Polycrystalline silicon tail gas recovery system and polycrystalline silicon production system

Abstract

The utility model relates to the technical field of polycrystalline silicon production, in particular to a polycrystalline silicon tail gas recovery system and a polycrystalline silicon production system. The polycrystalline silicon tail gas recovery system comprises a tail gas input pipeline, a filter, a tail gas recovery pipeline and a condensate drain pipeline, the gas inlet end of the filter is connected with the tail gas input pipeline, the gas outlet end of the filter is connected with the tail gas recovery pipeline, one end of the condensate drain pipeline is connected to the tail gas input pipeline, and a first valve is arranged on the condensate drain pipeline. The condensate draining pipeline is additionally arranged on the tail gas input pipeline connected with the gas inlet end of the filter, and the first valve is arranged on the condensate draining pipeline, so that when accumulated liquid exists in the pipeline, the first valve can be opened, and the accumulated liquid in the tail gas input pipeline can be drained through the condensate draining pipeline, and therefore, pipeline pressure building is avoided, and the pipeline and the filter are prevented from being blocked; the cost of replacing the filter element is reduced, and long-term safe and stable operation of the system is facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of polysilicon production, and in particular to a polysilicon tail gas recovery system and a polysilicon production system. Background Art

[0002] The tail gas recovery process in the polysilicon production system mainly receives the tail gas (components H2, HCL, DCS, TCS, STC) and silicon powder produced by the reduction furnace, separates the H2, HCL and chlorosilane in the tail gas through process treatment, and supplies the purified H2 to the reduction furnace as raw material to participate in production again.

[0003] At present, the reduction tail gas pipeline in the polysilicon production system is sent to the recovery pipeline in a single pipeline or a series pipeline. During use, if there is liquid accumulation in the pipeline, it will cause pipeline pressure buildup, which will have a certain degree of impact on the reduction, and cause pressure buildup in the reduction furnace to cause interlocking, which is not conducive to the stable operation of the upstream and downstream. Moreover, in the early stage of production, the temperature of the reduction tail gas pipeline will climb, and the silane gas will condense into liquid due to the low temperature of the pipeline, forming liquid accumulation in the pipeline. The silicon powder carried by the tail gas in the subsequent reduction production process will also work with the liquid accumulation to cause the pipeline and filter to be blocked, which is not conducive to the use of the filter, increases the cost of replacing the filter element, and affects the safe and stable operation of the system. Utility Model Content

[0004] Based on this, the present application provides a polysilicon tail gas recovery system and a polysilicon production system to solve the problem of liquid accumulation in the pipeline, resulting in pipeline pressure buildup, pipeline and filter blockage, increased production costs, and affecting the safe and stable operation of the system.

[0005] On the one hand, the present application provides a polysilicon exhaust gas recovery system, including an exhaust gas input pipeline, a filter, an exhaust gas recovery pipeline and a condensate exhaust pipeline, the air inlet end of the filter is connected to the exhaust gas input pipeline, the air outlet end of the filter is connected to the exhaust gas recovery pipeline, one end of the condensate exhaust pipeline is connected to the exhaust gas input pipeline, and a first valve is provided on the condensate exhaust pipeline.

[0006] In a possible implementation, the polysilicon tail gas recovery system further includes a condensate drain tank, and the other end of the condensate drain pipeline is connected to the condensate drain tank.

[0007] In a possible implementation, the polysilicon tail gas recovery system further includes a control unit, the tail gas input pipeline is connected to a pressure device, and the control unit is respectively connected to the pressure device and the first valve.

[0008] In a possible implementation, the polysilicon tail gas recovery system further includes a liquid level meter, which is connected to the condensate discharge pipeline and is located between the first valve and the tail gas input pipeline.

[0009] In a possible implementation, the polysilicon tail gas recovery system further includes a buffer, which is disposed on the tail gas input pipeline, and one end of the condensate discharge pipeline is connected to the buffer.

[0010] In a possible implementation, the polysilicon tail gas recovery system also includes a parallel pipeline and a condenser. The condenser is arranged on the parallel pipeline. Both ends of the parallel pipeline are respectively connected to the tail gas input pipeline and are located on the side of the condensate discharge pipeline away from the filter.

[0011] In a possible implementation, the polysilicon tail gas recovery system further includes a second valve and a third valve, the second valve and the third valve are arranged on parallel pipelines, and the second valve and the third valve are respectively located on both sides of the condenser.

[0012] In a possible implementation, the polysilicon tail gas recovery system further includes a fourth valve, which is disposed on the tail gas input pipeline and located on a side of the condensate discharge pipeline away from the filter.

[0013] In a possible implementation, the first valve is a hard-sealed ball valve.

[0014] On the other hand, the present application provides a polysilicon production system, which includes the above-mentioned polysilicon tail gas recovery system.

[0015] The polysilicon tail gas recovery system and polysilicon production system provided by the present application are as follows. By adding a condensate discharge pipeline to the tail gas input pipeline connected to the air inlet end of the filter, and providing a first valve on the condensate discharge pipeline, when there is liquid accumulation in the pipeline, the first valve can be opened to discharge the liquid accumulation in the tail gas input pipeline through the condensate discharge pipeline, thereby avoiding pipeline pressure build-up, preventing pipeline and filter blockage, reducing the cost of replacing the filter element, and facilitating the long-term safe and stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. 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.

[0017] Figure 1 One of the structural schematic diagrams of the polysilicon tail gas recovery system provided in the embodiment of the present application;

[0018] Figure 2 This is the second structural schematic diagram of the polysilicon tail gas recovery system provided in an embodiment of the present application.

[0019] Description of reference numerals:

[0020] 100-polysilicon tail gas recovery system; 10-tail gas input pipeline; 11-pressure device; 12-buffer; 13-fourth valve; 14-eighth valve; 20-filter; 21-silicon powder collection pipeline; 22-sixth valve; 23-backblowing pipeline; 24-backblowing air bag; 25-seventh valve; 26-differential pressure gauge; 30-tail gas recovery pipeline; 31-ninth valve; 40-condensate discharge pipeline; 41-first valve; 42-condensate discharge tank; 43-liquid level gauge; 44-accumulated liquid discharge pipeline; 45-fifth valve; 50-control unit; 60-parallel pipeline; 61-second valve; 62-third valve; 70-condenser. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0022] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0024] The terms "first", "second" and "third" (if any) in the specification and claims of this application and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0025] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or display comprising a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or display.

[0026] The tail gas recovery process in the polysilicon production system mainly receives the tail gas (components H2, HCL, DCS, TCS, STC) and silicon powder produced by the reduction furnace, separates the H2, HCL and chlorosilane in the tail gas through process treatment, and supplies the purified H2 to the reduction furnace as raw material to participate in production again.

[0027] At present, the reduction tail gas pipeline in the polysilicon production system is sent to the recovery pipeline in a single pipeline or a series pipeline. During use, if there is liquid accumulation in the pipeline, it will cause pipeline pressure buildup, which will have a certain degree of impact on the reduction, and cause pressure buildup in the reduction furnace to cause interlocking, which is not conducive to the stable operation of the upstream and downstream. Moreover, in the early stage of production, the temperature of the reduction tail gas pipeline will climb, and the silane gas will condense into liquid due to the low temperature of the pipeline, forming liquid accumulation in the pipeline. The silicon powder carried by the tail gas in the subsequent reduction production process will also work with the liquid accumulation to cause the pipeline and filter to be blocked, which is not conducive to the use of the filter, increases the cost of replacing the filter element, and affects the safe and stable operation of the system.

[0028] After repeated thinking and verification, the inventor found that if a drainage pipeline is connected to the reduction tail gas pipeline without changing the original process to drain the accumulated liquid in the pipeline, there will be no accumulated liquid in the pipeline when the system is running, thus avoiding pipeline pressure, preventing pipeline and filter blockage, reducing the possible filter element replacement problem, reducing the production cost of the enterprise, and ensuring the long-term safe and stable operation of the system. At the same time, the accumulated liquid can also be processed and reused to reduce the discharge of waste, thereby achieving the effect of protecting the environment.

[0029] In view of this, the present application provides a polysilicon exhaust gas recovery system, including an exhaust gas input pipeline, a filter, an exhaust gas recovery pipeline and a condensate discharge pipeline, the air inlet end of the filter is connected to the exhaust gas input pipeline, the air outlet end of the filter is connected to the exhaust gas recovery pipeline, one end of the condensate discharge pipeline is connected to the exhaust gas input pipeline, and a first valve is provided on the condensate discharge pipeline.

[0030] By adding a condensate discharge pipeline to the exhaust gas input pipeline connected to the air inlet end of the filter, and setting a first valve on the condensate discharge pipeline, when there is liquid accumulation in the pipeline, the first valve can be opened to discharge the accumulated liquid in the exhaust gas input pipeline through the condensate discharge pipeline, thereby avoiding pipeline pressure buildup during system operation, preventing pipeline and filter blockage, reducing the possible filter element replacement problem, reducing the production cost of the enterprise, and ensuring the long-term safe and stable operation of the system. At the same time, the accumulated liquid can also be processed and reused to reduce the discharge of waste, thereby achieving the effect of protecting the environment.

[0031] The contents of the present application will be described in detail below in conjunction with the accompanying drawings so that those skilled in the art can understand the contents of the present application more clearly and in detail.

[0032] Figure 1 This is one of the structural schematic diagrams of the polysilicon tail gas recovery system provided in the embodiment of the present application. Figure 2 This is the second structural schematic diagram of the polysilicon tail gas recovery system provided in an embodiment of the present application.

[0033] like Figure 1 As shown, the polysilicon tail gas recovery system 100 provided in the embodiment of the present application includes a tail gas input pipeline 10, a filter 20, a tail gas recovery pipeline 30 and a condensate discharge pipeline 40. The air inlet end of the filter 20 is connected to the tail gas input pipeline 10. The air outlet end of the filter 20 is connected to the tail gas recovery pipeline 30. One end of the condensate discharge pipeline 40 is connected to the tail gas input pipeline 10.

[0034] The tail gas input pipeline 10 is used to connect the production equipment in the polysilicon production system, such as a reduction furnace, so as to transport the tail gas generated by it to the filter 20. The filter 20 is used to filter the tail gas input therein. The tail gas recovery pipeline 30 is used to recover the gas filtered by the filter 20 for processing and reuse. The condensate discharge pipeline 40 is used to discharge the accumulated liquid in the tail gas input pipeline 10.

[0035] Specifically, a first valve 41 is provided on the condensate discharge pipeline 40. The first valve 41 is used to control the opening of the condensate discharge pipeline 40, so that when it is opened, the accumulated liquid in the condensate discharge pipeline 40 is discharged, and when there is no accumulated liquid in the condensate discharge pipeline 40, the condensate discharge pipeline 40 is closed to prevent exhaust gas leakage.

[0036] In a possible implementation, the polysilicon tail gas recovery system 100 further includes a condensate drain tank 42, and the other end of the condensate drain pipeline 40 is connected to the condensate drain tank 42. The condensate drain tank 42 is used to collect the accumulated liquid discharged from the condensate drain pipeline 40.

[0037] In a possible implementation, a pressure gauge 11 is connected to the tail gas input pipeline 10. The pressure gauge 11 is located on a side of the condensate discharge pipeline 40 away from the filter 20. The pressure gauge 11 is used to monitor the pressure value of the tail gas input pipeline 10.

[0038] In a possible implementation, the polysilicon tail gas recovery system 100 further includes a control unit 50. The control unit 50 is connected to the pressure device 11 and the first valve 41 respectively. The control unit 50 is used to control the operation of the first valve 41.

[0039] Specifically, the control unit 50 is used to receive the pressure value of the pressure device 11, and determine whether the air pressure of the exhaust gas input pipeline 10 is normal based on the difference between the pressure value of the pressure device 11 and the preset pressure value. If the air pressure is too high, it means that there may be accumulated liquid in the exhaust gas input pipeline 10. The first valve 41 is controlled to open, and the accumulated liquid in the exhaust gas input pipeline 10 is discharged through the condensate discharge pipeline 40.

[0040] In a possible implementation, the polysilicon tail gas recovery system 100 further includes a liquid level meter 43, which is connected to the condensate discharge pipeline 40 and is located between the first valve 41 and the tail gas input pipeline 10. The liquid level meter 43 is used to display the amount of liquid accumulated in the condensate discharge pipeline 40, so as to facilitate the operator to operate the condensate discharge pipeline 40 and discharge the accumulated liquid.

[0041] In a possible implementation, the control unit 50 is also connected to the liquid level meter 43 .

[0042] Specifically, the control unit 50 is used to receive the liquid level signal of the liquid level meter 43, and judge whether the liquid accumulation in the condensate discharge pipeline 40 is normal based on the size of the liquid level signal and the preset signal value. If there is too much liquid accumulation, the first valve 41 is controlled to open to discharge the accumulated liquid in the condensate discharge pipeline 40 to ensure the smooth flow of the exhaust gas input pipeline 10.

[0043] like Figure 2 As shown, in a possible implementation, the polysilicon tail gas recovery system 100 further includes a buffer 12. The buffer 12 is provided on the tail gas input pipeline 10. One end of the condensate discharge pipeline 40 is connected to the buffer 12. The buffer 12 is used to temporarily store the tail gas input from the tail gas input pipeline 10, so that the accumulated liquid that may be formed in the tail gas input pipeline 10 can be retained therein.

[0044] Specifically, the bottom of the buffer 12 is connected to the condensate discharge pipeline 40. The air inlet end of the buffer 12 near the bottom is connected to the exhaust gas input pipeline 10. The air outlet end of the buffer 12 near the top is connected to the filter 20 through the exhaust gas input pipeline 10.

[0045] In a possible implementation, the polysilicon tail gas recovery system 100 further includes a parallel pipeline 60 and a condenser 70. The condenser 70 is disposed on the parallel pipeline 60. Both ends of the parallel pipeline 60 are respectively connected to the tail gas input pipeline 10, and are both located on the side of the condensate discharge pipeline 40 away from the filter 20.

[0046] By setting a condenser 70 on the parallel pipeline 60 connected in parallel with the exhaust gas input pipeline 10, when there are more easily condensed components such as silane gas in the exhaust gas generated by the production equipment, the exhaust gas can be passed through the condenser 70 to liquefy the silane gas and the like in advance, and then discharged through the condensate discharge pipeline 40, thereby avoiding liquid accumulation in subsequent pipelines and causing pressure buildup or blockage in the polysilicon exhaust gas recovery system 100.

[0047] Specifically, the condenser 70 may be a commonly used water-cooled heat exchanger.

[0048] In a possible implementation, the polysilicon tail gas recovery system 100 further includes a second valve 61 and a third valve 62. The second valve 61 and the third valve 62 are respectively disposed on the parallel pipeline 60, and the second valve 61 and the third valve 62 are respectively located on both sides of the condenser 70.

[0049] The second valve 61 and the third valve 62 are used to control the activation of the condenser 70 .

[0050] By setting the second valve 61 and the third valve 62, the condenser 70 can be activated to perform early liquefaction treatment on the tail gas when needed, and the condenser 70 can be disconnected when not needed, thereby improving the treatment efficiency of the tail gas.

[0051] In a possible implementation, the polysilicon tail gas recovery system 100 further includes a fourth valve 13 , which is disposed on the tail gas input pipeline 10 and is located on a side of the condensate discharge pipeline 40 away from the filter 20 .

[0052] Specifically, the fourth valve 13 is disposed between the two ends of the parallel pipeline 60. The fourth valve 13 is used to cooperate with the second valve 61 and the third valve 62 to control the flow direction of the exhaust gas.

[0053] In a possible implementation, the control unit 50 is also connected to the second valve 61 , the third valve 62 and the fourth valve 13 .

[0054] Specifically, the control unit 50 is used to determine whether the exhaust gas generated by the production equipment needs to be liquefied in advance according to the working conditions or sensors installed on the pipeline. If liquefaction treatment is required, the second valve 61 and the third valve 62 are controlled to be opened, and the fourth valve 13 is closed, so that the exhaust gas is first liquefied through the condenser 70 on the parallel pipeline 60; if no treatment is required, the fourth valve 13 is controlled to be opened, and the second valve 61 and the third valve 62 are closed, so that the exhaust gas is directly transported to the buffer 12 through the exhaust gas input pipeline 10.

[0055] In a possible implementation, the first valve 41 is a hard-sealed ball valve.

[0056] In a possible implementation, the condensate discharge tank 42 is connected to an accumulated liquid discharge pipeline 44. The accumulated liquid discharge pipeline 44 is disposed at the bottom of the condensate discharge tank 42. The accumulated liquid discharge pipeline 44 is used to discharge the accumulated liquid collected in the condensate discharge tank 42 to the outside.

[0057] In a possible implementation, the accumulated liquid discharge pipeline 44 is provided with a fifth valve 45. The fifth valve 45 is used to control the discharge of the accumulated liquid collected in the condensate discharge tank 42.

[0058] In a possible implementation, the bottom of the filter 20 is connected to a silicon powder collecting pipeline 21. The silicon powder collecting pipeline 21 is used to guide the silicon powder generated after filtering by the filter 20 out of the filter 20.

[0059] Specifically, the air inlet end of the filter 20 is arranged at one side of the filter 20 near the bottom, so that the exhaust gas input from the exhaust gas input pipeline 10 is input from the bottom into the filter 20. The air outlet end of the filter 20 is arranged at the top of the filter 20, and the filter element in the filter 20 is located above the air inlet end of the filter 20, so that the exhaust gas entering the filter 20 is filtered by the filter element and output from the top of the filter 20, and the silicon powder generated after filtration falls to the bottom of the filter 20.

[0060] In a possible implementation, the filter element in the filter 20 is made of a metal powder sintered filter element, the filter element is tubular and has a filtering accuracy of 1 μm-3 μm.

[0061] In a possible implementation, a sixth valve 22 is provided on the silicon powder collecting pipeline 21 .

[0062] The discharge of silicon powder collected at the bottom of the filter 20 can be controlled by opening and closing the sixth valve 22 .

[0063] In a possible implementation, the filter 20 is further connected to a backflush pipeline 23. The backflush pipeline 23 is used to provide backflush gas to the filter 20, so as to perform a backflush operation on the filter element in the filter 20.

[0064] Specifically, the gas outlet end of the backflush pipeline 23 is connected to one side of the top of the filter 20. The backflush pipeline 23 is used to send backflush gas into the cylinder of the filter 20 to blow off the silicon powder attached to the outer wall of the filter element in the filter 20.

[0065] In a possible implementation, the air inlet end of the back-blowing pipeline 23 is connected to a back-blowing air bag 24. The back-blowing air bag 24 provides back-blowing gas to the filter 20 through the back-blowing pipeline 23 to back-blow the filter element in the filter 20.

[0066] In a possible implementation, a seventh valve 25 is provided on the back-blowing pipeline 23 . The seventh valve 25 is used to control the blowing out of the back-blowing gas in the back-blowing gas bag 24 .

[0067] The control unit 50 is connected to the seventh valve 25. The control unit 50 is used to control the start and stop of the seventh valve 25.

[0068] In a possible implementation, a differential pressure gauge 26 is provided on the filter 20, and two ends of the differential pressure gauge 26 are respectively connected to two sides of the filter element of the filter 20. The differential pressure gauge 26 is used to display the differential pressure value on both sides of the filter element of the filter 20.

[0069] Specifically, the control unit 50 is connected to the differential pressure gauge 26. The control unit 50 receives the differential pressure value of the differential pressure gauge 26, and determines whether the differential pressure of the filter 20 is normal according to the differential pressure value of the differential pressure gauge 26 and the size of the preset differential pressure value. If it is normal, it means that the filter element can work normally; if it is abnormal, it means that the filter element is blocked and cannot work normally, and the seventh valve 25 needs to be controlled to open, and the backflush operation is performed through the backflush pipeline 23.

[0070] In a possible implementation, the tail gas input pipeline 10 is provided with an eighth valve 14 . The tail gas recovery pipeline 30 is provided with a ninth valve 31 .

[0071] By opening and closing the eighth valve 14 and the ninth valve 31, the filter 20 can be controlled to operate or be shut down for maintenance.

[0072] In a possible implementation, the control unit 50 is also connected to the eighth valve 14 and the ninth valve 31 respectively. The control unit 50 can judge whether the filter 20 is working normally according to the pressure difference value of the differential pressure gauge 26. If the filter 20 is working normally, the eighth valve 14 and the ninth valve 31 are controlled to be opened and work normally; if the filter 20 is not working normally, the eighth valve 14 and the ninth valve 31 are controlled to be closed, and the seventh valve 25 is opened to perform backflush operation or shut down for repair as needed.

[0073] In a possible implementation, the first valve 41, the second valve 61, the third valve 62, the fourth valve 13, the fifth valve 45, the sixth valve 22, the seventh valve 25, the eighth valve 14 and the ninth valve 31 are solenoid valves, which can be connected to the control unit 50 to achieve automated management.

[0074] When in use, the tail gas to be treated is input from the tail gas input pipeline 10, buffered in the buffer 12, and the accumulated liquid is settled. Then the tail gas enters the filter 20, and after being filtered by the filter 20, it is discharged from the tail gas recovery pipeline 30. As the system continues to operate, the accumulated liquid continues to increase. When the liquid level signal of the liquid level meter 43 reaches the preset signal value, or the pressure value of the pressure device 11 exceeds the preset pressure value, the control unit 50 controls the first valve 41 to open, and the accumulated liquid is discharged into the condensate discharge tank 42, completing the discharge and recovery of the accumulated liquid. Then the control unit 50 controls the first valve 41 to close, and the production operation continues.

[0075] The polysilicon tail gas recovery system 100 provided in the embodiment of the present application includes a tail gas input pipeline 10, a filter 20, a tail gas recovery pipeline 30 and a condensate discharge pipeline 40, the air inlet end of the filter 20 is connected to the tail gas input pipeline 10, the air outlet end of the filter 20 is connected to the tail gas recovery pipeline 30, one end of the condensate discharge pipeline 40 is connected to the tail gas input pipeline 10, and a first valve 41 is provided on the condensate discharge pipeline 40.

[0076] By adding a condensate discharge pipeline 40 to the exhaust gas input pipeline 10 connected to the air inlet end of the filter 20, and providing a first valve 41 on the condensate discharge pipeline 40, when there is liquid accumulation in the pipeline, the first valve 41 can be opened to discharge the liquid accumulated in the exhaust gas input pipeline 10 through the condensate discharge pipeline 40, thereby avoiding pipeline pressure build-up during system operation, preventing pipeline and filter 20 from being blocked, reducing the possible filter element replacement problem, reducing the production cost of the enterprise, and ensuring the long-term safe and stable operation of the system. At the same time, the accumulated liquid can also be processed and reused to reduce the discharge of waste, thereby achieving the effect of protecting the environment.

[0077] In addition, an embodiment of the present application further provides a polysilicon production system, in which the polysilicon tail gas recovery system 100 described above is provided.

[0078] The specific structure, working principle and function of the polysilicon tail gas recovery system 100 have been described in detail in the above embodiments and will not be repeated here.

[0079] It can be understood that in a polysilicon production system, multiple polysilicon tail gas recovery systems 100 can be set up, so that when pipeline pressure occurs in one of the polysilicon tail gas recovery systems 100, the accumulated liquid can be discharged and filtered by the remaining polysilicon tail gas recovery systems 100 without stopping for processing, which facilitates continuous production. In addition, multiple polysilicon tail gas recovery systems 100 can also improve production efficiency.

[0080] The polysilicon production system provided by the present application adds a condensate discharge pipeline 40 to the tail gas input pipeline 10 connected to the air inlet end of the filter 20, and sets a first valve 41 on the condensate discharge pipeline 40. When there is liquid accumulation in the pipeline, the first valve 41 can be opened to discharge the liquid accumulation in the tail gas input pipeline 10 through the condensate discharge pipeline 40, thereby avoiding pipeline pressure holding when the system is running, preventing the pipeline and the filter 20 from being blocked, reducing the possible filter element replacement problem, reducing the production cost of the enterprise, and ensuring the long-term safe and stable operation of the system. At the same time, the accumulated liquid can also be processed and reused to reduce the discharge of waste, thereby achieving the effect of protecting the environment.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application 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 with 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 application.

Claims

1. A polysilicon tail gas recovery system, characterized in that: The invention comprises an exhaust gas input pipeline (10), a filter (20), an exhaust gas recovery pipeline (30) and a condensate discharge pipeline (40), wherein the air inlet end of the filter (20) is connected to the exhaust gas input pipeline (10), the air outlet end of the filter (20) is connected to the exhaust gas recovery pipeline (30), one end of the condensate discharge pipeline (40) is connected to the exhaust gas input pipeline (10), and the condensate discharge pipeline (40) is provided with a first valve (41).

2. The polysilicon tail gas recovery system according to claim 1, characterized in that: The polysilicon tail gas recovery system (100) further comprises a condensate discharge tank (42), and the other end of the condensate discharge pipeline (40) is connected to the condensate discharge tank (42).

3. The polysilicon tail gas recovery system according to claim 1, characterized in that: The polysilicon tail gas recovery system (100) further comprises a control unit (50), the tail gas input pipeline (10) is connected to a pressure device (11), and the control unit (50) is respectively connected to the pressure device (11) and the first valve (41).

4. The polysilicon tail gas recovery system according to claim 1, characterized in that: The polysilicon tail gas recovery system (100) further comprises a liquid level meter (43), wherein the liquid level meter (43) is connected to the condensate discharge pipeline (40) and is located between the first valve (41) and the tail gas input pipeline (10).

5. The polysilicon tail gas recovery system according to claim 1, characterized in that: The polysilicon tail gas recovery system (100) further comprises a buffer (12), wherein the buffer (12) is arranged on the tail gas input pipeline (10), and one end of the condensate discharge pipeline (40) is connected to the buffer (12).

6. The polysilicon tail gas recovery system according to claim 1, characterized in that: The polysilicon tail gas recovery system (100) further comprises a parallel pipeline (60) and a condenser (70). The condenser (70) is arranged on the parallel pipeline (60). Both ends of the parallel pipeline (60) are respectively connected to the tail gas input pipeline (10) and are located on a side of the condensate discharge pipeline (40) away from the filter (20).

7. The polysilicon tail gas recovery system according to claim 6, characterized in that: The polysilicon tail gas recovery system (100) further comprises a second valve (61) and a third valve (62), wherein the second valve (61) and the third valve (62) are arranged on the parallel pipeline (60), and the second valve (61) and the third valve (62) are respectively located on both sides of the condenser (70).

8. The polysilicon tail gas recovery system according to claim 6, characterized in that: The polysilicon tail gas recovery system (100) further comprises a fourth valve (13), wherein the fourth valve (13) is arranged on the tail gas input pipeline (10) and is located on a side of the condensate discharge pipeline (40) away from the filter (20).

9. The polysilicon tail gas recovery system according to claim 1, characterized in that: The first valve (41) is a hard-sealed ball valve.

10. A polysilicon production system, characterized in that: The polysilicon production system comprises the polysilicon tail gas recovery system (100) as described in any one of claims 1 to 9.

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