Cleaning system of chlorosilane purification filter and method for cleaning filter

Abstract

The invention discloses a cleaning system of a chlorosilane purification filter and a method for cleaning the filter. The cleaning system comprises the filter and a cleaning device, a first inlet of the cleaning agent circulating tank is connected with a first outlet of the filter, an outlet of the cleaning agent circulating tank is connected with a first inlet of the filter, an alkaline solution in the cleaning agent circulating tank enters the filter through the first inlet of the filter for reverse cleaning, and the alkaline solution decomposes siloxane in the filter and peels off a filter element; an inlet of the gas-liquid separator is connected with a second outlet of the filter, and a first outlet of the gas-liquid separator is connected with a third inlet of the cleaning agent circulating tank; and the water-sealed tank is connected with the second outlet of the gas-liquid separator and is used for water sealing and exhaust gas discharge. According to the invention, overall cleaning of the filter is realized, cleaning treatment can be carried out only by using standby equipment and cutting off the target filter, shutdown is not needed, and production continuity is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of silicon chemical industry, and in particular relates to a cleaning system of a chlorosilane purification filter and a method for cleaning the filter. Background Art

[0002] Chlorosilane is an important raw material for the preparation of polysilicon or the synthesis of functional silanes. It is widely used because of the advantages of gas-solid direct synthesis process, such as simplicity, maturity and high efficiency. In this process, a large amount of gas-solid, liquid-solid and gas-liquid-solid heterogeneous mixtures will be formed as chlorosilane is generated. In order to achieve the purification and separation of chlorosilane, heterogeneous separation operations are involved.

[0003] At present, in the chlorosilane synthesis process, inertial sedimentation and filtration are routine operations for separating such heterogeneous mixtures. In the filtration operation, ceramic or powder metallurgy filters are widely used because of their advantages such as high filtration accuracy, high temperature resistance, high alkali resistance and long service life. However, in the chlorosilane synthesis process, it is inevitable to use water-containing materials, or due to reasons such as leakage of heat exchangers, chlorosilanes are hydrolyzed and polycondensed to produce a large amount of colloidal siloxanes. Such chemical substances work together with inorganic micropowders (Si powder, inorganic chlorides such as Cu, Fe, Al, etc.) that are not completely separated, and combine to form a colloid with strong adhesion.

[0004] As the ceramic filter is used for a longer time, a layer of gel of varying thickness forms on the filter surface. In severe cases, some of the gel will penetrate into the filter micropores, increasing the blockage of the filter element, causing the filter resistance to continue to increase and forcing it to be removed for maintenance, which in turn affects production efficiency and product quality. The traditional treatment method is to remove the filter as a whole and replace the blocked filter elements one by one. This method not only has a high labor intensity for maintenance personnel, but also affects production continuity, causing a large amount of resource waste, and increasing production costs. Summary of the invention

[0005] The technical problem to be solved by the present invention is to solve the above-mentioned deficiencies in the prior art, and to provide a cleaning system for a chlorosilane purification filter and a method for cleaning the filter, wherein the siloxane attached to the filter element surface or embedded in the filter element micropores is decomposed into small molecules by using the catalytic and dissolving effects of an alkaline cleaning agent (the alkali causes the Si-O, Si-H, and Si-Si bonds to break), and then peeled off from the inner and outer surfaces of the filter element until it is dissolved in an ethanol solution, thereby finally achieving the cleaning of the filter element for reuse.

[0006] The technical solution adopted to solve the technical problem of the present invention is to provide a cleaning system for a chlorosilane purification filter, comprising:

[0007] The filter comprises a filter body, a first filter inlet, a first filter outlet and a second filter outlet arranged on the filter body;

[0008] The cleaning agent circulation tank comprises a cleaning agent circulation tank body, a first cleaning agent circulation tank inlet, a second cleaning agent circulation tank inlet, a third cleaning agent circulation tank inlet and a cleaning agent circulation tank outlet arranged on the cleaning agent circulation tank body, wherein the first cleaning agent circulation tank inlet is connected to the first filter outlet, the second cleaning agent circulation tank inlet is used to introduce alkali and ethanol to form an alkaline solution, the cleaning agent circulation tank outlet is connected to the first filter inlet, the alkaline solution in the cleaning agent circulation tank enters the filter through the first filter inlet for backwashing, and the alkaline solution decomposes siloxane in the filter to generate sodium silicate and strip the filter element;

[0009] The gas-liquid separator comprises a gas-liquid separator body, a gas-liquid separator inlet arranged on the gas-liquid separator body, a first gas-liquid separator outlet, and a second gas-liquid separator outlet, wherein the gas-liquid separator inlet is connected to the second filter outlet, the first gas-liquid separator outlet is connected to the third inlet of the cleaning agent circulation tank, the first gas-liquid separator outlet is used to discharge gas phase separation, and the second gas-liquid separator outlet is used to discharge liquid phase separation;

[0010] The water seal tank is connected to the second outlet of the gas-liquid separator and is used for water sealing and exhausting waste gas.

[0011] Preferably, the cleaning system of the chlorosilane purification filter further includes: a cleaning agent circulation pump, which is arranged between the cleaning agent circulation tank outlet and the first inlet of the filter, the cleaning agent circulation pump inlet is connected to the cleaning agent circulation tank outlet, and the cleaning agent circulation pump outlet is connected to the first inlet of the filter.

[0012] Preferably, the cleaning agent circulation tank further comprises a cleaning agent circulation tank fourth inlet arranged on the cleaning agent circulation tank body, and the cleaning agent circulation pump outlet is also connected to the cleaning agent circulation tank fourth inlet.

[0013] Preferably, the cleaning system of the chlorosilane purification filter further comprises: a waste cleaning liquid outlet, which is arranged on the connecting pipe between the outlet of the cleaning agent circulation pump and the first inlet of the filter.

[0014] Preferably, the first inlet of the filter is arranged at the top of the filter body;

[0015] The first outlet of the filter is arranged at the bottom of the filter body;

[0016] The second filter outlet is arranged on the side of the filter body.

[0017] The present invention also provides a method for cleaning a filter using the cleaning system of the chlorosilane purification filter, comprising the following steps:

[0018] Adding alkali and ethanol into the cleaning agent circulation tank to form an alkaline solution;

[0019] Add the alkaline solution in the cleaning agent circulation tank into the filter for backwashing. The alkaline solution decomposes the siloxane in the filter to generate sodium silicate and peel off the filter element.

[0020] Passing a portion of the washing liquid in the filter into a gas-liquid separator for gas-liquid separation to obtain separated liquid phase separation products and gas phase separation products;

[0021] The gas phase separation product is passed into a water seal tank, through which water is sealed and waste gas is discharged;

[0022] Passing the liquid phase separation into the cleaning agent circulation tank;

[0023] Pass the remaining washing liquid in the filter into the cleaning agent circulation tank.

[0024] Preferably, the base is sodium hydroxide and / or potassium hydroxide.

[0025] Preferably, the mass percentage concentration of the alkaline solution is 25% to 32%.

[0026] Preferably, the temperature of the alkaline solution is 25 to 30°C.

[0027] Preferably, during cleaning, the filtration speed of the filter in the backwashing stage is 0.10 to 0.15 m / min, and the filtration pressure is 0.2 to 0.5 MPa (G).

[0028] Compared with the existing filter cleaning method, the cleaning system of the chlorosilane purification filter and the method for cleaning the filter in the present invention have the following beneficial effects:

[0029] (1) The overall cleaning of the filter is realized. It is necessary to clean the filter by simply putting the spare equipment into use (or reducing the load for a short time) and removing the target filter. There is no need to stop the operation, thus ensuring the continuity of production.

[0030] (2) Good cleaning effect and high efficiency. The cleaning agent can degrade all the colloids on the filter element surface and in the filter element micropores in just 5-8 hours. After simple treatment, the filter can be put into operation again, and the working hours are only about 1 / 5 of that of replacing the filter element.

[0031] (3) The cleaning process is highly automated and has low maintenance costs. The filter element can be restored to its original filtering capacity after cleaning, without the need to purchase and install new filter elements, which greatly reduces manual operation and maintenance costs.

[0032] (4) The overall cleaning system has a simple and compact structure and is easy to install and maintain.

[0033] (5) The cleaning agent is simple to configure, cheap, and has the advantages of good applicability, environmental protection, and high compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of the structure of the filter in Example 2 of the present invention;

[0035] Figure 2 is a schematic diagram of the structure of the filter in Example 2 of the present invention;

[0036] Figure 3 It is a structural schematic diagram of the cleaning system of the chlorosilane purification filter in Example 2 of the present invention.

[0037] In the figure: 1-filter body; 2-first inlet of the filter; 3-second inlet of the filter; 4-third inlet of the filter; 5-first outlet of the filter; 6-second outlet of the filter; 7-pressure gauge port; 8-filter element; 9-flower plate; 10-cleaning agent circulation tank body; 11-first inlet of the cleaning agent circulation tank; 12-second inlet of the cleaning agent circulation tank; 13-third inlet of the cleaning agent circulation tank; 14-cleaning agent circulation tank outlet; 15-gas-liquid separator body; 16-gas-liquid separator inlet; 17-first outlet of the gas-liquid separator; 18-second outlet of the gas-liquid separator; 19-water seal tank; 20-cleaning agent circulation pump; 21-fourth inlet of the cleaning agent circulation tank; 22-waste cleaning liquid outlet. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0039] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] In the description of this patent, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent.

[0041] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0042] Example 1

[0043] This embodiment provides a cleaning system for a chlorosilane purification filter, comprising:

[0044] The filter comprises a filter body, a first filter inlet, a first filter outlet and a second filter outlet arranged on the filter body;

[0045] The cleaning agent circulation tank comprises a cleaning agent circulation tank body, a first cleaning agent circulation tank inlet, a second cleaning agent circulation tank inlet, a third cleaning agent circulation tank inlet and a cleaning agent circulation tank outlet arranged on the cleaning agent circulation tank body, wherein the first cleaning agent circulation tank inlet is connected to the first filter outlet, the second cleaning agent circulation tank inlet is used to introduce alkali and ethanol to form an alkaline solution, the cleaning agent circulation tank outlet is connected to the first filter inlet, the alkaline solution in the cleaning agent circulation tank enters the filter through the first filter inlet for backwashing, and the alkaline solution decomposes the siloxane in the filter and peels off the filter element;

[0046] The gas-liquid separator comprises a gas-liquid separator body, a gas-liquid separator inlet arranged on the gas-liquid separator body, a first gas-liquid separator outlet, and a second gas-liquid separator outlet, wherein the gas-liquid separator inlet is connected to the second filter outlet, the first gas-liquid separator outlet is connected to the third inlet of the cleaning agent circulation tank, the first gas-liquid separator outlet is used to discharge gas phase separation, and the second gas-liquid separator outlet is used to discharge liquid phase separation;

[0047] The water seal tank is connected to the second outlet of the gas-liquid separator and is used for water sealing and exhausting waste gas.

[0048] This embodiment also provides a method for cleaning a filter using the above-mentioned cleaning system for the chlorosilane purification filter, comprising the following steps:

[0049] Adding alkali and ethanol into the cleaning agent circulation tank to form an alkaline solution;

[0050] Add the alkaline solution in the cleaning agent circulation tank into the filter for backwashing. The alkaline solution decomposes the siloxane in the filter and peels off the filter element.

[0051] Passing a portion of the washing liquid in the filter into a gas-liquid separator for gas-liquid separation to obtain separated liquid phase separation products and gas phase separation products;

[0052] The gas phase separation product is passed into a water seal tank, through which water is sealed and waste gas is discharged;

[0053] Passing the liquid phase separation into the cleaning agent circulation tank;

[0054] Pass the remaining washing liquid in the filter into the cleaning agent circulation tank.

[0055] Compared with the existing filter cleaning method, the cleaning system of the chlorosilane purification filter and the method for cleaning the filter in this embodiment have the following beneficial effects:

[0056] (1) The overall cleaning of the filter is realized. It is necessary to clean the filter by simply putting the spare equipment into use (or reducing the load for a short time) and removing the target filter. There is no need to stop the operation, thus ensuring the continuity of production.

[0057] (2) Good cleaning effect and high efficiency. The cleaning agent can degrade all the colloids on the filter element surface and in the filter element micropores in just 5-8 hours. After simple treatment, the filter can be put into operation again, and the working hours are only about 1 / 5 of that of replacing the filter element.

[0058] (3) The cleaning process is highly automated and has low maintenance costs. The filter element can be restored to its original filtering capacity after cleaning, without the need to purchase and install new filter elements, which greatly reduces manual operation and maintenance costs.

[0059] (4) The overall cleaning system has a simple and compact structure and is easy to install and maintain.

[0060] (5) The cleaning agent is simple to configure, cheap, and has the advantages of good applicability, environmental protection, and high compatibility.

[0061] Example 2

[0062] like Figure 3 As shown, this embodiment provides a cleaning system for a chlorosilane purification filter, comprising:

[0063] The filter comprises a filter body 1, a first filter inlet 2, a second filter inlet 3, a third filter inlet 4, a first filter outlet 5, and a second filter outlet 6, the second filter inlet 3 being used for introducing nitrogen, and the third filter inlet 4 being used for back-blowing nitrogen;

[0064] The cleaning agent circulation tank comprises a cleaning agent circulation tank body 10, a first cleaning agent circulation tank inlet 11, a second cleaning agent circulation tank inlet 12, a third cleaning agent circulation tank inlet 13, and a cleaning agent circulation tank outlet 14, wherein the first cleaning agent circulation tank inlet 11 is connected to the first filter outlet 5, the second cleaning agent circulation tank inlet 12 is used to introduce alkali and ethanol to form an alkaline solution, and the cleaning agent circulation tank outlet 14 is connected to the first filter inlet 2, and the alkaline solution in the cleaning agent circulation tank enters the filter through the first filter inlet 2 for backwashing, and the alkaline solution decomposes the siloxane in the filter to generate sodium silicate and peel off the filter element 8;

[0065] The gas-liquid separator comprises a gas-liquid separator body 15, a gas-liquid separator inlet 16 disposed on the gas-liquid separator body 15, a first gas-liquid separator outlet 17, and a second gas-liquid separator outlet 18, wherein the gas-liquid separator inlet 16 is connected to the second filter outlet 6, the first gas-liquid separator outlet 17 is connected to the third inlet 13 of the cleaning agent circulation tank, the first gas-liquid separator outlet 17 is used to discharge gas phase separations, and the second gas-liquid separator outlet 18 is used to discharge liquid phase separations;

[0066] The water seal tank 19 is connected to the second outlet 18 of the gas-liquid separator, and is used for water sealing and exhausting waste gas.

[0067] Preferably, the cleaning system of the chlorosilane purification filter further includes: a cleaning agent circulation pump 20, which is arranged between the cleaning agent circulation tank outlet 14 and the first inlet 2 of the filter, the inlet of the cleaning agent circulation pump 20 is connected to the cleaning agent circulation tank outlet 14, and the outlet of the cleaning agent circulation pump 20 is connected to the first inlet 2 of the filter.

[0068] Preferably, the cleaning agent circulation tank further comprises a cleaning agent circulation tank fourth inlet 21 arranged on the cleaning agent circulation tank body 10 , and the cleaning agent circulation pump 20 outlet is also connected to the cleaning agent circulation tank fourth inlet 21 .

[0069] Preferably, the cleaning system of the chlorosilane purification filter further comprises: a waste cleaning liquid outlet 22, which is arranged on the connecting pipe between the outlet of the cleaning agent circulation pump 20 and the first inlet 2 of the filter.

[0070] Preferably, the first filter inlet 2 is arranged at the top of the filter body 1;

[0071] The first filter outlet 5 is arranged at the bottom of the filter body 1;

[0072] The second filter outlet 6 is arranged on the side of the filter body 1 .

[0073] Specifically, the cleaning system of the chlorosilane purification filter in this embodiment is a chlorosilane purification integral heterogeneous separation filtration equipment cleaning system.

[0074] Specifically, in the filter body 1 of the present embodiment, a flower plate 9 and a filter element 8 are arranged in the filter body 1. The flower plate 9 is arranged on the filter element 8, and the filter body 1 is cylindrical.

[0075] The first inlet 2 of the filter is the N2 port, the second inlet 3 of the filter is the N5 port, the third inlet 4 of the filter is the N6 port, the first outlet 5 of the filter is the N3 port, the second outlet 6 of the filter is the N1 port, and the filter also includes the N4 port arranged on the filter body 1.

[0076] like Figure 1 , 2 As shown, when the filter is used for filtration, port N1 is the material inlet, port N2 is the fluid phase outlet, port N3 is the slag discharge port, port N4 is the pressure gauge port 7, and ports N5 and N6 are both nitrogen inlets.

[0077] This embodiment also provides a method for cleaning a filter using the above-mentioned cleaning system for the chlorosilane purification filter, comprising the following steps:

[0078] Adding alkali and ethanol into the cleaning agent circulation tank to form an alkaline solution;

[0079] Add the alkaline solution in the cleaning agent circulation tank into the filter for backwashing. The alkaline solution decomposes the siloxane in the filter to generate sodium silicate and peel off the filter element 8;

[0080] Passing a portion of the washing liquid in the filter into a gas-liquid separator for gas-liquid separation to obtain separated liquid phase separation products and gas phase separation products;

[0081] The gas phase separation product is passed into the water seal tank 19, and the water seal is performed through the water seal tank 19 and the waste gas is discharged;

[0082] Passing the liquid phase separation into the cleaning agent circulation tank;

[0083] Pass the remaining washing liquid in the filter into the cleaning agent circulation tank.

[0084] Preferably, the base is sodium hydroxide and / or potassium hydroxide.

[0085] Specifically, the base in this embodiment is potassium hydroxide.

[0086] Preferably, the mass percentage concentration of the alkaline solution is 25% to 32%. The alkaline solution is used as a detergent, and the tank volume of the cleaning agent circulation tank is tested based on a 10-min residence time.

[0087] Specifically, the mass percentage concentration of the alkaline solution in this embodiment is 30%.

[0088] Preferably, the temperature of the alkaline solution is 25 to 30°C.

[0089] Specifically, the temperature of the alkaline solution in this embodiment is 28°C.

[0090] Preferably, during cleaning, the filtration speed of the filter in the backwashing stage is 0.10 to 0.15 m / min, and the filtration pressure is 0.2 to 0.5 MPa (G).

[0091] Specifically, in the present embodiment, the filtration speed of the filter during the backwashing stage is 0.12 m / min, and the filtration pressure is 0.5 MPa (G).

[0092] In the process of chlorosilane synthesis, it is inevitable to use water-containing materials, or due to reasons such as heat exchanger leakage, chlorosilane hydrolysis and polycondensation produce a large amount of colloidal siloxane. Such chemical substances work together with inorganic micropowders (Si powder, Cu, Fe, Al and other inorganic chlorides) that are not completely separated to form a colloid with strong adhesion. As the ceramic filter is used for a longer time, a layer of gel layer of varying thickness is formed on the surface of the filter (gel formation). In severe cases, even part of the gel will penetrate into the micropores of the filter, increasing the degree of blockage of the filter element 8, causing the filter resistance to continue to increase and forcing it to be removed for maintenance, thereby affecting production efficiency and product quality.

[0093] By using the catalytic and dissolving effects of alkaline cleaning agents (alkali causes Si-O, Si-H, Si-Si bonds to break), the siloxane attached to the surface of the filter element 8 or embedded in the micropores of the filter element 8 is decomposed into small molecules and peeled off from the inner and outer surfaces of the filter element 8 until it is dissolved in the ethanol solution, thereby finally cleaning the filter element 8 for reuse. Furthermore, the filter can be operated safely and efficiently.

[0094] Specifically, the method for cleaning the filter using the cleaning system of the chlorosilane purification filter in this embodiment is as follows:

[0095] (1) Before the system is put into use, first close the root valves of the N1, N2, and N3 ports connecting the filter to the pipe network and effectively isolate them. The N1 port is the second outlet 6 of the filter, the N2 port is the first inlet 2 of the filter, and the N3 port is the first outlet 5 of the filter;

[0096] (2) Connect the N1, N2, and N3 ports of the target filter to the N1', N2', and N3' ports of the cleaning skid (including: cleaning agent circulation tank, cleaning agent circulation pump 20, gas-liquid separator, and water seal tank 19) through flexible connections, and add a certain amount of alkaline solution cleaning agent into the cleaning agent circulation tank in proportion after passing the air tightness test;

[0097] (3) Start the cleaning agent circulation pump 20, inject the alkaline solution cleaning agent from the filter N2 port (the first filter inlet 2), and circulate the cleaning agent in the filter through the cleaning agent circulation pump 20.

[0098] (4) The cleaning agent is extracted through the filter N1 port (filter second outlet 6) and enters the gas-liquid separator. The separated liquid flows back to the cleaning agent circulation tank from the bottom, and the gas phase is discharged into the atmosphere through the water seal tank 19.

[0099] (5) After cleaning is completed, the cleaning agent circulation pump 20 is turned off, the filter bottom outlet N3 (filter first outlet 5) is opened, and the residual liquid is discharged into the cleaning agent circulation tank at one time.

[0100] (6) After purging the inside of the filter with nitrogen, restore the original connection of the filter pipeline for standby use.

[0101] Before cleaning, the appropriate filtration rate must be selected by adjusting the flow rate of the solvent circulation pump according to the filter area. Cleaning requires adjusting parameters such as the flow rate, pressure and temperature of the cleaning agent so that the cleaning agent can fully contact the filter element 8 and clean out impurities such as siloxane attached to it.

[0102] The cleaning system of the chlorosilane purification filter and the method for cleaning the filter in this embodiment achieve the following two technical improvements:

[0103] 1) Selection of efficient cleaning agent

[0104] The cleaning agent can quickly decompose siloxane and peel the silicone gel on the surface of the filter element 8 and in the micropores from the filter element 8 matrix. It also meets the requirements of small dosage, low toxicity, low cost, etc.

[0105] 2) Cleaning system design

[0106] The cleaning system adopts skid-mounted and modular design. Before use, it can be quickly connected in series with the isolated filter to achieve overall cleaning, and the waste gas generated by the system can be safely discharged to the outside after being safely sealed with water. It can solve many problems that restrict the stable operation of the existing system, improve the system operation efficiency, and reduce the operation cost.

[0107] The cleaning system of the chlorosilane purification filter and the method for cleaning the filter in this embodiment are specifically improved as follows:

[0108] (1) Cleaning agent preparation and performance requirements

[0109] The cleaning agent is a mixture of industrial solid alkali (preferably KOH) and ethanol. Before use, the solid alkali is added to the ethanol in a preset ratio, and the solid alkali is dissolved in the ethanol solution by mechanical stirring to form a solution with a mass percentage concentration of w=25% to 32%.

[0110] To ensure the cleaning effect of the cleaning agent, the solution should be prepared to prevent external moisture from entering to reduce the solution concentration, and the solution temperature should be controlled at 25-30°C during use.

[0111] (2) Filter cleaning technology solution

[0112] The system includes a filter body 1, a cleaning liquid circulation, an exhaust gas emission, an automatic control system, and a public engineering system.

[0113] The filter body 1 is located in the original device and is connected to the cleaning skid through a pipeline. The cleaning liquid circulation system is used to inject alkaline cleaning agent into the filter and maintain the cleaning agent circulating in the filter to achieve the cleaning effect. The control system is used to control the start and stop of the entire cleaning process, and monitor and control parameters such as the flow and pressure of the cleaning agent. The utility system provides inert gas for purging and replacement when the system is started and stopped (relying on the original device).

[0114] In order to achieve a better cleaning effect, the filter adopts reverse cleaning, that is, the cleaning agent enters from the top of the filter after being pressurized by the circulation pump. The cleaning agent flowing through the filter is introduced from the side of the filter body 1 (the raw material inlet) to the gas-liquid separator located at the top of the filter. The liquid returns to the cleaning agent circulation tank from the bottom of the gas-liquid separator, and the waste gas is discharged outside the boundary through the water seal tank 19.

[0115] (3) System security design

[0116] Since there are certain amounts of compounds containing Si-H and Si-Si bonds in the hydrolysis of chlorosilane to varying degrees, such compounds will hydrolyze and release hydrogen under strong alkaline conditions, thus affecting the safe operation of the system to a certain extent. In order to eliminate such hidden dangers, a gas-liquid separator is connected in series after the filter to separate hydrogen from the cleaning agent and then safely discharged through the explosion-proof water seal in the water seal tank 19.

[0117] Compared with the existing filter cleaning method, the cleaning system of the chlorosilane purification filter and the method for cleaning the filter in this embodiment have the following beneficial effects:

[0118] (1) The overall cleaning of the filter is realized. It is necessary to clean the filter by simply putting the spare equipment into use (or reducing the load for a short time) and removing the target filter. There is no need to stop the operation, thus ensuring the continuity of production.

[0119] (2) Good cleaning effect and high efficiency. The cleaning agent can degrade all the colloids on the surface of the filter element 8 and in the micropores of the filter element 8 in just 5-8 hours. After a simple treatment, the filter can be put into operation again, and the working hours are only about 1 / 5 of that of replacing the filter element 8.

[0120] (3) The cleaning process is highly automated and has low maintenance costs. The filter element 8 can be restored to its original filtering capacity after cleaning, and there is no need to purchase or install a new filter element 8, which greatly reduces manual operation and maintenance costs.

[0121] (4) The overall cleaning system has a simple and compact structure and is easy to install and maintain.

[0122] (5) The cleaning agent is simple to configure, cheap, and has the advantages of good applicability, environmental protection, and high compatibility.

[0123] Example 3

[0124] This embodiment provides a method for cleaning a filter using the cleaning system of the chlorosilane purification filter in Embodiment 2, which is different from the method in Embodiment 2 in that:

[0125] The alkali in this embodiment is sodium hydroxide.

[0126] The mass percentage concentration of the alkaline solution in this embodiment is 32%.

[0127] The temperature of the alkaline solution in this embodiment is 25°C.

[0128] In this embodiment, the filtration speed of the filter in the backwash stage is 0.10 m / min, and the filtration pressure is 0.35 MPa (G).

[0129] Compared with the existing filter cleaning method, the cleaning system of the chlorosilane purification filter and the method for cleaning the filter in this embodiment have the following beneficial effects:

[0130] (1) The overall cleaning of the filter is realized. It is necessary to clean the filter by simply putting the spare equipment into use (or reducing the load for a short time) and removing the target filter. There is no need to stop the operation, thus ensuring the continuity of production.

[0131] (2) Good cleaning effect and high efficiency. The cleaning agent can degrade all the colloids on the surface of the filter element 8 and in the micropores of the filter element 8 in just 5-8 hours. After a simple treatment, the filter can be put into operation again, and the working hours are only about 1 / 5 of that of replacing the filter element 8.

[0132] (3) The cleaning process is highly automated and has low maintenance costs. The filter element 8 can be restored to its original filtering capacity after cleaning, and there is no need to purchase or install a new filter element 8, which greatly reduces manual operation and maintenance costs.

[0133] (4) The overall cleaning system has a simple and compact structure and is easy to install and maintain.

[0134] (5) The cleaning agent is simple to configure, cheap, and has the advantages of good applicability, environmental protection, and high compatibility.

[0135] Example 4

[0136] This embodiment provides a method for cleaning a filter using the cleaning system of the chlorosilane purification filter in Embodiment 2, which is different from the method in Embodiment 2 in that:

[0137] The alkali in this embodiment is sodium hydroxide and potassium hydroxide (mass ratio is 1:1).

[0138] The mass percent concentration of the alkaline solution in this embodiment is 25%.

[0139] The temperature of the alkaline solution in this embodiment is 30°C.

[0140] In this embodiment, the filtration speed of the filter during the backwashing stage is 0.15 m / min, and the filtration pressure is 0.2 MPa (G).

[0141] Compared with the existing filter cleaning method, the cleaning system of the chlorosilane purification filter and the method for cleaning the filter in this embodiment have the following beneficial effects:

[0142] (1) The overall cleaning of the filter is realized. It is necessary to clean the filter by simply putting the spare equipment into use (or reducing the load for a short time) and removing the target filter. There is no need to stop the operation, thus ensuring the continuity of production.

[0143] (2) Good cleaning effect and high efficiency. The cleaning agent can degrade all the colloids on the surface of the filter element 8 and in the micropores of the filter element 8 in just 5-8 hours. After a simple treatment, the filter can be put into operation again, and the working hours are only about 1 / 5 of that of replacing the filter element 8.

[0144] (3) The cleaning process is highly automated and has low maintenance costs. The filter element 8 can be restored to its original filtering capacity after cleaning, and there is no need to purchase or install a new filter element 8, which greatly reduces manual operation and maintenance costs.

[0145] (4) The overall cleaning system has a simple and compact structure and is easy to install and maintain.

[0146] (5) The cleaning agent is simple to configure, cheap, and has the advantages of good applicability, environmental protection, and high compatibility.

[0147] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A cleaning system for a chlorosilane purification filter, characterized in that: include: The filter comprises a filter body, a first filter inlet, a first filter outlet and a second filter outlet arranged on the filter body; The cleaning agent circulation tank comprises a cleaning agent circulation tank body, a first cleaning agent circulation tank inlet, a second cleaning agent circulation tank inlet, a third cleaning agent circulation tank inlet and a cleaning agent circulation tank outlet arranged on the cleaning agent circulation tank body, wherein the first cleaning agent circulation tank inlet is connected to the first filter outlet, the second cleaning agent circulation tank inlet is used to introduce alkali and ethanol to form an alkaline solution, the cleaning agent circulation tank outlet is connected to the first filter inlet, the alkaline solution in the cleaning agent circulation tank enters the filter through the first filter inlet for backwashing, and the alkaline solution decomposes the siloxane in the filter and peels off the filter element; The gas-liquid separator comprises a gas-liquid separator body, a gas-liquid separator inlet arranged on the gas-liquid separator body, a first gas-liquid separator outlet, and a second gas-liquid separator outlet, wherein the gas-liquid separator inlet is connected to the second filter outlet, the first gas-liquid separator outlet is connected to the third inlet of the cleaning agent circulation tank, the first gas-liquid separator outlet is used to discharge gas phase separation, and the second gas-liquid separator outlet is used to discharge liquid phase separation; The water seal tank is connected to the second outlet of the gas-liquid separator and is used for water sealing and exhausting waste gas.

2. The cleaning system for chlorosilane purification filter according to claim 1, characterized in that: Also includes: The cleaning agent circulation pump is arranged between the cleaning agent circulation tank outlet and the first filter inlet, the cleaning agent circulation pump inlet is connected to the cleaning agent circulation tank outlet, and the cleaning agent circulation pump outlet is connected to the first filter inlet.

3. The cleaning system for chlorosilane purification filter according to claim 2, characterized in that: The cleaning agent circulation tank also includes a cleaning agent circulation tank fourth inlet arranged on the cleaning agent circulation tank body, and the cleaning agent circulation pump outlet is also connected to the cleaning agent circulation tank fourth inlet.

4. The cleaning system for chlorosilane purification filter according to claim 2, characterized in that: Also includes: The waste cleaning liquid outlet is arranged on the connecting pipe between the outlet of the cleaning agent circulation pump and the first inlet of the filter.

5. The cleaning system for chlorosilane purification filter according to claim 1, characterized in that: The first inlet of the filter is arranged at the top of the filter body; The first outlet of the filter is arranged at the bottom of the filter body; The second filter outlet is arranged on the side of the filter body.

6. A method for cleaning a filter using the cleaning system for a chlorosilane purification filter according to any one of claims 1 to 5, characterized in that: The following steps are involved: Adding alkali and ethanol into the cleaning agent circulation tank to form an alkaline solution; Add the alkaline solution in the cleaning agent circulation tank into the filter for backwashing. The alkaline solution decomposes the siloxane in the filter and peels off the filter element. Passing a portion of the washing liquid in the filter into a gas-liquid separator for gas-liquid separation to obtain separated liquid phase separation products and gas phase separation products; The gas phase separation product is passed into a water seal tank, through which water is sealed and waste gas is discharged; Passing the liquid phase separation into the cleaning agent circulation tank; Pass the remaining washing liquid in the filter into the cleaning agent circulation tank.

7. The method for cleaning a filter according to claim 6, characterized in that: The base is sodium hydroxide and / or potassium hydroxide.

8. The method for cleaning a filter according to claim 6, characterized in that: The mass percentage concentration of the alkaline solution is 25% to 32%.

9. The method for cleaning a filter according to claim 6, characterized in that: The temperature of the alkaline solution is 25-30°C.

10. The method for cleaning a filter according to claim 6, characterized in that: During cleaning, the filtration speed of the filter in the backwash stage is 0.10-0.15 m / min, and the filtration pressure is 0.2-0.5 MPa (G).

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