Tail gas recycling and filtering device

Abstract

The utility model provides a tail gas recycling and filtering device. The tail gas recycling and filtering device comprises a tank body, wherein a filtering cavity is defined in the tank body; the multiple filter elements are arranged in the filter cavity in an array mode, all the filter elements are fixedly connected to the top wall of the filter cavity, and the filter elements extend in the axial direction of the tank body; and at least part of the structure of the silicon removal mechanism is arranged in the filter cavity in the axial direction of the tank body in a liftable mode, and the silicon removal mechanism is configured to clean solid impurities on the surface of the filter element and the inner wall of the filter cavity in the lifting process. According to the tail gas recycling and filtering device, solid impurities formed on the inner wall of the filter element and the inner wall of the tank body due to the solidification and aggregation effects of liquid chlorosilane in the filtering device can be removed, and the influence on the production process is reduced.

Description

Technical Field

[0001] This application relates to the field of silicon crystal processing equipment technology, and in particular to a tail gas recovery and filtration device. Background Technology

[0002] In the polysilicon production industry, the modified Siemens process is a widely used technology. This method mainly uses chemical vapor deposition to reduce trichlorosilane into high-purity polysilicon.

[0003] The exhaust gas generated by the reduction reaction contains a large amount of silicon powder and other impurities, which need to be recovered and treated to improve resource utilization and reduce environmental pollution. Typically, silicon powder has a particle size greater than 1 μm, so filters with a filtration precision of less than 1 μm can be used to intercept silicon powder and particulate impurities in the exhaust gas. However, in addition to silicon powder, liquid chlorosilanes may also be present in the exhaust gas. These chlorosilanes solidify during cooling and accumulate on the filter walls and filter elements. These solids can cause filter blockage, reduce the effective filtration area, and affect filtration efficiency.

[0004] Because of reduced filtration efficiency, the filters need to be disassembled and cleaned frequently. This not only increases the complexity and labor intensity of maintenance, but also leads to production interruptions and reduces production efficiency. Utility Model Content

[0005] This application provides a tail gas recovery and filtration device, which is beneficial for removing solid impurities formed on the filter element and inner wall of the tank due to the solidification and aggregation of liquid chlorosilane, thereby reducing the impact on the production process.

[0006] This application provides a tail gas recovery and filtration device for silicon crystal production equipment, comprising: a tank body defining a filtration chamber within the tank body; a plurality of filter elements arranged in an array within the filtration chamber, each filter element being fixed to the top wall of the filtration chamber and extending axially along the tank body; and a silicon removal mechanism, at least a portion of which is vertically and flexibly disposed within the filtration chamber along the axial direction of the tank body, the silicon removal mechanism being configured to clean solid impurities from the surface of the filter elements and the inner wall of the filtration chamber during vertical movement.

[0007] The filtration device of this invention cleans solid impurities on the surface of the filter element and the inner wall of the filter chamber by lifting and moving a portion of the silicon removal mechanism. This reduces the frequency of manual disassembly and cleaning, lowering the maintenance complexity and labor intensity of the filtration device. Simultaneously, because the silicon removal mechanism automatically cleans solidified and accumulated chlorosilane solids, frequent clogging of the filtration device is avoided, eliminating the need to interrupt the production process for cleaning, thereby improving production efficiency.

[0008] In some embodiments, the silicon removal mechanism includes: a silicon removal unit, which is vertically and flexibly disposed in the filter chamber along the axial direction of the tank to remove solid impurities from the surface of the filter element and the inner wall of the filter chamber; and a drive unit, which is connected to the silicon removal unit to drive the silicon removal unit to move vertically and flexibly along the axial direction of the tank.

[0009] In some embodiments, the silicon removal unit includes a scraper that is slidably disposed within the filter chamber along the axial direction of the tank. The scraper has a first region that is opposite to the filter element along the axial direction of the tank. The first region has a first scraping portion that is adapted to scrape off silicon powder from the surface of the filter element during the sliding of the scraper.

[0010] According to some embodiments of the present invention, the first region has cleaning holes that correspond one-to-one with the filter element, the filter element and the cleaning holes are opposite each other along the axial direction of the tank, and the cleaning holes constitute the first scraping part.

[0011] According to some embodiments of this utility model, the inner diameter D1 of the cleaning hole and the diameter D2 of the filter element satisfy: 1cm≤D1-D2≤3cm.

[0012] According to some embodiments of the present invention, the inner wall of the cleaning hole is provided with a cleaning element, which contacts the peripheral wall of the filter element.

[0013] According to some embodiments of the present invention, the scraper further includes a second region surrounding the first region, at least a portion of the structure of the second region protruding toward the top wall of the tank to form a scraping ring platform, the peripheral wall of the scraping ring platform contacting the inner wall of the tank, and the second region having a discharge groove extending through the tank axially.

[0014] According to some embodiments of the present invention, the inner wall of the scraper ring platform forms a discharge slope, so that the inner diameter of the scraper ring platform gradually decreases in the direction close to the scraper along the tank axial direction, and the top of the discharge slope coincides with the peripheral wall of the scraper ring platform, and at least a part of the structure of the discharge groove is located on the discharge slope.

[0015] According to some embodiments of the present invention, the drive unit includes at least a telescopic device, which is fixedly installed on the tank and extends into the filter chamber. The silicon removal unit is located at the telescopic end of the telescopic device.

[0016] According to some embodiments of the present invention, it further includes: a material collection mechanism, the material collection mechanism including a conical material collection hopper and a material collection bin located at the lower end of the tank body, the bottom outlet of the material collection bin and the conical material collection hopper being connected by a discharge pipe, the discharge pipe being provided with a discharge valve, and an auxiliary air inlet pipe being connected to the side wall of the conical material collection hopper, the auxiliary air inlet pipe being connected to the filter chamber. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the exhaust gas recovery and filtration device according to an embodiment of the present utility model;

[0019] Figure 2 This is a schematic diagram of the scraper structure in Embodiment 1 of this utility model;

[0020] Figure 3 This is a schematic diagram of the scraper structure in Embodiment 2 of this utility model.

[0021] Explanation of reference numerals in the attached figures:

[0022] 100. Filtering device;

[0023] 110. Tank body; 111. Filter chamber; 112. Conical hopper;

[0024] 120. Filter element;

[0025] 130. Silicon removal mechanism;

[0026] 131, Silicon removal unit; 1311, Scraper; 1311a, First area; 1311b, First scraping section; 1311c, Cleaning hole; 1311d, Second area; 1311e, Scraper ring platform; 1311f, Discharge chute; 1311h, Discharge ramp;

[0027] 132. Drive unit; 1321. Telescopic device;

[0028] 140. Material collection mechanism; 141. Material collection bin; 142. Discharge pipe; 143. Discharge valve;

[0029] 150. Auxiliary air intake pipe.

[0030] 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

[0031] 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.

[0032] In existing polysilicon production processes, the reduction exhaust gas needs to be recovered and treated. The liquid chlorosilanes contained in the exhaust gas solidify during the cooling process and accumulate on the filter walls and filter elements. These solids can clog the filters, reduce the effective filtration area, and affect filtration efficiency.

[0033] In view of this, the present invention provides a tail gas recovery and filtration device, which is beneficial for removing solid impurities formed on the filter element and inner wall of the tank due to the solidification and aggregation of liquid chlorosilane, thereby reducing the impact on the production process.

[0034] 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 be described below with reference to the accompanying drawings.

[0035] refer to Figures 1 to 3 The exhaust gas recovery and filtration device 100 of this utility model is used in silicon crystal production equipment, such as modified CVD reactors (modified chemical vapor deposition reactors) or multi-tube reactors.

[0036] refer to Figure 1 The exhaust gas recovery and filtration device 100 may include a tank 110, multiple filter elements 120, and a silicon removal mechanism 130.

[0037] The tank body 110 defines a filter chamber 111 for containing and filtering the tail gas of the reduction reaction. The outer wall of the tank body 110 has an inlet end and an outlet end that communicate with the filter chamber 111. The reduction tail gas enters the filter chamber 111 from the inlet end for processing, and the processed gas is output from the outlet end.

[0038] Optionally, in order to increase the contact area between the exhaust gas and the filter components (such as filter element 120) in the filter chamber 111, the air inlet and outlet can be positioned with the air inlet below the air outlet.

[0039] Multiple filter elements 120 are arranged in an array inside the filter chamber 111, and all filter elements 120 are fixed to the top wall of the filter chamber 111 and extend along the axial direction of the tank 110. In this way, while increasing the filtration area, the interception efficiency of silicon powder and other particulate impurities in the exhaust gas is also improved, thereby ensuring the filtration effect of the filter device 100.

[0040] At least a portion of the structure of the silicon removal mechanism 130 is axially and vertically disposed within the filter chamber 111 along the tank body 110. The silicon removal mechanism 130 is configured to clean solid impurities from the surface of the filter element 120 and the inner wall of the filter chamber 111 during the lifting and lowering process. Exemplarily, the silicon removal mechanism 130 may include at least a silicon removal unit 131, which is axially and vertically movable along the tank body 110. The silicon removal unit 131 may be a plurality of flexible brush heads or scrapers 1311, which simultaneously contact the surface of the filter element 120 and the inner wall of the filter chamber 111. During the lifting and lowering process, the flexible brush heads or scrapers 1311 clean solid impurities from the surface of the filter element 120 and the inner wall of the filter chamber 111.

[0041] Furthermore, in some embodiments, the cleaning angle and cleaning intensity of the silicon removal unit 131 can be set and adjusted as needed to clean impurities of different accumulation levels, thereby improving the cleaning effect and extending the service life of the filter device 100.

[0042] The filter device 100 of this invention cleans solid impurities on the surface of the filter element 120 and the inner wall of the filter chamber 111 by lifting and lowering the silicon removal mechanism 130. This reduces the frequency of manual disassembly and cleaning, lowering the maintenance complexity and labor intensity of the filter device 100. Simultaneously, because the silicon removal mechanism 130 can automatically clean solidified and accumulated chlorosilane solids, frequent clogging of the filter device 100 is avoided, thus eliminating the need to interrupt the production process for cleaning, thereby improving production efficiency.

[0043] refer to Figure 1 In some embodiments, the silicon removal mechanism 130 may include a silicon removal unit 131 and a drive unit 132. The silicon removal unit 131 is vertically and flexibly disposed in the filter chamber 111 along the axial direction of the tank 110 to remove solid impurities from the surface of the filter element 120 and the inner wall of the filter chamber 111. The drive unit 132 is driven by the silicon removal unit 131 to drive the silicon removal unit 131 to move vertically and flexibly along the axial direction of the tank 110. Exemplarily, the silicon removal unit 131 may be multiple flexible brush heads or scrapers 1311, and the drive unit 132 may include a control module and a drive device. The drive device and the flexible brush heads or scrapers 1311 may be driven by a lead screw, or the flexible brush heads or scrapers 1311 and the drive device may also be connected by a telescopic rod. The control module may be used to control the lifting height of the drive device and the cleaning frequency and cleaning force of the silicon removal unit 131.

[0044] In this way, the silicon removal unit 131 can precisely rise and fall along the axial direction of the tank 110, ensuring complete coverage of the surface of the filter element 120 and the inner wall of the filter chamber 111, effectively removing solid impurities and maintaining the efficient operation of the filter device 100. The drive unit 132 can be connected to the silicon removal unit 131 through an automated control system to achieve automatic lifting and cleaning, eliminating the need for manual disassembly of the filter device 100 and interruption of the production process for cleaning, reducing the labor intensity of workers, and allowing cleaning to be performed without stopping the machine, which helps to ensure the continuity of the production process and thus improve production efficiency. In addition, the modular design of the drive unit 132 and the silicon removal unit 131 makes the maintenance and component replacement of the filter device 100 simpler and faster, reducing the maintenance cost and time of the filter device 100.

[0045] refer to Figure 2 and Figure 3 In some embodiments, the silicon removal unit 131 may include a scraper 1311, which is slidably disposed within the filter chamber 111 along the axial direction of the tank 110. The scraper 1311 has a first region 1311a, which is axially opposite to the filter element 120 along the tank 110. The first region 1311a has a first scraping portion 1311b, which is adapted to scrape silicon powder from the surface of the filter element 120 during the sliding of the scraper 1311. Exemplarily, the first scraping portion 1311b may have an annular structure corresponding to the filter element 120. During the lifting and lowering movement of the scraper 1311, the filter element 120 passes through the annular structure. The inner diameter of the annular structure may be adapted to the diameter of the filter element 120 or slightly larger than the diameter of the filter element 120. When solid impurities condense on the peripheral wall of the filter element 120, affecting the filtration effect, the overall diameter of the filter element 120 increases due to the presence of impurities. As the scraper 1311 moves axially along the tank 110, the protruding solid impurities on the peripheral wall of the filter element 120 are impacted by the annular structure and fall off the surface of the filter element 120, thereby cleaning the surface of the filter element 120. Of course, the first scraping part 1311b can also be other structures that come into contact with the protruding solid impurities on the peripheral wall of the filter element 120 during the lifting and lowering movement of the scraper 1311, such as a U-shaped structure, a C-shaped structure, or a V-shaped structure, etc. This embodiment does not limit this.

[0046] In this way, it can be ensured that during the lifting and lowering movement of the scraper 1311, the first scraping part 1311b scrapes away the silica powder and other impurities adhering to the surface of the filter element 120, ensuring the cleanliness of the filter element 120 surface and guaranteeing the filtration effect. Regularly cleaning the silica powder on the surface of the filter element 120 ensures that the filter element 120 can maintain high-efficiency filtration performance, improving the stability and reliability of exhaust gas treatment. At the same time, regularly scraping away accumulated silica powder can also reduce wear on the filter element 120, which helps extend the service life of the filter element 120 and the entire filter device 100, reducing the maintenance and replacement costs of the filter device 100.

[0047] refer to Figure 2 According to some embodiments of the present invention, the first region 1311a has cleaning holes 1311c that correspond one-to-one with the filter element 120. The filter element 120 and the cleaning holes 1311c are axially opposite to each other along the tank body 110. The cleaning holes 1311c constitute the first scraping part 1311b.

[0048] In this way, the cleaning holes 1311c correspond one-to-one with the filter elements 120, ensuring that the surface of each filter element 120 can be effectively cleaned. The design of the cleaning holes 1311c makes the scraping process more precise and can effectively remove silica powder and other impurities from the surface of the filter element 120.

[0049] Understandably, when the first scraping section 1311b forms a cleaning hole 1311c, during the lifting and lowering of the scraper 1311, solid impurities such as silica powder condensed on the surface of the filter element 120 are detached by the impact of the end walls at both ends of the cleaning hole 1311c of the scraper 1311. When the scraper 1311 slides from bottom to top, the solid impurities detached from the surface of the filter element 120 fall onto the upper surface of the scraper 1311, which is not conducive to collection. Furthermore, if the inner wall of the cleaning hole 1311c is equal to the diameter of the filter element 120, there may be a situation where solid impurities are tightly condensed on the surface of the filter element 120. In this case, when the scraper 1311 slides up and down to scrape off the solid impurities on the surface of the filter element 120, the tightly condensed solid impurities may cause deformation of the filter element 120 or even damage to the filter element 120. Therefore, the inner wall of the cleaning hole 1311c can have a certain gap with the surface of the filter element 120. On the one hand, this avoids the filter element 120 from being directly in contact with the scraper 1311, which would cause the filter element 120 to be damaged by impact. On the other hand, it also makes it easier for the scraper 1311 to remove solid impurities so that the material can fall between the inner wall of the cleaning hole 1311c and the surface of the filter element 120.

[0050] According to some embodiments of the present invention, the inner diameter D1 of the cleaning hole 1311c and the diameter D2 of the filter element 120 satisfy the following condition: 1cm≤D1-D2≤3cm. For example, the value of D1-D2 can be 1cm, 1.5cm, 2cm, 2.5cm or 3cm. Of course, the value of D1-D2 can also be other values, and this application does not limit this.

[0051] Thus, on the one hand, it avoids the difference between the inner diameter D1 of the cleaning hole 1311c and the diameter D2 of the filter element 120 being too small (e.g., less than 1cm), resulting in an insufficient gap between the surface of the filter element 120 and the cleaning hole 1311c, making it difficult for material to fall. On the other hand, it avoids the difference between the inner diameter D1 of the cleaning hole 1311c and the diameter D2 of the filter element 120 being too large (e.g., exceeding 3cm), resulting in an excessively large gap between the surface of the filter element 120 and the inner wall of the cleaning hole 1311c. When the deposition height of solid impurities on the filter element 120 is less than 3cm, the solid impurities will not contact the end face of the cleaning hole 1311c during the up-and-down movement of the scraper 1311, resulting in poor cleaning effect on the filter element 120.

[0052] refer to Figure 3 Optionally, in other embodiments of this utility model, the first scraping part 1311b may also be a plurality of cleaning rings arrayed in the first region 1311a, with the filter element 120 and the through hole in the middle of the cleaning ring facing each other along the axial direction of the tank body 110, and the diameter of the through hole of the cleaning ring being slightly larger than the diameter of the filter element 120. During the lifting and lowering movement of the scraper 1311, the cleaning ring scrapes the impurities attached to the peripheral wall of the filter element 120, resulting in a large scraping area and good cleaning effect.

[0053] Meanwhile, the cleaning rings are fixedly connected by connecting ribs, thus forming a mesh structure within the first region 1311a, with hollow structures formed between the connecting ribs. When the scraper 1311 moves to scrape off impurities, the impurities can fall through the hollow structure under the action of gravity and will not accumulate on the scraper 1311, which is conducive to continuous cleaning work and thus improves production efficiency.

[0054] According to some embodiments of this utility model, the inner wall of the cleaning hole 1311c is provided with a cleaning element, which contacts the peripheral wall of the filter element 120. For example, the cleaning element can be flexible bristles spaced apart around the axis of the cleaning hole 1311c; alternatively, the cleaning element can be multiple sponge blocks arranged spaced apart around the axis of the cleaning hole 1311c. Since the inner diameter of the cleaning hole 1311c exceeds the outer diameter of the filter element 120, when the scraper 1311 moves up and down, there is a certain gap between the end wall of the cleaning hole 1311c, which acts as a scraper, and the filter element 120. This results in some impurities remaining on the filter element 120. Further cleaning of the surface of the filter element 120 by the cleaning element helps improve the cleaning effect of the filter element 120, thereby improving the filtration effect of the filtration device 100.

[0055] refer to Figure 2 and Figure 3According to some embodiments of the present invention, the scraper 1311 further includes a second region 1311d surrounding the first region 1311a. At least a portion of the structure of the second region 1311d protrudes toward the top wall of the tank 110 to form a scraping ring platform 1311e. Exemplarily, the second region 1311d may include an annular portion outside the first region 1311a of the scraper 1311. The protruding portion of the second region 1311d may be the periphery of the scraper 1311 protruding toward the top wall of the tank 110 to form the scraping ring platform 1311e, or the entire annular portion outside the first region 1311a may protrude toward the top wall of the tank 110 to form the scraping ring platform 1311e. The peripheral wall of the scraper ring platform 1311e contacts the inner wall of the tank 110. Thus, during the sliding process of the scraper 1311, the end wall of the scraper ring platform 1311e scrapes and cleans the solid impurities condensed on the inner wall of the filter chamber 111, thereby achieving a cleaning effect on the inner wall of the filter chamber 111.

[0056] refer to Figure 2 and Figure 3 The second region 1311d has a discharge trough 1311f that runs through the tank body 110 axially. In this way, solid impurities scraped by the scraper ring 1311e can fall and be collected along the discharge trough 1311f under the action of gravity, thus avoiding the accumulation of solid impurities in the filter chamber 111 and the impact on the filtration effect of the filter device 100.

[0057] According to some embodiments of the present invention, the inner wall of the scraper ring platform 1311e forms a discharge slope 1311h, so that the inner diameter of the scraper ring platform 1311e gradually decreases in the direction close to the scraper 1311 along the axial direction of the tank body 110. In other words, the discharge slope 1311h makes the inner side of the scraper ring platform 1311e form a trumpet-shaped structure that is larger at the top and smaller at the bottom, so that the solid impurities scraped off by the scraper ring platform 1311e can fall through the discharge slope 1311h, avoiding the accumulation of solid impurities and affecting the filtration effect of the filter device 100.

[0058] The top of the feeding inclined surface 1311h coincides with the peripheral wall of the scraping ring platform 1311e, thus forming a blade-like structure at the top of the scraping ring platform 1311e, which provides better cleaning effect for solid impurities on the inner wall of the filter chamber 111.

[0059] At least a portion of the structure of the discharge trough 1311f is located on the discharge slope 1311h. For example, the discharge trough 1311f may be located in the middle of the discharge slope 1311h, or it may be located at the bottom end of the discharge slope 1311h. Alternatively, a portion of the structure of the discharge trough 1311f may be located at the bottom end of the discharge slope 1311h, while another portion is located in the first region 1311a. This ensures that solid impurities scraped off by the scraper ring 1311e can be discharged via the discharge trough 1311f, thereby reducing the residue of solid impurities and ensuring the filtration effect of the filter device 100.

[0060] refer to Figure 1 According to some embodiments of the present invention, the drive unit 132 includes at least a telescopic device 1321, which is fixedly installed on the tank body 110, and the telescopic end of the telescopic device 1321 extends into the filter chamber 111. The silicon removal unit 131 is disposed at the telescopic end of the telescopic device 1321. Exemplarily, the telescopic device 1321 can be an electric telescopic cylinder, with a guide hole in the tank body 110. The telescopic end of the electric telescopic cylinder passes through the guide hole and extends into the filter chamber 111, telescopically extending and retracting along the axial direction of the tank body 110. The scraper 1311 is fixedly connected to the telescopic end of the electric telescopic cylinder. Alternatively, the telescopic device 1321 can also be a drive motor and a lead screw mechanism. The drive motor is disposed on the tank body 110, and the lead screw is connected to the output end of the drive motor. The lead screw passes through the tank body 110 and extends into the filter chamber 111. The scraper 1311 is rotatably connected to the lead screw, and the drive motor drives the lead screw to rotate to achieve the lifting and lowering movement of the scraper 1311 along the axial direction of the tank body 110.

[0061] Continue to refer to Figure 1 According to some embodiments of this utility model, the filtration device 100 may further include a collection mechanism 140, which includes a conical hopper 112 and a collection bin 141 located at the lower end of the tank 110. The collection bin 141 and the bottom outlet of the conical hopper 112 are connected by a discharge pipe 142, which is equipped with a discharge valve 143. During or after the cleaning of the filter element 120 and the inner wall of the filter chamber 111 by the desiliconization unit 131, the discharge valve 143 can be opened, and solid impurities will fall into the collection bin 141 for collection under the collection effect of the conical hopper 112 and their own gravity. In this way, the entire process of cleaning the filtration device 100 does not require opening the filtration device 100, making the cleaning operation convenient and greatly reducing the labor intensity of workers. At the same time, it also avoids unnecessary disassembly and maintenance of the filtration device 100, saving production time and improving production efficiency.

[0062] An auxiliary air inlet pipe 150 is connected to the side wall of the conical hopper 112, and the auxiliary air inlet pipe 150 communicates with the filter chamber 111. Exemplarily, the auxiliary air inlet pipe 150 can introduce an inert gas (such as nitrogen) that does not react with the exhaust gas into the filter chamber 111. During the cleaning process of the silicon removal unit 131 into the filter chamber 111, too many solid impurities may occur, causing blockage of the discharge channels such as the discharge chute 1311f on the scraper 1311. At this time, the scraper 1311 is positioned above the auxiliary air inlet pipe 150, the air inlet pipe of the tank 110 is closed, and nitrogen is introduced into the filter chamber 111 through the auxiliary air inlet pipe 150. The air pressure is used to open the blocked discharge chute 1311f, thereby improving the reliability of the cleaning process of the filter device 100.

[0063] Understandably, the auxiliary air inlet pipe 150 is not normally open to avoid blowing scraped solid impurities from the outlet of the tank 110 to downstream equipment.

[0064] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility model 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.

[0065] 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 tail gas recovery and filtration device (100) for use in silicon crystal production equipment, characterized in that, include: A tank (110) having a filter chamber (111) defined within it. Multiple filter elements (120) are arranged in an array in the filter chamber (111). Each filter element (120) is fixed to the top wall of the filter chamber (111) and extends axially along the tank body (110). A silicon removal mechanism (130) is provided, at least a portion of which is axially movable within the filter chamber (111) along the tank body (110). The silicon removal mechanism (130) is configured to clean solid impurities from the surface of the filter element (120) and the inner wall of the filter chamber (111) during the lifting process.

2. The exhaust gas recovery and filtration device (100) according to claim 1, characterized in that, The silicon removal mechanism (130) includes: A silicon removal unit (131) is provided vertically and flexibly in the filter chamber (111) along the axial direction of the tank (110) to remove solid impurities from the surface of the filter element (120) and the inner wall of the filter chamber (111); A drive unit (132) is connected to the silicon removal unit (131) to drive the silicon removal unit (131) to move up and down along the tank body (110) axially.

3. The exhaust gas recovery and filtration device (100) according to claim 2, characterized in that, The silicon removal unit (131) includes a scraper (1311), which is slidably disposed within the filter chamber (111) along the axial direction of the tank body (110). The scraper (1311) has a first region (1311a), which is axially opposite to the filter element (120) along the tank body (110). The first region (1311a) has a first scraping part (1311b) adapted to scrape off the silicon powder on the surface of the filter element (120) during the sliding of the scraper (1311).

4. The exhaust gas recovery and filtration device (100) according to claim 3, characterized in that, The first region (1311a) has cleaning holes (1311c) that correspond one-to-one with the filter element (120). The filter element (120) and the cleaning holes (1311c) are axially opposite to each other along the tank body (110). The cleaning holes (1311c) constitute the first scraping part (1311b).

5. The exhaust gas recovery and filtration device (100) according to claim 4, characterized in that, The inner diameter D1 of the cleaning hole (1311c) and the diameter D2 of the filter element (120) satisfy the following condition: 1cm≤D1-D2≤3cm.

6. The exhaust gas recovery and filtration device (100) according to claim 4, characterized in that, The inner wall of the cleaning hole (1311c) is provided with a cleaning element, which is in contact with the peripheral wall of the filter element (120).

7. The exhaust gas recovery and filtration device (100) according to claim 3, characterized in that, The scraper (1311) further includes a second region (1311d) surrounding the first region (1311a), at least a portion of the structure of the second region (1311d) protruding toward the top wall of the tank (110) to form a scraping ring platform (1311e), the peripheral wall of the scraping ring platform (1311e) contacting the inner wall of the tank (110). The second region (1311d) has a discharge chute (1311f) that extends through the tank body (110) axially.

8. The exhaust gas recovery and filtration device (100) according to claim 7, characterized in that, The inner wall of the scraper ring platform (1311e) forms a discharge slope (1311h) such that the inner diameter of the scraper ring platform (1311e) gradually decreases in the direction along the axial direction of the tank body (110) towards the scraper (1311), and the top of the discharge slope (1311h) coincides with the peripheral wall of the scraper ring platform (1311e). At least a portion of the structure of the discharge chute (1311f) is located on the discharge ramp (1311h).

9. The exhaust gas recovery and filtration device (100) according to claim 2, characterized in that, The drive unit (132) includes at least a telescopic device (1321), which is fixedly installed on the tank (110), and the telescopic end of the telescopic device (1321) extends into the filter chamber (111). The silicon removal unit (131) is located at the telescopic end of the telescopic device (1321).

10. The exhaust gas recovery and filtration device (100) according to claim 1, characterized in that, Also includes: The material collection mechanism (140) includes a conical hopper (112) and a collection bin (141) located at the lower end of the tank (110). The bottom outlets of the collection bin (141) and the conical hopper (112) are connected by a discharge pipe (142), and the discharge pipe (142) is equipped with a discharge valve (143). An auxiliary air inlet pipe (150) is connected to the side wall of the conical hopper (112), and the auxiliary air inlet pipe (150) is connected to the filter chamber (111).

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