if necessary, the coarse filter unit 8020 can operate in the normal manner (and not in the self-cleaning mode), with the filter unit waste outlet valve 8003 closed.

A general method or process for filtering a suspension typically includes: providing a filter unit comprising a filter screen, an upper cavity formed above the filter screen, and a lower cavity formed below the filter screen; forcing compressed air and water into the lower cavity to produce a stream of aerated water; passing the stream of aerated water through the filter screen into the upper cavity; feeding an unfiltered suspension into an upper chamber of the filter unit; and passing the unfiltered suspension through the filter screen in a direction countercurrent to the stream of aerated water to produce a filtrate. Accordingly, the filter unit operates in a self-cleaning mode when the waste outlet valve 8003 is opened to remove a portion of the suspension with captured large particles sliding along the upper surface of the filter mesh 8021, through the waste outlet 8024 of the filter unit 8020 simultaneously with passing the remaining portion of the unfiltered suspension downwards through the filter mesh in a countercurrent direction to the flow of aerated water to obtain a filtrate. The upper surface of the filter mesh is arcuately curved from one side to the other side and has a concave shape, forming a trough that facilitates the direction of large particles along the mesh to the waste outlet 8024. The flow of aerated water passing through the filter mesh 8021 and entering the upper cavity of the filter unit 8020 from below the mesh sets in motion and displaces particles from the upper surface of the mesh, so that they are swept off the mesh so as not to impede the efficiency of the suspension filtration. In some implementations, to produce a flow of aerated water, water may first be injected into the lower cavity 8028b, followed by the application of air pressure to the lower cavity.

Closed loop slurry recirculation - Density measurement

Components that are part of a closed loop 8002 slurry recirculation used in conjunction with slurry density measurement to determine an actual water to solids (agricultural) mass ratio for comparison with a target water to solids mass ratio required to produce a flowable slurry suitable for efficient further sample processing and chemical analysis in an analysis subsystem 3003 and its flow pattern will now be described. As described earlier in this document, the subsystem 3003 ultimately measures analytes (e.g., chemical/elemental constituents) in the agricultural slurry to characterize the sample from a chemical standpoint. In one non-limiting example, the agricultural material to be analyzed for analytes (e.g., soil nutrient levels such as nitrogen, phosphorus, potassium, etc.) may be soil, and the ratio is a water/soil ratio (water to soil ratio).

The present closed loop 8002 for recirculating the slurry shown in Fig. 34-35 is a modification of the recirculation loop 7059 shown in Fig. 4. In the present loop 8002, similar components are rearranged in the flow path of the slurry, and additional components are added, as described below, to optimize the accuracy of the measurement of the density of the slurry to achieve a target water/solids ratio. The loop 8002 is configured and operated in such a way as to provide stable flow rates while maintaining the slurry in a fully mixed homogeneous state, which advantageously improves the accuracy of the density measurements of the agricultural slurry. This information is ultimately used to add dilution water to the loop 8002 to achieve the target agricultural water to solids mass ratio.

In one embodiment of the invention, the slurry recirculation loop 8002 generally comprises, in communication with each other, a mixing device 8030, a slurry recirculation pump 7080 that directs the recirculation flow through a closed recirculation loop, an accumulator 8050, an agricultural solids measuring device 8060, a density measuring device 8070, and a fine filter unit 8080. The direction of circulation or flow of the slurry in the loop is indicated by the slurry flow arrows in Fig. 34-35.

Mixing device

The mixing device 8030 is a liquid lock for introducing a coarsely filtered suspension (filtrate) from the mixing device 8010 through the filter unit 8020 into the suspension recirculation circuit 8002. The filtrate flows from the filter unit into the mixing device 8030 under the action of a driving force created by a compressed air supply line 8006 connected to an air source 8005 located upstream of the filter unit, if used, as described earlier in this document. In other embodiments of the invention, the filtrate can flow to the mixing device only by gravity without the help of air pressure or pumping into the mixing device.

In Fig. 51-63, various types of mixing device 8030 are shown separately and in more detail. In one embodiment of the invention, mixing device 8030 may be a mixing device of the mixing type, although specially designed to agitate the slurry less aggressively, since larger bulk agricultural solids do not need to be broken down into smaller particles to initially form a slurry. Instead, the mixing device is designed to more gently agitate and maintain a homogeneous mixture of water and agricultural solids (e.g., soil) for density measurement in a closed loop 8002 slurry recirculation shown in Fig. 34-35 and described elsewhere herein.

The mixing device 8030 generally comprises a sealed and vertically elongated hollow body formed by a shell 8094 forming a mixing chamber 8031 for holding a volume of filtered suspension (filtrate), and a rotating paddle mechanism 8035. The paddle mechanism 8035 is designed with the possibility of shaking the agricultural suspension to a degree sufficient to hold agricultural solids or particles in suspension in water, which is a carrier liquid (diluent) of the suspension, but not excessively shaking the suspension, which entrains air, which negatively affects the measurements of the density of the suspension. The chamber 8031 forms an integral part of the suspension recirculation circuit 8002 and the suspension flow path. In one embodiment of the invention, the mixing device and chamber operate at atmospheric pressure, although the recirculation stream entering the chamber is under pressure generated by the slurry LDM pump 7080.

The housing 8094 of the mixing device has a top side 8100, a bottom side 8101, a right side 8103, a left side 8104, a front side 8105 and a back side 8106. In one embodiment of the invention, the housing 8094 contains several parts or sections that can include a removable top cover 8090, an upper section 8091, a middle section 8092 and a lower section 8093. The sections 8091-8093 can be connected to each other permanently or with the possibility of separating, or a combination of both. In one embodiment of the invention, at least the lower section 8093 is removably connected to the middle section 8092 by means of threaded fasteners 8095. The upper cover 8090 may similarly be removably connected to the upper section 8091 of the housing 8094 by means of threaded fasteners 8095. It should be noted that for brevity, only one or more fasteners may be shown in the figures, taking into account that similar fasteners are inserted into other similar openings in the housing of the mixing device.

The fluid connections of the mixing device 8030, which are in fluid communication with the mixing chamber 8031, include an inlet 8032 for slurry, which receives slurry from the mixing device 8010, an inlet 8033a for recirculating the slurry, an outlet 8033b for recirculating the slurry, an overflow pipe 8096 and a waste outlet 8049 for providing flushing and cleaning of the mixing chamber with water between passes of the slurry. The overflow pipe 8096 removes excess slurry added to the chamber 8031 from the upstream mixing device 8010. The overflow pipe is configured to be connected to a hose/tube that is under atmospheric pressure. This, in turn, creates atmospheric pressure in the mixing chamber 8031 of the mixing device 8030 during operation.

In one embodiment of the invention, the slurry inlet formed in the upper section 8091 of the housing 8094 may be inclined relative to the vertical centerline 8040 of the mixing device 8030 to feed the slurry at the same angle into the mixing chamber 8031. Each of these connections may have a corresponding open/close valve 8003, as shown in Fig. 34 (except for the overflow means in one embodiment of the invention) to stop or allow flow through or from these connections.

The vane mechanism 8035 typically comprises a vane assembly 8034 and a drive assembly, such as an electric motor 8038, coupled to an impeller or drive shaft 8036 of the vane assembly. The vane assembly 8034 also comprises one or more sets of impellers or blades 8037 mounted on the drive shaft 8036, which can rotate at a constant predetermined speed or at variable speeds by operating the motor 8038. Any suitable commercially available electric motor with a fixed or variable speed can be used for this.

Compared to the mixing device 8010, which performs a more intense agitation, the mixing chamber 8031 can be at least as large in volume to accommodate the entire content of the agricultural suspension prepared in the mixing chamber 8013, which enters the mixing chamber 8031 for measuring the density and adjusting the water/solids mass ratio, as described later in this document. In one embodiment of the invention, the volumetric capacity of the mixing chamber 8031 can be larger than that of the mixing chamber 8013 of the device 8010 (for example, by about 20% or more) to ensure that the entire suspension can be accommodated.

The paddle mechanism 8014 of the mixing device 8010 is designed to impart more energy (i.e., input energy) and provide more aggressive agitation of the slurry than the mixing device 8030 in order to break up the agricultural solids in the carrier water to form an initial, relatively homogeneous slurry mixture. From a design standpoint, this can be achieved in several ways. In some implementations, for example, the paddle mechanism 8014 of the mixing device 8010 can be operated at a higher rotational speed (rpm - revolutions per minute) than the paddle mechanism 8035 of the mixing device 8030 in order to more vigorously mix the bulk agricultural material and water together to form a slurry mixture. This is not necessary for the mixing device, the purpose of which is to simply agitate the already prepared slurry just enough to prevent the agricultural solids from settling out of solution (i.e., to maintain the slurry in a homogeneous state for the purpose of measuring the density of the slurry). Without a mixing device, the suspension mixture is prone to separation of solids, which negatively affects the achievement of an accurate density of the suspension. In one illustrative, but non-limiting example, the paddle mechanism 8014 of the mixing device can have a rotational speed of about 15,000 rpm in combination with several more aggressive spaced apart sets of paddles 8016 on the impeller/drive shaft 8017, as shown, which are configured to more agitate the mixture of agricultural material and water. In contrast, as one non-limiting example, the paddle mechanism 8035 of the mixing device can have one set of paddles 8037 on the drive shaft 8036 of the paddle assembly and a lower rotational speed of about 1000 rpm. Accordingly, in some embodiments of the invention, the paddle mechanism 8014 of the mixing device can have a rotational speed at least 10 times greater than that of the mixing device 8030. Several other speeds can be used if necessary, depending on the nature of the agricultural material from which the sample is formed.

In other embodiments of the invention, to achieve more aggressive mixing in the mixing device 8010, the length of the blades 8016 may be different, so that the blades of the mixing device are longer than those of the mixing device 8030, thereby providing higher blade tip speeds even at the same or lower rotational speeds than the blades in the mixing device. As noted above, the paddle mechanism 8035 of the mixing device may have a smaller number of paddles 8037 and/or a less aggressive configuration of the paddles for a gentler mixing of the suspension than the paddles 8016 of the mixing device 8010. Depending on the speed of rotation of the paddle assembly, the number and/or length of the paddles, their configuration or the speed of the tips of the paddles, a more aggressive mixing of the suspension in the mixing device 8010 is carried out with more energy or power supplied to the suspension than in the mixing device 8030 for breaking up the solids in the initial suspension being prepared. Accordingly, the power consumption of the drive motor 8016 of the mixing device 8010 is greater than the power consumption of the drive motor 8038 of the mixing device 8030 in all preferred cases of mixing.

The shape or configuration of the mixing chamber 8013 and the mixing chamber 8031 may also differ due to the different functions of the mixing device 8010 and the mixing device 8030. As shown in Fig. 61, the mixing chamber 8031 in some embodiments of the invention may have an hourglass, peanut, or "figure 8" configuration with a narrower middle zone, as described later in this document, designed to accommodate two separately rotating drive shafts 8036, which may be provided to improve the mixing of the slurry. In some embodiments of the invention, the two drive shafts 8036 may also rotate in opposite directions relative to each other to further enhance the mixing of the slurry. These features help mix the slurry while reducing turbulence (air that "vortexes" down the shaft), since it is undesirable to introduce air into the slurry recirculation circuit 8002, since this negatively affects the accuracy of the density measurement of the slurry. Additionally, the slurry circulating in the slurry recirculation loop 8002 may be reintroduced or returned to the mixing chamber 8031 via the tangential recirculation inlet 8033a to further reduce air entrainment, as described below.

Now, additional features and details of the mixing device 8030 and the above-mentioned features will be described. As follows from Fig. 51-63, the mixing device 8030 may include a vertically elongated housing defining a vertical centerline 8040 passing through the geometric center of the mixing device. The housing simultaneously forms a vertically elongated mixing chamber 8031 in which a pair of blade assemblies 8034 are located. The mixing chamber 8031 may be non-circular and oblong in shape, having a greater transverse width in the direction from one side to the other side than the depth in the direction from front to back (best seen in Fig. 61). The shafts 8036 of the blade assembly may extend parallel to each other, as shown in the figure.

The mixing chamber 8031 can be divided in the transverse/horizontal direction into first and second sections 8031a, 8031b, separated by a narrowed neck 8041, defined by a pair of opposite and inwardly projecting partitions 8042 on opposite sides of the centerline 8040 (see, for example, Fig. 61). The partitions can have a convex and arcuate shape, extending both inwardly horizontally and vertically over most of the height of the mixing chamber 8031 (see, for example, Fig. 59). As shown, one blade assembly 8034 is located in the center of each section 8031a, 8031b of the chamber between the sides of the mixing device. The baffles 8042 serve to enhance the mixing of the slurry so that the slurry cannot simply move around the outer or peripheral portion of the chamber 8031 along the inner side walls 8043 of the housing of the mixing device to avoid mixing. The baffles 8042 force the slurry to flow inward toward the vertical centerline 8040 in the region of the throat 8041 and to be mixed, which helps to maintain a homogeneous mixture of the slurry of agricultural solids and water. In one embodiment of the invention, the inlet 8032 for the slurry passing through the upper section 8091 of the housing 8094 can be inclined relative to the vertical centerline 8040 of the mixing device 8030 to feed the slurry at the same angle into the mixing chamber 8031 in the region of the throat 8041 at the upper ends of the baffles 8042 (see, for example, Fig. 59). The inner bottom wall 8097 of the mixing device 8030 inside the mixing chamber 8031 can be inclined downwardly and inwardly towards a centrally located waste outlet 8049 in the bottom wall of the mixing chamber 8031 on each side of the mixing device for effective washing of sediment from the chamber during periodic cleaning with wash water between different cycles of suspension preparation.

The mixing device 8030 also includes a drive mechanism for driving the blade assemblies 8034. In one embodiment of the invention, the drive mechanism comprises a gearbox 8044, in which a gear mechanism or transmission 8045 is placed, comprising several gear wheels that are in mesh. The shaft of the motor 8038 includes a drive gear 8038a, and each blade assembly includes a driven gear 8036a, operatively connected to the drive gear of the motor and rotated by it through intermediate gears 8046 (see, for example, Fig. 60). The gearbox 8044 can be located in the upper part of the mixing device near the motor 8038. In one embodiment of the invention, the gearbox 8044 can be formed by the upper cover 8090 (see, for example, Figs. 58-59). The gear train 8045 is operatively connected to the motor 8038 and each of the shafts 8036 of the blade assembly. The motor 8038 drives the gear train 8045, which in turn rotates the blade assemblies 8034. In some embodiments of the invention, as described earlier in this document, the blade assemblies can rotate in opposite directions relative to each other to improve the mixing of the agricultural slurry (see, for example, Fig. 61 with rotation arrows). The gear train 8025 is configured to create this type of counter-rotational motion of the pair of blade assemblies. The intermediate gears 8046 can be configured and arranged so as to provide counter-rotational motion of the blade assemblies 8034 (see, for example, Fig. 60). In other embodiments of the invention, the blade assemblies can rotate in the same direction of rotation. It should be noted that other gear train arrangements are also possible. In addition, other methods can be used to rotate the blade assemblies instead of gear transmission, such as belt drives or pneumatic drives via an air impeller connected to the main drive shaft, which in turn drives the gear transmission.

During operation, the filtered slurry enters the mixing chamber 8031 through the inlet 8032 from the coarse filter unit 8020. The vane assemblies 8034 rotate with the aid of the aforementioned gear mechanism to mix the slurry and prevent the solids from settling out of the slurry. If the slurry recirculation loop 8002 is initially empty, the slurry may at least partially fill the loop depending on the diameter of the loop piping. Therefore, in some cases, the slurry may not completely fill the loop until the slurry recirculation pump 7080 is started, so that the pump is started when the slurry is initially introduced into the loop through the mixing device 8030. In any case, the slurry recirculation pump 7080 will begin to pump the slurry through the loop (see, for example, Figs. 34-35). The slurry is pumped directly into the recirculation inlet 8033a of the mixing device 8030, where it is agitated to maintain a uniform consistency. The slurry then exits the mixing device through the recirculation outlet 8033b and returns to the circuit 8002 to continue circulating around the circuit and other devices shown under the driving force of the pump 7080. Any excess slurry in the circuit is removed through the overflow pipe 8096.

It should be noted that the recirculated slurry from the slurry recirculation circuit 8002 flows tangentially into the mixing chamber 8031 and enters (via the slurry recirculation inlet 8033a) into one of the two circular sections of the mixing chamber 8031, such as, for example, section 8031b (see, for example, Figs. 59 and 61). In one preferred, but non-limiting embodiment of the invention, the slurry is reintroduced tangentially along one of the side walls 8043 of section 8031b of the mixing chamber to reduce air entrainment in the slurry, which negatively affects the slurry density measurements, as described earlier in this document. The suspension may be withdrawn from chamber 8031 within a narrow neck 8041 between chamber sections 8031a, 8031b, where the suspension will tend to be thoroughly mixed and agitated into a homogeneous state.

In some embodiments of the invention, the operation of the paddle assemblies 8034 with respect to the degree of agitation of the suspension in the mixing device 8030 can be controlled and automatically adjusted by the system controller 2820 based on the level of the suspension (and, accordingly, its volume) in the mixing chamber 8031. If the level of the suspension is lower, then it is necessary to rotate the paddle assemblies at a lower speed (rpm) in order to reduce agitation, thereby minimizing the ingress of air into the suspension, which negatively affects the measurements of the density of the suspension. If the level of the suspension is higher, then the operation of the paddle assemblies can be accelerated in order to ensure that the suspension mixture remains homogeneous and the solids are kept in suspension.

In order to achieve the above-mentioned scheme of operation, a level sensor 8039 can be provided, which is configured to measure the level of the suspension in the chamber 8031 of the mixing device 8030 in real time. Any suitable commercially available sensor can be used, such as, for example, but not limited to, an ultrasonic level sensor. The level sensor and the motor 8038 can be operatively and communicatively connected to the system controller 2820 for controlling the speed of agitation of the suspension. The motor can be a motor with variable speed rotation, the speed of which is adjusted based on the level of the suspension detected by the controller 2820, in order to achieve the desired degree of agitation of the suspension by decreasing or increasing the speed of rotation of the blade assemblies 8034. Therefore, the motor 8038 can include a speed control circuit responsive to control signals from the controller 2820, for adjusting the speed of the motor based on the level of the suspension.

The method or process for controlling the blade assemblies 8034 of the mixing device 8030 can be summarized as the following actions performed by the controller 2820: determining the level of the slurry in the mixing chamber 8031 using the level sensor 8039; increasing or decreasing the speed of rotation of the motor 8038 operatively connected to the pair of blade assemblies 8034 based on the detected level; and rotating the blade assemblies at a speed corresponding to the speed of rotation of the motor. If the controller 2820 detects a first level of the slurry in the chamber 8031, then the controller rotates the blade assemblies at a first speed. If the controller 2820 detects a second level of the slurry, then the controller rotates the blade assemblies at a second speed different from the first speed. If the first level of the slurry is lower than the second level of the slurry, then the controller rotates the blade assemblies at a slower speed than at the second level of the slurry, and vice versa. Other options for operating with a variable speed of rotation of the blades are also possible. In some embodiments of the invention, the paddle assemblies may rotate at a constant speed regardless of the level of the slurry in the mixing chamber 8031, which may depend on the type of agricultural slurry prepared and the accompanying tendency of the solids to fall out of suspension or other factors.

Battery

In Fig. 44-50, an accumulator 8050 is shown separately and in more detail. The accumulator is designed to dampen pressure surges or pulsations in the suspension circulating along the suspension recirculation circuit 8002. In one embodiment of the invention, the accumulator 8050 may be a straight-through design, in which the flow enters the accumulator, passes through it and exits the accumulator along a linear or straight flow path along one axis. The accumulator 8050 has a longitudinally elongated and detachable housing, generally comprising a first half-section 8051a and a second half-section 8051b, connected to each other with the possibility of detachment, for example, with the help of threaded fasteners. Other methods of detachable connection may also be used. When connected to each other, the half-sections 8051a, 8051b form an internal cavity 8053 elongated in the longitudinal direction.

The longitudinally extended elastomeric elastically deformable membrane 8054 extends at least along the entire length and width of the cavity 8053 and, preferably, is slightly larger in width and length than the cavity. The membrane 8054 can be flat and oblong in shape (best shown in Fig. 46-47) to match the horizontally elongated configuration of the cavity 8053 of the accumulator. The peripheral edges of the membrane 8054 can be clamped between the first and second half-sections 8051a, 8051b of the housing, which hold the membrane in the required position. It divides the cavity 8053 into an upper, gas sub-cavity 8053a and a lower, suspension sub-cavity 8053b, isolated from the gas sub-cavity. Both the upper and lower sub-cavities may have a dome-shaped concave shape in cross-section (best seen in Fig. 50). When the membrane reaches full displacement (full contact with the cavity wall), this does not create an excessive load on the membrane, forcing it to conform to any sharp angles that can lead to rupture of the membrane during numerous operating cycles due to fatigue failure. Sub-cavity 8053a is in fluid communication with an opening 8057 for supplying compressed gas for creating pressure of the pre-introduced gas for the accumulator by connecting to a source of compressed inert gas. The upper sub-cavity 8053a, pre-filled with gas, can be filled with compressed inert gas, such as air or nitrogen, for example, to pre-fill the accumulator 8050 with a volume of gas to compensate for pressure fluctuations in the slurry flowing through the slurry recirculation circuit 8002. Such pressure fluctuations (increases/decreases) may be caused by the 7080 slurry recirculation pump starting/stopping, causing flow and pressure fluctuations, or other factors associated with the slurry handling system. Some pumps are designed to create pressure pulses that can be significant in magnitude, which can cause various problems, including adversely affecting the measurement of slurry density.

The sub-cavity 8053b for the slurry receives the slurry and forms the main part of the linear/straight channel for the flow of the slurry passing through the accumulator from one end to the other end. The lowermost part of the sub-cavity 8053b may include a single-piece, longitudinally extending trough 8053c having an arcuately curved lower surface in cross-section. The trough 8053c may have a semi-circular cross-sectional shape, as best seen in Fig. 50, which differs from the cross-sectional shape of the lower sub-cavity 8053b. The trough 8053c effectively prevents the membrane from blocking the outlet during periods of high shear due to fluctuations in the pressure of the slurry by providing a flow path that is difficult for the membrane to completely block, and also helps maintain the rapid movement of any sediment through the accumulator in a linear direction in order to prevent the formation of deposits and clogging of the accumulator.

The slurry sub-cavity 8053b is in fluid communication with a slurry inlet 8055 at one end of the second half-section 8051b and a slurry outlet 8056 that may be formed at the opposite end in the lower slurry sub-cavity 8053b. The inlet 8055 is coaxial with the outlet 8056, defining a longitudinal flow axis Lf that extends between them along the length of the accumulator housing. Most accumulators have a single combined inlet and outlet that, when used with slurry, will not be effectively cleaned due to deposits formed as a result of agricultural solids settling out of the slurry.

For this reason, it is advantageous to use a straight-through accumulator according to the present invention with a specially configured linear channel for processing a slurry with captured solids, which has such a ratio of the cross-sectional areas measured immediately adjacent to and under the flexible movable membrane 8054 (i.e. on the wet side) of the accumulator 8050, which can allow the flow of the slurry (liquid) to continuously wash and effectively clean the accumulator from the sediment between the sample preparation/processing cycles. In one embodiment of the invention, for example, without limitation, the cross-sectional area A1 of the flow path of the lower sub-cavity 8053b, determined transversely to the flow axis Lf, preferably exceeds by no more than 20 times, and more preferably by no more than 30 times, the minimum cross-sectional area A2 of the inlet or outlet of the accumulator in the preferred embodiments of the invention. The inlet 8055 and the outlet 8056 for the slurry can have different or the same cross-sectional areas A2. In the non-limiting embodiment shown, the cross-sectional areas of the inlet and outlet for the suspension are the same.

In total, the cross-sectional area A2 of the inlet and/or outlet is preferably less than the total cross-sectional area A1 of the sub-cavity 8053b of the accumulator located under the elastically deformable membrane 8054, measured when the membrane is in a resting state (i.e. not deformed as a result of surges or a drop in pressure in the liquid system). Preferably, such a size and the total ratio of the cross-sectional areas of the sub-cavity 8053b and the area of the inlet and/or outlet 8055, 8056 helps to prevent the precipitation of solids from the suspension and clogging of the accumulator between cycles of processing the suspension.

In order that solids or sediment do not fall out of suspension and accumulate inside the lower sub-cavity 8053b of the accumulator, between cycles of processing the suspension due to the fact that the cross-sectional area A1 of the lower sub-cavity is substantially larger than the cross-sectional area A2 of the inlet and outlet 8055, 8056 for the suspension (for example, not less than 20 times), as indicated above, the inlet and outlet for the suspension (and, accordingly, the longitudinal flow axis Lf, defined between them), are preferably located with an offset and below the horizontally extending geometric longitudinal centerline C1 of the lower sub-cavity 8053b. The centerline C1 passes through the geometric center of the lower sub-cavity 8053b and is vertically located in the middle between the lower point of the lower sub-cavity 8053b at the bottom of the semicircular trough 8053c and the membrane 8054, as indicated in Fig. 48. Preferably, the slurry inlet and outlet 8055, 8056 are located at the very bottom of the sub-cavity 8053b, as best shown in Figs. 48 and 50. In one embodiment of the invention, the sub-cavity 8053b comprises a pair of opposing inclined and arcuately curved concave side walls 8053d that help direct heavy sediment/solids entrained in the slurry flowing through the accumulator downwards to the bottom of the sub-cavity where the flow has the highest velocity between the slurry inlet and outlet 8055, 8056 along the longitudinal axis Lf. This advantageously eliminates any corners or dead spots in the lower sub-cavity where sediment/solids may accumulate between slurry processing cycles.

In cross-section (relative to the longitudinal axis Ca of the cavity), the lower sub-cavity 8053b may not have a completely semi-circular configuration, as best shown in Fig. 50. Instead, the arcuately curved concave side walls 8053d may converge to a pointed apex 8053e at the very bottom of the sub-cavity 8053b. This may be similar to the apex formed in the upper sub-cavity 8053a at the top. The lowermost trough 8053c for the slurry in the lower sub-cavity 8053b, previously described in this document, intersects the apex 8053e. The lowest point on the bottom of the semicircular trough 8053c (in cross-section, as shown in Fig. 50) is located below the point or apex where the curved converging lower side walls 8053d of the sub-cavity meet (see also Figs. 46 and 48). It can be considered that the curved concave side walls 8053d of the lower sub-cavity 8053b form a substantially V-shaped cross-sectional shape, as opposed to the semicircular cross-sectional shape of the trough 8053c. The term "substantially" as used herein means that the curved side walls 8053d are not flat and, therefore, do not form a perfect V-shape. The upper sub-cavity 8053a can be formed complementary to the lower sub-cavity 8053b, wherein each of them has a substantially V-shaped cross-section; one is a mirror image of the other from opposite sides of the membrane 8054 (see, for example, Fig. 50).

In addition to preventing the membrane 8054 from completely blocking the inlet and outlet 8055, 8056 for the slurry during maximum downward deformation of the membrane, as noted earlier in this document, the trough 8053c also preferably promotes higher flow rates of the slurry therein through the accumulator 8050 to help move the heavy sediment/solids entrained in the slurry through the accumulator as it flows between the inlet 8055 for the slurry and the outlet 8056 for the slurry. This also helps prevent the accumulation or deposition of sediment/solids between slurry processing cycles.

The accumulator 8050 is an energy storage device and operates in the usual manner. During operation, the suspension flows through the sub-cavity 8053b, while the sub-cavity 8053a holds the volume of compressed gas. If a pressure surge occurs in the suspension recirculation circuit 8002, the excess pressure, which deforms the membrane 8054 (in the direction of the gas sub-cavity 8053a), absorbs the pressure pulse and maintains a relatively constant pressure in the circuit. If the suspension pressure in the circuit drops below the pre-fill pressure of the accumulator, the membrane moves to the sub-cavity 8053b for the suspension in order to increase the suspension pressure in the flow circuit. The relatively constant pressure maintained by the accumulator in the suspension recirculation circuit 8002 improves the overall accuracy of the suspension density measurements by the density measuring devices in the circuit.

Main and recirculation pumps for suspension

Now, the main slurry pump 7081 shown in Fig. 3-4 and the slurry recirculation pump 7080 shown in Fig. 4 and 35 will be further described, which circulates the slurry flow through the closed slurry recirculation loop 8002. In one embodiment of the invention, a positive displacement pump, such as an air-operated double diaphragm (ADD) pump, can be used for one or both pumps 7080, 7081 with a unique pump head design that includes modifications to the internal fluid delivery path designed specifically for handling agricultural slurries, such as soil sample slurries or others in which the heavy solids or sediment component of the slurry tend to fall out of suspension easily. By comparison, this type of slurry is somewhat similar to water and sand slurries. For these slurries, standard off-the-shelf PDM pumps are prone to heavy sludge or sediment buildup in the bottom of the pump chambers. These sediment deposits create flow restrictions and reduce pumping performance, which negatively impacts pumping performance. Cleaning the pump between samples also becomes significantly more difficult because the sediment is not easily flushed into the flow stream during the cleaning process.

The present 7080 LDM pump with innovative design solutions, designed to minimize or eliminate sediment accumulation in the pumping chambers, overcomes the shortcomings of the above-mentioned standard LDM pumps for pumping slurries containing heavy particles or solids, such as soil slurries.

For convenience, the LDM slurry pump will be described with reference to the slurry recirculation pump, given that the same pump description applies to the main slurry pump 7081 if the same design is used. However, it should be understood that in some other implementations of slurry processing systems, pumps of a different type may be used either as the pump 7080 or as the pump 7081.

Figs. 64-70 illustrate features of the LDM pump 7080 for recirculating slurry in the slurry recirculation circuit 8002 in accordance with the present invention. Figs. 64 and 65 are successive cross-sectional views showing the internal structure and operation of the pump with internal slurry flow paths during pump strokes. These figures depict the pump in its normal vertical operating position.

As shown in Fig. 64-70, first of all, the pump 7080 for recirculating the suspension typically comprises a pump housing 8200 having an upper end 8210, a lower end 8211, opposite right and left side faces 8212a, 8212b and a vertical longitudinal axis LA passing through the geometric center of the pump housing for convenience of description. On opposite sides of the longitudinal axis LA, right and left pump chambers 8201, 8202 are formed.

The inlet manifold 8203 and the outlet manifold 8204 are connected to the opposite upper and lower ends 8210, 8211 of the housing. Each manifold contains an internal flow channel for receiving suspension from the suspension recirculation circuit 8002 into the pump 7080 or discharging/returning suspension back to the circuit from the pump. The inlet manifold 8203 comprises one inlet 8203a and a pair of inlet passages 8203b, each of which is in fluid communication with one of the two inlet check valves 8220. The inlet manifold bifurcates or divides and distributes the inlet flow of the slurry from the recirculation circuit 8002 into each pump chamber 8201, 8202. The outlet manifold 8204 comprises one outlet 8204a and a pair of outlet passages 8204b, each of which is in fluid communication with one of the outlet check valves 8221. And vice versa, the outlet manifold combines the slurry from each pump chamber 8201, 8202 and returns the combined flow to the recirculation circuit 8002 from the pump outlet. In one embodiment of the invention, the aforementioned channels of the inlet and outlet manifolds can have a cylindrical shape with a circular cross-section.

The slurry recirculation pump 7080 also comprises right and left pump heads 8230a, 8230b, detachably connected to the pump housing 8200 laterally, adjacent to the right and left pump chambers 8201, 8202 (see, for example, Figs. 64-65). In one embodiment of the invention, the pump heads can have the same configuration and can be configured to perform both a flow-through function and a closing function for the pump chambers, as described below.

The function of ensuring the flow of each pump head 8230a, 8230b is ensured by several internal flow channels communicating with each other via fluid medium, which are a longitudinal flow channel 8231 communicating via fluid medium with the inlet and outlet manifolds 8203, 8204, an upper channel 8232 for air release and a lower channel 8233 for exchanging suspension. As shown, the upper air release channel and the lower slurry exchange channel are in fluid communication with the corresponding longitudinal flow channel and the right pump chamber 8201 or the second pump chamber 8202. It should be noted that the longitudinal flow channels 8231 are connected to the pump chambers 8201, 8202 only through the upper air release channel and the lower slurry exchange channel 8232, 8233. In one embodiment of the invention, all channels may have an elongated configuration (i.e., their length is greater than their diameter), having a cylindrical shape with a circular cross-section. It should be noted that, although the channels may be referred to as "air release" and "slurry exchange" channels, each of the channels will have a certain amount of slurry and air passing through at various stages of the pump operating cycle (e.g., during filling, pumping, flushing/cleaning and air purging).

In one embodiment of the invention, the longitudinal flow channels 8231 of the pump heads 8230a, 8230b can be oriented vertically and parallel to the vertical longitudinal axis LA of the pump 7080. Such orientation prevents the accumulation of sediment from the suspension inside the channels. The upper channels 8232 for air release and the lower channels 8233 for exchanging the suspension can be oriented transversely to the longitudinal channels 8231. In one embodiment of the invention, the upper channels for air release and the lower channels for exchanging the suspension can be oriented perpendicular to the longitudinal channels. The upper channels 8232 for air release can have a smaller diameter than the lower channels 8233 for exchanging the suspension, due to the function of these flow channels. The upper air release channels 8232 are in fluid communication with the upper end portion of the pumping chambers 8201, 8202 to displace the air trapped in the chambers into the longitudinal flow channels 8231 during the pumping stroke. The lower slurry exchange channels 8233 are in fluid communication with the lower end portion of the pumping chambers to discharge sediment back from the chambers during the pumping stroke. Preferably, this prevents the accumulation of heavy sediment in the suspension in the chambers under the action of gravity, which maintains the pumping performance by eliminating flow restrictions caused by sediment accumulation. Therefore, the lower slurry exchange channels 8233 can have a larger diameter than the upper air release channels 8232, and they are designed for bidirectional/two-way flow during the pumping strokes. The slurry is drawn into the pumping chambers through the lower slurry exchange channels in one direction during the suction stroke of the pump and is expelled back from the chamber in the opposite direction during the discharge or pumping stroke, carrying any heavy particles or sediment entrained in the slurry out of the pumping chambers 8201, 8202 along with the slurry. Consequently, the upper air discharge channels 8232 may have a smaller diameter since their primary function is to remove air trapped in the chambers during the discharge stroke (although some small amount of slurry may be removed with the air). The smaller diameter upper air discharge channels ensure that during the pumping stroke, primarily air is expelled from the pumping chambers, especially during pump start-up and the beginning of the pumping cycle, rather than slurry, in order to remove any residual air accumulated in the pumping chambers when it is not in operation. Once the air has been removed from the pumping system and the pumping chambers, these channels 8232, 8233 will transfer (i.e. exchange) between the longitudinal channels 8231 in the pump heads and the pumping chambers 8201, 8202 mainly the suspension.

It should be noted that the presence of internal flow channels (channels 8231-8233) distinguishes the present LDM pump 7080 from conventional pumps of a similar type, in which only a simple closing cover or plate without internal flow channels is used to close the pump chambers. In such known designs, the diaphragms 8241 perform reciprocating movements entirely inside the pump chambers. However, in the present design of the LDM pump, the diaphragms do not enter the longitudinal channels 8231. Both the pump chambers and the diaphragms are physically separated/isolated from the longitudinal channels formed in the pump heads by a partition 8231a formed from the material of the pump heads 8230a, 8230b themselves (see, for example, Fig. 64). In other words, the partition is formed as a single unit with the housings of the pump heads.

In some embodiments of the invention, the inlet 8232a, 8233a of each upper channel 8232 for releasing air and lower channel 8233 for exchanging slurry into the first pumping chamber may comprise a concave recess to facilitate the expulsion of the slurry and the sediment in the slurry out of the first pumping chamber (see, for example, Figs. 69-70). In particular, at least the lower channel for exchanging slurry may preferably comprise a concave recess, since most of the slurry entering and exiting the pumping chambers 8201, 8202 passes through the channel 8233 with the longitudinal channel 8231 in the pump heads 8230a, 8230b. For this purpose, the concave recess associated with the lower channel 8233 for exchanging the suspension may extend all the way to the bottom of the pumping chambers (see, for example, Fig. 70) in order to avoid any dead zones at the bottom of the chambers where heavy sediment may accumulate during repeated cycles of pumping the suspension. However, in other embodiments of the invention, the entrances to the channels may not have a concave recess.

The function of closing the pump chamber is as follows: the pump heads 8230a, 8230b are configured to completely close the internal concavity 8234a of the pump chambers 8201, 8202, formed in the pump housing 8200. An external concavity 8234b of the pump chambers is formed in the pump heads. Accordingly, each of the pump heads contains an external concavity that is an integral part thereof, which is combined with the corresponding internal concavity of the pump housing 8200, forming a common continuous total volume, which in combination forms each of the pump chambers 8230a, 8230b. The concavities 8234a, 8234b can be made complementary, so that each of them has an arcuately curved wall 8234c, which can be a mirror image of the opposite curved wall, as shown in Fig. 64-65. In one embodiment of the invention, the upper air release channels 8232 and the lower slurry exchange channels 8233 pass through arcuately curved walls 8234c of the outer concavities 8234b of the pump heads (see, for example, Figs. 64, 65, 68 and 70). The walls 8234c physically separate the longitudinal flow channels 8231 of the pump heads from the pump chambers 8201, 8202.

In one embodiment of the invention, the pump heads 8230a, 8230b can be formed from a single monolithic part or block of metallic or non-metallic (e.g. plastic) material that forms the housing of the pump heads. The longitudinal channels 8231, the upper channel 8232 for air release and the lower channel 8233 for exchanging slurry, described earlier in this document, can be formed as an integral part in the block by molding, casting and/or machining (e.g. drilling/boring), depending in part on the type of material used and the manufacturing method (e.g. casting, forging, injection molding, etc.). Accordingly, the channels 8231-8233 can have a cylindrical configuration having a corresponding circular cross-sectional shape, forming separate channels that are separated from the pump chambers 8201, 8202 and are not part of them. In other words, the slurry enters or exits the pump chambers only through the passages 8231-8233, and not directly from the inlet or outlet manifolds 8203, 8204, unlike previous LDM pump designs. The pump heads 8230a, 8230b are configured to be removably attached to the pump housing to provide access to the membranes for replacement and other maintenance of the pump. In one embodiment of the invention, the pump heads can be connected to the pump housing 8200 using threaded fasteners 8235 (Fig. 67).

The LDM pump 7080 for recirculating the suspension also includes a working or pumping mechanism including a laterally movable working rod 8240 containing an elastically deformable membrane 8241 attached to each of the opposite ends of the rod. One membrane is located in each of the pump chambers 8201, 8202. The rod 8240 is oriented perpendicular to the vertical longitudinal axis LA of the pump and performs a reciprocating movement forward and backward (for example, left and right) during the pump strokes. Any suitable elastically deformable elastomer material can be used for the membranes 8241. The rod 8240 is preferably made of metal.

The membranes 8241 have a generally circular, disc-shaped or annular configuration. In one embodiment of the invention, the circumferential peripheral edge 8242 can be clamped between the pump heads 8230a, 8230b and the central portion of the pump housing 8200 (best shown in Figs. 64-65) to secure the membranes in place. The ends of the operating rod 8240 are rigidly connected to the central portion of the membranes such that the rod can push or pull the membranes during opposing movements during pump strokes. Any suitable commercially available elastically deformable polymeric material with shape restoration ability can be used for the membrane.

The pumping mechanism is driven by an air distribution system 8250 configured to alternately pump air into or extract air from the pumping chambers 8201, 8202 to move the shaft back and forth during the reciprocating strokes of the pump. The air distribution system is shown schematically in Fig. 64-65. The air distribution system includes a compressed air source 8252 in fluid communication with each of the chambers 8201, 8202 via an air duct 8251 that functions both to supply air to one of the chambers during the pumping stroke and to simultaneously exhaust air from the other chamber during the return stroke, and vice versa (see the dotted air flow direction arrows). Any suitable commercially available pneumatic (compressed air) distribution system commonly used with LDM pumps can be used.

In each pump head 8230a, 8230b, two sets of check valves 8260a, 8260b are provided for alternately regulating the flow of suspension into or out of the longitudinal flow channels 8231. As shown in Fig. 64-70, the inlet check valve 8260a is located between each flow channel 8231 and the inlet manifold 8203. The outlet check valve 8260b is located between each longitudinal flow channel and the outlet manifold 8204. The inlet check valves are detachably attached to the upper end of the pump heads, for example, by means of threaded fasteners 8267, and the outlet check valves are similarly attached to the lower end of the pump heads.

The check valves 8260a, 8260b in one embodiment may be ball-type check valves. Each of the ball check valves typically includes a ball 8261, a cage 8263 for the ball and a valve body 8265 that forms an internal channel 8262 that completely passes through each end of the valve for communicating with the longitudinal flow channels 8231 of the pump head and the flow channels of the inlet and outlet manifolds 8203, 8204 (see, for example, in Fig. 64, 65, 68 and 70). The ball and the cage are located in the channel 8262, which may have any suitable shape. An annular valve seat 8264 is formed in each valve body inside the channel 8262 for installing the ball and closing one of the channels. The 8265 valve bodies may have any suitable polygonal or non-polygonal configuration. Each 8265 valve body may be formed from a suitable metallic or non-metallic (e.g., plastic) material and may have a monolithic construction.

In some embodiments of the invention, a pair of end plates 8266 may be provided, each of which comprises a flow hole 8266a. The flow holes 8266a are in fluid communication with the internal channel 8262 of the valve bodies, as shown in the figure. A cage 8263 for a ball may be fixedly attached to one of the end plates in each pair. The cages 8263 for balls in one embodiment of the invention may be formed by circumferentially spaced and axially extended finger-like projections 8263a. The finger-like projections limit the movement of the ball 8261. Between the finger-like projections 8263a, openings 8263b are formed to allow the slurry to pass through and exit the check valves. The cage for the ball is designed so that the ball adjoins the end portion of the finger-shaped projections, but does not completely pass between them, so that the openings 8263b remain free for the suspension to pass through them. It should be noted that the end plate, including the cage 8263, is attached to the outlet or exit side of the check valves 8260a, 8260b (see, for example, Fig. 64-65). The valve seat 8264 is on the inlet side of the valves. Thus, as shown, for the outlet check valves 8260b, a pair of end plates stacked on each other can be attached to the same end of the valve body.

Now, with reference to Figs. 64-65, a process or method for pumping a slurry using the slurry recirculation pump 7080 described earlier in this document will be briefly described. In these figures, the slurry flow arrows are shown as solid and the air flow arrows are shown as dotted.

The method generally includes moving the working rod 8240 with the membranes 8241 in the first direction (for example, to the right), shown in Fig. 64. The method continues by drawing the suspension from the inlet manifold 8203 (communicating with the suspension recirculation circuit 8002 on the inlet side of the pump) into the pump chamber 8202 through the inlet shut-off valve 8260a, and then through the longitudinal flow channel 8231 and the lower opening for exchanging the suspension, which are formed in the left head 8230b of the pump (see the arrows of the flow of the suspension with the solid substance). The suspension is drawn into the lower end of the chamber through the channel 8233 for exchanging the suspension due to the vacuum created on the wet or liquid side of the left membrane of the pump chamber by means of the rod 8240 moving to the right. The piston rod 8240 is moved linearly and laterally in this first direction by applying air pressure to the dry or gas side of the diaphragm 8241 in the opposite right pump chamber 8201 (see dotted air flow arrows). At the same time, air is released from the left pump chamber 8202 through the air distribution system 8250.

After the suspension has been drawn into the left pump chamber 8202 by the vacuum created inside the chamber by the movement of the operating rod 8240 and the membrane 8241, the process continues by moving the operating rod with the membranes in a second, opposite direction (for example, to the left) using the air distribution system 8250, as shown in Fig. 65. The membrane 8241 in the left pump chamber 8202 creates pressure in the suspension and pushes it back out of the same lower channel 8233 for exchanging the suspension (opposite to the direction of filling the chamber) and into the longitudinal flow channel 8231 in the left pump head 8203b. The displaced or released suspension re-enters and then flows upward along the longitudinal flow channel 8231 through the outlet shut-off valve 8260b and into the outlet manifold 8204 for release back into the suspension recirculation circuit 8002.

While the suspension is being expelled from the left pump chamber 8202, the membrane simultaneously expels any air that may have been drawn into the chamber during the previous pump stroke to draw in the suspension, through the upper air passage and into the longitudinal flow passage 8231 in the left pump head 8230b. Any air present in the left pump chamber 8202 would tend to rise and accumulate in the upper end portion of the chamber 8202, which is therefore the location where the air outlet passage is in fluid communication with the chamber.

The air-driven operating rod 8240 of the pump 7080 rapidly reciprocates to the right and left to repeat the above process and pump/circulate the slurry through the slurry recirculation circuit 8002. During the inlet and outlet strokes of the pump, the inlet and outlet check valves 8260a, 8260b are alternately opened and closed, as shown in Fig. 64-65. During the inlet stroke for each pump chamber 8201 or 8202, the inlet check valve opens to draw slurry into the chamber, while the outlet check valve simultaneously closes to prevent slurry from being drawn back into the pump from the outlet manifold 8204. Conversely, during the pumping stroke, the opposite valve actuation occurs.

Although the slurry recirculation pump 7080 is described as an air-operated double diaphragm (ADD) pump, in one non-limiting embodiment of the invention, an electric double diaphragm (EDD) pump with specially configured pump heads as described herein may alternatively be used. Electric double diaphragm pumps use an electric motor and a gear or cam mechanism to move the actuator rod-diaphragm assembly laterally, and such pumps are well known in the art without undue elaboration.

Although in one non-limiting embodiment of the invention the pump 7080 for recirculating the slurry is described as a pneumatic double diaphragm pump (PDM), in other embodiments of the invention the pump can be a pneumatic or electric single diaphragm pump having one pump head, a pump chamber and a diaphragm driven by an operating rod that can move linearly or with the possibility of rotation to provide a pumping action of the diaphragm. In other embodiments of the invention more than two diaphragms can be used in the pump for recirculating the slurry. Alternatively, an electric double diaphragm (EDM) pump with specially configured pump heads described in this document can be used. The electrically driven rod can be driven using an electric motor, which can include a gear and/or a cam mechanism for driving the diaphragm.

Fine filter block

Returning to Fig. 34-35, the fine filter unit 8080 in the slurry recirculation circuit 8002 may be any of the fine filter units 8050 or 8060 previously described in this document. The filter screens of these units are configured to filter out larger solid particles or sediment in the slurry of a size that is not conducive to further processing of the slurry and analysis in the chemical analysis subsystem 3003 and its components, which may include various microfluidic processing disk devices that have extremely small flow channel or passage sizes that are easily clogged by such large particles. In contrast, the coarse filter unit 8020 has a mesh size that prevents debris from the agricultural slurry from entering the slurry recirculation circuit 8002 and the devices located therein, as described previously in this document.

Device for measuring the density of suspension

The device 8070 for measuring the density of the suspension in the slurry recirculation loop 8002 may be, preferably, a digital density meter of any suitable type designed to measure the density of the suspension under dynamic flow conditions when the suspension circulates through the slurry recirculation loop 8002, and under static flow conditions. In some embodiments of the invention, the device 8070 may be any of the previously disclosed versions of the U-shaped oscillating tube density measuring device 7010. However, other digital density meters may also be used.

Agricultural solids particle density measuring device

The device 8060 for measuring the particle density of agricultural solids (PSD) in the slurry recirculation loop 8002 may be any digital device suitable for measuring the density of solids or a particulate component of an aqueous agricultural slurry. The density data measured by the sensors associated with the device 8060 may be used in combination with the overall slurry density measurements obtained from the slurry density measuring device 8070 to characterize the water to solids ratio (water/solids) in the slurry circulating in the slurry recirculation loop 8002. This information may then be used to determine the appropriate amount of water to be metered and added to the slurry by the mixing device 8030 to achieve a target water to solids ratio in the slurry for subsequent processing in the chemical analysis subsystem. Any suitable commercially available product or electronic circuits and associated sensors may be used for the particle density measuring device 8060, such as, but not limited to, such circuits and associated sensors used in the SmartFirmer from Precision Planting, LLC of Tremont, Illinois, which is described in publications WO2014/153157, WO2014/186810, WO2015/171908, US20180168094, WO2019070617, and/or WO2020161566.

The devices, apparatus and components described in this document may be constructed from any suitable metallic materials, non-metallic materials (e.g. plastic) and combinations thereof suitable for the intended use and operating conditions described in this document.

In some embodiments of the invention, the main slurry pump 7081 previously described in this document may have the same configuration as the above-described slurry recirculation pump 7080 and also be an air-operated double diaphragm pump (ADP). Accordingly, such an ADP pump design disclosed in this document may be used either for the main slurry pump or for the recirculation pump.

Examples

The following are non-limiting examples.

Example 1 - a system for preparing agricultural samples, comprising: a mixing device in fluid communication with a water source, wherein the mixing device is intended for and configured to receive an agricultural sample and mix the sample with water to obtain a suspension;

a mixing device in fluid communication with the first mixing device, wherein the mixing device is configured to receive and maintain the suspension in a shaken mixed state; and

a density measuring device in fluid communication with a mixing device, wherein the density measuring device is intended for receiving a suspension and is configured to measure the density of the suspension.

Example 2 - the system of example 1, which further comprises a closed suspension recirculation loop in fluid communication with a mixing device, wherein the mixing device comprises a mixing chamber that forms an integral part of the suspension recirculation loop.

Example 3 - The system of example 2, wherein the slurry recirculation loop comprises a slurry recirculation pump designed to circulate the slurry through the slurry recirculation loop, including a mixing device.

Example 4 - The system of Example 3, wherein the slurry recirculation loop is fluidly isolated from the mixing device as the slurry circulates through the slurry recirculation loop.

Example 5 - The system of example 3 or 4, wherein the suspension recirculation loop contains a density measuring device.

Example 6 - the system of example 5, in which the density measuring device is a vibrating density meter with a U-shaped tube, designed with the possibility of measuring the suspension in a dynamic state of flowing through the meter or in a static state.

Example 7 - a system according to any one of examples 2-6, in which the suspension recirculation loop is in fluid communication with a suspension analysis subsystem configured to analyze the suspension for the presence of an analyte.

Example 8 - The system of Example 7, in which the analyte has a property of agricultural significance.

Example 9 - a system according to example 7 or 8, in which the suspension recirculation loop additionally contains a fine filter unit in fluid communication with the suspension analysis subsystem, wherein the fine filter unit is designed to pass a suspension having a specified maximum particle size.

Example 10 - a system according to any of examples 1-9, which further comprises a coarse filter unit connected via a fluid medium between the mixing device and the agitation device, wherein the coarse filter unit is designed with the possibility of removing large particles from the suspension entering the agitation device from the mixing device.

Example 11 - The system of example 10, wherein the coarse filter unit includes an inlet for pressurized air and an inlet for pressurized water, which together form a bubbler for removing large particles from the filter screen of the coarse filter unit.

Example 12 - a system according to any of examples 3-11, in which the suspension recirculation loop further comprises a straight-through accumulator configured to suppress pressure surges created by the suspension recirculation pump in the suspension recirculation loop.

Example 13 - the system of example 12, in which the battery contains:

a body that forms an elongated chamber;

a slurry inlet at a first end of the chamber and a slurry outlet at a second end of the chamber, the slurry inlet and slurry outlet defining a longitudinal flow axis passing therethrough; and

an elastically deformable membrane dividing the chamber into a pre-filled gas part and a suspension part, through which the suspension passes from the inlet to the outlet along a linear path.

Example 14 - The system of example 13, wherein the cross-sectional area of the chamber, measured across the longitudinal axis of the flow, is approximately thirty times greater than the cross-sectional area of the inlet and outlet for the suspension.

Example 15 - the system according to example 2, in which the mixing device comprises a mixing chamber in which shaking is carried out by means of a rotating mixing blade mechanism, while in the mixing chamber of the mixing device, shaking is carried out by a rotating mixing blade mechanism.

Example 16 - The system of example 15, wherein the mixing paddle mechanism is designed for and configured to impart greater energy and more aggressive agitation to the suspension in the mixing device than the stirring paddle mechanism in the mixing device.

Example 17 - the system according to example 16, which further comprises a level sensor configured to measure the level of the suspension in the mixing device, wherein the rotation speed of the mixing blade mechanism is controlled and regulated based on the level of the suspension measured by the level sensor.

Example 18 - The system of any one of Examples 2-17, wherein the mixing device comprises a water inlet for adding water to the slurry to dilute the slurry to a target ratio of water to agricultural solids.

Example 19 - A system according to any one of examples 2-18, wherein the mixing device comprises a slurry inlet for receiving slurry from the mixing device, a slurry recirculation inlet in fluid communication with the slurry recirculation loop, and a slurry recirculation outlet in fluid communication with the slurry recirculation loop.

Example 20 - a double-diaphragm pump comprising: a pump housing defining a vertical longitudinal axis and forming first and second pumping chambers; an inlet manifold and an outlet manifold connected to the pump housing; a first pump head connected to the housing, adjacent to the first pumping chamber, wherein the first pump head comprises a longitudinal flow channel separated from the first pumping chamber and fluidly communicated with the inlet and outlet manifolds, an upper channel for releasing air and a lower channel for exchanging suspension, wherein each of the upper channel for releasing air and the lower channel for exchanging suspension, in turn, fluidly connects the longitudinal flow channel to the first pumping chamber; and a working rod connected to an elastically deformable membrane, wherein the membrane is located in the first pumping chamber; wherein the rod is configured to move during the stroke of the pump for pumping fluid through the longitudinal channel of the first pump head and the first pumping chamber from the inlet manifold to the outlet manifold; wherein the upper air release channel has a smaller diameter than the lower channel for exchanging the suspension, so that during the pump stroke, air is primarily displaced from the first pump chamber, and not the suspension.

Example 21 - a pump according to example 20, which additionally comprises an inlet shut-off valve in fluid communication with the lower end of the longitudinal flow channel and the inlet manifold, and an outlet shut-off valve in fluid communication with the upper end of the longitudinal flow channel and the outlet manifold.

Example 22 - a pump according to example 20 or 21, in which the membrane does not enter the longitudinal channel of the first pump head during the pump stroke.

Example 23 - a pump according to any of examples 20-22, in which the lower channel for exchanging suspension is intended for and is designed with the possibility of providing a bidirectional exchange of fluid between the longitudinal channel and the first pump chamber.

Example 24 - a pump according to any of examples 20-23, in which the upper channel for releasing air and the lower channel for exchanging suspension are oriented transversely relative to the longitudinal flow channel and are made as an integral part in the first head of the pump.

Example 25 - a pump according to example 24, in which the longitudinal flow channel is oriented vertically, and the upper channel for releasing air and the lower channel for exchanging suspension are located perpendicular to the longitudinal flow channels.

Example 26 - a pump according to any of examples 20-25, in which the upper channel for releasing air is in fluid communication with the upper end portion of the first pump chamber, and the lower channel for exchanging suspension is in fluid communication with the lower end portion of the first pump chamber.

Example 27 - a pump according to any of examples 20-26, in which there are no other channels connecting the first pump chamber with the first longitudinal channel via a fluid medium, except for the upper channel for releasing air and the lower channel for exchanging suspension.

Example 28 - a pump according to any of examples 20-27, which further comprises an air distribution system in fluid communication with the first pumping chamber on the dry side of the membrane, wherein the air distribution system is configured to alternately pump or remove air from the first pumping chamber to move the rod forward and backward to pump the fluid.

Example 29 - a pump according to any of examples 20-28, in which the first pump head comprises an integral outer concavity having an arcuately curved wall, which is combined with a corresponding and complementary inner concavity having an arcuately curved wall and is formed as an integral part in the pump body, to form a common volume, which together forms the first pump chamber.

Example 30 - a pump according to any of examples 20-29, in which the upper channel for releasing air and the lower channel for exchanging suspension are in direct fluid communication with the outer concavity.

Example 31 - a pump according to example 29 or 30, in which the arcuately curved wall of the inner concavity is a mirror image of the arcuately curved wall of the outer concavity.

Example 31A - a pump according to any of examples 20-30, in which the longitudinal flow channel, the upper air release channel and the lower suspension exchange channel have a cylindrical configuration with a circular cross-section.

Example 32 - A pump according to any of examples 20-31A, in which the longitudinal flow channel is physically separated from the first pump chamber by a partition formed as a single unit with the body of the first pump head.

Example 33 - a pump according to any of examples 20-32, which is a double-diaphragm pump, further comprising: a second pump head connected to the housing, adjacent to the second pump chamber, wherein the second pump head comprises a second longitudinal flow channel separated from the second pump chamber and fluidly communicated with the inlet and outlet manifolds, a second upper channel for releasing air and a second lower channel for exchanging suspension, wherein each of the second upper channel for releasing air and the second lower channel for exchanging suspension, in turn, fluidly connects the second longitudinal flow channel to the second pump chamber; wherein the working rod is configured to move linearly and is connected to an elastically deformable second diaphragm, wherein the second diaphragm is located in the second pump chamber; wherein the rod is configured to move back and forth during the reciprocating stroke of the pump for pumping fluid alternately through the longitudinal channel of the first pump head and the second longitudinal channel of the second pump head from the first and second pump chambers.

Example 34 - a method for pumping a suspension, including: providing a double-diaphragm pump for a suspension, comprising a vertical longitudinal axis, first and second pump chambers, first and second pump heads, forming the first and second pump chambers, respectively, and a movable working rod, comprising an elastically deformable membrane, connected to each of the opposite ends of the rod, wherein one membrane is located in each of the first and second pump chambers; moving the working rod in a first direction during a suction stroke; drawing the suspension from an inlet manifold into the first pump chamber through a longitudinal channel of the first pump head and a lower channel for exchanging the suspension, each of which is formed in the first pump head separately from the first pump chamber; moving the working rod in a second direction during a pumping stroke; and displacing the slurry back through the lower slurry exchange channel during the pumping stroke from the first pumping chamber back into the longitudinal channel of the first pumping head, simultaneously displacing air from the first pumping chamber into the longitudinal channel of the first pumping head through the upper air release channel; and displacing air from the first pumping chamber through the upper air release channel during the pumping stroke into the longitudinal flow channel of the first pump head simultaneously with the step of displacing the slurry; wherein the upper air release channel has a smaller diameter than the lower slurry exchange channel, so that air is primarily displaced from the first pumping chamber, and not the slurry.

Example 35 - The method of example 34, wherein the displacement step further includes passing the suspension through a longitudinal channel of the first pump head into the outlet manifold.

Example 36 - The method of Example 35, wherein the suspension enters the outlet manifold through the outlet shut-off valve.

Example 37 - The method of example 35 or 36, wherein the drawing step further comprises drawing the suspension first through the longitudinal flow channel from the inlet manifold before drawing the suspension through the lower suspension exchange channel into the first pump chamber.

Example 38 - a method according to any of examples 35-37, in which the upper air outlet channel fluidly connects the longitudinal flow channel of the first pump head directly to the upper part of the first pump chamber, and the lower channel for exchanging suspension fluidly connects the longitudinal flow channel of the first pump head directly to the lower part of the first pump chamber.

Example 38A - The method of example 38, wherein there are no other channels fluidly connecting the first pump chamber to the longitudinal channel of the first pump head, except for the upper channel for releasing air and the lower channel for exchanging suspension.

Example 39 - the method of any one of examples 34-38A, wherein in the drawing step the slurry is drawn from the inlet manifold through the inlet shutoff valve.

Example 40 - a method according to any of examples 34-39, in which the step of moving the working rod in the second direction includes moving the membrane in the first pump chamber towards the first pump head, and the step of moving the working rod in the first direction includes moving the membrane in the first pump chamber away from the first pump head in the opposite direction.

Example 41 - a method according to any of examples 34-40, which further includes drawing the suspension from the inlet manifold into the second pump chamber through the longitudinal flow channel and the lower suspension exchange channel formed in the second pump head, simultaneously with the step of displacing the suspension back through the lower suspension exchange channel into the first pump head.

Example 42 - a method according to any of examples 34-41, in which the rod is moved by supplying compressed air to the membranes in the first or second pump chamber, which deforms the membranes to move the rod.

Example 42A - the method of example 34, wherein the longitudinal channel is oriented vertically and is elongated, and the inlet and outlet manifolds are oriented horizontally and are elongated.

Example 42B - The method of example 42, wherein during the slurry drawing step, the slurry flows upward along the longitudinal channel, while during the slurry displacing step, the slurry flows downward along the longitudinal channel.

Example 42C - The method of example 34, wherein the inlet of each of the lower slurry exchange channels into the first pumping chamber comprises a concave recess to facilitate the expulsion of sediment captured in the slurry out of the first pumping chamber.

Example 43 - a method of forming and processing an agricultural slurry, comprising adding water and agricultural solids to a mixing chamber of a mixing device; agitating the water and agricultural solids with the mixing device to form a slurry; discharging the slurry into a flow channel; pressurizing the flow channel to force the slurry into a filter unit containing a filter screen; filtering the slurry through the filter screen to remove particles of the slurry that are larger than a predetermined particle size; and discharging the filtered slurry from the filter unit.

Example 44 - The method of example 43, which further comprises forcing compressed air and pressurized water into the filter unit during the filtration step.

Example 45 - the method of example 44, wherein the filtering step comprises passing the suspension through the filter mesh in a first direction and passing compressed air and water under pressure through the filter mesh in a second direction opposite to the direction of passage of the suspension.

Example 46 - the method according to example 45, in which the suspension is directed into the first cavity of the filter block from the first side of the filter mesh, and compressed air and water under pressure are injected into the second cavity of the filter block from the second side of the mesh, opposite the first side.

Example 47 - The method of example 46, wherein the filter unit comprises a slurry inlet configured to pass the slurry along a linear flow path through the first cavity, a waste outlet configured to release large particles from the first cavity along the same linear flow path, and a slurry outlet configured to release filtered slurry in a direction transverse to the linear flow path.

Example 48 - a method according to any of examples 43-47, in which the suspension is directed into the filter unit in a direction parallel to the direction in which the filtered suspension is discharged.

Example 49 - A method according to any one of examples 43-48, wherein the mixing device is fluidly isolated from the flow channel during the pressure generation step.

Example 50 - a linear accumulator for reducing pressure in a system of flow channels for a suspension, comprising: a housing forming an elongated chamber; an inlet for the suspension at a first end of the chamber and an outlet for the suspension at a second end of the chamber, wherein the inlet for the suspension and the outlet for the suspension are located coaxially and define a longitudinal flow axis passing through them; and an elastically deformable membrane dividing the chamber into a pre-filled gas part and a suspension part, along which the suspension passes from the inlet to the outlet along a linear path; wherein the membrane is designed with the possibility of deformation due to an increase or decrease in the pressure of the suspension to maintain a relatively constant pressure in the system of flow channels for the suspension.

Example 51 - an accumulator according to example 50, which comprises an axially elongated trough having a concave shape, which extends between the slurry inlet and the slurry outlet.

Example 52 - a filter unit for a suspension, comprising: a housing having an internal portion forming an upper cavity and a lower cavity; a filter mesh located between the upper and lower cavities; an inlet for unfiltered suspension, in fluid communication with the upper cavity; a waste outlet, in fluid communication with the upper cavity opposite the inlet for unfiltered suspension, which defines an input flow path for the suspension in the upper cavity; an outlet for filtered suspension, in fluid communication with the lower cavity; wherein the filter unit is configured to pass the suspension through the filter mesh from the first cavity to the second in a direction transverse to the input flow path for the suspension.

Example 53 - a filter unit for a suspension according to example 52, in which the inlet flow path of the suspension is linear.

Example 54 - a filter unit for a suspension according to example 51 or 52, which further comprises an inlet for compressed air intended for pumping air, and an inlet for pressurized water intended for pumping water, together forming a bubbler for removing large particles from the filter mesh.

Example 55 - a filter unit for a suspension according to example 54, in which the inlets for compressed air and water under pressure are fluidly connected to the lower cavity under the filter mesh.

Example 56 - a filter unit for a suspension according to example 55, in which air and water pass through the filter mesh in the direction from the lower cavity to the upper cavity.

Example 57 - A slurry filter unit according to any one of examples 51-56, wherein the filter mesh is elongated and arcuately curved in a configuration forming a concave side facing the upper cavity and a convex side facing the lower cavity.

Example 58 - a filter unit for a suspension according to any of examples 51-57, in which the inlet for the unfiltered suspension comprises an elastically deformable segmented pipe coupling containing several radially deformable elongated fingers with longitudinal slots separating the fingers along the circumference, wherein the pipe coupling is intended for inserting a tube inside it.

Example 59 - A slurry filter unit according to any one of examples 51-58, wherein the inlet for the unfiltered slurry and the outlet for the filtered slurry define respective centerlines that are parallel to each other.

Example 60 - a suspension mixing device comprising: an elongated body defining a vertical centerline and a mixing chamber; a suspension inlet configured to receive the suspension, a suspension recirculation inlet configured to communicate via a fluid medium with a closed suspension recirculation loop, and a suspension recirculation outlet configured to communicate via a fluid medium with the suspension recirculation loop; and a rotating paddle mechanism configured to maintain the suspension in a shaken mixed state in the mixing chamber.

Example 61 - a suspension mixing device according to example 60, which additionally comprises a motor operatively connected to the blade mechanism and configured to rotate the blade mechanism.

Example 62 - a suspension mixing device according to example 60 or 61, in which the blade mechanism comprises at least a first blade assembly including a first drive shaft operatively connected to the motor and a first set of blades rigidly connected thereto.

Example 63 - a suspension mixing device according to example 62, in which the first drive shaft is oriented vertically and the first set of blades is located at the bottom of the suspension chamber.

Example 64 - a suspension mixing device according to example 63, which further comprises a second blade assembly including a vertical second drive shaft operatively connected to the engine, and a second set of blades rigidly connected thereto and located in the lower part of the suspension chamber.

Example 65 - a suspension mixing device according to example 64, in which the first and second drive shafts are operatively connected to the engine by means of a gear transmission.

Example 66 - a suspension mixing device according to example 64 or 65, in which the first blade assembly is configured to rotate in a first direction of rotation, and the second blade assembly is configured to rotate in a second direction of rotation.

Example 67 - a suspension mixing device according to example 66, in which the inlet for recirculating the suspension is configured to feed the suspension from the suspension recirculation circuit tangentially to the inner side wall of the mixing chamber.

Example 68 - a suspension mixing device according to example 67, in which the inlet for recirculating the suspension is additionally configured to feed the suspension into the mixing chamber in the same direction as the second direction of rotation of the second blade assembly.

Example 69 - a suspension mixing device according to any one of examples 64-68, in which the mixing chamber has a figure-eight shape in cross-section, forming a first section and a second section separated by a narrowed neck of the mixing chamber.

Example 70 - a suspension mixing device according to example 69, in which the first blade assembly is located in the first section of the mixing chamber, and the second blade assembly is located in the second section of the mixing chamber.

Example 71 - a suspension mixing device according to example 69 or 70, in which the outlet for recirculating the suspension is located in a narrowed neck of the mixing chamber between the first and second sections.

Example 72 - A suspension mixing device according to any of examples 60-71, which further comprises an overflow pipe in fluid communication with the upper end of the mixing chamber, and a waste outlet in fluid communication with the lower part of the mixing chamber.

Example 73 - A suspension mixing device according to any of examples 60-72, which further comprises a water inlet for adding water to the suspension to dilute the suspension.

Example 74 - a suspension mixing device according to any of examples 60-73, which further comprises a level sensor configured to measure the level of the suspension in the mixing chamber, wherein the rotation speed of the mixing blade mechanism is controlled and adjusted based on the level of the suspension in the mixing chamber measured by the level sensor.

Example 75 - A suspension mixing device according to any one of examples 60-74, wherein the mixing device body has a segmented structure comprising a removable top cover, an upper section, a middle section and a lower section.

Additional examples - Method for forming/processing agricultural suspension

1A. A method for forming and processing an agricultural slurry, comprising: adding water and agricultural solids to a mixing chamber of a mixing device; agitating the water and agricultural solids at a first speed by the mixing device to form a slurry; discharging the slurry from the mixing device into a filter unit through a flow passage fluidly connecting them; coarsely filtering the slurry through a filter screen of a coarse filter to remove particles of the slurry that are larger than a predetermined first maximum particle size; receiving the filtered slurry from the filter unit in a mixing chamber of the mixing device defining a mixing chamber; and agitating the slurry at a second speed different from the first speed in the mixing device.

2A. The method of example 1A, wherein the mixing device includes a rotating first paddle mechanism that rotates during the step of agitating the water and agricultural solids to form a suspension, and the stirring device includes a rotating second paddle mechanism that rotates during the step of agitating the suspension.

3A. The method of example 1A or 2A, wherein the first speed is higher than the second speed.

4A. The method according to any of examples 1A-3A, wherein the mixing chamber of the mixing device forms an integral part of a closed loop of suspension recirculation, communicating via a fluid medium with the coarse filter unit.

5A. The method of example 4A, wherein the slurry recirculation loop comprises a slurry recirculation pump configured to circulate the slurry through the slurry recirculation loop and a mixing device.

6A. The method of example 5A, wherein the slurry recirculation loop is fluidly isolated from the mixing device as the slurry circulates through the slurry recirculation loop.

7A. The method of example 5A or 6A, wherein the mixing device is designed to maintain the suspension in a mixed, homogeneous state when the suspension is circulated through the suspension recirculation loop.

8A. The method of example 7A, which further comprises measuring the density of the suspension in a mixed homogeneous state simultaneously with circulation of the suspension through the suspension recirculation loop.

9A. The method of example 8A, wherein the slurry recirculation loop comprises a density measuring device configured to measure the density of the slurry.

10A. The method of example 9A, wherein the density measuring device is a vibrating U-tube density meter configured to measure the suspension in a dynamic state of flowing through the meter or in a static state.

11A. The method of any one of examples 1A-10A, wherein the slurry recirculation loop is in fluid communication with a slurry chemical analysis subsystem configured to analyze the slurry for the presence of an analyte of agricultural significance.

12A. The method of example 11A, which further comprises finely filtering the suspension by means of a fine filter unit located in the suspension recirculation loop, prior to the step of feeding the filtered suspension from the fine filter unit to the suspension chemical analysis subsystem.

13A. The method according to example 12A, in which the fine filter unit is configured to remove solid particles of the suspension having a predetermined second maximum particle size smaller than the predetermined first maximum particle size of the coarse filter unit.

14A. The method according to any one of examples 1A-13A, which further comprises creating pressure in the flow channel between the mixing device and the agitating device using air to pass the suspension through the coarse filter unit into the agitating device.

15A. The method of example 14A, wherein the mixing device is fluidly isolated from the flow channel during the pressure generating step.

16A. The method of example 1A, which further comprises introducing compressed air and pressurized water to form an aerated flow through the coarse filter unit during the coarse filtration step to prevent clogging of the filter screen by solid particles that are larger than a predetermined first maximum particle size.

17A. The method of example 16A, wherein the coarse filtration step comprises passing the suspension through the filter screen in a first direction and passing the aerated stream through the filter screen in a second direction opposite to the first direction.

18A. The method according to example 17A, in which the suspension is directed into the first cavity of the coarse filter block from the first side of the filter mesh, and compressed air and water under pressure are injected into the second cavity of the filter block from the second side of the mesh opposite the first side.

19A. The method of example 18A, wherein the coarse filter unit comprises a slurry inlet configured to allow the slurry to flow along a linear flow path through the first cavity, a waste outlet configured to release large particles from the first cavity along the same linear flow path, and a slurry outlet configured to release filtered slurry in a direction transverse to said linear flow path.

20A. The method according to any one of examples 5A-19A, in which the slurry recirculation circuit further comprises an accumulator located upstream of the slurry pump, and the accumulator is configured to dampen pressure surges in the slurry recirculation circuit.

Additional examples - Battery

1B. A linear accumulator for reducing pressure in a system of flow channels for a suspension, comprising: a housing forming an elongated chamber; an elastically deformable membrane dividing the chamber into an upper sub-cavity intended for preliminary filling with an inert gas, and a lower sub-cavity intended for the suspension to pass through it; wherein the lower sub-cavity defines a geometric longitudinal axial line; an inlet for the suspension formed at a first end of the lower sub-cavity, and an outlet for the suspension formed at the opposite, second end of the lower sub-cavity, wherein the inlet for the suspension and the outlet for the suspension are located coaxially with each other and define a longitudinal flow axis passing between them; wherein the longitudinal flow axis defined by the inlet and outlet for the suspension is vertically offset from the longitudinal central line of the lower sub-cavity; wherein the membrane is designed with the possibility of deformation due to an increase or decrease in the suspension pressure in order to maintain a constant pressure in the system of flow channels for the suspension.

2B. The accumulator of example 1B, wherein the slurry is allowed to flow through the lower sub-cavity from the slurry inlet to the slurry outlet along a linear flow path.

3B. An accumulator according to example 1B or 2B, in which the lower sub-cavity contains a longitudinally elongated trough formed on the bottom of the housing in the lower sub-cavity and designed with the possibility of collecting and moving sediment captured in the suspension through the lower sub-cavity as the suspension flows.

4B. An accumulator as in example 3B, in which the trough extends completely along the length of the housing between the slurry inlet and the slurry outlet.

5B. An accumulator similar to 3B or 4B, in which the trough is coaxially aligned with the inlet and outlet for the suspension.

6B. The accumulator of any one of examples 3B-5B, wherein the trough has a semicircular cross-sectional shape.

7B. An accumulator according to example 6B, in which the trough has a cross-sectional shape different from the cross-sectional shape of the lower sub-cavity.

8B. An accumulator according to example 7B, in which the lower sub-cavity has a substantially V-shaped cross-section.

9B. A battery according to any of examples 3B-8B, in which the lower sub-cavity is formed by inclined and converging arcuately curved concave side walls of the battery housing that intersect the groove.

10B. An accumulator according to any of examples 1B-9B, wherein the slurry inlet and slurry outlet are located at the bottom of the lower sub-cavity.

11B. The accumulator of example 1B, wherein the lower sub-cavity has a cross-sectional area that is no more than 30 times greater than the minimum cross-sectional area of the slurry inlet or slurry outlet of the accumulator.

12B. An accumulator according to example 11B, in which the slurry inlet and slurry outlet have the same cross-sectional area.

13B. The accumulator of example 1B, in which the lower sub-cavity has a substantially V-shaped cross-section.

14B. An accumulator according to example 13B, in which the upper sub-cavity has a substantially V-shaped cross-sectional shape complementary to the cross-sectional shape of the lower sub-cavity.

15B. A battery according to any of examples 1B-14B, in which the membrane is clamped between first and second half-sections of the housing, which are releasably connected to each other.

16B. An accumulator according to example 1B, which includes an opening for supplying compressed gas, intended for pre-filling the upper subcavity with an inert gas.

17B. The accumulator of any one of examples 1B-16B, wherein the slurry is an agricultural slurry.

18B. The accumulator of example 17B, wherein the agricultural suspension is a soil suspension.

It should be noted that the unique features listed in previous examples 1B-18B and described in more detail earlier in this document relate to an accumulator specifically designed to successfully handle slurries with entrained/suspended solids and sediment, such as soil slurries, as opposed to previous accumulator designs that only handle liquids that do not contain significant amounts of suspended solids.

Additional examples - Filtration of suspension

1C. A filter unit for a suspension, comprising: a Y-shaped body having an internal portion forming an upper cavity and a lower cavity; a filter mesh located between the upper and lower cavities; an inlet for unfiltered suspension, in fluid communication with the upper cavity; a waste outlet, in fluid communication with the upper cavity opposite the inlet for unfiltered suspension, which defines an input flow path for the suspension in the upper cavity; an outlet for filtered suspension, in fluid communication with the lower cavity; wherein the filter unit is configured to pass the suspension through the filter mesh from the first to the second cavity in a direction transverse to the input flow path for the suspension.

2C. The slurry filter unit of example 1C, wherein the inlet flow path of the slurry is linear such that the slurry flows parallel to the length of the filter screen.

3C. A filter unit for a suspension according to examples 1C or 2C, which further comprises a compressed air inlet intended for pumping air, and a pressurized water inlet intended for pumping water, together forming a bubbler for removing large particles from the filter mesh.

4C. A filter unit for a suspension according to example 3C, in which the inlets for compressed air and pressurized water are in fluid communication with the lower cavity under the filter mesh.

5C. A slurry filter unit as in example 4C, wherein the inlets for compressed air and pressurized water are arranged to direct the compressed air and pressurized water upward through the filter screen in a direction from the lower cavity to the upper cavity to remove large particles from the filter screen.

6C. A filter unit for a suspension according to example 5C, which is designed so that compressed air and water under pressure pass upward through the filter mesh from the lower cavity to the upper cavity.

7C. A slurry filter unit according to any one of Examples 1C-6C, wherein the filter mesh is arcuately curved from one side to the other side in a configuration forming a concave side facing the upper cavity and a convex side facing the lower cavity.

8C. A slurry filter unit according to any one of Examples 1C-7C, wherein the upper cavity is inclined downwardly relative to a horizontal reference plane such that the slurry passes over the filter screen along the same inclined flow path.

9C. A slurry filter unit according to any one of examples 2C, 7C or 8C, wherein the inlet for unfiltered slurry is located at one end of the upper cavity and the outlet for waste is located at the opposite end thereof.

10C. A slurry filter unit according to example 9C, wherein the upper cavity is designed such that large particles captured by the slurry mixture that are too large to pass through the openings of the filter mesh move along a linear path along the concave upper surface of the mesh to a waste outlet.

11C. A filter unit for a suspension according to any of examples 1C-10C, in which the inlet for the unfiltered suspension comprises an elastically deformable segmented pipe coupling containing several radially deformable elongated fingers with longitudinal slots separating the fingers along the circumference, and the pipe coupling is intended for insertion of a tube inside it.

12C. A slurry filter unit according to any one of Examples 1C-11C, wherein the unfiltered slurry inlet and the filtered slurry outlet define respective centerlines that are parallel to each other.

13C. A slurry filter unit according to any one of Examples 1C-12C, which is oriented such that the upper cavity is located above the lower cavity when the filter unit is in use, and the filter mesh extends horizontally between the upper and lower cavities.

14C. A filter unit for a suspension according to any one of examples 1C-13C, wherein the suspension comprises water and agricultural sample material.

15C. A filter unit for a suspension according to example 14C, wherein the agricultural sample material is soil.

16C. A filter unit for a suspension according to any of examples 1C-15C, in which the lower cavity has an inclined truncated-conical shape, so that the lower cavity narrows when moving downwards in a direction from the upper part adjacent to the filter mesh to the outlet for the filtered suspension located at the bottom of the lower cavity.

17C. A slurry filter unit according to any one of Examples 1C-16C, wherein the upper cavity of the housing is covered with a transparent plastic cover allowing the user to see the filter mesh.

18C. A method of filtering a suspension, comprising: providing a filter unit containing a filter mesh, an upper cavity formed above the filter mesh, and a lower cavity formed below the filter mesh; pumping compressed air and water under pressure into the lower cavity to produce a flow of aerated water; passing the flow of aerated water through the filter mesh into the upper cavity; introducing an unfiltered suspension into the upper chamber of the filter unit; and passing the unfiltered suspension through the filter mesh in a direction countercurrent to the flow of aerated water to produce a filtrate.

19C. The method of example 18C, wherein the filter unit has a Y-shaped housing.

20C. The method of example 18C or 19C, which further comprises: introducing unfiltered slurry into the upper chamber in a direction parallel to the filter screen and passing it along the length of the filter screen from the unfiltered slurry inlet of the filter unit; passing a portion of the slurry with captured large particles that are too large to pass through the openings of the filter screen, along a linear flow path along the upper surface of the filter screen to a waste outlet in the upper chamber located immediately opposite the unfiltered slurry inlet.

21C. The method of example 20C, wherein the upper surface of the filter mesh is arcuately curved from one side to the other side and has a concave shape, forming a groove.

22C. The method according to example 20C or 21C, in which the flow of the suspension with captured large particles through the waste outlet is controlled by means of a drain valve in fluid communication with it that opens and closes.

23C. The method of example 22C, wherein the filter unit operates in a self-cleaning mode when the drain valve is opened to remove a portion of the suspension with captured large particles simultaneously with the step of passing the unfiltered suspension through the filter mesh in a counter-current direction to the flow of aerated water to obtain a filtrate.

24C. The method according to any of examples 18C-23C, in which, at the stage of pumping compressed air and water under pressure into the lower cavity, water under pressure is first pumped, after which compressed air is supplied to obtain a flow of aerated water.

25C. The method according to any of examples 18C-24C, in which air is forced through an air inlet in the lower cavity, which is separated from the water inlet section through which water is supplied under pressure.

Although the above description and drawings relate to some examples of systems, it should be understood that various additions, modifications and substitutions can be made therein without departing from the spirit, scope and range of equivalents of the appended claims. In particular, it will be clear to those skilled in the art that the present invention can be implemented in other forms, structures, arrangements, proportions, sizes and with other elements, materials and components without departing from the spirit or its essential characteristics. In addition, numerous changes can be made to the methods/processes described herein. It will also be clear to those skilled in the art that the invention can be used with many modifications of the design, arrangement, proportions, sizes, materials and components, as well as in other ways used in the practice of the invention, which are adapted to a particular working environment and working requirements without departing from the principles of the present invention. Accordingly, the embodiments of the invention disclosed herein are to be considered in all respects as illustrative and not restrictive, and the scope of protection of the invention is defined by the appended claims and their equivalents and is not limited by the above description or embodiments of the invention. The appended claims are to be interpreted broadly so as to include other embodiments of the invention that may be realized by those skilled in the art without departing from the scope and range of equivalents of the invention.

Claims (18)

1. A method for forming and processing an agricultural slurry, comprising the steps of adding water and agricultural solids to a mixing chamber of a mixing device; mixing the water and agricultural solids at a first speed using the mixing device to form a slurry; discharging the slurry from the mixing device into a filter unit through a flow channel fluidly connecting them; performing coarse filtration of the slurry using a coarse filter screen to remove particles from the slurry whose size exceeds a predetermined first maximum particle size; receiving the filtered suspension from the filter unit in the mixing chamber of the mixing device, limiting the mixing chamber, wherein the mixing chamber of the mixing device forms a component of a closed suspension recirculation loop, fluidly connected to the coarse filter unit, mixing the suspension at a second speed, different from the first speed, in the mixing device, measuring the density of the suspension, which is in a mixed homogeneous state, simultaneously with the direction of the suspension along the suspension recirculation loop, and measuring the density of the solid component of the agricultural suspension using a device for measuring the density of solid particles, located in the said suspension recirculation loop. 2. The method of claim 1, wherein the mixing device includes a rotating first paddle mechanism that rotates during the step of mixing water and agricultural solids to form a slurry, and the mixing device includes a rotating second paddle mechanism that rotates during the step of mixing the slurry. 3. The method according to claim 1 or 2, wherein the first speed is higher than the second speed. 4. The method of claim 1, wherein the slurry recirculation loop comprises a slurry recirculation pump that directs the slurry through the slurry recirculation loop and a mixing device. 5. The method of claim 4, wherein the slurry recirculation circuit is isolated from the mixing device when the slurry is directed along the slurry recirculation circuit. 6. The method according to claim 4 or 5, wherein when directing the suspension along the suspension recirculation circuit, the mixing device operates to maintain the suspension in a mixed homogeneous state. 7. The method of claim 1, wherein the suspension recirculation loop comprises a density measuring device that measures the density of the suspension. 8. The method according to claim 7, wherein the density measuring device is a vibrating density meter with a U-shaped tube, designed with the possibility of measuring the suspension in a dynamic state, when the suspension flows through the meter, or in a state of stagnant flow. 9. The method according to any one of claims 1 to 8, wherein the suspension recirculation loop is fluidly connected to a suspension chemical analysis subsystem configured to analyze the suspension for the presence of an analyte of agricultural significance. 10. The method according to item 9, in which fine filtration of the suspension is carried out by means of a fine filter unit located in the suspension recirculation circuit, before the stage of feeding the filtered suspension from the fine filter unit to the suspension chemical analysis subsystem. 11. The method according to claim 10, wherein the fine filter unit is designed to remove solid particles from the suspension having a specified second maximum particle size that is smaller than the specified first maximum particle size of the coarse filter unit, wherein the second maximum particle size is selected in such a way as to avoid clogging of the flow channels in the suspension chemical analysis subsystem, which includes microfluidic devices. 12. The method according to any one of paragraphs. 1-11, in which increased air pressure is created in the flow channel between the mixing device and the stirring device to move the suspension through the coarse filter unit into the stirring device. 13. The method according to claim 12, wherein the mixing device is isolated from the flow channel at the stage of creating increased pressure. 14. The method according to claim 1, wherein during the rough filtration stage, compressed air and water under pressure are introduced through the rough filter unit, forming an aerated flow, to prevent clogging of the filter mesh with solid particles whose size exceeds the specified first maximum particle size. 15. The method according to claim 14, wherein at the stage of coarse filtration the suspension is directed in a first direction through the filter mesh, and the aerated flow is directed through the filter mesh in a second direction opposite to the first direction. 16. The method according to claim 15, wherein the suspension is introduced into the first cavity in the coarse filter block from the first side of the filter mesh, and air and water under pressure are introduced into the second cavity in the filter block from the second side of the mesh, opposite the first side. 17. The method according to claim 16, wherein the coarse filter unit comprises a suspension inlet configured to allow the suspension to flow along a linear flow path through the first cavity, a waste outlet configured to allow large particles to be released from the first cavity along the same linear flow path, and a suspension outlet configured to allow filtered suspension to be released in a direction transverse to said linear flow path. 18. The method according to any one of claims 4-17, wherein the suspension recirculation circuit comprises an accumulator located in front of the suspension pump, wherein the accumulator is designed to dampen pressure surges in the suspension recirculation circuit.