RU2841943C1 - Flow-type pulsation apparatus - Google Patents

Abstract

FIELD: performing operations.

SUBSTANCE: invention is intended for the dispersion and mass transfer processes intensification in the liquid-solid particles, liquid-gas, liquid-liquid with continuous liquid phase systems, including for mixing solutions, emulsification, gas dispersion, absorption, extraction, dissolution, including with chemical reactions, and can be used in chemical, petrochemical, pharmaceutical, food industries, biotechnology, waste water treatment, construction industry and other industries. Proposed device comprises one or several parallel channels, each including several sections with cross section varying periodically in length and alternating with sections with invariable cross section. Each of sections with cross section periodically changing along the length includes several shaped elements of Venturi tube type, which are connected in series to each other. Elements of Venturi tube type include constriction zone, neck, expansion zone, zone with constant maximum cross section. Ends of sections with cross section periodically varying in length are connected to sections of constant cross section. Channels are made of deformable tubular articles clamped by means of tightening devices between shaped shoes, inner surface of which forms required surface of tubular elements. Area of neck of each channel is calculated according to formula S_n=nS_w, (1), where S_n is neck cross section area, m; S_w is the cross-sectional area of the section with the largest cross-section, m², n-coefficient, taken in range from 1/8 to 1/2.

EFFECT: invention simplifies the design of the device, reduces the cost of its manufacture, expands the possibilities for choosing corrosion-resistant materials, and increases ease of use.

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Description

The proposed device is intended for intensification of dispersion and mass transfer processes in liquid-solid particle, liquid-gas, liquid-liquid systems with a continuous liquid phase, including for mixing solutions, emulsification, gas dispersion, absorption, extraction, dissolution, including with chemical reactions, and can be used in the chemical, petrochemical, pharmaceutical, food industries, in biotechnology, wastewater treatment, in the construction industry and in other industries.

A method for intensifying dispersion and mass transfer processes and a device for implementing the same (prototype invention) are known (RU Patent No. 2264847). The method for intensifying reaction and mass exchange processes in heterogeneous systems consists of exciting oscillations in a heterogeneous system by passing it through a pipe with a variable cross-section, wherein the excitation of oscillations in the heterogeneous system during its movement alternates with the absence of oscillatory effects, and gas is introduced into the heterogeneous system one or more times. The device intended for implementing the said method consists of a compressor and one or more pipes with a variable cross-section, devices for supplying components and removing products, wherein the pipe consists of sections with a periodically changing cross-section, alternating with sections with a constant cross-section. The known invention makes it possible to increase efficiency, reduce hydraulic losses and simplify the design of the device in comparison with existing analogues.

In this case, generally accepted construction materials are usually chosen as the material of the known device - most often - steel pipes and rods of round cross-section, which are processed on metal-cutting machines and then welded. At the same time, pipes even from special steels do not always provide a high level of corrosion resistance (for example, in concentrated acids and alkalis, including strong acids - sulfuric, hydrochloric, phosphoric), and the cost of processing high-alloy steels increases significantly compared to carbon steels. The cost of products from corrosion-resistant steels is quite high, and their use is not always justified, especially at moderate working pressures.

In addition, the presence of a large number of welds, especially for devices with long pipes, reduces the overall reliability of the system, since the risk of damage to any of the welds leads to a loss of tightness of the device and the risk of contamination of the environment with the media contained in the device.

In addition, the device, made of metal pipes with a relatively complex shape of the internal volume, when solid deposits (the so-called "incrustation") appear on the internal surface, is quite difficult to clean from these deposits, especially with a large length of pipes. For this, it is necessary to equip the device with flanges, which significantly increases the metal consumption of the device.

Thus, the disadvantages of the known device include (the technical problem solved by creating the invention): 1) certain difficulties in serial production of the elements of the device having multiple conical surfaces, both on metal-cutting equipment and modern three-dimensional (so-called 3D) printing, their subsequent welding; 2) the practical impossibility of using polymer or elastomeric materials for the manufacture of the device, due to the difficulties of giving them a complex shape (there is a risk of breakage of products during their processing on machines); 3) limitations in the use of the device with aggressive environments, in which traditionally used structural materials (including different types of steel) have low corrosion resistance; 4) the high cost of manufacturing the device from steel and other metals.

The technical problem consists both in creating an object of the invention that is free from a number of shortcomings of the prototype (simplification of the design, manufacturing and assembly methods), and in expanding the arsenal of technical means that have a purpose that coincides with the purpose of the prototype (the possibility of using polymer and elastomeric materials, the possibility of manufacturing a neck with a cross-section of various shapes, simplifying the process of cleaning the inner surface, easy disassembly of the device and replacement of channels).

The use of other materials with high corrosion resistance, including non-metallic ones - polymers, elastomers and composites based on them (including reinforced ones), is difficult for the manufacture of a device with a complex shape of the internal volume. This means that special methods are required to use the said materials, allowing the formation of channels of the device with a complex shape of the internal volume. One of such methods is proposed in this invention.

The objective of the proposed invention (the technical result achieved by the invention) is to simplify the design of the apparatus, reduce the cost of its manufacture, expand the possibilities for choosing corrosion-resistant materials, and increase ease of use.

The stated task is achieved in that in a flow-type pulsating apparatus containing one or more parallel channels, each of which includes several sections with a cross-section periodically changing along the length, alternating with sections of constant cross-section, wherein each of the sections with a cross-section periodically changing along the length contains several shaped elements of the Venturi tube type, connected to each other in series, the elements of the Venturi tube type include a narrowing zone, a neck, an expansion zone, a zone with a constant maximum cross-section, and sections of constant cross-section are connected to the ends of the sections with a cross-section periodically changing along the length, according to the invention, the channels are made of deformable tubular articles clamped by means of tightening devices between shaped shoes, the inner surface of which forms the necessary surface of the tubular elements, and the area of the neck of each channel is calculated according to the formula

where S _g is the cross-sectional area of the neck, m ² ;

S _ш - cross-sectional area of the section with the largest cross-section, ^m2 ;

n is a coefficient accepted in the range from 1/8 to 1/2. Terms used in the application materials:

neck - a section of a channel with the smallest cross-sectional area;

deformable tubular products - tubes (hoses) made of various materials, mainly polymers, elastomers and composites based on them (including reinforced ones), with high corrosion resistance, as well as tubes made of easily deformable metals - copper and copper alloys, thin-walled tubes made of chromium-nickel steels, coated on the inside with a polymer protective film;

shoes - two paired parts with a shaped inner surface, necessary for the formation of apparatus channels between them when deformable tubular products are placed between them and pulled together using tightening devices, while the shoes are equipped with centering structural elements on the mating (paired) parts (protrusions and depressions, tenons and grooves, etc.), ensuring the coaxiality of the mating elements of the shoe;

a pack (stack) of pads - a set of pads with shaped recesses, laid on top of each other in several layers;

tightening devices - any devices that allow for a tight connection of paired parts of the pads, compression of deformable tubular products, allowing them to be given the shape of the inner surface of the pads, as well as maintaining this shape when the pressure inside the channels formed by the deformable tubular products increases; tightening devices can be made in the form of threaded - bolt or stud - connections, in the form of clamps of various types, for large-sized devices - in the form of hydraulic presses or other available devices.

The advantages of the proposed invention are:

1) the possibility of using non-metallic materials for the manufacture of the device - polymeric, elastomeric and composite materials based on them (including reinforced ones), which have high corrosion resistance, as well as from tubes of easily deformable metals - copper and copper alloys, thin-walled tubes made of chromium-nickel steels, coated from the inside with a polymer protective film;

2) easy disassembly of the device and the ability to clean the internal volume of the device, including in areas of narrowing of the flow when opening the shaped pads;

3) reducing the cost of the device through the use of mass-produced finished products - hoses made of polymer, elastomeric materials and composite materials based on them;

4) the possibility of completely eliminating welded seams when using long hoses;

5) reducing the cost of the device due to the use of high-strength polymer materials for the production of shaped pads.

Detailed description of the advantages of the proposed invention over existing solutions:

1) Ease of manufacture from finished products - hoses, mass-produced by industry.

2) The possibility of using commercially available hoses made of corrosion-resistant materials that are relatively easy to deform - plasticized polyvinyl chloride (PVC-P), silicone, polyurethane, neoprene rubber, styrene-butadiene rubber, butyl rubber, fluorosilicone rubber and other polymers or elastomers.

If it is necessary to use the device at high pressures, PVC-P, silicone hoses reinforced with high-strength steel threads, fiberglass or synthetic threads, including Kevlar (aramid), carbon threads or nanothreads can be used.

3) Shaped pads can be made in the form of cassettes with parallel channels, there can be several dozen or hundreds of such channels. Pads can be collected in packages (stacks)

4) The shape of the pads can be quite complex, they can be made using traditional methods of material removal on CNC machines, or modern methods of three-dimensional printing (3D printing).

The surfaces are open to processing and can be easily processed, including sanding and polishing.

5) The pads can be combined into packs (stacks) consisting of two, three or more pairs of pads.

Fig. 1-5 present graphic materials explaining the composition and operation of the proposed device. Fig. 1 includes two cross-sections (A-A and B-B, Fig. 1a, Fig. 16), as well as an image of a longitudinal section of the proposed device (Fig. 1c).

Fig. 1 shows a fragment of the proposed flow-type pulsating apparatus, containing one or several parallel channels 1, including several sections with a cross-section periodically changing along the length, alternating with sections of constant cross-section. Each of the sections with a cross-section periodically changing along the length contains several shaped elements 2 of the Venturi pipe (nozzle) type, connected to each other in series. Elements 2 of the Venturi pipe (nozzle) type include a narrowing zone 3, a neck 4, an expansion zone 5, a zone 6 with a constant maximum cross-section. Sections of constant cross-section 8, having the same cross-section as zone 6, are connected to the ends of sections 7 with a cross-section periodically changing along the length.

Channels 1 are made of deformable tubular products (hoses), the material of which can be polymers, elastomers, including those reinforced with high-strength fiberglass threads, polyamide, polyester, as well as metal wire. Polyethylene, polytetrafluoroethylene, plasticized polyvinyl chloride, silicones (polyorganosiloxanes) and other polymers with chemical resistance to the processed media can serve as polymeric materials for tubular products. Rubbers of various compositions with chemical resistance to the processed media can serve as elastomeric materials for tubular products. If necessary, channels 1 can be made of thin-walled metal pipes, the material of which is copper or copper alloys, chromium-nickel austenitic steels, capable of deforming without the risk of damage.

Sections 7 with a cross-section periodically changing in length are clamped between shaped blocks 9a and 9b, the inner surface of which forms the necessary surface of the tubular elements, using tightening devices 10 (bolts with nuts and washers, clamps or others). The inner surface of shaped blocks 9a and 9b forms the necessary surface of sections 7 with a cross-section periodically changing in length.

In this case, the area of the neck of each channel is calculated according to the formula

where S _g is the cross-sectional area of the neck, m ² ;

S _ш - cross-sectional area of the section with the largest cross-section, ^m2 ;

n is a coefficient taken in the range from 1/8 to 1/2.

In section A-A in Fig. 1 the zone of the narrowest part of the apparatus is shown - neck 4, and in section B-B in Fig. 1 - zone 6 with a constant maximum cross-section.

Fig. 2 shows a longitudinal section of shaped blocks 9a and 9b with a parting plane 11 and their inner surface 12.

The cross-section of the channel neck can be round, rectangular with rounded edges, elliptical, in the form of intersecting ellipses with roundings between them, with the main axes of the ellipses located in the plane of the connector of the shaped blocks or at an angle of 45° to it.

Fig. 3 shows embodiments of the inner surface of the shaped blocks 9a and 9b in the area of the neck 4, providing the shape of the cross-section of the neck 4 of the channels 1 (section options A-A in Fig. 1): in the form of ellipses (Fig. 3a); in the form of two intersecting ellipses (Fig. 3b); in the form of three intersecting ellipses (Fig. 3b); in the form of four intersecting circles (Fig. 3d).

Other variants of the cross-section of the shaped blocks 9a and 9b in the neck area 4 are also possible, for example, in the form of rectangles or squares with rounded edges.

The choice of a specific shape is determined by the elastic and plastic properties of the material from which channels 1 are made, and can be determined experimentally or by mathematical modeling using computer programs.

Fig. 4 shows a variant of the arrangement of the pads 9a and 9b in the form of stacks (section B-B to the drawing in Fig. 1), i.e. when several pairs of pads are installed one above the other. Due to such an arrangement of the pads, the device can contain a large number of parallel channels 1.

The number N of parallel channels 1 is determined by the total capacity of the apparatus Q and the cross-sectional area of the throat 4 of a single channel according to the calculation formula

where w _g is the average speed in the throat of 4 channels 1, which is recommended to be taken in the range from 2 to 12 m/s.

Higher values of w _g (from 6 to 12 m/s) must be specified in mass-exchange apparatuses in which fine dispersion of the dispersed phase - liquid or gas - must be carried out. Low values of w _g (from 2 to 6 m/s) must be specified in apparatuses where low-viscosity solutions are mixed with the same solvent (for example, aqueous solutions), or where solid phase particles are dissolved.

The production of channels from deformable tubular products simplifies the design of the device and reduces the cost of its manufacture, and expands the possibilities for choosing corrosion-resistant materials among polymer and elastomeric materials.

The use of shaped blocks, the inner surface of which forms the required surface of tubular elements, with tightening devices also helps to simplify the design of the device, and the ability to quickly disassemble the blocks with tightening devices ensures ease of use, since it becomes possible to quickly assemble the device, clean the inner surface of the channels along their entire length, and replace deformable tubular products (from which the channels are formed) that have become unusable.

The execution of the neck area of each channel according to the calculation formula (1) allows achieving the necessary useful effect in the proposed device.

Smaller values of the coefficient n (from 1/8 to 1/4) provide a more significant change in the cross-sectional area of the throat S _g compared to the cross-sectional area S _w of the section with the largest cross-section, i.e. in this case the velocity in the throat w _g increases from 4 to 8 times. Such a significant increase in velocity helps to create a favorable hydrodynamic environment for the dispersion of droplets and bubbles, dissolution of solid phase particles caused by the occurrence of Kelvin-Helmholtz instability, powerful turbulent tangential stresses in the flow core and laminar tangential stresses in the boundary layer. The same applies to the processing of mixtures with increased viscosity (significantly higher than the viscosity of water, i.e. more than 50-60 mPa⋅s). For example, at a velocity in the wide part of 1.5 m/s, the velocity in the throat can be from 6 to 12 m/s; such values, as is known from the literature (Abiev RS, Galushko AS Bubbles size and mass transfer in a pulsating flow type apparatus with gas-liquid mixture// Journal of Flow Chemistry (2021) 11, p. 369-391. https://doi.org/10.1007/s41981-021-00177-y; Vasilev MP, Abiev R.Sh. Intensity and efficiency of droplet dispersion: Pulsating flow type apparatus vs. static mixers// Chem. Eng. Res. & Des., 2018, Vol. 137, P. 329-349. DOI: 10.1016/j.cherd.2018.07.029), provide the above effect of gas and liquid dispersion.

Higher values of the coefficient n (from 1/4 to 1/2) provide a less significant change in the cross-sectional area of the neck S _g compared to the cross-sectional area S _w of the section with the largest cross-section, while the velocity in the neck w _g increases by 2 to 4 times. This level of increase in the velocity in the neck is quite sufficient for mixing solutions based on a common solvent (for example, water), homogenization of mixtures with a relatively low viscosity (approximately corresponding to the viscosity of water). For example, at a velocity in the wide part of 1.5 m/s, the velocity in the neck can be from 3 to 6 m/s; such values do not lead to an excessively high level of specific energy dissipation velocity, but allow for efficient implementation of processes in low-viscosity media.

The pads can be made of structural metals or alloys (various grades of steel, brass, bronze, aluminum alloys), of hard polymers (polypropylene, polyvinyl chloride), including reinforced ones, and also (when used in systems with low and moderate pressure) - of hard wood (oak, beech, ash, birch).

The following linear and angular dimensions of the inner surface of channel 1 formed by shoes 9a and 9b are preferable; similar recommendations apply to the shape of the shoes. The ratio of the cross-sectional areas of neck 4 and section 6 with the largest cross-section is determined by calculation formula (1). The angle at the cone apex in narrowing zone 3 is recommended to be in the range from 30° to 65° (higher values will lead to an increase in hydraulic resistance, lower values - to an irrational increase in the length of the channel and shoes). The angle at the cone apex in expansion zone 5 is recommended to be in the range from 4° to 14° (higher values will lead to flow separation from the channel walls, the occurrence of return flows and an increase in hydraulic resistance, lower values - to an irrational increase in the length of the channel and shoes). The ratio of the neck length to its diameter is recommended to be in the range from 1.5 to 4.0. The ratio of the length of zone 6 (with a constant maximum cross-section) to its diameter is recommended to be performed in the range from 1.0 to 4.0. In the case of performing a non-circular cross-section of channel 1, these recommendations can be applied in relation to the equivalent diameter d _e of the channel in the current cross-section, which is calculated using the well-known formula

where S is the cross-sectional area of the considered arbitrary section of the channel 1, ^m2 ; П is the perimeter of the specified section, m.

Fig. 5 shows one of the embodiments of the constriction zone 3: Fig. 5a is a cross-section of the wide part (section 6 with the largest cross-section) with a diameter D, Fig. 5g is a cross-section of the neck 4 of an elliptical shape with semi-axes 2a and 2b. Fig. 5b shows the generating lines of the constriction zone 3, connecting section 6 with the neck 4 in the longitudinal section of the channel 1, passing through the minor semi-axis of the ellipse 2b, and Fig. 5c shows similar generating lines connecting section 6 with the neck 4 in the longitudinal plane passing through the major semi-axis of the ellipse 2a.

The above recommendations for angular dimensions apply to the smaller of the two angles shown in Fig. 5b and Fig. 5c (i.e., angle 2a) in the section of the narrowing sections. Similar recommendations apply to the widening sections.

For a neck cross-section shape other than elliptical (Fig. 3b, Fig. 3c, Fig. 3d), all of the above recommendations for angular dimensions apply to the smallest dimension in the neck cross-section 4.

The longitudinal shape of the inner surface of the pads is preferably linear, but can also be of another smooth shape.

The proposed device operates as follows.

The assembly of the flow-type pulsating apparatus is carried out by placing the lower pads 9b on a horizontal surface along a straight line with a specified distance between them, laying a hose with a calculated internal diameter of mm made of a polymer or elastomer material, including reinforced, in them, placing the mating parts - pads 9a - on top of the pads 9b, installing studs in the holes made in the pads 9a and 96, screwing nuts with washers onto them and tightening the nuts until the pads 9a and 9b are in complete contact.

As a result of tightening the threaded elements (studs with nuts and washers), the hose placed in the blocks is deformed in such a way that the hose takes the shape of the inner surface of the blocks 9a and 9b, as shown in Fig. 1a - Fig. 1c.

In general, the shape of the inner surface in the neck area 4 may be different; for example, as shown in Fig. 3a - Fig. 3d.

After assembly, the processed media are fed into channels 1 at a given flow rate. As a result of the change in speed in the zones of narrowing, throats and expansion of the flow, intensive dispersion of the dispersed phase (gas or liquid) and intensive mixing of solutions occur, which contributes to the intensification of mass transfer in the device.

If it is necessary to clean the inner surface of channels 1 made of polymer, elastomer and composite materials based on them, the tightening devices can be loosened, and the hose takes a shape close to the original, which allows cleaning the inner surface of the channels using mechanical methods, as well as external impact on the walls of the channels 1 - crushing, bending, ultrasonic impact, which helps to separate deposits from the walls.

The assembly procedure and operation of the proposed device are also described in the following examples of specific implementation.

Example of specific implementation 1. The flow-type pulsating apparatus contains one channel 1, which includes three sections 7 with a cross-section periodically changing in length, alternating with four sections 8 of a constant cross-section with a diameter of 20 mm, as shown in Fig. 1. Channel 1 is made of a hose with an internal diameter of 20 mm and a wall thickness of 2.5 mm, the material of which is plasticized polyvinyl chloride, reinforced with a diagonal mesh of nylon threads, which allows it to be used for most solutions of strong acids at moderate temperatures (no more than 80-100 ° C). The working pressure of such a hose can reach 10 bar.

Each of the sections 7 with a cross-section periodically changing in length contains three shaped elements of type 2 of the Venturi pipe (nozzle), connected to each other in series. Elements of type 2 of the Venturi pipe (nozzle) include a narrowing zone 3, a neck 4, an expansion zone 5, a zone 6 with a constant maximum cross-section. Three shaped elements of type 2 of the Venturi pipe (nozzle) are formed by a pair of shoes 9a and 9b, each 400 mm long (total length 1200 mm), made of steel 40, with a shaped inner surface made in accordance with the diagram shown in Fig. 1. The tightening elements are M8 studs with nuts and washers, all made of steel 20X13, 2 studs for every 80 mm of the length of shoes 9a and 9b. The neck 4 of channel 1 after compression in blocks 9a and 9b has a diameter of 10 mm. Thus, the areas of the wide part (the section with the largest cross-section) and the neck are related by the calculation formula (1) with the coefficient n=1/4. The device with such a value of the coefficient n is universal and suitable, as the results of studies show, both for processes with the dissolution of solid phase particles, dispersion of liquid or gas, and for the processes of mixing solutions.

The inner surface of the pads provides a smooth decrease in the internal diameter of the channels from 20 mm to 10 mm in the conical constriction zone 3 (the constriction angle at the cone apex is 35°), and a subsequent smooth increase in the cross-section in the conical expansion zone 5 (the expansion angle at the cone apex is 12°). The length of each of the sections 8 of the constant (maximum) cross-section is 600 mm (the total length is 2400 mm). Thus, the total length of channel 1 is 1200+2400=3600 mm.

The assembly of the flow-type pulsating apparatus of the specified geometry is carried out by placing the lower pads 9b on a horizontal surface along a straight line with a specified distance between them (600 mm in this example), laying a hose with an internal diameter of 20 mm made of plasticized polyvinyl chloride, reinforced with a mesh, in them, placing the mating parts - pads 9a - on top of the pads 9b, installing studs in the holes made in the pads 9a and 9b, screwing nuts with washers onto them and tightening the nuts until the pads 9a and 9b are in complete contact.

The entire assembly procedure of the device by one fitter takes no more than 40-50 minutes, and the disassembly procedure (if necessary to clean or replace the materials of channels 1 that have failed due to aging) takes no more than 20 minutes. This significantly reduces operating costs and increases ease of use. The total cost of the source materials for the manufacture of the device according to the proposed invention - a hose, pads and tightening elements - is approximately 45,000 rubles in 2024 prices and is significantly lower than the cost of materials for the manufacture of a device of the same geometry from pipes and round rolled products (rod) made of chromium-nickel steel, with their subsequent grinding, polishing and welding (approximately 250,000 rubles in 2024 prices), made according to the prototype invention.

Thus, both capital and operating costs when using the proposed invention are significantly lower than for the known solution. The design of the device is simplified, the cost of its manufacture is reduced, the possibilities for choosing corrosion-resistant materials are expanded, and ease of use is increased.

Example of specific implementation 2. The apparatus according to the proposed invention contains four parallel channels 1 formed by blocks 9a and 9b with four parallel internal surfaces, as shown in Fig. 1a and Fig. 1b, as well as in Fig. 3. Channel 1 is made of a hose, the material of which is silicone, enclosed in a wire mesh (braid) made of chromium-nickel steel.

The diameter of the zone with a constant maximum cross-section is 60.0 mm. The neck 4 has the shape of an ellipse (Fig. 3a) with the length of the semi-axes a = 15 mm, b = 7.5 mm (as shown in Fig. 5), the equivalent diameter of the neck 4 (in terms of the area of the circular cross-section) is 21.213 mm. The cross-sectional areas of the neck 4 and the zone 6 with a constant maximum cross-section are related according to the calculation formula (1) with a coefficient n = 1/8. This allows, as shown by the research results, to carry out processes that require high flow rates, and therefore higher values of the specific rate of energy dissipation, for example, gas dispersion in liquid or emulsification. For this reason, the apparatus of the specified configuration can be used, for example, for carrying out biochemical processes (growing aerobic biomass, requiring saturation of the culture liquid with oxygen).

The length of the pads is 1200 mm, their width is 360 mm. In each channel of the pads, three consecutive elements of the Venturi tube type are formed, five pads 9a and 96. Thus, the total length of the hose in the pads will be 6000 mm, and the total length of six sections 6 with a maximum diameter (1500 mm each) will be 9000 mm. The total length of each of the four parallel channels is 15 m, which ensures the required residence time. If necessary, channels 1 can be included in the recycle to achieve even higher residence times.

Specific embodiment example 3. The apparatus according to the proposed invention contains sixteen parallel channels 1 formed by a stack of four blocks 9a and 96, as shown in Fig. 4. As in specific embodiment example 2, the diameter of the zone with a constant maximum cross-section is 60.0 mm, but the neck 4 has the shape of an ellipse (Fig. 3a) with the length of the semi-axes a=30 mm, b=15 mm (as shown in Fig. 5). In this case, the decrease in the cross-sectional area is less significant, i.e. the coefficient in formula (1) has the value n=1/2. Such a value, as shown by the research results, makes it possible to provide conditions sufficient for mixing homogeneous solutions, for example, two or more aqueous solutions. The remaining geometric parameters of the channel and blocks are the same as in example 2, but the hose is made of silicone with a wall thickness of 5 mm without additional reinforcement. The lack of need for reinforcement is due to the reduced pressure in the apparatus, which, in turn, is associated with the reduced hydraulic resistance of the apparatus.

Thus, the presented examples demonstrate the simplification of the device design, reduction of its manufacturing cost, expansion of the possibilities for choosing corrosion-resistant materials, and increased ease of use.

n is a coefficient taken in the range from 1/8 to 1/2.

The proposed device allows to simplify the design of the device, reduce the cost of its production, expand the possibilities for choosing corrosion-resistant materials, and increase ease of use.

Claims (5)

A flow-type pulsating apparatus comprising one or more parallel channels, each of which includes several sections with a cross-section periodically changing in length, alternating with sections of constant cross-section, wherein each of the sections with a cross-section periodically changing in length contains several shaped elements of the Venturi tube type, connected to each other in series, the elements of the Venturi tube type include a narrowing zone, a neck, an expansion zone, a zone with a constant maximum cross-section, and sections of constant cross-section are connected to the ends of the sections with a cross-section periodically changing in length, characterized in that the channels are made of deformable tubular products clamped by means of tightening devices between shaped shoes, the inner surface of which forms the required surface of the tubular elements, and the area of the neck of each channel is calculated according to the formula where S _g is the cross-sectional area of the neck, m ² ; S _ш - cross-sectional area of the section with the largest cross-section, ^m2 ; n is a coefficient taken in the range from 1/8 to 1/2.