System for discharging anti-disproportionated resin and boron-phosphorus adsorption resin by utilizing vacuum replacement

Abstract

The invention discloses a system for discharging anti-disproportionated resin and boron-phosphorus adsorption resin by utilizing vacuum replacement, which comprises a resin column, a discharging pipeline connected to the upper part of the resin column, a replacement device, a vacuum recovery device and a sampling device communicated with the discharging pipeline, and a resin discharging device connected to the lower part of the resin column, the nitrogen pressurizing device is communicated with the upper part and the lower part of the resin column; the replacement device comprises a first replacement pipeline communicated with the discharge pipeline, a silicon tetrachloride collection tank connected to the first replacement pipeline, and a second replacement pipeline connected to a discharge hole in the lower part of the resin column and the silicon tetrachloride collection tank; the vacuum recovery device comprises a third replacement pipeline communicated with the discharging pipeline, a first valve body installed on the third replacement pipeline, a vacuum pump connected to the third replacement pipeline and a condensation recoverer. The efficiency and safety of replacing and discharging the anti-disproportionated resin and the boron-phosphorus adsorption resin can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of polysilicon production equipment, and in particular, relates to a system for unloading anti-disproportionated resin and boron-phosphorus adsorption resin by vacuum displacement. Background Art

[0002] Polysilicon is a high-purity silicon material widely used in solar cells, semiconductor devices and the electronics industry. The synthesis of trichlorosilane is the first step in the production of polysilicon. In order to achieve the high purity standard required for the production of polysilicon, the synthesized trichlorosilane needs to be distilled and purified to remove impurities. However, distillation technology cannot completely separate the impurities in trichlorosilane. For example, trace impurities such as boron and phosphorus need to be adsorbed by boron-phosphorus adsorption resins, and the by-product dichlorosilane in the production process needs to be removed by deprotonation resins.

[0003] As a widely used separation and purification technology, resin adsorption is highly efficient and widely applicable, but its adsorption capacity is limited by the resin capacity. When the adsorption reaches saturation, the resin needs to be regenerated or replaced. The larger the capacity of the resin adsorption and anti-disproportionation device, the more complicated the replacement process before unloading the resin, the lower the replacement efficiency, and there may also be safety risks caused by incomplete replacement. For example, when using nitrogen replacement, resin combustion is likely to occur during the resin discharge stage.

[0004] Therefore, improving the efficiency and safety of replacement and discharge of anti-disproportionate resins and boron-phosphorus adsorption resins is of great significance to promoting the sustainable and healthy development of the photovoltaic industry. Summary of the invention

[0005] The purpose of the present application is to provide a system for discharging anti-disproportionate resin and boron-phosphorus adsorption resin by vacuum displacement, so as to improve the efficiency and safety of discharging anti-disproportionate resin and boron-phosphorus adsorption resin by vacuum displacement.

[0006] In order to achieve the above-mentioned technical effect, the present application provides a system for unloading anti-disproportionated resin and boron-phosphorus adsorption resin by vacuum displacement, comprising: a resin column, a discharge pipe connected to the upper part of the resin column, a displacement device connected to the discharge pipe, a vacuum recovery device and a sampling device, a resin unloading device connected to the lower part of the resin column, and a nitrogen pressurizing device connected to the upper and lower parts of the resin column; the displacement device comprises: a first displacement pipe connected to the discharge pipe, a silicon tetrachloride collection tank connected to the first displacement pipe, and a second displacement pipe connected to the lower discharge port of the resin column and the silicon tetrachloride collection tank; the vacuum recovery device comprises: a third displacement pipe connected to the discharge pipe, a first valve body installed on the third displacement pipe, a vacuum pump connected to the third displacement pipe, and a condensation recovery device.

[0007] The scheme provided by the application is input by silicon tetrachloride through the feed port of resin column, and the adsorbate (such as trichlorosilane, dichlorosilane, boron and phosphorus, etc.) on the resin column is replaced. After the replacement is completed, the pressure in the resin column is reduced by the vacuum recovery device connected to the resin column, thereby reducing the boiling point of silicon tetrachloride in the resin column, so that silicon tetrachloride is evaporated and extracted to the condensation recovery device by the vacuum pump for recovery. And the resin in the resin column is input to the resin discharge device for discharge. The scheme provided by the application is also pressurized by arranging a nitrogen pressure device to the resin column of negative pressure state, and the efficiency of silicon tetrachloride release is higher by repeatedly negative pressure and pressurization process. Compared with traditional long-cycle nitrogen replacement system, the scheme of the application can effectively reduce the usage and replacement time of nitrogen, improve the efficiency and safety of replacement and discharge of anti-disproportionation resin and boron phosphorus adsorption resin.

[0008] As an improvement of the above-mentioned nitrogen pressurizing device in the present application, the nitrogen pressurizing device includes: a first nitrogen pipeline connected to the discharge pipeline, a second nitrogen pipeline connected to the second replacement pipeline, and a second valve body and a third valve body respectively installed on the first nitrogen pipeline and the second nitrogen pipeline.

[0009] As an improvement of the technical solution of the present application, the system for unloading the anti-disproportionated resin and the boron-phosphorus adsorption resin by vacuum displacement also includes: a pressure interlocking device connected to the resin column, the pressure interlocking device includes a pressure gauge and an automatic control valve connected to the resin column, and the automatic control valve includes the first valve body and the third valve body.

[0010] As an improvement of the above-mentioned resin unloading device in the present application, the resin unloading device includes: a hydrolysis tank, a resin unloading pipe with one end connected to the lower part of the resin column and the other end passing into the bottom of the hydrolysis tank, and a plate and frame filter press connected to the discharge port at the lower part of the hydrolysis tank, and a plate and frame filter press pump is connected between the hydrolysis tank and the plate and frame filter press.

[0011] The solution provided in the present application is to guide the resin out from the bottom of the resin column and transport it to the bottom of the hydrolysis tank through a resin discharge pipe for hydrolysis, and then separate the hydrolyzed resin solids and water through a plate and frame filter press, and retain the resin solids in the plate and frame for recovery, thereby achieving efficient, safe and environmentally friendly treatment of the resin and reducing environmental pollution and production costs.

[0012] As an improvement of the above-mentioned hydrolysis tank in the present application, an exhaust pipe is connected to the upper part of the hydrolysis tank.

[0013] As an improvement of the above-mentioned hydrolysis tank in the present application, a water replenishment pipe and a filtrate return pipe are also connected to the upper part of the hydrolysis tank, and the other end of the filtrate return pipe is connected to the liquid outlet of the plate and frame filter press.

[0014] As an improvement of the above-mentioned hydrolysis tank in the present application, a liquid alkali input pipe is also connected to the upper part of the hydrolysis tank.

[0015] As an improvement of the technical solution of the present application, the system for unloading the anti-disproportionation resin and the boron-phosphorus adsorption resin by vacuum displacement also includes: an exhaust gas emission pipeline connected to the discharge pipeline and an exhaust gas treatment device connected to the exhaust gas emission pipeline.

[0016] As an improvement of the technical solution of the present application, valve bodies are installed on each connecting pipeline in the discharge pipeline, the replacement device, the vacuum recovery device, the sampling device, the resin unloading device and the nitrogen pressurizing device.

[0017] The beneficial effects of this application are:

[0018] 1. The scheme provided by the application is that silicon tetrachloride is input through the feed port of resin column, and the adsorbate (such as trichlorosilane, dichlorosilane, boron and phosphorus, etc.) on the resin column is replaced. After the replacement is completed, the pressure in the resin column is reduced by the vacuum recovery device connected to the resin column, thereby reducing the boiling point of silicon tetrachloride in the resin column, and silicon tetrachloride is extracted to the condensation recovery device by the vacuum pump after evaporation for recovery. And the resin in the resin column is input to the resin discharge device for discharge. The scheme provided by the application is also pressurized by arranging a nitrogen pressure device to the resin column of negative pressure state, and the efficiency of silicon tetrachloride release is higher by multiple negative pressure and pressurization processes. Compared with traditional long-cycle nitrogen replacement system, the scheme of the application can effectively reduce the usage and replacement time of nitrogen, and improve the efficiency and safety of replacement and discharge of anti-disproportionation resin and boron phosphorus adsorption resin.

[0019] 2. The solution provided in the present application is to guide the resin out from the bottom of the resin column and transport it to the bottom of the hydrolysis tank through a resin discharge pipe for hydrolysis, and then separate the hydrolyzed resin solids and water through a plate and frame filter press, and retain the resin solids in the plate and frame for recovery, thereby achieving efficient, safe and environmentally friendly treatment of the resin, reducing environmental pollution and production costs.

[0020] The structure of the present application and its other inventive objectives and beneficial effects will be more clearly understood through the description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1It is a connection diagram of a system for unloading anti-disproportionation resin and boron-phosphorus adsorption resin by vacuum displacement in an embodiment of the present application.

[0023] Description of reference numerals:

[0024] 1. Resin column; 11. Feed inlet; 2. Discharge pipeline; 21. Tail gas emission pipeline; 3. Replacement device; 31. First replacement pipeline; 32. Silicon tetrachloride collection tank; 33. Second replacement pipeline; 4. Vacuum recovery device; 41. Third replacement pipeline; 42. First valve body; 43. Vacuum pump; 44. Condensate recovery device; 5. Sampling device; 6. Resin discharge device; 61. Hydrolysis tank; 62. Resin discharge pipe; 63. Plate and frame filter press; 64. Plate and frame filter press pump; 65. Exhaust pipe; 66. Water supply pipe; 67. Filtrate return pipe; 68. Liquid alkali input pipe; 7. Nitrogen pressurizing device; 71. First nitrogen pipeline; 72. Second nitrogen pipeline; 73. Second valve body; 74. Third valve body; 8. Pressure interlock device; 81. Pressure gauge; 82. Automatic control valve; 9. Tail gas treatment device. DETAILED DESCRIPTION

[0025] The embodiments of the technical solution of the present application will be described in detail below. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] Figure 1 A schematic diagram of a system for discharging an anti-disproportionation resin and a boron-phosphorus adsorption resin by vacuum displacement provided in some embodiments of the present application. Figure 1 The system for unloading the anti-disproportionated resin and the boron-phosphorus adsorption resin by vacuum displacement shown in the figure comprises: a resin column 1, a discharge pipe 2 connected to the upper part of the resin column 1, a displacement device 3 connected to the discharge pipe 2, a vacuum recovery device 4 and a sampling device 5, a resin unloading device 6 connected to the lower part of the resin column 1, and a nitrogen pressurizing device 7 connected to the upper and lower parts of the resin column 1; the displacement device 3 comprises: a first displacement pipe 31 connected to the discharge pipe 2, a silicon tetrachloride collection tank 32 connected to the first displacement pipe 31, and a second displacement pipe 33 connected to the lower discharge port of the resin column 1 and the silicon tetrachloride collection tank 32; the vacuum recovery device 4 comprises: a third displacement pipe 41 connected to the discharge pipe 2, a first valve body 42 installed on the third displacement pipe 41, a vacuum pump 43 connected to the third displacement pipe 41, and a condensation recovery device 44.

[0027] Specifically, the resin column 1 is mainly composed of at least one of an anti-disproportionated resin and a boron-phosphorus adsorption resin. A feed port 11 for connecting a feed pipe is provided on the resin column 1, and the claim does not involve the feed port 11. The feed pipe is initially connected to a reaction vessel for synthesizing trichlorosilane. After the resin column 1 is saturated with adsorption, the feed pipe is switched to silicon tetrachloride with a purity greater than 99%, so as to replace the adsorbents (such as trichlorosilane, dichlorosilane, boron and phosphorus, etc.) on the resin column 1 with silicon tetrachloride, and discharge it through the discharge pipe 2. The sampling device 5 is used to determine whether the silicon tetrachloride replacement process is completed or not. The specific operation process is: sampling and testing from the sampling port connected to the discharge pipe 2. When the test results show that the content of trichlorosilane and dichlorosilane in the sample is low, the replacement reaction tends to end. The replacement reaction is completed when the silicon tetrachloride content in the sample is greater than 99%. When the replacement reaction is coming to an end, the discharge pipe 2 is closed, and the first replacement pipe 31 is opened, so that silicon tetrachloride and a small amount of trichlorosilane and dichlorosilane enter the silicon tetrachloride collection tank 32. When the replacement reaction is completed, the first replacement channel 31 is closed, and the second replacement channel 33 is opened, so that the silicon tetrachloride in the resin column 1 enters the silicon tetrachloride collection tank 32 through the second replacement channel 33.

[0028] The operation process of replacing the resin column 1 includes: closing the pipeline connected to the resin column 1, opening the first valve body 42 of the third replacement pipeline 41 and the vacuum pump 43 to extract negative pressure, so that the negative pressure in the resin column 1 reaches -0.08 MPa. Then close the first valve body 42, open the nitrogen pressurizing device 7 connected to the lower part of the resin column 1, pressurize the resin 1 to 0.1 MPa, and then close the nitrogen pressurizing device 7. Repeat the above-mentioned negative pressure extraction and pressurization operations to replace the resin column 1. Since the boiling point of silicon tetrachloride at room temperature is 57.6°C, the boiling point of silicon tetrachloride decreases after the negative pressure is extracted, and it is easier to volatilize. And through multiple negative pressure extraction and pressurization processes, the silicon tetrachloride adsorbed in the resin column 1 is easier to release, which is shorter than the time required for simple nitrogen replacement, and the replacement effect is better. After the silicon tetrachloride volatilizes, it is pumped to the condensation recovery device 44 by the vacuum pump 43 for condensation and recovery. It should be understood that in order to ensure the safety of the vacuum replacement process, the resin column 1 should select a pressure vessel that can withstand negative pressure. When sampling is performed from the sampling port to check that no silicon tetrachloride gas is discharged, the replacement operation is stopped and the vacuum pump 43 is turned off.

[0029] Optionally, the gas outlet of the condensation recovery device 44 can be connected to a tail gas treatment device to recover nitrogen and reduce environmental pollution.

[0030] Optionally, the vacuum pump 43 includes an oil-free Roots vacuum pump.

[0031] As can be seen from this, the scheme provided by the present application inputs silicon tetrachloride through the feed port 11 of the resin column, and the adsorbents such as trichlorosilane, dichlorosilane, boron and phosphorus on the resin column 1 are replaced. After the replacement is completed, the pressure in the resin column 1 is reduced by the vacuum recovery device 4 connected to the resin column 1, thereby reducing the boiling point of silicon tetrachloride in the resin column 1, so that silicon tetrachloride is evaporated and extracted to the condensation recovery device 44 by the vacuum pump 43 for recovery. And the resin in the resin column 1 is input to the resin discharge device 6 for discharge. The scheme provided by the present application is also pressurized by arranging the nitrogen pressurizing device 7 to the resin column 1 in the negative pressure state, and the efficiency of silicon tetrachloride release is higher by multiple negative pressure and pressurization processes. Compared with traditional long-cycle nitrogen replacement systems, the scheme of the present application can effectively reduce the usage and replacement time of nitrogen, and improve the efficiency and safety of replacement and discharge of anti-disproportionation resin and boron phosphorus adsorption resin.

[0032] Continue to view Figure 1 Based on the previous embodiment, in one implementation, the nitrogen pressurizing device 7 includes: a first nitrogen pipeline 71 connected to the discharge pipeline 2, a second nitrogen pipeline 72 connected to the second replacement pipeline 33, and a second valve body 73 and a third valve body 74 respectively installed on the first nitrogen pipeline 71 and the second nitrogen pipeline 72.

[0033] Specifically, the first nitrogen pipeline 71 and the second nitrogen pipeline 72 are both connected to the nitrogen inlet device. In order to ensure that all the silicon tetrachloride in the resin column 1 is discharged into the silicon tetrachloride collection tank 32 during replacement, the second replacement channel 32 can be pressurized through the first nitrogen pipeline 71. In addition to pressurizing the resin column 1, the second nitrogen pipeline 72 can also pressurize when the silicon tetrachloride enters the silicon tetrachloride collection tank 32 through the second replacement channel 33, thereby improving the release efficiency of the silicon tetrachloride.

[0034] Continue to view Figure 1 On the basis of the above embodiment, the system also includes: a pressure interlocking device 8 connected to the resin column 1, the pressure interlocking device 8 includes a pressure gauge 81 connected to the resin column 1 and an automatic control valve 82, and the automatic control valve 82 includes the first valve body 42 and the third valve body 74.

[0035] Specifically, since the vacuum replacement process requires repeated negative pressure extraction and pressurization operations on the resin column 1, in order to improve the efficiency and safety of the vacuum replacement process, this embodiment uses a pressure gauge 81 and an automatic control valve 82 to automatically close the first valve body 42 and open the third valve body 74 for pressurization when the negative pressure in the resin column 1 reaches -0.08 MPa; and when the negative pressure in the resin column 1 reaches 0.1 MPa, the third valve body 74 is automatically closed and the first valve body 42 is opened to perform negative pressure extraction.

[0036] Optionally, the pressure interlock device 8 can use a PLC control system to control the opening or closing of the first valve body 42 and the third valve body 74, thereby achieving a technical effect of automatic control.

[0037] Continue to view Figure 1 On the basis of the above embodiment, the system further includes: an exhaust gas emission pipeline 21 connected to the discharge pipeline 2 and an exhaust gas treatment device 9 connected to the exhaust gas emission pipeline 21 .

[0038] Specifically, the tail gas treatment device 9 is used to recover and treat the tail gas generated during the replacement process, ensuring that the system for unloading the anti-disproportionation resin and the boron-phosphorus adsorption resin by vacuum replacement meets environmental protection and safety standards.

[0039] Continue to view Figure 1 In one implementation, the resin unloading device 6 includes: a hydrolysis tank 61, a resin unloading pipe 62 with one end connected to the lower part of the resin column 1 and the other end passing into the bottom of the hydrolysis tank 61, and a plate and frame filter press 63 connected to the lower discharge port of the hydrolysis tank 61, and a plate and frame filter press pump 64 is connected between the hydrolysis tank 61 and the plate and frame filter press 63.

[0040] Specifically, the resin discharge pipe 62 is connected to the bottom of the hydrolysis tank 61 to fully hydrolyze the resin. The hydrolysis tank 61 is a container for mixing resin and water for hydrolysis reaction, which can separate the substances adsorbed on the resin and improve the recovery purity of the resin. The plate and frame filter press 63 is used to separate the resin and water. The separated resin solids can enter the solid waste storage through the discharge port of the plate and frame filter press 63 for secondary utilization.

[0041] In one implementation, a water supply pipe 66 and a filtrate return pipe 67 are further connected to the upper part of the hydrolysis tank 61, and the other end of the filtrate return pipe 67 is connected to the liquid outlet of the plate-frame filter press 63. Specifically, the water separated by the plate-frame filter press 63 can be recycled to the hydrolysis tank 61 through the filtrate return pipe 67 for reuse, thereby reducing costs.

[0042] It can be seen that the present embodiment achieves efficient, safe and environmentally friendly treatment of the resin by leading the resin out from the bottom of the resin column 1 and transporting it to the bottom of the hydrolysis tank through the resin discharge pipe 62 for hydrolysis, and then separating the hydrolyzed resin solids and water through the plate and frame filter press 63, and retaining the resin solids in the plate and frame for recovery, thereby reducing environmental pollution and production costs.

[0043] Continue to view Figure 1Based on the previous embodiment, in one implementation, an exhaust pipe 65 is connected to the upper part of the hydrolysis tank 62. Specifically, during the hydrolysis process, the volatile substances adsorbed on the resin may be released into the atmosphere to form tail gas. In order to ensure the safety of the hydrolysis reaction, the tail gas should be discharged in time through the exhaust pipe 65. Optionally, the other end of the exhaust pipe 65 can be connected to the tail gas treatment device 9 for treatment to avoid environmental pollution.

[0044] Continue to view Figure 1 In one implementation, a liquid alkali inlet pipe 68 is further connected to the upper part of the hydrolysis tank 61. Specifically, since the resin carries a small amount of silicon tetrachloride, and the hydrolysis of silicon tetrachloride produces hydrogen chloride, making the liquid in the hydrolysis tank 61 acidic, the liquid alkali inlet pipe 68 can timely neutralize the liquid in the hydrolysis tank 61 to ensure the effect of resin hydrolysis.

[0045] In order to ensure the safety of the system working process, in one implementation, valve bodies are installed on each connecting pipe in the discharge pipe 2, the replacement device 3, the vacuum recovery device 4, the sampling device 5, the resin unloading device 6 and the nitrogen pressurizing device 7.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for discharging anti-disproportionation resin and boron-phosphorus adsorption resin by vacuum displacement, characterized in that: include: A resin column (1), a discharge pipe (2) connected to the upper part of the resin column (1), a replacement device (3) connected to the discharge pipe (2), a vacuum recovery device (4) and a sampling device (5), a resin discharge device (6) connected to the lower part of the resin column (1), and a nitrogen pressurizing device (7) connected to the upper and lower parts of the resin column (1); The replacement device (3) comprises: a first replacement pipeline (31) connected to the discharge pipeline (2), a silicon tetrachloride collection tank (32) connected to the first replacement pipeline (31), and a second replacement pipeline (33) connected to the lower discharge port of the resin column (1) and the silicon tetrachloride collection tank (32); The vacuum recovery device (4) comprises: a third displacement pipeline (41) connected to the discharge pipeline (2), a first valve body (42) installed on the third displacement pipeline (41), a vacuum pump (43) connected to the third displacement pipeline (41), and a condensation recovery device (44).

2. The system according to claim 1, characterized in that The nitrogen pressurizing device (7) comprises: a first nitrogen pipeline (71) connected to the discharge pipeline (2), a second nitrogen pipeline (72) connected to the second replacement pipeline (33), and a second valve body (73) and a third valve body (74) respectively installed on the first nitrogen pipeline (71) and the second nitrogen pipeline (72).

3. The system according to claim 2, characterized in that The system further comprises: a pressure interlock device (8) connected to the resin column (1), the pressure interlock device (8) comprising a pressure gauge (81) connected to the resin column (1) and an automatic control valve (82), the automatic control valve (82) comprising the first valve body (42) and the third valve body (74).

4. The system according to claim 1, characterized in that The resin discharge device (6) comprises: a hydrolysis tank (61), a resin discharge pipe (62) one end of which is connected to the lower part of the resin column (1) and the other end of which is passed into the bottom of the hydrolysis tank (61), and a plate-frame filter press (63) connected to the discharge port at the lower part of the hydrolysis tank (61); a plate-frame filter press pump (64) is connected between the hydrolysis tank (61) and the plate-frame filter press (63).

5. The system according to claim 4, characterized in that The upper portion of the hydrolysis tank (61) is connected to an exhaust pipe (65).

6. The system according to claim 4, characterized in that The upper part of the hydrolysis tank (61) is also connected to a water replenishment pipe (66) and a filtrate return pipe (67), and the other end of the filtrate return pipe (67) is connected to the liquid outlet of the plate and frame filter press (63).

7. The system according to claim 4, characterized in that The upper part of the hydrolysis tank (61) is also connected to a liquid caustic soda input pipe (68).

8. The system of claim 1, wherein: Also includes: A tail gas discharge pipeline (21) connected to the discharge pipeline (2) and a tail gas treatment device (9) connected to the tail gas discharge pipeline (21).

9. The system according to claim 1, characterized in that Each connecting pipeline in the discharge pipeline (2), the replacement device (3), the vacuum recovery device (4), the sampling device (5), the resin discharge device (6) and the nitrogen pressurizing device (7) is installed with a valve body.

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