Device for homogenizing polydisperse systems

Abstract

A device for homogenizing polydisperse systems comprises a working tank with inlet and outlet fittings that is connected to a circulation pipe having control and regulating valves mounted thereon; a homogenizing pump; feed and discharge tanks for a working medium, which contain a working medium; and a stirrer disposed in the working tank and consisting of two rotating shafts. The device further comprises a mixing chamber containing an air-powder mixture of charged finely dispersed and / or ultra-dispersed electrically conductive particles, to which is connected an air circulation conduit with a fan; a chamber with high-voltage electrodes; and inlet valves connected to tanks containing finely dispersed and / or ultra-dispersed chemical elements. One of the shafts of the stirrer, namely a main shaft, is connected to an electric motor that is controlled by a unit for controlling and adjusting the rate of rotation, and the other shaft, namely an auxiliary shaft, is clamped to the main shaft, wherein a gap exists between said shafts that is adjustable by means of a clamping and braking device. The invention makes it possible to optimize the process of manufacturing passive electronic components and thick-film resistive heating elements, as well as to eliminate local defects.

Description

[0001] DEVICE FOR HOMOGENIZATION OF POLYDISPERSES

[0002] SYSTEM

[0003] Field of technology to which the invention relates

[0004] The invention relates to process equipment that is intended for homogenizing conductive and resistive pastes used in the manufacture of thick-film passive electronic components, as well as in the manufacture of thick-film resistive heating elements for various electric heating systems in household, medical, agricultural and other technical devices.

[0005] State of the art

[0006] A high-pressure homogenizer is known, described in patent RU2621773 (B01F 15 / 00, published 07.06.2017), which includes a set of pump pistons for feeding the liquid to be homogenized to a manifold, wherein each piston is connected to a corresponding oil-hydraulic cylinder; a homogenizing valve located downstream of said pump pistons; and an electronic system for monitoring and adjusting said pump pistons, independently ensuring control of the law of motion of each individual piston.

[0007] The said electronic control system is connected to a sensor located on the manifold for controlling the oil supply to individual cylinders of the corresponding pistons in accordance with the pressure of the liquid to be homogenized, measured in the manifold, pumped by the said pistons, in order to maintain a stable flow rate and pressure, which ensures the elimination of the pulsation effect during pumping in order to reduce the stress leading to damage to the homogenizing valve and the above-mentioned elements.

[0008] A mixer-homogenizer RU2314149 (B01F 5 / 00 published 10.01.2008) is known, containing a cylindrical body with inlet and outlet pipes.

[0009] 5 outlets of the working medium and a nozzle with nozzle channels and a mixing chamber with a disperser fixed at a distance of 10-20 calibers of the nozzle channel from the nozzle, placed in the housing along the direction of movement of the working medium. The end of the disperser is beveled along the direction of movement of the working medium at an angle greater than 90° relative to the direction of movement of the working medium, the bevel of the end of the disperser is made profiled. The housing is equipped with an additional input branch pipe placed behind the disperser along the direction of movement of the working medium.

[0010] A wave homogenizer RU152197 (B01F 9 / 00, B01F 9 / 02; B01F 11 / 00, published 10.05.2015) is known, containing a base mounted

[0011] 15 cylindrical working chamber with a branch pipe on the lid, mixing elements placed inside the chamber, a system for loading raw materials and unloading the mixture, a torsional vibration motor rigidly connected to the bottom of the working chamber, a rotation drive, a control unit for adjusting the rotation frequency and angular amplitude of the torsional vibration motor

[0012] 20 and the number of revolutions of the rotation drive. The device is equipped with a frame and a brush-contact device for supplying power to the torsional vibration motor, a pair of vertical rigidly connected supports is used as a base, between which a horizontal shaft is installed, the frame is made in the form of a platform with a pair of posts perpendicular to its surface, the torsional vibration motor is installed between the posts in bearing supports, the brush-contact device is installed on one of the frame posts, the rotation drive is installed on the frame platform and connected to the torsional vibration motor by means of a belt transmission, the frame is fixed on the shaft between the supports, and the raw material loading and mixture unloading system includes a frame rotation mechanism installed on the base post and connected to the shaft. The raw material loading and mixture unloading system includes loading and unloading pipes that are not kinematically connected to the working chamber, and also includes a shutter on the pipe located on the cover of the working chamber.

[0013] The closest analogue is a device for mixing particles of a substance with a liquid, described in patent RU2137535 (B01F 3 / 12 B01F 13 / 02 published 20.09.1999), which contains a container, an inlet for placing particles of a substance in the container, a means for spraying a liquid over the particles of the substance in the container, a stirrer located in the container, and an outlet for releasing the substance mixed with the liquid from the container. The fluidization means is adapted for fluidizing the particles of the substance in the container during the mixing operation.

[0014] The disadvantage of known devices is that they do not provide a sufficient degree of homogeneity of the distribution of chemical elements and phases throughout the volume of the heterophase system, which leads to the formation of local defects in thick-film passive electronic components and to uneven heating of the surface of thick-film resistive heating elements.

[0015] To eliminate this drawback, thick-film passive electronic components and thick-film resistive heating elements are currently manufactured in several operations involving the successive application of layers and their heat treatment, which significantly complicates the manufacturing process.

[0016] Disclosure of invention

[0017] The objective of the claimed technical solution is to create a device that allows for spatial uniform distribution of current-conducting finely dispersed and ultra-dispersed chemical elements in a dielectric binder, which will ensure stability of electrophysical characteristics and increase the value of specific power, which will optimize the technological process of manufacturing passive electronic components and thick-film resistive heating elements, as well as eliminate local defects.

[0018] The technical result of the claimed invention is an increase in the productivity of the homogenization device, a reduction in the technological process, a decrease in material consumption, and an increase in the reliability of the final product.

[0019] The set task is achieved in that in a device for homogenizing polydisperse systems, comprising a working tank with inlet and outlet pipes connected to a circulation pipeline on which control and regulating valves are installed, a homogenizer pump, tanks for loading and unloading the working medium containing the working medium, a mixer placed in the working tank consisting of two rotating shafts, wherein the device additionally comprises a mixing chamber with an air-powder mixture of charged finely dispersed and / or ultra-dispersed conductive particles, to which a circulation air duct with a fan is connected, a chamber with high-voltage electrodes, inlet valves connected to tanks with finely dispersed and ultra-dispersed chemical elements, wherein one of the mixer shafts - the main one, is connected to an electric motor controlled by a speed adjustment control unit, the second shaft - an additional one, is pressed against the main shaft with a gap between them,adjustable by a clamping and braking device,

[0020] In a particular embodiment, in a chamber with high-voltage electrodes, the high-voltage electrodes are installed hermetically through a dielectric threaded connection to charge conductive particles and break up conglomerates that form during storage of powder materials.

[0021] In a particular embodiment, the amount of air-powder mixture of charged finely dispersed and / or ultra-dispersed conductive particles in the mixing chamber is formed by feeding powders from sealed containers with maintained constant pressure, installed on the circulation air duct through electromagnetic valves, which are controlled by an arithmetic logic electronic device.

[0022] In a particular embodiment, the speed of movement of the air-powder mixture particles is determined by the fan and the speed control unit.

[0023] In a particular embodiment, the thickness of the uniform distribution of the dielectric binder along the working and additional shaft is achieved by means of a gap between them, which is adjusted using a clamping and braking device.

[0024] In a particular embodiment, the loading and unloading tanks for the working medium contain the working medium in the form of a dielectric binder or conductive paste or resistive paste.

[0025] Brief description of the drawings

[0026] The general view of the device for homogenization of polydisperse systems is shown in Fig. 1.

[0027] The following structural elements are indicated by numbers on the figure:

[0028] 1 - base, 2 - working tank, 3 - inlet pipe, 4 - outlet pipe, 5 - working medium, 6 - homogenizer pump, 7 - circulation pipeline, 8 - electromagnetic valve No. 1, 9 - electromagnetic valve No. 2, 10 - electromagnetic valve No. 3, I - working medium loading tank, 12 - electromagnetic valve No. 4 with a pipe for unloading the working medium, 13 - receiving tank, 14 - working shaft, 15 - electric motor, 16 - additional shaft, 17 - clamping and braking device, 18 - mixing chamber, 19 - circulation air duct, 20 - fan, 21 - air-powder mixture, 22 - chamber, 23 - high-voltage electrodes, 24 - high-voltage source, 25 - sealed containers, 26 - electromagnetic valve No. 5, 27 - pressure gauge, 28 - electromagnetic valve No. 6, 29 - arithmetic logic electronic device, 30 - speed control unit.

[0029] Implementation of the invention

[0030] The device for homogenizing polydisperse systems consists of a base 1 on which, using bolted connections, a working tank 2 is installed with an inlet pipe 3 and an outlet pipe 4, through which the working medium 5 is supplied by a homogenizer pump 6 along a circulation pipeline 7, which is connected by coupling connections. Electromagnetic valves are installed on the pipeline using a flange connection: No. 1-8 - on the inlet pipe 3 and No. 2-9 - on the outlet pipe 4. Electromagnetic valve No. 3-10, which is connected to the working medium loading tank I, and electromagnetic valve No. 4-12 with a pipe for unloading the working medium into the receiving tank 13 are connected to the circulation pipeline using flange connections.Directly under the inlet pipe, inside the working tank, a working shaft 14 is installed using gland connections, which is driven by an electric motor 15, and an additional shaft 16, which is pressed against the working shaft using a clamping and braking device 17. Above the main tank, a mixing chamber 18 is attached using bolted connections, to which a circulation air duct 19, a fan 20 and a chamber 22 are connected using flange connections, through which an air-powder mixture 21 is supplied, the particles of which are charged with an electric charge in the chamber 22 with high-voltage electrodes 23 hermetically installed through a dielectric threaded connection, which are connected to a high-voltage source 24 through.

[0031] 5 detachable connection. The powder mixture enters the air duct from sealed containers 25, installed with the help of coupling connections in which a constant pressure is maintained, regulated by electromagnetic valve No. 5 26 and controlled by pressure gauge 27, mounted with the help of a threaded connection. The amount of powder mixture supplied is regulated by electromagnetic valves with flange connection No. 6-28. The operation of the valves is controlled by arithmetic-logical electronic device 29, the rotation speed of the homogenizer pump motors, fan and main shaft is controlled by the frequency control unit

[0032] 15 rotations 30, which are connected using detachable connections.

[0033] The device works as follows:

[0034] A dielectric binder (for example, a copolymer of methacrylic acid and butyl ester of methacrylic acid dissolved in butyl acetate) is fed into a container 2 installed on a base 1.

[0035] 20 from the working medium loading tank 11 using the homogenizer pump (for example, the NGD series homogenizer pump), the feed rate is regulated by the rotation speed adjustment control unit. For this purpose, using the arithmetic logic device, electromagnetic valve No. 1-8 and electromagnetic valve No. 3-10 are switched to the open state. Through the inlet pipe 3, the dielectric binder gets onto the working 14 and additional 16 shafts, the gap between the shafts is adjusted using the clamping and braking device 17, the main shaft is driven by the engine 15, which is also controlled by the rotation speed adjustment control unit 3. The dielectric binder is evenly distributed over the shafts with a layer thickness equal to the gap between the shafts, gradually being replaced by a new batch, and the distributed batch flows down to the lower part of the working tank.After filling the working tank with the required amount of dielectric binder, the arithmetic logic unit closes valve No. 3-10 and opens valve No. 2-9, the dielectric liquid begins to move along the circulation pipeline 7 in a closed cycle. Based on the method of mutual attraction of opposite-polarity particles, using which charged particles are uniformly distributed over the surface of dielectric or conductive materials, as, for example, described in the patent for a volumetric dispenser of powder materials for electrostatic application of coatings on bulbs of electric lamps RU2200939 (G01F 11 / 18, B05B 5 / 00 published on 20.03.2003) or in the patent for a method for manufacturing a thick-film resistive heater RU2463748 (H05B 3 / 00, published on 10.10.2012), a mixing chamber 18 is installed above the main container, in which an air-powder mixture of charged finely dispersed and / or ultra-dispersed conductive particles is formed, which are uniformly distributed over the surface of the dielectric binder uniformly distributed over the shafts, the number of uniformly distributed parts depends on the magnitude of their charge.

[0036] The speed of movement of particles is determined by fan 20 and speed adjustment control unit, air-powder mixture moves in a closed cycle along circulation air duct in which chamber 22 is installed with high-voltage electrodes against which conductive particles strike, thereby their charge is carried out and conglomerates that are formed during storage of powder materials are broken up. The magnitude of the charge is regulated by high-voltage source 24, the amount of finely dispersed and / or ultra-dispersed conductive particles by electromagnetic valves No. 6 - 28, which are fed into circulation air duct from sealed containers 25, in which constant pressure is maintained, controlled by pressure gauge 27 and regulated by electromagnetic valve No. 5 - 26. The number of valves and containers is set depending on the amount of chemical elements introduced into the composition of the prepared conductive or resistive pastes.After several mixing cycles, the working medium obtained in the working tank is discharged through electromagnetic valve No. 4 with discharge branch pipe 12 into receiving tank 13.

[0037] In accordance with the above, the device ensures the achievement of the declared technical result and task:

[0038] This device ensures the required degree of homogeneity of distribution of chemical elements and phases throughout the volume of a heterophase system.

[0039] - After the homogenization process of conductive and resistive pastes is completed, there are no local defects in them, which increases the reliability of thick-film passive electronic components and eliminates uneven heating of the surface of thick-film resistive heating elements.

[0040] - The device allows processing ready-made conductive and resistive pastes, additionally introducing finely dispersed and ultra-dispersed conductive particles into their composition, which allows changing their electrical resistance, stabilizing electrical resistance, and increasing specific power.

[0041] - The device allows to increase productivity and reduce the technological process of production of thick-film passive electronic components and thick-film resistive heating elements, and also allows to reduce material consumption, increase reliability, eliminate local defects in thick-film passive elements and in thick-film heating elements.

Claims

CLAUSES OF THE INVENTION 1. A device for homogenizing polydisperse systems, comprising a working tank with inlet and outlet pipes connected to a circulation pipeline on which control and regulating valves are installed, a homogenizer pump, tanks for loading and unloading the working medium containing the working medium, a mixer placed in the working tank consisting of two rotating shafts, characterized in that the device additionally comprises a mixing chamber with an air-powder mixture of charged finely dispersed and / or ultradispersed conductive particles, to which a circulation air duct with a fan is connected, a chamber with high-voltage electrodes, inlet valves connected to tanks with finely dispersed and ultradispersed chemical elements, wherein one of the mixer shafts - the main one, is connected to an electric motor controlled by a speed control unit, the second shaft - additional, is pressed against the main shaft with a gap between them,adjustable by a clamping and braking device.

2. A device for homogenizing polydisperse systems according to paragraph 1, characterized in that in the chamber with high-voltage electrodes, the high-voltage electrodes are installed hermetically through a dielectric threaded connection for charging conductive particles and breaking up conglomerates that form during storage of powder materials.

3. A device for homogenizing polydisperse systems according to claim 1, characterized in that the amount of air-powder mixture of charged finely dispersed and / or ultra-dispersed conductive particles in the mixing chamber is formed by feeding powders from sealed containers with maintained constant pressure, installed on a circulation air duct through electromagnetic valves, which are controlled by an arithmetic logic electronic device.

4. A device for homogenizing polydisperse systems according to paragraph 3, characterized in that the speed of movement of the air-powder mixture particles is determined by a fan and a speed control unit.

5. A device for homogenizing polydisperse systems according to paragraph 1, characterized in that the thickness of the uniform distribution of the working medium along the working and additional shaft is achieved by means of a gap between them, which is adjusted using a clamping and braking device.

6. A device for homogenizing polydisperse systems according to paragraph 1, characterized in that the containers for loading and unloading the working medium contain the working medium in the form of a dielectric binder or conductive paste or resistive paste.

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