Reduced tail gas filtration system and dust collection device

Abstract

The application provides a reduction tail gas filtering system and a dust collecting device, and relates to the technical field of chemical production. The reduction tail gas filtering system comprises a sealing part, a first through hole is arranged at the top of the outer side of the sealing part, the sealing part is connected with a dust separation device through a first pipeline, the dust separation device is connected with a filtering device through a second pipeline, and the positions of the dust separation device and the filtering device are higher than the position of the sealing part; a dust bag is arranged in the sealing part, the dust bag comprises gas phase hot silane and silicon powder, the silicon powder comprises first type silicon powder, second type silicon powder and third type silicon powder; the dust separation device is used for separating the gas phase hot silane and the third type silicon powder in the first mixture from the first mixture and conveying them to the filtering device; and the filtering device is used for separating the gas phase hot silane and the third type silicon powder. The application can provide a closed reduction tail gas filtering system for the secondary collection stage of silicon powder and prevent coarse particle dust from accumulating.

Description

Technical Field

[0001] This application relates to the field of chemical production technology, and in particular to a reduction tail gas filtration system and a dust collection device. Background Technology

[0002] When recovering reduction tail gas in the polysilicon recovery process, the main components are a mixture of fumed thermal silane, silicon powder particles, and other gases. Removing fumed thermal silane can reduce the hydrogen purification process and lower energy-saving costs. It can also effectively extract and collect silicon powder, which can improve economic efficiency. However, the silicon powder collection tank is quite large, and it collects a large amount of silicon powder and a significant amount of fumed thermal silane each time. Existing recovery tail gas filtration devices cannot completely extract fumed thermal silane. Therefore, further filtration of fumed thermal silane is required in the secondary silicon powder collection stage.

[0003] Currently, existing reduction tail gas filtration systems mainly connect one end of a hydrogen pipe to the top of the silicon powder collection tank and the other end to a filter device. The polysilicon recovery system ventilates the silicon powder filter device to allow gaseous thermal silane and silicon powder to pass through the hydrogen pipe and enter the filter device, which can filter out the gaseous thermal silane. However, when coarse silicon powder enters the filter device, it may not be able to enter the filter element, and long-term accumulation of coarse silicon powder may damage the filter device. Moreover, in the secondary silicon powder collection stage, two workers work together to connect the ton bag to the port of the silicon powder collection tank to collect silicon powder without performing corresponding gaseous thermal silane filtration. If silicon powder mixed with gaseous thermal silane is collected in the ton bag, leakage of silicon powder and gaseous thermal silane gas due to ton bag damage can cause harm to human personnel. Therefore, a closed reduction tail gas filtration system that prevents the accumulation of coarse dust is needed in the secondary silicon powder collection stage. Utility Model Content

[0004] This application provides a reducing exhaust gas filtration system and a dust collection device to solve the problems of silicon powder and reducing gas leakage, as well as the accumulation of silicon powder on the outside of the filter element in the filtration device caused by coarse silicon powder particles.

[0005] In a first aspect, this application provides a reducing exhaust gas filtration system, comprising: a sealing part, wherein a first through hole is provided on the top of the outer side of the sealing part, the sealing part is connected to a dust separation device through a first pipe, and the dust separation device is connected to a filter device through a second pipe, wherein the positions of the dust separation device and the filter device are higher than the position of the sealing part;

[0006] A dust bag is provided inside the sealing part. The dust bag includes fumed thermal silane and silicon powder. The silicon powder includes a first type of silicon powder, a second type of silicon powder and a third type of silicon powder. The particle size of the first type of silicon powder is larger than that of the second type of silicon powder, and the particle size of the second type of silicon powder is larger than that of the third type of silicon powder.

[0007] The sealing part is used to convey the first mixture to the dust separation device under the action of the air source. The first mixture includes gaseous thermal silane, second type silicon powder and third type silicon powder.

[0008] A dust separation device is used to separate gaseous thermal silane and third-type silicon powder from the first mixture and convey them to a filtration device;

[0009] A filtration device for separating gaseous thermal silanes and type III silicon powder.

[0010] In one possible implementation, the sealing part includes: a sealing part body and a sealing cover; the sealing cover is fixedly connected to the sealing part body, and the edge of the dust bag is sandwiched between the sealing part body and the sealing cover; a first through hole is provided at the top outer side of the sealing part body for communicating the dust bag with the first pipe.

[0011] In one possible implementation, a through hole is provided in the middle of the sealing cap to allow the first mixture to be fed into the dust bag;

[0012] The inner wall of the through hole is configured as a double conical structure.

[0013] In one possible implementation, the first pipe is provided with a first valve;

[0014] The first valve is used to control the connection between the dust separation device and the dust bag.

[0015] In one possible implementation, the dust separation device is a hydrocyclone, with an inlet and an outlet respectively provided on both sides of the hydrocyclone.

[0016] The input port is connected to one end of the first pipe;

[0017] The output port is connected to one end of the second pipe.

[0018] In one possible implementation, it further includes: a third pipe, wherein a dust discharge port is provided at the bottom of the hydrocyclone, and one end of the third pipe is connected to the dust discharge port; a second through hole is provided below the first through hole, and the other end of the third pipe is connected to the second through hole;

[0019] One end of the third pipe is higher than the other end;

[0020] The third pipe is used to transport the second type of silicon powder flowing out of the dust discharge port into the dust bag.

[0021] In one possible implementation, the filtration device includes: a removable filter element and a connection port located at the bottom outer side of the removable filter element;

[0022] The detachable filter element and the connection port located at the bottom of the outer side of the detachable filter element are fixedly connected to the other end of the second pipe.

[0023] In one possible implementation, it further includes: a dust backflushing device, a second valve, and a fourth pipe; one end of the fourth pipe is connected to the second pipe via the second valve; the other end of the fourth pipe is connected to the third pipe; the fourth pipe is higher than the third pipe, and one end of the fourth pipe is higher than the other end;

[0024] The second valve is used to control the connection between the fourth pipe and the second pipe;

[0025] The dust backflushing device is used to pass the third type of silicon powder through the second pipe and the fourth pipe so that it falls into the dust bag.

[0026] In one possible implementation, it further includes: a fifth pipe; a connection port is also provided at the middle position of the dust backflushing device, and the connection port at the middle position of the dust backflushing device is connected to one end of the fifth pipe; a connection port is also provided at the middle position of the other outer side of the detachable filter element, and the other end of the fifth pipe is connected to the connection port at the middle position of the other outer side of the detachable filter element.

[0027] The fifth pipe is equipped with a third valve; the third valve is used to control the connection between the dust backflushing device and the filter.

[0028] On the other hand, this application provides a dust collection device, including: a dust collection tank, a sixth pipe, a dust bag, and the reduction exhaust gas filtration system described in the first aspect;

[0029] The dust bag is fixed in the reduction exhaust gas filtration system;

[0030] The dust collection tank is connected to the reduction exhaust gas filtration system via the sixth pipe.

[0031] The reduction exhaust gas filtration system and dust collection device provided in this application include a sealing section with a first through hole on the top of its outer side. The sealing section is connected to a dust separation device via a first pipe, and the dust separation device is connected to a filter device via a second pipe. The dust separation device and the filter device are positioned higher than the sealing section. A dust bag is installed inside the sealing section, containing fumed thermal silane and silicon powder. The silicon powder includes three types: type I, type II, and type III. The particle size of type I silicon powder is larger than that of type II silicon powder, and the particle size of type II silicon powder is larger than that of type III silicon powder. The sealing section is used to convey a first mixture, comprising fumed thermal silane, type II silicon powder, and type III silicon powder, to the dust separation device under the action of an air source. Silicon powder; a dust separation device for separating fumed thermal silane and third-type silicon powder from a first mixture and conveying them to a filter device; the filter device for separating fumed thermal silane and third-type silicon powder; therefore, silicon powder and fumed thermal silane can be conveyed in a closed environment through the sealing part and various pipelines to prevent leakage of silicon powder and fumed thermal silane; furthermore, the dust separation device can separate fumed thermal silane and third-type silicon powder to prevent second-type silicon powder from entering the filter device; finally, the filter device can effectively filter out fumed thermal silane to separate third-type silicon powder; thereby preventing leakage of silicon powder and reducing gas and preventing coarse silicon powder particles from accumulating in the filter device. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0033] Figure 1 This is a schematic diagram of the reduction exhaust gas filtration system provided in an embodiment of this application;

[0034] Figure 2 This is a schematic diagram of a reduction exhaust gas filtration system provided in another embodiment of this application;

[0035] Figure 3 This is a schematic diagram of a dust collection device provided in an embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 10-Sealing part; 11-Sealing part body; 12-Sealing cover; 20-First pipe; 30-Dust separation device; 40-Second pipe; 50-Filter device; 60-Dust collection tank; 61-Dust collection tank switch valve; 70-First valve; 80-Third pipe; 90-Dust backflushing device; 100-Second valve; 110-Fourth pipe; 120-Fifth pipe; 130-Third valve; 140-Sixth pipe.

[0038] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0039] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0040] Currently, existing reduction tail gas filtration systems mainly connect one end of a hydrogen pipe to the top of the silicon powder collection tank and the other end to a filter device. The polysilicon recovery system ventilates the silicon powder filter device to promote the upward flow of gaseous thermal silane towards the hydrogen pipe. When a small portion of silicon powder particles, due to the downward force of gravity being less than the airflow pressure, also flow towards the hydrogen pipe with the thermal silane, the silicon powder mixes with the reduction tail gas and enters the filter device, where the filter device can filter out the gaseous thermal silane. However, when coarse silicon powder particles enter the filter device, they may not be able to penetrate the filter element, leading to long-term contamination. Accumulation of particulate silicon powder can damage filters. Furthermore, during the secondary collection stage of silicon powder, one worker holds a ton bag and connects it to the port of the silicon powder collection tank, while another worker secures the ton bag to the port of the collection tank before collecting the silicon powder. No corresponding gas-phase thermal silane filtration treatment is performed. If silicon powder mixed with gas-phase thermal silane is collected in the ton bag, leakage of silicon powder and gas-phase thermal silane gas due to ton bag damage can also cause harm to the human body. Therefore, a closed reduction tail gas filtration system that prevents the accumulation of coarse particulate dust is required during the secondary collection stage of silicon powder.

[0041] Therefore, to address the aforementioned technical problems and prevent leakage of silicon powder and reduction gas, the reduction gas filtration system of this application is equipped with a sealing part, a first pipe, and a second pipe. The sealing part can seal the dust bag, thereby providing a closed transport environment for the silicon powder and gaseous thermal silane transported to the dust bag. Furthermore, to prevent the second type of silicon powder from entering the filtration device and accumulating in it, a dust separation device can be installed in the reduction gas filtration system. The dust separation device can separate the second type of silicon powder and transport the gaseous thermal silane and the third type of silicon powder in the first mixture to the filtration device. Finally, to filter out the gaseous thermal silane, a filtration device is installed in the reduction gas filtration system, and the filtration device and the dust separation device are connected through the second pipe. The dust separation device separates the gaseous thermal silane and the third type of silicon powder in the first mixture and transports them to the filtration device to separate the third type of silicon powder. This achieves the prevention of leakage of silicon powder and reducing gas, as well as the prevention of coarse silicon powder accumulation in the filtration device.

[0042] Furthermore, the reduction exhaust gas filtration system of this application can be applied to various scenarios where reduction exhaust gas is mixed with dust particles and reduction exhaust gas filtration is required; optionally, when reducing exhaust gas is recovered in the polysilicon recovery section, the reduction exhaust gas recovery system can be connected to the reduction exhaust gas filtration system of this application, the reduction exhaust gas recovery system provides air source for the reduction exhaust gas filtration system, and the reduction exhaust gas filtration system separates gaseous thermal silane and silicon powder.

[0043] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0044] Figure 1 This is a schematic diagram of the reduction exhaust gas filtration system provided in the embodiments of this application, as shown below. Figure 1 As shown, it includes: a sealing part 10, a first through hole provided on the top of the outer side of the sealing part 10, the sealing part 10 being connected to a dust separation device 30 through a first pipe 20, the dust separation device 30 being connected to a filter device 50 through a second pipe 40, and the positions of the dust separation device 30 and the filter device 50 being higher than the position of the sealing part 10.

[0045] The sealing part 10 is a structure used to seal the dust bag, and can be a sealing structure that meets the design requirements for sealing the dust bag. The top of the sealing part 10 may have a through hole to allow the dust collection can inlet to be connected to the through hole in the sealing part 10 via an air duct, thereby allowing the collection of silicon powder falling from the dust collection canlet. Exemplarily, the sealing part 10 may include a rigid container and a lid, but other components are not specifically limited in this embodiment.

[0046] The first through hole is a hole interface located on the top of the outer side of the sealing part 10, used to connect the sealing part 10 and the first pipe 20. Optionally, the first through hole can be set as a socket so that after the first pipe 20 is inserted into the first through hole, the connection position between the first pipe 20 and the first through hole is sealed to prevent leakage of silicon powder and gaseous thermal silane.

[0047] The first pipe 20 can be a flexible pipe, a metal pipe, etc., and this embodiment does not make a specific limitation. All pipes mentioned in this application can be the above-mentioned flexible pipes, metal pipes, etc., and will not be repeated hereafter.

[0048] The dust separation device 30 can be used to separate dust particles with a diameter greater than or equal to 1 μm. It can be a single hydrocyclone or a multi-stage series hydrocyclone, etc. In this embodiment, no specific limitation is made. Optionally, hydrocyclones that separate dust particles of different diameters can be selected according to the dust separation requirements. In this embodiment, no specific limitation is made.

[0049] The filtration device 50 can be a bag filter, a ceramic filter, or other types of filter; this embodiment does not impose any limitations. Optionally, the filter element in the above filter can be a removable filter element of model D50, or a removable filter element thereof; this embodiment does not impose any specific limitations.

[0050] The dust bag can be a ton bag or other container capable of holding gaseous thermal silane and reducing gas. The dust bag is provided with a through hole, and a valve is provided at the position of the through hole. The through hole is located on the outside of the ton bag at the same position as the first through hole, so that the first pipe 20 can be connected to the through hole on the dust bag.

[0051] Specifically, the first pipe 20 can be positioned at least 45 degrees to the horizontal line where the center of the first through hole is located, and one end of the first pipe 20 can be sealed and fixed to the first through hole; the dust separation device 30 can be positioned above the sealing part 10, and the other end of the first pipe 20 can be connected to the connection port on the outside of the dust separation device 30; a filter device 50 can be installed in the area formed by the parallel lines between the top and bottom of the dust separation device 30, and one end of the second pipe 40 can be connected to the connection port on the other side of the dust separation device 30, and the other end of the second pipe 40 can be connected to the connection port on the outside of the filter device 50. The second pipe 40 can be positioned on the same straight line as the first pipe 20.

[0052] Understandably, the purpose of setting the first pipe 20 at at least 45 degrees to the horizontal line where the center of the first through hole is located is so that, after the reduction of the third type of silicon powder, when collecting silicon powder, the third type of silicon powder can fall into the dust bag through the tilt of the pipe. Therefore, when setting each pipe, it is necessary to make a certain angle between each pipe and the horizontal line where the center of the first through hole is located. This can be adjusted arbitrarily according to the needs, and no specific limitation is made in this embodiment. The pipe setting and the center line where the center of the through hole is located mentioned in this application are all to achieve the technical effect of the third type of silicon powder falling into the dust bag through the tilt of the pipe when collecting silicon powder, which will not be repeated hereafter.

[0053] In this embodiment, a dust bag is provided inside the sealing part 10. The dust bag includes fumed thermal silane and silicon powder. The silicon powder includes a first type of silicon powder, a second type of silicon powder, and a third type of silicon powder. The particle size of the first type of silicon powder is larger than that of the second type of silicon powder, and the particle size of the second type of silicon powder is larger than that of the third type of silicon powder. The sealing part 10 is used to transport a first mixture to the dust separation device 30 under the action of an air source. The first mixture includes fumed thermal silane, second type of silicon powder, and third type of silicon powder. The dust separation device 30 is used to separate the fumed thermal silane and the third type of silicon powder from the first mixture and transport them to the filter device 50. The filter device 50 is used to separate the fumed thermal silane and the third type of silicon powder.

[0054] Specifically, the through-hole of the dust bag can be connected to one end of the first pipe 20; the edge of the dust bag can be clamped onto a rigid container and the lid can be fixedly connected to the rigid container; then, the dust collection tank in the reduction exhaust gas recovery system can be connected to the through-hole on the lid through a pipe, and the switch valve at the inlet of the dust collection tank can be opened. The air source in the reduction exhaust gas recovery system blows from the top of the dust collection tank to the bottom and finally into the dust bag. Silica powder and gaseous thermal silane fall into the dust bag under the action of the air source. Among them, the first type of silica powder, with a larger particle size, is subject to greater gravity than the influence of the air source and can fall to the bottom of the dust bag; due to the Bernoulli effect... Due to the influence of high-speed downward airflow, the pressure near the airflow decreases, and the first mixture is drawn into the low-pressure area, replenishing the low-pressure area with airflow. Since the inside of the first pipe 20 is relatively narrow and has no air source, it is a low-pressure area, so the first mixture can enter the first pipe 20. After the first mixture enters the dust separation device 30 through the first pipe 20, the dust separation device 30 can separate the gaseous thermal silane and the third type of silicon powder in the first mixture. The dust separation device 30 can push the gaseous thermal silane and the third type of silicon powder towards the second pipe 40 and into the filter device 50 through its own rotational force, and the filter device 50 can separate the third type of silicon powder.

[0055] In this embodiment, the reduction exhaust gas filtration system and dust collection device provided in this application include a sealing part 10 with a first through hole on its outer top. The sealing part 10 is connected to a dust separation device 30 via a first pipe 20, and the dust separation device 30 is connected to a filter device 50 via a second pipe 40. The positions of the dust separation device 30 and the filter device 50 are higher than the position of the sealing part 10. A dust bag is provided inside the sealing part 10, containing fumed thermal silane and silicon powder. The silicon powder includes first-type silicon powder, second-type silicon powder, and third-type silicon powder. The particle size of the first-type silicon powder is larger than that of the second-type silicon powder, and the particle size of the second-type silicon powder is larger than that of the third-type silicon powder. The sealing part 10 is used to transport a first mixture, including fumed thermal silane, to the dust separation device 30 under the action of an air source. The mixture contains two types of silicon powder: a second type and a third type; a dust separation device 30, used to separate the gaseous thermal silane and the third type of silicon powder from the first mixture and convey them to a filter device 50; the filter device 50 is used to separate the gaseous thermal silane and the third type of silicon powder; therefore, the silicon powder and gaseous thermal silane can be conveyed in a closed environment through the sealing part 10 and each pipe to prevent leakage of silicon powder and gaseous thermal silane; furthermore, the dust separation device 30 can separate the gaseous thermal silane and the third type of silicon powder to prevent the second type of silicon powder from entering the filter device 50; finally, the filter device 50 can effectively filter out the gaseous thermal silane to separate the third type of silicon powder; thereby preventing leakage of silicon powder and reducing gas and preventing coarse silicon powder particles from accumulating in the filter device 50.

[0056] As an optional implementation, the sealing part 10 includes: a sealing part body 11 and a sealing cover 12; the sealing cover 12 is fixedly connected to the sealing part body 11, and the edge of the dust bag is sandwiched between the sealing part body 11 and the sealing cover 12; a first through hole is provided at the top of the outer side of the sealing part body 11 for communicating with the first pipe 20.

[0057] The sealing body 11 refers to the three-dimensional structure used to seal and support the dust bag. For example, it can be a cubic container or other types, and no specific limitation is made in this embodiment.

[0058] The sealing cover 12 can be a quick-release sealing cover 12 to achieve sealing of the dust bag by combining with the sealing part body 11.

[0059] The sealing cap 12 and the sealing part body 11 can be fixedly connected by screw threads; they can be fixedly connected by setting a hinge structure; or they can be other fixed connection methods. This embodiment does not make specific limitations.

[0060] Optionally, a rubber gasket can be attached to the top edge of the sealing body 11. When the sealing body 11 is fixed to the sealing cover 12, the rubber gasket can fill the gap between the sealing body 11 and the sealing cover 12 to prevent leakage of the first mixture.

[0061] Optionally, a quick connector can be provided at one end of the first pipe 20 that connects to the dust bag; a through hole is provided on the outside of the dust bag at the same location as the first through hole, and a dust cover is provided at the through hole location on the dust bag; specifically, after one end of the first pipe 20 is connected to the first through hole and passes through the first through hole, when it is necessary to connect the dust bag and the first pipe 20, the dust bag can be opened first, and then the quick connector of the first pipe 20 can be connected to the through hole on the dust bag. Then, the connection position between the quick connector of the first pipe 20 and the through hole on the dust bag can be sealed by an O-ring to prevent leakage of silicon powder and gaseous thermal silane. All through holes provided on the dust bag and the connection method with the pipe in this application can be designed according to the above scheme, and will not be repeated hereafter.

[0062] In this embodiment, the sealing part includes: a sealing part body 11 and a sealing cover 12; the sealing cover 12 is fixedly connected to the sealing part body 11, and the edge of the dust bag is sandwiched between the sealing part body 11 and the sealing cover 12; it can achieve the sealing and fixing of the dust bag, so as to provide a closed conveying environment for the silicon powder and gaseous thermal silane falling into the dust bag, and can prevent the leakage of silicon powder and gaseous thermal silane; a first through hole is provided at the top of the outer side of the sealing part body 11, which can enable the dust bag to communicate with the first pipe 20.

[0063] As an alternative implementation, the sealing cap 12 has a through hole at the center to allow the first mixture to be fed into the dust bag; the inner wall of the through hole is configured as a double conical structure.

[0064] Specifically, the dust collection tank can be fixedly connected to one end of the pipe, and the other end of the pipe passes through the double conical through hole on the sealing cover 12. A silicone sealing sleeve can be fixedly installed on the inner wall of the double conical through hole on the sealing cover 12. When the pipe passes through the double conical through hole, the silicone sealing sleeve can be compressed so that the silicone sealing sleeve can seal the connection gap between the double conical through hole and the pipe. After the dust collection tank and the sealing cover 12 are connected through the pipe, the switch valve at the position of the dust collection tank can be opened, and the first mixture can fall into the dust bag.

[0065] In this embodiment, a through hole is provided in the middle of the sealing cap 12 to input the first mixture into the dust bag; the inner wall of the through hole is set as a double conical structure, so setting the inner wall of the through hole as a double conical structure can enhance the sealing performance when the inner wall of the through hole is connected to the pipe and can quickly realize the installation with the pipe. Therefore, it is also convenient to connect with the through hole in the middle of the sealing cap 12.

[0066] Figure 2 This is a schematic diagram of a reduction exhaust gas filtration system provided in another embodiment of this application, as shown below. Figure 2 As shown, the exhaust gas filtration system also includes: a first valve 70, a third pipe 80, a dust backflushing device 90; a second valve 100, a fourth pipe 110, a fifth pipe 120, and a third valve.

[0067] As an optional implementation, the first pipe 20 is provided with a first valve 70; the first valve 70 is used to control the connection between the dust separation device 30 and the dust bag.

[0068] The first valve 70 can be located near the connection end between the first pipe 20 and the dust bag. The first valve 70 can be a butterfly valve, ball valve, rotary valve, etc., and is not specifically limited in this embodiment. When it is necessary to filter the first mixture to separate the second type of silicon powder and the third type of silicon powder, the first valve 70 can be opened to connect the dust separation device 30 with the dust bag for subsequent separation of the second and third dust particles in the first mixture. All valve structures mentioned in this application can be the above-mentioned butterfly valve, ball valve, rotary valve, etc., and will not be repeated hereafter.

[0069] In this embodiment, the first pipe 20 is provided with a first valve 70; the first valve 70 is used to control the connection between the dust separation device 30 and the dust bag. Furthermore, by providing the first valve 70, the first valve 70 can be closed in a timely manner when the separation of the first mixture is stopped, thereby also preventing the first mixture from entering the first pipe 20 in a timely manner.

[0070] As an optional implementation, the dust separation device 30 is a hydrocyclone, with an inlet and an outlet respectively provided on both sides of the hydrocyclone; the inlet is connected to one end of the first pipe 20; and the outlet is connected to one end of the second pipe 40.

[0071] The hydrocyclone may include a cylindrical section and a conical section; the cylindrical section is used to form a high-speed rotating flow field to initially separate the second type of silicon powder in the first mixture; the conical section is connected below the cylindrical section and is used to reduce the rotating flow field, enhance centrifugal force, and promote further separation of the second type of silicon powder.

[0072] The input port is located above the side wall of the cylindrical section, and the output port is located in the middle of the conical section.

[0073] Specifically, after the first mixture enters the first pipe 20, it enters the cylindrical section of the hydrocyclone through the inlet. The cylindrical section forms a vortex that stretches and amplifies, creating a strong swirling field. This causes the coarse silicon powder particles to collide with the wall and slide down to the bottom of the hydrocyclone. The remaining first mixture continues to rotate with the rotating airflow to the conical section of the hydrocyclone. The conical section continues to form a swirling field, and the remaining first mixture rotates with the swirling field, further separating out the coarse silicon powder particles. The coarse silicon powder particles separated by the cylindrical and conical sections are the second type of silicon powder. The pressure at the outlet of the conical section of the hydrocyclone is greater than the pressure in the second pipe 40. The conical section of the hydrocyclone pushes the third type of silicon powder and the gaseous thermal silane in the first mixture towards the second pipe 40.

[0074] In this embodiment, the dust separation device 30 is a hydrocyclone, with an inlet and an outlet on each side. The inlet is connected to one end of the first pipe 20, and the outlet is connected to one end of the second pipe 40. The hydrocyclone has the advantage of high accuracy in gas-solid separation, so using the hydrocyclone as the dust separation device 30 can effectively separate the second type of silicon powder.

[0075] As an optional implementation, it further includes: a third pipe 80, the bottom of the cyclone separator is provided with a dust discharge port, one end of the third pipe 80 is connected to the dust discharge port; a second through hole is provided below the first through hole, the other end of the third pipe 80 is connected to the second through hole; one end of the third pipe 80 is higher than the other end; the third pipe 80 is used to transport the second type of silicon powder flowing out of the dust discharge port to the dust bag.

[0076] The dust discharge port can be used to discharge the second type of silicon powder separated by the cyclone separator.

[0077] The center of the second through hole can be on the same straight line as the center of the first through hole, and the distance between the center of the second through hole and the center of the first through hole is the shortest. It can also be set in other positions. This embodiment does not make specific limitations.

[0078] Optionally, one end of the third pipe 80 can be equipped with a quick connector, allowing the third pipe 80 to be placed at an angle of 45 degrees or more to the horizontal line where the center of the third through hole is located. This allows one end of the third pipe 80 to be higher than the other end. Then, one end of the third pipe 80 can pass through the second through hole, and the connector on the third pipe 80 connects to another through hole on the dust bag. When the hydrocyclone separates the second type of silicon powder, because the third pipe 80 is placed at a certain angle to the dust bag, the second type of silicon powder can fall into the dust bag under the influence of gravity. The other through hole on the dust bag can be the through hole located at the closest position below the dust bag through hole connected to the first pipe 20, and the center of the other through hole on the dust bag and the center of the dust bag through hole connected to the first pipe 20 are on the same straight line.

[0079] Optionally, the connection method between the third pipe 80 and the second through hole is similar to the connection method between the first pipe 20 and the first through hole described above, and will not be repeated in this embodiment.

[0080] Optionally, the connection method between the quick connector of the third pipe 80 and the other through hole of the dust bag is similar to that between the quick connector on the first pipe 20 and the through hole on the dust bag, which will not be repeated in this embodiment.

[0081] In this embodiment, it also includes: a third pipe 80, and a dust discharge port is provided at the bottom of the hydrocyclone. One end of the third pipe 80 is connected to the dust discharge port; a second through hole is provided below the first through hole, and the other end of the third pipe 80 is connected to the second through hole; one end of the third pipe 80 is higher than the other end; the third pipe 80 is used to transport the second type of silicon powder flowing out of the dust discharge port to the dust bag; the third pipe 80 realizes the connection between the bottom of the hydrocyclone and the dust bag, which can quickly transport the second type of silicon powder separated by the hydrocyclone to the dust bag, and the dust bag is in the sealed part 10, which can also prevent the leakage of the separated second type of silicon powder; this design also simplifies the structure, eliminating the need for other intermediate structures to collect the second type of silicon powder, which facilitates the collection of the second type of silicon powder.

[0082] As an optional implementation, the filtration device 50 includes: a removable filter element and a connection port located at the bottom outer side of the removable filter element; the connection port located at the bottom outer side of the removable filter element is fixedly connected to the other end of the second pipe 40.

[0083] Among them, the removable filter element can be a removable filter element selected according to needs for separating silicon powder and gaseous thermal silane.

[0084] The detachable filter element can also be equipped with a connection port at the bottom, which can be connected to one end of a rigid pipe, and the other end of the rigid pipe can be connected to the port of a high-pressure cylinder.

[0085] Specifically, firstly, before filtering the gas-phase thermal silane and the third type of silicon powder, the operating temperature of the filter device 50 can be set to the high-temperature range. Setting the filter operating temperature to the high-temperature range can decompose the gas-phase thermal silane and prevent silicon powder from adsorbing onto the filter element. When the gas-phase thermal silane and the third type of silicon powder in the first mixture separated by the hydrocyclone and transported to the second pipeline 40 enter the detachable filter element through the connection port at the bottom of the outer side of the detachable filter element, after being filtered by the high temperature of the detachable filter element, the third type of silicon powder obtained by filtration is trapped inside the filter element; the gas-phase thermal silane after high-temperature decomposition decomposes into hydrogen and other gases, which enter the high-pressure cylinder through the pipeline due to the pressure of the filter itself. Thus, the third type of silicon powder can be separated from the gas-phase thermal silane.

[0086] In this embodiment, the filtration device 50 includes: a detachable filter element and a connection port located at the bottom outer side of the detachable filter element; the detachable filter element and the connection port located at the bottom outer side of the detachable filter element are fixedly connected to the other end of the second pipe 40. The detachable filter element in the filtration device 50 allows for flexible selection of filter elements with different pore sizes according to different filtration needs, thereby improving the accuracy of silicon powder separation. Fixedly connecting the connection port located at the bottom outer side of the detachable filter element to the other end of the second pipe 40 ensures a tighter connection, preventing leakage of the third type of silicon powder and gaseous thermal silane due to loose connection. Furthermore, connecting the second pipe 40 to the connection port at the bottom outer side of the filter element allows the third type of silicon powder to sink after entering the filter element due to gravity, facilitating the filter element's interception of the third type of silicon powder.

[0087] As an optional implementation, it further includes: a dust backflushing device 90, a second valve 100, and a fourth pipe 110; one end of the fourth pipe 110 is connected to the second pipe 40 through the second valve 100; the other end of the fourth pipe 110 is connected to the third pipe 80; the fourth pipe 110 is higher than the third pipe 80, and one end of the fourth pipe 110 is higher than the other end; the second valve 100 is used to control the connection between the fourth pipe 110 and the second pipe 40; the dust backflushing device 90 is used to pass the third type of silicon powder through the second pipe 40 and the fourth pipe 110 so that it falls into the dust bag.

[0088] The dust backflushing device 90, the second valve 100, and the fourth pipe 110 can be used when collecting third-class silicon powder.

[0089] The dust backflushing device 90 can be a device or equipment that can be used to clean the third type of silicon powder in the filter element and prevent dangerous chemical reactions with silicon powder and gaseous thermal silane. For example, the dust backflushing device 90 can be a nitrogen backflushing device.

[0090] When it is necessary to collect the third type of silica powder in the filter element, the second valve 100 can be opened. After the second valve 100 is opened, the second pipe 40 and the fourth pipe 110 are connected.

[0091] Understandably, the fourth conduit 110 is used to form a passage with the second conduit 40 and the third conduit 80 to convey the third type of silicon powder into the dust bag.

[0092] The fourth pipe 110 can be set on the straight line where the third pipe 80 is located. Since the third pipe 80 is placed at a 45-degree angle to the horizontal line of the center of the second through hole, the fourth pipe 110 is also placed at a 45-degree angle to the horizontal line of the center of the second through hole, and thus one end of the fourth pipe 110 is higher than the other end.

[0093] Specifically, when the nitrogen backflushing device is connected to the outside of the filter device 50 through a pipe, and the third type of silicon powder is collected, the second valve 100 can be opened first, and then the nitrogen backflushing device can be opened. The nitrogen backflushing and the third type of silicon powder and the gaseous thermal silane flow into the filter device 50 are blown in high-pressure nitrogen in the opposite direction. The airflow formed by the high-pressure nitrogen generates an instantaneous impact force. The impact force formed by the airflow can destroy the electrostatic adsorption force between the third type of silicon powder and the surface of the filter material. The airflow of high-pressure nitrogen generates a pulse backflushing at the same time, which simultaneously drives the third type of silicon powder to detach from the filter element and flow into the second pipe 40 with the direction of the high-pressure nitrogen airflow. Since the second pipe 40 is also placed at a certain angle to the horizontal line where the center of the first through hole is located, the third type of silicon powder falls on the second pipe 40 under gravity. During the falling process, it enters the fourth pipe 110. The third type of silicon powder continues to fall under gravity and flows to the third pipe 80, and finally flows into the dust bag.

[0094] In this embodiment, a dust backflushing device 90, a second valve 100, and a fourth pipe 110 are included. One end of the fourth pipe 110 is connected to the second pipe 40 via the second valve 100; the other end of the fourth pipe 110 is connected to the third pipe 80. The fourth pipe 110 is higher than the third pipe 80, and one end of the fourth pipe 110 is higher than the other end. The second valve 100 is used to control the connection between the fourth pipe 110 and the second pipe 40. The dust backflushing device 90 is used to transport the third type of silicon powder through the second pipe 40 and the fourth pipe 110 to fall into the dust bag. The dust backflushing device 90 is used to transport the third type of silicon powder in the filter element with high efficiency and without damaging the filter element. Moreover, by forming a connection path with the dust bag through the pipe, the third type of silicon powder in the filter element can be quickly transported to the dust bag by the dust backflushing device 90, ensuring that the third type of silicon powder is collected in a closed pipe and preventing leakage of the third type of silicon powder.

[0095] As an optional implementation, it further includes: a fifth pipe 120; a connection port is also provided at the middle position of the dust backflushing device 90, and the connection port at the middle position of the dust backflushing device 90 is connected to one end of the fifth pipe 120; a connection port is also provided at the middle position of the other outer side of the detachable filter element, and the other end of the fifth pipe 120 is connected to the connection port at the middle position of the other outer side of the detachable filter element; the fifth pipe 120 is provided with a third valve 130; the third valve 130 is used to control the connection between the dust backflushing device 90 and the filter.

[0096] When it is necessary to collect the third type of silicon powder in the filter element or to clean the filter element, the third valve 130 can be opened. After the third valve 130 is opened, the filter device 50 and the dust backflushing device 90 are connected.

[0097] In this embodiment, a connection port is also provided at the middle position of the dust backflushing device 90, which is connected to one end of the fifth pipe 120; a connection port is also provided at the middle position of the other outer side of the detachable filter element, and the other end of the fifth pipe 120 is connected to the connection port at the middle position of the other outer side of the detachable filter element; a third valve 130 is provided in the fifth pipe 120; the third valve 130 is used to control the connection between the dust backflushing device 90 and the filter; connecting the filter device 50 to the middle position of the dust backflushing device 90 enables the dust backflushing device 90 to blow back air evenly onto the filter element when providing backflushing airflow, thereby avoiding uneven separation of the third type of silicon powder in the filter element caused by airflow bias; the third valve 130 can be provided to close or stop the dust backflushing device 90 from separating the third type of silicon powder in the filter element in a timely manner.

[0098] Figure 3 This is a schematic diagram of a dust collection device provided in an embodiment of this application, as shown below. Figure 3 As shown, the dust collection device includes: a dust collection tank 60, a sixth pipe 140, a dust bag, and a reduction exhaust gas filtration system; the dust bag is fixed in the reduction exhaust gas filtration system; the dust collection tank 60 is connected to the reduction exhaust gas filtration system through the sixth pipe 140.

[0099] The dust collection tank 60 also includes a dust collection tank switch valve 61 at the inlet position, which is used to control the outflow of the first mixture.

[0100] Specifically, firstly, the dust bag is connected to the first pipe 20, and then the dust bag is fixed in the sealing part 10 of the reduction exhaust gas filtration system; then, the dust collection tank switch valve 61 and the first valve 70 can be opened; the first mixture enters the dust bag through the sixth pipe 140, and the first type of silicon powder in the first mixture falls to the bottom of the dust bag; the second type of silicon powder, the third type of silicon powder, and the gaseous thermal silane in the first mixture enter the dust separation device 30, the dust separation device 30 separates the second type of silicon powder, and it falls into the dust bag through the third pipe 80; the third type of silicon powder and the gaseous thermal silane in the first mixture flow into the filter through the second pipe 40. The filter device 50 separates the third type of silicon powder. When the dust bag has a certain loading capacity left, the dust collection tank switch valve 61 and the first valve 70 are closed to stop the first mixture from falling from the dust collection tank 60. At the same time, the dust separation device is stopped. The dust collection tank 60 is connected to the reduction tail gas filtration system through the sixth pipe 140. It can effectively separate the first type of silicon powder, the second type of silicon powder and the third type of silicon powder in a closed reduction tail gas filtration system that prevents the accumulation of coarse particles and dust, and collect various types of silicon powder during the separation process. Moreover, all silicon powder transportation processes are closed, which can also effectively prevent the leakage of silicon powder and gaseous thermal silane.

[0101] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0102] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A reduced tail gas filtration system, characterized in that, include, A sealing part (10) is provided with a first through hole on the top of its outer side. The sealing part (10) is connected to a dust separation device (30) through a first pipe (20). The dust separation device (30) is connected to a filter device (50) through a second pipe (40). The positions of the dust separation device (30) and the filter device (50) are higher than the position of the sealing part (10). A dust bag is provided inside the sealing part (10). The dust bag includes gaseous thermal silane and silicon powder. The silicon powder includes a first type of silicon powder, a second type of silicon powder and a third type of silicon powder. The particle size of the first type of silicon powder is larger than that of the second type of silicon powder, and the particle size of the second type of silicon powder is larger than that of the third type of silicon powder. The sealing part (10) is used to convey the first mixture to the dust separation device (30) under the action of the air source. The first mixture includes gaseous thermal silane, second type silicon powder and third type silicon powder. A dust separation device (30) is used to separate gaseous thermal silane and third-type silicon powder from the first mixture and convey them to a filter device (50). A filter device (50) is used to separate gaseous thermal silane and third-type silicon powder.

2. The reduced tail gas filtration system of claim 1, wherein, The sealing part (10) includes: a sealing part body (11) and a sealing cover (12); the sealing cover (12) is fixedly connected to the sealing part body (11), and the edge of the dust bag is sandwiched between the sealing part body (11) and the sealing cover (12); a first through hole is provided at the top of the outer side of the sealing part body (11) for communicating the dust bag with the first pipe (20).

3. The reduced tail gas filtration system of claim 2, wherein, The sealing cap (12) has a through hole in the middle to allow the first mixture to be fed into the dust bag; The inner wall of the through hole is configured as a double conical structure.

4. The reduced tail gas filtration system of claim 1, wherein, The first pipe (20) is equipped with a first valve (70); The first valve (70) is used to control the connection between the dust separation device (30) and the dust bag.

5. The reduced tail gas filtration system of claim 2, wherein, The dust separation device (30) is a hydrocyclone, and the hydrocyclone has an inlet and an outlet on both sides respectively; The input port is connected to one end of the first pipe (20); The output port is connected to one end of the second pipe (40).

6. The reducing exhaust gas filtration system according to claim 5, characterized in that, Also includes: The third pipe (80) is provided with a dust discharge port at the bottom of the hydrocyclone, and one end of the third pipe (80) is connected to the dust discharge port; a second through hole is provided below the first through hole, and the other end of the third pipe (80) is connected to the second through hole; One end of the third pipe (80) is higher than the other end; The third pipe (80) is used to transport the second type of silicon powder flowing out of the dust discharge port into the dust bag.

7. The reducing exhaust gas filtration system according to claim 6, characterized in that, The filtration device (50) includes: a removable filter element and a connection port located at the bottom of the outer side of the removable filter element; The removable filter element and the connection port located at the bottom of the outer side of the removable filter element are fixedly connected to the other end of the second pipe (40).

8. The reducing exhaust gas filtration system according to claim 7, characterized in that, Also includes: The dust backflushing device (90), the second valve (100), and the fourth pipe (110) are provided. One end of the fourth pipe (110) is connected to the second pipe (40) through the second valve (100). The other end of the fourth pipe (110) is connected to the third pipe (80). The fourth pipe (110) is higher than the third pipe (80), and one end of the fourth pipe (110) is higher than the other end. The second valve (100) is used to control the connection between the fourth pipe (110) and the second pipe (40); The dust backflushing device (90) is used to pass the third type of silicon powder through the second pipe (40) and the fourth pipe (110) so that it falls into the dust bag.

9. The reducing exhaust gas filtration system according to claim 8, characterized in that, Also includes: The fifth pipe (120); a connection port is also provided in the middle of the dust back-blowing device (90), and the connection port in the middle of the dust back-blowing device (90) is connected to one end of the fifth pipe (120); a connection port is also provided in the middle of the other outer side of the detachable filter element, and the other end of the fifth pipe (120) is connected to the connection port in the middle of the other outer side of the detachable filter element; The fifth pipe (120) is equipped with a third valve (130); the third valve (130) is used to control the connection between the dust backflushing device (90) and the filter device.

10. A dust collection device, characterized in that, Includes a dust collection tank (60), a sixth pipe (140), a dust bag, and a reducing exhaust gas filtration system as described in any one of claims 1-9; The dust bag is fixed in the reduction exhaust gas filtration system; The dust collection tank (60) is connected to the reduction exhaust gas filtration system through the sixth pipe (140).

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