RU2848714C1 - Device for the production of iron chloride and iron sulphate coagulants - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a device for producing iron chloride and iron sulphate coagulants used in the purification of water from pollutants, and can be used in the field of domestic and technical water supply and wastewater treatment. The device for producing iron chloride and iron sulphate coagulants comprises a reactor connected to an acid supply pipe, a pipe with a pump for supplying pulp from a mixer-repulper, and a mixer-repulper. The mixer-repulper and the pump are connected by a looped pipeline, to which the pipeline for supplying pulp to the reactor is directly connected.

EFFECT: improvement of the technical device through rational simplification, increased functionality and performance of the device.

1 cl, 1 dwg

Description

The invention relates to the chemical industry, specifically to a device for producing ferric chloride and iron sulfate coagulants used in water purification from contaminants and can be used in domestic and industrial water supply, as well as wastewater treatment. Ferrous sulfate can be used in livestock farming as a feed additive for disease prevention and as an antiseptic. Ferrous sulfate can also be used in crop production.

A known method for producing a coagulant for water purification involves loading a reactor with standard aluminum ingots and copper scrap. Anhydrous aluminum chloride is dissolved in water, and the resulting solution is poured into the reactor. The reaction mixture is heated, maintaining a constant solution level by adding additional water as it evaporates (see RU Patent No. 2327643 IPC C01F 7/56).

The disadvantage of this method is the difficulty of adjusting the amount of pulp components when feeding into the reactor to obtain the reaction solution, the lack of automation of the process of feeding the reaction solution components, the difficulty of monitoring processes in the reactor and dosing the amount of pulp fed.

A method for producing a coagulant for water purification is known, which includes obtaining aluminum hydroxide, dissolving it with hydrochloric acid, wherein the process of obtaining an amorphous reactive gel of aluminum hydroxide is carried out by neutralizing the aluminate solution with a bicarbonate solution obtained by gasification of a soda solution from alumina production with industrial gas containing up to 5% CO ₂ , followed by decomposition of the resulting sodium aluminocarbonate with industrial water, the process of interaction of hydrochloric acid with the gel of the resulting aluminum hydroxide is carried out at room temperature and a product with an acid modulus of 1.0-2.0 is obtained (see patent RU No. 2139248 IPC C01F 7/56).

The disadvantage of this method is the complexity of the technology for obtaining the aluminum hydroxide gel ingredient.

A method for producing a coagulant for water purification is known (see patent No. RU 2 835 453 C1 C01F 7/57), which includes mixing aluminum hydroxide with water in a mixer-repulpator, feeding the resulting pulp through a pipeline using a pump through a measuring tank into reactors, feeding an acid solution into the reactors, feeding excess aluminum hydroxide pulp with water that does not pass into the measuring tank through a pipeline for returning excess pulp back to the mixer-repulpator, characterized in that more than one mixer-repulpator is used, from which the prepared aluminum hydroxide pulp is fed through a measuring tank into the reactors.

The method for producing coagulants described in this invention involves feeding raw materials through a measuring tank using conveyor systems and more than one mixer-repulper. This invention utilizes a measuring tank for intermittent operation and more than one mixer-repulper for continuous operation.

The disadvantage of this device is that it is complicated by the installation of a measuring container, additional mixer-repulpers and other assembly units.

The closest analogues to the claimed invention are two inventions under patents of the Russian Federation No. RU 2764534 and No. RU 2715542.

The first of these is a device for producing coagulants for water purification, according to patent No. RU 2764534 C1 C01F 7/56, which utilizes a measuring and buffer tank, with an additional pipeline for removing pulp when the measuring tank is filled. The method for producing coagulants for water purification described in the device involves continuously feeding aluminum hydrate pulp from a mixer-repulper, a buffer tank, and a measuring tank into a reactor. A disadvantage of this device is that it is complicated by the installation of additional assemblies in the form of a buffer and measuring tank.

The second invention is a water purification coagulant production unit, according to patent No. RU 2715542 C1 C01F 7/56. It features an additional pipeline connecting the valve to the repulping mixer, a flow meter for determining the quantity, and a density meter for determining the quality of the slurry fed to the reactor during the production of various grades of coagulants. This unit has several drawbacks, including the installation of an additional flow meter, the requirement for highly skilled operators, and the need to maintain the pipelines and other units in a clean condition. During extended shutdowns due to breakdowns or accidents, the prepared slurry settles and solidifies. This necessitates extensive cleaning of all units, which reduces the equipment's performance.

The objective was to create an efficient, improved, technically rational and productive device for the production of coagulants for water purification.

Experience shows that any flow meter has errors when dosing at different densities, which means it is difficult to achieve the proper quality of the finished product when producing coagulants of different types and brands.

The proposed coagulant production system, which utilizes a looped pulp feed line between the mixer-repulper and the pump, is an efficient and productive device for producing coagulants for water purification. The looped pulp feed line between the mixer-repulper and the pump prevents pulp sedimentation and solidification during process and emergency shutdowns.

In the claimed device, the measured volume of the pulp solution is determined by preliminary weighing of the pulp components and determining the required volume of water when loading into the mixer-repulper by production operators, followed by feeding the required concentration of the pulp solution into the rector.

It's also possible for production operators to load the required volume of pulp components into the mixer-repulper using a measuring scale marked on the mixer-repulper wall for various components, depending on the type and grade of product being manufactured. In this case, the mixer-repulper functions as a measuring container.

In the device, the mixer-repulper also functions as a buffer tank. Due to the looped nature of the pulp feed pipeline to the reactor, the prepared pulp, which is not fed into the reactor due to the valve closing, is returned to the mixer-repulper. The pulp is then fed through the loop into the pipeline by the pump. The pulp continuously moves through the looped pipeline until the valve on the pipeline leading to the reactor opens.

Pulp for the production of coagulants for water purification is obtained by mixing iron scale or fine iron sand with a measured volume of water.

The device consists of several functionally interconnected assemblies to meet the specified technical specifications. The device is mechanically assembled into a single structure using bolted flange connections and consists of the following assemblies: reactor 1, mixer-repulper 3, pump 4, pipeline 2 for feeding pulp from the mixer-repulper to the reactor, loop pipeline 5 between the mixer-repulper and the pump, and pipeline 7 for feeding acid solution.

An improvement from the point of view of the technical rationality of the device is that a looped pipeline 5 is provided here between the mixer-repulper 3 and the pump 4 with a valve 6 on this pipeline, to which a pipeline 2 with a valve 6 is connected for feeding the pulp to the reactor 1. A valve mechanism or other automatic devices can be used in place of the valve.

The use of a loop pipeline between the mixer-repulper and the pump increases the productivity of the device, as it prevents the sedimentation and solidification of the pulp in the assembly units of the device during the production of high-density coagulants, as well as during forced stops in the supply of pulp to the reactor, during the unloading of finished products from the reactor.

The invention allows for higher productivity of the device since the supplied raw material in the form of pulp is constantly in motion in the assembly units, which prevents the settling and solidification of the pulp suspension in them during long stops of the device for various reasons, which in turn does not lead to lengthy cleaning of the assembly units of the device from solidified raw material.

The invention makes it possible to connect several reactors to the device or to alternately disconnect them according to production needs by using valves 6, without stopping the technological process of producing coagulants.

The invention allows the operation of the device to continue uninterrupted during the unloading of the finished product from a separate reactor or during maintenance work, while other reactors are actively operating in the production process.

The use of a loop pipeline 5 in the device, the determination of the measured volume of pulp components by weighing when loading into the mixer-repulper or the determination of the measured volume of pulp components according to the measuring scale of the mixer-repulper by production operators, allows for rational simplification, improvement of the device and an increase in the productivity of the device.

The technical result achieved by using the claimed device is the improvement of the technical device through rational simplification, improved design, increased functionality and performance of the device.

The device is illustrated by a drawing, which schematically depicts a device for the production of coagulants ferric chloride and ferric sulfate.

What is new in the device is that a looped pipeline 5 with a valve 6 is used between the mixer-repulper 3 and the pump 4, to which the pipeline for feeding the pulp 2 into the reactor with a valve 6 is connected.

The measured volume of pulp in the device is determined by batch weighing the ingredients or by batching the measured volume of pulp ingredients using the mixer-repulper scale by the production operators, followed by batch feeding of the pulp into the reactor. Mechanical stirrers 9 are installed in reactor 1 and mixer-repulper 3.

By using a looped pipeline between the mixer-repulper and the pump, the device's functionality is effectively simplified, technically improved, and increased. Productivity is also increased by preventing pulp solidification in the assemblies during extended shutdowns due to a reactor failure or accident, which would require lengthy cleaning of the assemblies. The looped pipeline prevents the finished pulp from solidifying in the assemblies by continuously circulating the pulp around the loop. Pulp solidification in the assemblies would interrupt production for a long time and reduce productivity.

Due to operation in an aggressive environment, the device's assembly units are made from corrosion-resistant and abrasion-resistant materials such as polypropylene, stainless steel, and others.

The assembly units of the device: reactor, mixer-repulper, pump are connected to each other by pipelines, using flange connections on high-strength bolts installed in the above-mentioned assembly units.

The device for producing ferric chloride and ferrous sulfate coagulants operates as follows. The operator doses a measured volume of scrap iron scale or fine iron sand and a measured volume of water, depending on the type and grade of the product being manufactured, into the repulping mixer, adhering to production standards. The pulp is prepared by mixing the pulp components with water in a repulping mixer with a mechanical stirrer. A specified amount of water is stored in a measured volume and then drains by gravity into the repulping mixer.

After filling the mixer-repulper with the required volume of water, the mixer is turned on. The specified volume of pulp ingredients is prepared in a container and transferred via lifting mechanisms to the feeder bin. After the mixer-repulper's mechanical mixer is turned on, the raw materials are dosed from the feeder bin into the mixer-repulper. The raw materials are fed at a specified rate with constant mixing to prevent the formation of dry lumps. The flow rate of the pulp components is determined according to the approved process. The duration of the mixing operation is also determined according to the approved process documentation, depending on the type and grade of the product being manufactured, as well as on the density test results.

In addition to manual loading, mechanized and automatic loading of pulp components is used, using modern automated chemical process control systems (APCS). The fine iron sand content in the pulp is monitored using a density meter.

The resulting pulp is fed into the reactor using a pump and mixed with a mechanical stirrer, where the required acid has already been collected in advance.

In the mixer-repulpator 3, a measured volume of components for preparing pulp in the form of iron scale with water, or fine iron sand with water is mechanically mixed to approximately 1.10-1.85 g/ ^cm3 , and the resulting pulp mixture is fed into the reactor 1 through pipelines using a pump 4. The volume of water for mixing the ingredients is determined by the manufacturing technology of a particular type and grade of product. Also, from the tank 8, a measured volume of acid is fed through the pipeline 7 into the reactor 1. The excess pulp, fed by the pump 4 through the pipelines into the reactor 1 and not passing through the valve 6 of the pipeline 2 when it is closed, is fed back into the mixer-repulpator 3 through the loop pipeline 5. The device allows the pulp mixture to be pumped continuously in a circle using the mixer-repulpator as a buffer tank, which in turn allows the pulp solution not to lose its quality, not to stratify and not to settle in the assembly units, clogging them.

The possibility of implementing the invention and ensuring technical results expressed in the creation of an effective, improved, technically rational and productive device for the production of coagulants for water purification, iron chloride and iron sulfate, due to the implementation of the device using a looped pipeline, is confirmed by the provided drawing and description of the device.

The use of the entire set of essential features given in the invention formulas allows the new device to achieve the declared technical result.

Claims (1)

A device for producing coagulants of ferric chloride and ferric sulfate, comprising a reactor to which an acid supply pipeline is connected, a pipeline with a pump for supplying pulp from a mixer-repulper, a mixer-repulper, characterized in that the mixer-repulper and the pump are connected to each other by a loop pipeline, to which the pipeline for supplying pulp to the reactor is directly connected.