Polycrystalline silicon hydrogen purging system

Abstract

The utility model discloses a polycrystalline silicon hydrogen purging system, comprising: an adsorption column, the upper end of which is connected to a first gas inlet pipeline so as to make blowback gas enter the adsorption column; the regeneration subsystem is used for cooling back blowing gas blown out of the adsorption column; the filtering assembly is suitable for filtering dust, one end of the filtering assembly is connected with the bottom end of the adsorption column, and the other end of the filtering assembly is connected with the regeneration subsystem. The filter assembly is arranged between the adsorption column and the regeneration subsystem, so that dust entering the regeneration subsystem is reduced, and the risk of blockage of each device and tube pass caused by condensation liquid and dust caking is reduced.

Description

Technical Field

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

[0002] In the field of polysilicon production, the modified Siemens method is mainly used for the production and manufacturing of polysilicon. After production, the equipment needs to be purged using a hydrogen purge system. During the purge process, a large amount of tail gas will be generated, the main components of which are hydrogen, chlorosilane, and hydrogen chloride, which have a high recycling value. The existing method is to treat the tail gas after the purge through an adsorption tower. The adsorption column in the adsorption tower usually uses activated carbon as a material to adsorb the tail gas. After the adsorption is completed, hydrogen needs to be back-blown to achieve the purification function, so that the adsorption column can be regenerated and reused. The gas after backblowing enters the regeneration system, and then the hydrogen and chlorosilane are separated through multi-stage condensation.

[0003] However, when the adsorption column is backflushed, the powdered aluminum gel in the hydrogen purge system will enter the regeneration subsystem with the gas. After passing through the condensation heat exchanger, the condensed liquid and the aluminum gel dust will agglomerate, gradually blocking various components, pipes, elbows, showers, etc. Cleaning various components and pipes in the system requires suspending the entire hydrogen purge system, and the maintenance is difficult and time-consuming, causing great workload and danger to the maintenance personnel. Utility Model Content

[0004] One purpose of the present application is to provide a polysilicon hydrogen purge system, which can reduce the aluminum gel dust from entering the subsequent regeneration subsystem, thereby helping to reduce the risk of blockage of various devices and pipes.

[0005] To achieve the above objectives, the technical solution adopted in the present application is: a polysilicon hydrogen purge system, comprising: an adsorption column, the upper end of which is connected to a first air inlet pipe to allow backblowing gas to enter the adsorption column; a regeneration subsystem for cooling the backblowing gas blown out from the adsorption column; a filter assembly suitable for filtering dust, one end of the filter assembly being connected to the bottom end of the adsorption column, and the other end of the filter assembly being connected to the regeneration subsystem.

[0006] Preferably, the filter assembly comprises a solid filter, one end of the solid filter is connected to the bottom end of the adsorption column, and the other end of the solid filter is connected to the regeneration subsystem.

[0007] Preferably, the filter assembly further comprises a second air inlet duct and an exhaust duct, wherein the second air inlet duct is connected to one end of the solid filter for allowing back-blowing air to enter the solid filter, and the exhaust duct is connected to the other end of the solid filter for allowing dust to be discharged from the solid filter.

[0008] Preferably, the filter assembly further comprises a first valve, which is disposed in the second air intake duct and is used to open or close the second air intake duct.

[0009] Preferably, the filter assembly further comprises a collecting tank, which is connected to the discharge pipe to collect dust discharged from the solid filter.

[0010] Preferably, the filter assembly further comprises a second valve and a pressure relief device, wherein the second valve is arranged on the discharge pipe for opening or closing the discharge pipe, and the pressure relief device is connected to the collection tank for connecting the collection tank with the outside to relieve pressure.

[0011] Preferably, the filter assembly further comprises a control device for controlling the opening or closing of the first valve, the second valve and the pressure relief device.

[0012] Preferably, the filter assembly comprises a basket filter, one end of which is connected to the bottom end of the adsorption column, and the other end of which is connected to the regeneration subsystem.

[0013] Preferably, the regeneration subsystem includes a heat exchanger, a condensation component, a phase separation component and a compression component, one end of the heat exchanger is connected to the filtration component, the other end of the heat exchanger is connected to one end of the condensation component, the other end of the condensation component is connected to one end of the phase separation component, and the other end of the phase separation component is connected to the compression component.

[0014] As a preferred embodiment, the condensation component includes a water cooler and a low-pressure cryogenic freezer, the low-pressure cryogenic freezer includes a cryogenic tube side and a cryogenic shell side, one end of the water cooler is connected to the heat exchanger, the other end of the water cooler is connected to one end of the cryogenic tube side, the other end of the cryogenic tube side is connected to one end of the phase separation component, the other end of the phase separation component is connected to one end of the cryogenic shell side, and the other end of the cryogenic shell side is connected to the compression component.

[0015] Compared with the prior art, the beneficial effects of this application are:

[0016] By providing a filter assembly between the adsorption column and the regeneration subsystem, the dust entering the regeneration subsystem can be reduced, thereby reducing the risk of condensate and dust agglomeration leading to blockage of various components and pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a polysilicon hydrogen purge system according to some embodiments of the present application;

[0018] Figure 2is a schematic diagram of a polysilicon hydrogen purge system according to some other embodiments of the present application.

[0019] In the figure: 10, adsorption column; 11, first air inlet pipe; 20, filter assembly; 31, solid filter; 32, second air inlet pipe; 33, first valve; 34, discharge pipe; 35, collection tank; 36, second valve; 37, pressure relief device; 38, control device; 41, basket filter; 50, regeneration subsystem; 51, heat exchanger; 52, condensation assembly; 521, water cooler; 522, low-pressure cryogenic refrigerator; 5221, cryogenic tube side; 5222, cryogenic shell side; 60, phase separation assembly; 61, phase separation tank; 70, compression assembly; 71, filter; 72, buffer tank; 73, compressor. DETAILED DESCRIPTION

[0020] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0021] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present application.

[0022] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0023] A polysilicon hydrogen purge system, such as Figure 1 and Figure 2 As shown, it includes: an adsorption column 10, a regeneration subsystem 50 and a filter assembly 20. The upper end of the adsorption column 10 is connected to the first air inlet pipe 11 so that the back-blowing air enters the adsorption column 10; the regeneration subsystem 50 is used to cool the back-blowing air blown out from the adsorption column 10; one end of the filter assembly 20 is connected to the bottom end of the adsorption column 10, and the other end of the filter assembly 20 is connected to the regeneration subsystem 50, which is suitable for filtering dust.

[0024] That is to say, the adsorption column 10, the filter assembly 20 and the regeneration subsystem 50 are connected in sequence, and the backblowing gas enters the adsorption column 10 from the air inlet pipe to "activate" the adsorption column 10, so that the adsorption column 10 can be regenerated and reused. The backblowing gas passing through the adsorption column 10 enters the filter assembly 20 to filter the dust in the backblowing gas, especially the aluminum gel dust, thereby reducing the dust entering the subsequent regeneration subsystem 50, and reducing the risk of condensate and dust agglomeration causing blockage of various components and pipes.

[0025] In some embodiments, Figure 1 As shown, the filter assembly 20 includes a solid filter 31, one end of the solid filter 31 is connected to the bottom end of the adsorption column 10, and the other end of the solid filter 31 is connected to the regeneration subsystem 50. It can be understood that when the backwash gas blown out from the adsorption column 10 passes through the solid filter 31, hydrogen, chlorosilane and hydrogen chloride, etc. are able to pass through the filter medium and enter the regeneration subsystem 50 under the action of pressure, while the dust is trapped on the surface of the filter medium to form filter residue.

[0026] Furthermore, the filter assembly 20 also includes a second air inlet pipe 32 and a discharge pipe 34. The second air inlet pipe 32 is connected to one end of the solid filter 31 for allowing the back-blowing air to enter the solid filter 31, and the discharge pipe 34 is connected to the other end of the solid filter 31 for discharging dust from the solid filter 31. It is understandable that during long-term use, filter residues will accumulate on the surface of the filter medium, which will affect the normal operation of the solid filter 31 and even reduce the service life of the solid filter 31. The back-blowing air is passed into the solid filter 31 through the second air inlet pipe, and the filter residue is discharged from the discharge pipe 34 through the back-blowing air that has not passed through the adsorption column 10, so as to clean the filter residue in the solid filter 31, which is conducive to the normal operation of the solid filter 31 to ensure the filtration quality and filtration efficiency.

[0027] It is worth mentioning that the back-blowing gas that has not passed through the adsorption column 10 is used to back-blow the solid filter 31, so as to avoid introducing foreign impurities into the polysilicon purge hydrogen system.

[0028] Furthermore, the filter assembly 20 further includes a first valve 33, which is disposed in the second air inlet pipe 32 and is used to open or close the second air inlet pipe 32. It is understandable that by adjusting the opening and closing of the first valve 33, the opening or closing of the second air inlet pipe 32 can be controlled, thereby adjusting the duration of backflushing the solid filter 31 and controlling the frequency of backflushing. In other words, according to the actual situation of the filter residue accumulated in the solid filter 31, the opening or closing of the second air inlet pipe 32 can be flexibly controlled to clean the filter residue in the solid filter 31.

[0029] In some embodiments, Figure 1As shown, the filter assembly 20 further includes a collection tank 35, which is connected to the discharge pipe 34 to collect dust discharged from the solid filter 31. It can be understood that by providing the collection tank 35, the filter residue discharged from the solid filter 31 can be stored in the collection tank 35, and it is not necessary to empty the filter residue every time the solid filter 31 is back-blown, thereby reducing the frequency of emptying the filter residue.

[0030] Furthermore, the filter assembly 20 further includes a second valve 36 and a pressure relief device 37. The second valve 36 is disposed in the discharge pipe 34 and is used to open or close the discharge pipe 34. The pressure relief device 37 is connected to the collection tank 35 and is used to connect the collection tank 35 with the outside to relieve pressure. It is understood that, under normal circumstances, the second valve 36 and the first valve 33 are opened or closed at the same time. That is, when the first valve 33 is opened to pass back-blowing gas into the solid filter 31, the second valve 36 is also opened to allow the filter residue in the solid filter 31 to enter the collection tank 35 through the discharge pipe 34.

[0031] The pressure relief device 37 is used to relieve the pressure of the collection tank 35. Specifically, when it is necessary to open the collection tank 35 to clear the filter residue, first close the second valve 36 to disconnect the collection tank 35 from the solid filter 31, then open the pressure relief device 37 to make the air pressure in the collection tank 35 consistent with the external atmospheric pressure, and then open the collection tank 35 to clear the filter residue to improve operational safety.

[0032] Furthermore, the filter assembly 20 further includes a control device 38 for controlling the opening or closing of the first valve 33, the second valve 36 and the pressure relief device 37. It is understandable that, through the control device 38, the backflush duration and the backflush frequency can be adjusted according to the design load, so as to achieve the regular discharge of the filter residue in the solid filter 31, which is conducive to improving the automation of the polysilicon purge hydrogen system. In a specific embodiment, the first valve 33 and the second valve 36 are solenoid valves, and the control device 38 can control the opening or closing of the first valve 33 and the second valve 36 by turning on and off the power, which is conducive to reducing the complexity of the control process.

[0033] In other embodiments, Figure 2 As shown, the filter assembly 20 includes a basket filter 41, one end of the basket filter 41 is connected to the bottom end of the adsorption column 10, and the other end of the basket filter 41 is connected to the regeneration subsystem 50. It is understandable that after the basket filter 41 has been used for a period of time, filter residue will be precipitated in the filter basket, causing the pressure drop in the basket filter 41 to increase and the flow rate to decrease, so it is necessary to regularly clean and remove the filter residue in the filter basket or replace the filter basket. It is worth mentioning that the basket filter 41 is easy to clean and maintain, which is conducive to reducing the complexity of maintenance and saving time costs while maintaining the long-term operating efficiency of the polysilicon hydrogen purge system.

[0034] In some embodiments, Figure 1 and Figure 2 As shown, the regeneration subsystem 50 includes a heat exchanger 51, a condensation component 52, a phase separation component 60 and a compression component 70. One end of the heat exchanger 51 is connected to the filter component 20, the other end of the heat exchanger 51 is connected to one end of the condensation component 52, the other end of the condensation component 52 is connected to one end of the phase separation component 60, and the other end of the phase separation component 60 is connected to the compression component 70. Specifically, the heat exchanger 51 is used to perform heat exchange between the back-blowing gas with a higher temperature blown out from the adsorption column 10 and the back-blowing gas with a lower temperature that has not yet entered the adsorption column 10. The condensation component 52 is used to perform step-by-step low-pressure condensation and separation of the back-blowing gas blown out from the adsorption column 10, so that most of the chlorosilane is condensed and separated. The phase separation component 60 is used to separate the condensed chlorosilane and the mixed gas of hydrogen and hydrogen chloride. The compression component 70 is used to pressurize and heat the mixed gas.

[0035] Further, the condensation assembly 52 includes a water cooler 521 and a low-pressure cryogenic cooler 522, the low-pressure cryogenic cooler 522 includes a cryogenic tube 5221 and a cryogenic shell 5222, one end of the water cooler 521 is connected to the heat exchanger 51, the other end of the water cooler 521 is connected to one end of the cryogenic tube 5221, the other end of the cryogenic tube 5221 is connected to one end of the phase separation assembly 60, the other end of the phase separation assembly 60 is connected to one end of the cryogenic shell 5222, and the other end of the cryogenic shell 5222 is connected to the compression assembly 70. Specifically, the phase separation assembly 60 includes a phase separation tank 61. The compression assembly 70 includes a filter 71, a buffer tank 72 and a compressor 73 connected in sequence.

[0036] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A polysilicon hydrogen purging system, characterized in that: include: An adsorption column, the upper end of which is connected to the first air inlet pipe so that the backwash gas enters the adsorption column; a regeneration subsystem, used for cooling the back-blowing gas blown out from the adsorption column; The filter assembly is suitable for filtering dust, one end of the filter assembly is connected to the bottom end of the adsorption column, and the other end of the filter assembly is connected to the regeneration subsystem.

2. The polysilicon hydrogen purging system according to claim 1, characterized in that: The filter assembly comprises a solid filter, one end of which is connected to the bottom end of the adsorption column, and the other end of which is connected to the regeneration subsystem.

3. The polysilicon hydrogen purging system according to claim 2, characterized in that: The filter assembly also includes a second air inlet pipe and an exhaust pipe, wherein the second air inlet pipe is connected to one end of the solid filter for allowing back-blowing air to enter the solid filter, and the exhaust pipe is connected to the other end of the solid filter for allowing dust to be discharged from the solid filter.

4. The polysilicon hydrogen purging system according to claim 3, characterized in that: The filter assembly further includes a first valve, which is disposed in the second air intake duct and is used to open or close the second air intake duct.

5. The polysilicon hydrogen purging system according to claim 4, characterized in that: The filter assembly further comprises a collecting tank, which is connected to the discharge pipe and is capable of collecting dust discharged from the solid filter.

6. The polysilicon hydrogen purging system according to claim 5, characterized in that: The filter assembly also includes a second valve and a pressure relief device. The second valve is arranged on the discharge pipe and is used to open or close the discharge pipe. The pressure relief device is connected to the collection tank and is used to connect the collection tank and the outside to relieve pressure.

7. The polysilicon hydrogen purging system according to claim 6, characterized in that: The filter assembly further comprises a control device for controlling the opening or closing of the first valve, the second valve and the pressure relief device.

8. The polysilicon hydrogen purging system according to claim 1, characterized in that: The filter assembly comprises a basket filter, one end of which is connected to the bottom end of the adsorption column, and the other end of which is connected to the regeneration subsystem.

9. The polysilicon hydrogen purging system according to any one of claims 1 to 8, characterized in that: The regeneration subsystem includes a heat exchanger, a condensation component, a phase separation component and a compression component. One end of the heat exchanger is connected to the filtration component, the other end of the heat exchanger is connected to one end of the condensation component, the other end of the condensation component is connected to one end of the phase separation component, and the other end of the phase separation component is connected to the compression component.

10. The polysilicon hydrogen purging system according to claim 9, characterized in that: The condensation component includes a water cooler and a low-pressure cryogenic cooler, and the low-pressure cryogenic cooler includes a cryogenic tube side and a cryogenic shell side. One end of the water cooler is connected to the heat exchanger, and the other end of the water cooler is connected to one end of the cryogenic tube side, and the other end of the cryogenic tube side is connected to one end of the phase separation component, and the other end of the phase separation component is connected to one end of the cryogenic shell side, and the other end of the cryogenic shell side is connected to the compression component.

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