Integrated multi-stage adsorption and impurity removal treatment device for polycrystalline silicon preparation
By using an integrated multi-stage adsorption and impurity removal device with differentiated configuration of regenerable adsorbents, the problem of fluctuating impurity removal efficiency in polysilicon production has been solved, achieving efficient and economical impurity separation and continuous equipment operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-03-31
AI Technical Summary
Existing metal impurity removal technologies in polysilicon production suffer from poor adaptability and difficulty in rapid adaptive adjustment, leading to fluctuations in impurity removal efficiency. Furthermore, the adsorption materials exhibit poor selectivity and rapid saturation, impacting continuous production efficiency and costs.
An integrated multi-stage adsorption and impurity removal device is adopted, including a primary crude distillation column, a first adsorption component, a second adsorption component, a primary rectification column, a secondary rectification column, and a cold hydrogenation device. Through the differentiated configuration of regenerable adsorbents, multi-stage separation and regeneration cycle are achieved, reducing equipment investment and energy consumption.
It improves the efficiency of impurity removal, reduces equipment investment and production energy consumption, ensures continuous equipment operation, reduces the frequency of consumable replacement, and enhances production stability and economy.
Smart Images
Figure CN121754918A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polycrystalline silicon preparation technology, and in particular to an integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation. Background Technology
[0002] Polysilicon is a core material in high-end manufacturing fields such as photovoltaic power plants and semiconductor chips. Its purity directly determines the performance stability and lifespan of the end products. The residual amount of metal impurities (such as boron (B) and phosphorus (P)) needs to be controlled at the ppb level to meet the requirements of high conversion efficiency of photovoltaic modules and low defect density of semiconductor devices. Therefore, the removal of metal impurities is a core technical step in the polysilicon production purification process.
[0003] Currently, the main technologies for removing metal impurities during polysilicon production include chemical precipitation, vacuum distillation, adsorption, and membrane separation. Among these, adsorption is the most widely used technology in large-scale polysilicon production lines due to its advantages such as simple operation, low equipment investment cost, and no need for large amounts of chemical reagents. Existing adsorption methods typically use adsorption materials such as porous ceramics, ion exchange resins, and modified activated carbon to capture metal ions in the polysilicon feed solution and reduce the exhaust gas through physical or chemical adsorption, thereby achieving impurity separation.
[0004] In polysilicon production, multi-stage removal technology for metal impurities has formed a technical system with "multi-stage separation process" and "adsorption-distillation coupling" as its core, but there is still significant room for optimization.
[0005] In multi-stage separation processes, the industry mainstream adopts multi-stage series distillation columns or partitioned columns to achieve stepwise removal of impurities. For example, by connecting 3-5 distillation columns in series, the boiling point difference between metal chlorides and chlorosilanes is used to separate high- and low-boiling-point impurities step by step. Some systems introduce partitioned column designs, achieving synergistic pre-separation and deep purification through zoning within a single column, reducing equipment footprint by more than 30%. However, such technologies are not efficient enough for separating trace impurities at the ppb level with similar boiling points.
[0006] Adsorption-distillation coupling technology is an important approach to improve impurity removal accuracy. Existing systems often use a fixed adsorption bed before distillation, employing materials such as alumina gel to capture metal ions, followed by multi-stage distillation for deep purification, which can reduce boron and phosphorus impurities to the ppb level. However, adsorption materials suffer from poor selectivity and rapid saturation: a single material cannot effectively handle the directional adsorption of multiple types of impurities, and once saturated, the system must be shut down for adsorbent replacement, affecting the continuous operation efficiency of multi-stage systems. This is especially problematic in large-scale production, where consumable replacement costs account for a significant portion of the overall cost. Summary of the Invention
[0007] The technical problem to be solved by the present invention is that the existing technology has poor adaptability to complex working conditions such as raw material fluctuations or changes in production load, and it is difficult to quickly adapt and adjust, resulting in fluctuations in impurity removal efficiency. To this end, we propose an integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation.
[0008] To achieve the above objectives, this application adopts the following technical solution: an integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation, comprising a primary crude distillation column, a first adsorption component, a second adsorption component, a primary rectification column, a secondary rectification column, and a cold hydrogenation device. The raw material chlorosilane in the cold hydrogenation device enters the primary crude distillation column for primary separation. Light impurities in the raw material chlorosilane in the primary crude distillation column are collected from the top and enter the second adsorption component. The second adsorption component removes the light impurities through adsorption with a regenerable adsorbent before entering the cold hydrogenation device. Heavy impurities in the raw material chlorosilane in the primary crude distillation column are collected from the bottom and enter the first… The adsorption unit consists of two stages. First, the chlorosilanes, after being adsorbed by a regenerable adsorbent with most heavy impurities, enter a primary distillation column for secondary separation. Heavy impurities in the chlorosilanes within the primary distillation column are collected from the bottom and enter a second adsorption unit. Light impurities in the chlorosilanes within the primary distillation column are collected from the top and enter a secondary distillation column for tertiary separation. Heavy impurities in the chlorosilanes within the secondary distillation column are collected from the bottom and enter the second adsorption unit. Second, the chlorosilanes, after being adsorbed by a regenerable adsorbent with most heavy impurities removed, return to the cold hydrogenation unit. The secondary distillation column produces trichlorosilane, which is used in the reduction workshop to produce polysilicon. Both the first adsorption component and the second adsorption component include multiple shells. The side walls of the multiple shells are provided with circular grooves, and the inner walls of the multiple circular grooves are provided with annular grooves. A rotating ring is slidably connected to the inner wall of the annular groove. The upper and lower ends of the ring are provided with first grooves. An adsorption column is fixedly connected through the inner walls of two first grooves.
[0009] Preferably, filter holes are provided at both the bottom and top of the adsorption column, and two sieve plates are slidably connected to the inner wall of the adsorption column. Adsorbent is provided in the space formed by the side walls of the two sieve plates that are close to each other and the inner wall of the adsorption column.
[0010] Preferably, a second groove is provided at the top and bottom of the annular groove, and a third groove is provided on the inner walls of both sides of the annular groove. The inner wall of the lower second groove is fixedly connected to a feed pipe, and the inner wall of the upper second groove is fixedly connected to a discharge pipe. One of the third grooves is fixedly connected to a liquid inlet pipe, and the other is fixedly connected to a liquid outlet pipe. A motor is fixedly connected to the side wall of the shell, and the output end of the motor is fixedly connected to the side wall of the adsorption column. During rotation, both first grooves cooperate with the two second grooves or the two third grooves.
[0011] Preferably, the adsorption column is provided with a loosening mechanism, which includes a groove formed on the side wall of the adsorption column. A U-shaped rod is slidably connected through the inner wall of the groove. The upper and lower ends of the U-shaped rod inside the adsorption column are respectively engaged with the side walls of two sieve plates that are far apart from each other. The upper and lower ends of the U-shaped rod inside the adsorption column are rotatably connected to the side walls of their corresponding sieve plates through a rotating rod.
[0012] Preferably, an L-shaped plate is fixedly connected to the outer wall of the U-shaped rod, the side wall of the L-shaped plate is elastically connected to the inner wall of the ring through multiple springs, a first arched plate is fixedly connected to the inner wall of the circular groove, and a second arched plate is fixedly connected to the side wall of the L-shaped plate near the spring.
[0013] Preferably, the adsorption column is provided with a mixing mechanism, which includes a rotating shaft that is rotatably and sealingly connected to the top of the adsorption column. The lower side wall of the rotating shaft is slidably and sealingly fitted with the sieve plate located above it. A mixing tank is fixedly connected to the lower end of the rotating shaft. Multiple adjusting tanks are fixedly connected to the inner wall of the mixing tank. T-shaped rods are slidably and sealingly connected to the inner walls of the multiple adjusting tanks. The side walls of the T-shaped rods are slidably and sealingly connected to the side walls of the mixing tanks. The multiple T-shaped rods are staggered.
[0014] Preferably, the inner walls of two adjacent regulating barrels are fixedly connected by a connecting pipe, and the inner wall of the first groove located above is fixedly connected to a rotary joint by a bracket. The output end of the rotary joint is fixedly connected to the inner wall of the uppermost regulating barrel by a rigid pipe, and the rigid pipe passes through the side wall of the rotating shaft.
[0015] Preferably, an oil storage frame is fixedly connected to the top of the adsorption column, and the top of the oil storage frame is fixedly connected to the input end of the rotary joint through a connecting pipe. A T-shaped plate is slidably connected to the inner wall of the oil storage frame, and the lower end of the T-shaped plate is fixedly connected to the upper end of the sieve plate located above. Hydraulic oil is provided in multiple adjusting tanks and oil storage frames.
[0016] Preferably, the housing is provided with a rotating mechanism, which includes two cylinders fixedly connected to the side wall of the housing. The output ends of the two cylinders are fixedly connected to a horizontal plate. An arc-shaped helical tooth plate is fixedly connected to the side wall of the horizontal plate. The side wall of the arc-shaped helical tooth plate is slidably and sealingly connected to the inner wall of the circular groove. The arc-shaped helical tooth plate is located near the liquid inlet pipe. A through groove is opened on the side wall of the first groove located above the arc-shaped helical tooth plate. The side wall of the arc-shaped helical tooth plate fits against the inner wall of the through groove. A helical gear is fixedly connected to the upper side wall of the rotating shaft.
[0017] Preferably, the boron content after treatment by the first adsorption component is ≤50ppb, the boron content after treatment by the second adsorption component is ≤20ppb, and the boron content after treatment by the distillation secondary column is ≤10ppb. The first adsorption component consists of two shells connected in parallel, one of which is in operation and the other is in standby. The second adsorption component consists of five shells connected in parallel, three of which are in operation and the other two are in standby.
[0018] The technical effects and advantages of this invention are as follows: 1. This treatment device eliminates the original process flow's distillation system and high / low boiling waste recovery system, including the original process flow's primary distillation column, secondary distillation column, primary high / low boiling waste column, secondary high / low boiling waste column, tertiary high / low boiling waste column, quaternary high / low boiling waste column, high / low boiling waste system adsorption column, high / low boiling waste system adsorption column, and high / low boiling waste system adsorption column. This reduces a total of six distillation columns and four adsorption column locations, resulting in eight adsorption columns. A first adsorption assembly and a second adsorption assembly are added. The first adsorption assembly utilizes the original high / low boiling waste system adsorption column, and the second adsorption assembly utilizes the original high / low boiling waste system adsorption column, high / low boiling waste system adsorption column, and high / low boiling waste system adsorption column. No additional equipment investment is required.
[0019] 2. Adopting a series integrated design of "adsorption-distillation coupling-deep purification", a first adsorption component and a second adsorption component are added to form a staged treatment unit. Through the differentiated adsorption configuration of the dual adsorption columns, the precise stepwise removal of impurities such as boron and phosphorus is achieved, which greatly improves the overall impurity removal efficiency. At the same time, the number of operating distillation equipment is reduced, thus reducing equipment investment and production energy consumption.
[0020] 3. The adsorbent selected is a regenerable domestic boron removal B and phosphorus removal P aluminum gel, which has a better impurity removal rate than the adsorbent originally used in the system. At the same time, relying on its regenerable characteristics, it avoids material loss caused by single use, and balances adsorption performance and economic efficiency.
[0021] 4. The parallel backup architecture of the adsorption units is adopted to ensure continuous operation of the equipment and avoid production interruptions caused by maintenance of a single set of equipment. Combined with the adsorption material regeneration and circulation system, the frequency of purchasing and replacing fresh consumables is reduced, and the energy consumption during equipment operation is reduced, forming a dual cost control system for consumables and energy consumption. Attached Figure Description
[0022] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of the structure of an integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to the present invention; Figure 2 This is a schematic diagram of the structure of the shell in an integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to the present invention; Figure 3 for Figure 2 A schematic diagram of the structure after the annular groove and the circular ring are separated; Figure 4 for Figure 2 A schematic diagram of the vertical sectional structure; Figure 5 for Figure 4 Enlarged structural diagram at point A; Figure 6 for Figure 2 A top-view sectional structural diagram; Figure 7 for Figure 5 Enlarged structural diagram at point B; Figure 8 for Figure 2 A schematic diagram of the rear view structure of the middle ring; Figure 9 for Figure 2 A schematic diagram of the rear view structure.
[0023] Legend: 1. First-stage crude distillation column; 2. First adsorption unit; 3. Second adsorption unit; 4. First-stage rectification column; 5. Second-stage rectification column; 6. Cold hydrogenation unit; 7. Shell; 8. First tank; 9. Annular tank; 10. Circular ring; 11. Adsorption column; 12. Filter holes; 13. Sieve plate; 14. Second tank; 15. Feed pipe; 16. Discharge pipe; 17. Third tank; 18. Liquid inlet pipe; 19. Liquid outlet pipe; 20. Motor; 21. Slide chute; 22. 23. U-shaped rod; 24. Rotating rod; 25. L-shaped plate; 26. Spring; 27. First arched plate; 28. Second arched plate; 29. Rotating shaft; 20. Mixing tank; 31. Adjusting tank; 32. T-shaped rod; 33. Connecting pipe; 34. Rigid pipe; 35. Rotary joint; 36. Oil reservoir frame; 37. T-shaped plate; 38. Connecting pipe; 39. Helical gear; 40. Arc-shaped helical gear plate; 41. Cylinder; 42. Horizontal plate; 43. Through groove; 44. Circular groove. Detailed Implementation
[0024] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.
[0025] Reference Figure 1 - Figure 9As shown, the present invention provides a technical solution: an integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation, comprising a primary distillation column 1, a first adsorption component 2, a second adsorption component 3, a primary rectification column 4, a secondary rectification column 5, and a cold hydrogenation device 6. The raw material chlorosilane in the cold hydrogenation device 6 enters the primary distillation column 1 for primary separation. Light impurities in the raw material chlorosilane in the primary distillation column 1 are collected from the top and enter the second adsorption component 3. After the light impurities are removed by adsorption with a regenerable adsorbent in the second adsorption component 3, the material enters the cold hydrogenation device 6. Heavy impurities in the raw material chlorosilane in the primary distillation column 1 are collected from the bottom and enter the first adsorption component 6. Component 2: After the first adsorption component 2 adsorbs most of the heavy impurities, the chlorosilane enters the first-stage distillation column 4 for secondary separation. The heavy impurities in the chlorosilane in the first-stage distillation column 4 are collected from the bottom and enter the second adsorption component 3. The light impurities in the chlorosilane in the first-stage distillation column 4 are collected from the top and enter the second-stage distillation column 5 for tertiary separation. The heavy impurities in the second-stage distillation column 5 are collected from the bottom and enter the second adsorption component 3. After the second adsorption component 3 adsorbs most of the heavy impurities and removes them with the regenerable adsorbent, it returns to the cold hydrogenation unit 6. The second-stage distillation column 5 produces trichlorosilane, which is used in the reduction workshop to produce polysilicon.
[0026] This treatment device eliminates the original process flow's distillation system and high / low boiling waste recovery system, including the original process's primary distillation column 4, secondary distillation column 5, primary high / low boiling column, secondary high / low boiling column, tertiary high / low boiling column, quaternary high / low boiling column, high / low boiling system adsorption column, high / low boiling system adsorption column, high / low boiling system adsorption column, and high / low boiling system adsorption column. This reduces six distillation columns and four adsorption column locations, totaling eight adsorption columns. It adds a first adsorption assembly 2 and a second adsorption assembly 3. The first adsorption assembly 2 utilizes the existing high / low boiling system adsorption column, and the second adsorption assembly 3 utilizes the existing high / low boiling system adsorption columns, high / low boiling system adsorption columns, and high / low boiling system adsorption columns. No additional equipment investment is required. It adopts a series integrated design of "adsorption-distillation coupling-deep purification," with the addition of the first adsorption assembly 2 and the second adsorption assembly 3 forming a staged treatment unit. Through the differentiated adsorption configuration of the dual adsorption columns, it achieves precise stepwise removal of boron and phosphorus impurities, significantly improving the overall impurity removal efficiency. Simultaneously, it reduces the number of operating distillation equipment, lowering equipment investment and production energy consumption.
[0027] The first adsorption component 2 and the second adsorption component 3 both include multiple housings 7. The side walls of the multiple housings 7 are provided with circular grooves 43. The inner walls of the multiple circular grooves 43 are provided with annular grooves 9. A rotating ring 10 is slidably connected to the inner wall of the annular groove 9. The upper and lower ends of the ring 10 are provided with first grooves 8. An adsorption column 11 is fixedly connected through the inner walls of the two first grooves 8.
[0028] The adsorption column 11 has filter holes 12 at both the bottom and top. Two sieve plates 13 are slidably connected to the inner wall of the adsorption column 11. The space formed by the side walls of the two sieve plates 13 and the inner wall of the adsorption column 11 contains the adsorbent. Furthermore, the adsorbent is a regenerable domestic boron removal B and phosphorus removal P aluminum gel with a better impurity removal rate than the adsorbent originally used in the system. At the same time, relying on its regenerable characteristics, it avoids material loss caused by single use and takes into account both adsorption performance and economic efficiency.
[0029] The boron content after treatment by the first adsorption component 2 is ≤50ppb, the boron content after treatment by the second adsorption component 3 is ≤20ppb, and the boron content after treatment by the distillation secondary column 5 is ≤10ppb. The first adsorption component 2 is composed of two shells 7 connected in parallel, one of which is in operation and the other is in standby. The second adsorption component 3 is composed of five shells 7 connected in parallel, three of which are in operation and the other two are in standby.
[0030] The system adopts a parallel backup architecture for adsorption units to ensure continuous operation of the equipment and avoid production interruptions caused by maintenance of a single unit. Combined with an adsorption material regeneration and recycling system, it reduces the frequency of purchasing and replacing fresh consumables, while also reducing energy consumption during equipment operation, thus forming a dual cost control system for consumables and energy consumption.
[0031] The annular groove 9 has a second groove 14 at the top and bottom, and a third groove 17 on each side of the inner wall. The inner wall of the lower second groove 14 is fixedly connected to the feed pipe 15, and the inner wall of the upper second groove 14 is fixedly connected to the discharge pipe 16. One of the third grooves 17 is fixedly connected to the liquid inlet pipe 18, and the other third groove 17 is fixedly connected to the liquid outlet pipe 19. A motor 20 is fixedly connected to the side wall of the shell 7. The output end of the motor 20 is fixedly connected to the side wall of the adsorption column 11. During the rotation, the two first grooves 8 cooperate with the two second grooves 14 or the two third grooves 17.
[0032] It should be noted that both the feed pipe 15 and the discharge pipe 16 are equipped with electric butterfly valves, which can control the flow of the raw material. The raw material chlorosilane, after being processed by the primary distillation column 1, the primary rectification column 4, and the secondary rectification column 5, enters the adsorption column 11 through the feed pipe 15 and then flows out through the discharge pipe 16. At this point, the adsorbent can adsorb impurities in the raw material chlorosilane. After the adsorbent becomes saturated with adsorption over a long period, the two electric butterfly valves close the feed pipe 15 and the discharge pipe 16. Subsequently, the drive motor 20 rotates the adsorption column 11 90 degrees clockwise (e.g., ...). Figure 4 and Figure 6As shown, the ring 10 is rotated 90 degrees clockwise, so that the two first grooves 8 correspond to the two third grooves 17 respectively. Then, the acid washing solution can be flowed in the adsorption column 11 through the liquid inlet pipe 18 and the liquid outlet pipe 19 to desorb the adsorbent. Then, pure water is flowed to rinse and remove the acid washing solution from the adsorbent. Finally, inert gas is flowed to clean the residual liquid in the adsorbent, so that the adsorbent can be restored to a gas phase environment, thereby realizing the regeneration treatment of the adsorbent and avoiding the material loss caused by the single use of the adsorbent.
[0033] The adsorption column 11 is provided with a loosening mechanism, which includes a groove 21 opened on the side wall of the adsorption column 11. A U-shaped rod 22 is slidably connected through the inner wall of the groove 21. The upper and lower ends of the U-shaped rod 22 inside the adsorption column 11 are respectively engaged with the side walls of two sieve plates 13 that are far apart from each other. The upper and lower ends of the U-shaped rod 22 inside the adsorption column 11 are rotatably connected to the side walls of their corresponding sieve plates 13 through a rotating rod 23.
[0034] An L-shaped plate 24 is fixedly connected to the outer wall of the U-shaped rod 22. The side wall of the L-shaped plate 24 is elastically connected to the inner wall of the ring 10 through multiple springs 25. A first arched plate 26 is fixedly connected to the inner wall of the circular groove 43. A second arched plate 27 is fixedly connected to the side wall of the L-shaped plate 24 near the spring 25.
[0035] When the two first grooves 8 are directly opposite the two second grooves 14, the first arched plate 26 and the second arched plate 27 are in contact. Under the pressure of the first arched plate 26, the second arched plate 27 moves towards the screen plate 13 via the L-shaped plate 24 and the U-shaped rod 22. The two rotating rods 23 drive the two screen plates 13 to move closer to each other, compacting the adsorbent and increasing the adsorption effect. When the two first grooves 8 are directly opposite the two third grooves 17, the first arched plate 26 and the second arched plate 27 separate. Under the action of multiple springs 25, the L-shaped plate 24 drives the U-shaped rod 22 to move away from the screen plate 13. The two U-shaped rods 22 drive the two screen plates 13 to move away from each other, making the adsorbent loose, which facilitates the desorption of the adsorbent by the acid and increases the regeneration capacity of the adsorbent.
[0036] The adsorption column 11 is equipped with a mixing mechanism, which includes a rotating shaft 28 that is rotatably connected to the top of the adsorption column 11 through a seal. The lower side wall of the rotating shaft 28 is slidably and sealed to the sieve plate 13 located above. A mixing tank 29 is fixedly connected to the lower end of the rotating shaft 28. Multiple adjusting tanks 30 are fixedly connected to the inner wall of the mixing tank 29. T-shaped rods 31 are slidably and sealed to the inner walls of the multiple adjusting tanks 30. The side walls of the T-shaped rods 31 are slidably and sealed to the side walls of the mixing tank 29 through a seal. The multiple T-shaped rods 31 are staggered.
[0037] The inner walls of two adjacent regulating tanks 30 are fixedly connected by a connecting pipe 32. The inner wall of the first groove 8 located above is fixedly connected to a rotary joint 34 by a bracket. The output end of the rotary joint 34 is fixedly connected to the inner wall of the regulating tank 30 located at the top through a rigid pipe 33. The rigid pipe 33 passes through the side wall of the rotating shaft 28.
[0038] An oil storage frame 35 is fixedly connected to the top of the adsorption column 11. The top of the oil storage frame 35 is fixedly connected to the input end of the rotary joint 34 through a connecting pipe 37. A T-shaped plate 36 is slidably connected to the inner wall of the oil storage frame 35. The lower end of the T-shaped plate 36 is fixedly connected to the upper end of the sieve plate 13 located above. Hydraulic oil is provided in multiple adjusting tanks 30 and the oil storage frame 35.
[0039] During adsorbent regeneration, the two sieve plates 13 move away from each other. One of the sieve plates 13 drives the T-shaped plate 36 to move and squeeze the hydraulic oil in the oil storage frame 35, so that the hydraulic oil enters the multiple regulating tanks 30 through the connecting pipe 37, rotary joint 34, rigid pipe 33 and multiple connecting pipes 32, and extends the multiple T-shaped rods 31 from the multiple regulating tanks 30.
[0040] The housing 7 is equipped with a rotating mechanism, which includes two cylinders 40 fixedly connected to the side wall of the housing 7. The output ends of the two cylinders 40 are fixedly connected to a horizontal plate 41. An arc-shaped helical toothed plate 39 is fixedly connected to the side wall of the horizontal plate 41. The side wall of the arc-shaped helical toothed plate 39 is in a sealed sliding connection with the inner wall of the circular groove 43. The arc-shaped helical toothed plate 39 is located near the liquid inlet pipe 18. A through groove 42 is opened on the side wall of the first groove 8 located above near the arc-shaped helical toothed plate 39 (e.g., Figure 8 As shown), the side wall of the arc-shaped helical tooth plate 39 is fitted with the inner wall of the through groove 42, and a helical gear 38 is fixedly connected above the side wall of the rotating shaft 28.
[0041] After the ring 10 rotates 90 degrees clockwise, the through groove 42 is aligned with the arc-shaped helical tooth plate 39. Then, the two cylinders 40 are adjusted to retract, and the arc-shaped helical tooth plate 39 is driven by the horizontal plate 41 to pass through the through groove 42 and enter the first groove 8, so that the arc-shaped helical tooth plate 39 meshes with the helical gear 38. Then, the drive motor 20 rotates clockwise and counterclockwise intermittently, driving the adsorption column 11 and the ring 10 to rotate clockwise and counterclockwise intermittently, driving the helical gear 38 to rotate in both directions intermittently. The rotating shaft 28 drives the mixing tank 29 to rotate, driving the multiple extended T-shaped rods 31 to rotate, slightly stirring the adsorbent, increasing the contact area and force between the adsorbent and the acid, and further accelerating the desorption treatment of the adsorbent.
[0042] Working principle: The raw material chlorosilane in the cold hydrogenation unit 6 enters the crude distillation first-stage column 1 for primary separation. Light impurities in the raw material chlorosilane in the crude distillation first-stage column 1 are collected from the top and enter the second adsorption unit 3. After the light impurities are removed by the adsorption of the regenerable adsorbent in the second adsorption unit 3, the chlorosilane enters the cold hydrogenation unit 6. Heavy impurities in the raw material chlorosilane in the crude distillation first-stage column 1 are collected from the bottom and enter the first adsorption unit 2. After most of the heavy impurities are removed by the regenerable adsorbent in the first adsorption unit 2, the chlorosilane enters the rectification first-stage column 4 for secondary separation. Heavy impurities in the chlorosilane in the rectification first-stage column 4 are collected from the bottom and enter the second adsorption unit 3. Light impurities in the chlorosilane in the rectification first-stage column 4 are collected from the top and enter the rectification second-stage column 5 for tertiary separation. Heavy impurities in the chlorosilane in the rectification second-stage column 5 are collected from the bottom and enter the second adsorption unit 3. After most of the heavy impurities are removed by the adsorption of the regenerable adsorbent in the second adsorption unit 3, the chlorosilane returns to the cold hydrogenation unit 6. The rectification second-stage column 5 produces trichlorosilane, which is used in the reduction workshop to produce polysilicon.
[0043] This treatment device eliminates the original process flow's distillation system and high / low boiling waste recovery system, including the original process flow's primary distillation column 4, secondary distillation column 5, primary high / low boiling column, secondary high / low boiling column, tertiary high / low boiling column, quaternary high / low boiling column, high / low boiling system adsorption column, high / low boiling system adsorption column, high / low boiling system adsorption column, and high / low boiling system adsorption column. This reduces six distillation columns and four adsorption column locations, totaling eight adsorption columns. It adds a first adsorption assembly 2 and a second adsorption assembly 3. The first adsorption assembly 2 utilizes the existing high / low boiling system adsorption column, and the second adsorption assembly 3 utilizes the existing high / low boiling system adsorption columns, high / low boiling system adsorption columns, and high / low boiling system adsorption columns. No additional equipment investment is required. It adopts a series integrated design of "adsorption-distillation coupling-deep purification," with the addition of the first adsorption assembly 2 and the second adsorption assembly 3 forming a staged treatment unit. Through the differentiated adsorption configuration of the dual adsorption columns, it achieves precise stepwise removal of boron and phosphorus impurities, significantly improving the overall impurity removal efficiency. Simultaneously, it reduces the number of operating distillation equipment, lowering equipment investment and production energy consumption. In the above adsorption process, the raw material chlorosilane, after being processed by the first-stage crude distillation column 1, the first-stage rectification column 4, and the second-stage rectification column 5, enters the adsorption column 11 through the feed pipe 15 and then flows out through the discharge pipe 16. At this time, the adsorbent can adsorb impurities in the raw material chlorosilane. After the adsorbent is saturated for a long time, the feed pipe 15 and the discharge pipe 16 are sealed by two electric butterfly valves. Then, the drive motor 20 drives the adsorption column 11 to rotate 90 degrees clockwise (e.g., ...). Figure 4 and Figure 6As shown, the ring 10 is rotated 90 degrees clockwise, so that the two first grooves 8 correspond to the two third grooves 17 respectively. Then, the acid washing solution can be flowed in the adsorption column 11 through the liquid inlet pipe 18 and the liquid outlet pipe 19 to desorb the adsorbent. Then, pure water is flowed to rinse and remove the acid washing solution from the adsorbent. Finally, inert gas is flowed to clean the residual liquid in the adsorbent, so that the adsorbent can be restored to a gas phase environment, thereby realizing the regeneration treatment of the adsorbent and avoiding the material loss caused by the single use of the adsorbent. When the two first grooves 8 are directly opposite the two third grooves 17, the first arched plate 26 and the second arched plate 27 are separated. Under the action of multiple springs 25, the L-shaped plate 24 drives the U-shaped rod 22 to move away from the sieve plate 13. The two U-shaped rods 22 drive the two sieve plates 13 to move away from each other, making the adsorbent loose, which facilitates the desorption treatment of the adsorbent by the acid and increases the regeneration capacity of the adsorbent. At this time, one of the screen plates 13 drives the T-shaped plate 36 to move and squeeze the hydraulic oil in the oil storage frame 35. This causes the hydraulic oil to enter the multiple regulating tanks 30 through the connecting pipe 37, rotary joint 34, rigid pipe 33, and multiple connecting pipes 32. This causes multiple T-shaped rods 31 to extend from the multiple regulating tanks 30. After the ring 10 rotates 90 degrees clockwise, the through groove 42 is aligned with the arc-shaped helical toothed plate 39. Then, the two cylinders 40 are adjusted to retract, and the arc-shaped helical toothed plate 39 is driven through the through groove 42 by the horizontal plate 41. After entering the first groove 8, the arc-shaped helical tooth plate 39 meshes with the helical gear 38. Then, the drive motor 20 rotates intermittently clockwise and counterclockwise, causing the adsorption column 11 and the ring 10 to rotate intermittently clockwise and counterclockwise, which in turn causes the helical gear 38 to rotate intermittently in both directions. This, in turn, causes the mixing tank 29 to rotate via the rotating shaft 28, which in turn causes the multiple extended T-shaped rods 31 to rotate, slightly stirring the adsorbent, increasing the contact area and force between the adsorbent and the acid solution, and further accelerating the desorption treatment of the adsorbent.
[0044] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.
Claims
1. An integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation, characterized in that: The system includes a primary crude distillation column, a first adsorption unit, a second adsorption unit, a primary rectification column, a secondary rectification column, and a cold hydrogenation unit. The raw material chlorosilane in the cold hydrogenation unit enters the primary crude distillation column for primary separation. Light impurities in the raw material chlorosilane in the primary crude distillation column are collected from the top and enter the second adsorption unit. After the second adsorption unit removes the light impurities with a regenerable adsorbent, the chlorosilane enters the cold hydrogenation unit. Heavy impurities in the raw material chlorosilane in the primary crude distillation column are collected from the bottom and enter the first adsorption unit. After the first adsorption unit adsorbs most of the heavy impurities with a regenerable adsorbent, the chlorosilane enters the primary rectification column for secondary separation. Heavy impurities in the chlorosilane in the primary rectification column are collected from the bottom and enter the second adsorption unit. Light impurities in the chlorosilane in the primary rectification column are collected from the top and enter the secondary rectification column for tertiary separation. Heavy impurities in the chlorosilane in the secondary rectification column are collected from the bottom and enter the second adsorption unit. After the second adsorption unit removes most of the heavy impurities with a regenerable adsorbent, the chlorosilane returns to the cold hydrogenation unit. The secondary rectification column produces trichlorosilane, which is used in the reduction workshop to produce polysilicon. Both the first adsorption component and the second adsorption component include multiple shells. The side walls of the multiple shells are provided with circular grooves, and the inner walls of the multiple circular grooves are provided with annular grooves. A rotating ring is slidably connected to the inner wall of the annular groove. The upper and lower ends of the ring are provided with first grooves. An adsorption column is fixedly connected through the inner walls of two first grooves.
2. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 1, characterized in that: The adsorption column has filter holes at both the bottom and top. Two sieve plates are slidably connected to the inner wall of the adsorption column. The space formed by the side walls of the two sieve plates and the inner wall of the adsorption column contains the adsorbent.
3. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 1, characterized in that: The annular groove has a second groove at the top and bottom, and a third groove on each of the inner walls of the annular groove. The inner wall of the lower second groove is fixedly connected to a feed pipe, and the inner wall of the upper second groove is fixedly connected to a discharge pipe. One of the third grooves is fixedly connected to a liquid inlet pipe, and the other is fixedly connected to a liquid outlet pipe. A motor is fixedly connected to the side wall of the shell, and the output end of the motor is fixedly connected to the side wall of the adsorption column. During rotation, the two first grooves cooperate with the two second grooves or the two third grooves.
4. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 2, characterized in that: The adsorption column is provided with a loosening mechanism, which includes a groove formed on the side wall of the adsorption column. A U-shaped rod is slidably connected through the inner wall of the groove. The upper and lower ends of the U-shaped rod inside the adsorption column are respectively engaged with the side walls of two sieve plates that are far apart from each other. The upper and lower ends of the U-shaped rod inside the adsorption column are rotatably connected to the side walls of their corresponding sieve plates through a rotating rod.
5. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 4, characterized in that: An L-shaped plate is fixedly connected to the outer wall of the U-shaped rod. The side wall of the L-shaped plate is elastically connected to the inner wall of the ring through multiple springs. A first arched plate is fixedly connected to the inner wall of the circular groove. A second arched plate is fixedly connected to the side wall of the L-shaped plate near the spring.
6. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 3, characterized in that: The adsorption column is equipped with a mixing mechanism, which includes a rotating shaft that is rotatably and sealingly connected to the top of the adsorption column. The lower side wall of the rotating shaft is slidably and sealingly fitted with the sieve plate located above it. A mixing tank is fixedly connected to the lower end of the rotating shaft. Multiple adjusting tanks are fixedly connected to the inner wall of the mixing tank. T-shaped rods are slidably and sealingly connected to the inner walls of the multiple adjusting tanks. The side walls of the T-shaped rods are slidably and sealingly connected to the side walls of the mixing tanks. The multiple T-shaped rods are arranged alternately.
7. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 6, characterized in that: The inner walls of the two adjacent regulating barrels are fixedly connected by a connecting pipe. The inner wall of the first groove located above is fixedly connected to a rotary joint by a bracket. The output end of the rotary joint is fixedly connected to the inner wall of the uppermost regulating barrel by a rigid pipe, and the rigid pipe passes through the side wall of the rotating shaft.
8. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 7, characterized in that: An oil storage frame is fixedly connected to the top of the adsorption column. The top of the oil storage frame is fixedly connected to the input end of the rotary joint through a connecting pipe. A T-shaped plate is slidably connected to the inner wall of the oil storage frame. The lower end of the T-shaped plate is fixedly connected to the upper end of the sieve plate located above. Hydraulic oil is provided in multiple adjusting tanks and oil storage frames.
9. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 6, characterized in that: The housing is provided with a rotating mechanism, which includes two cylinders fixedly connected to the side wall of the housing. The output ends of the two cylinders are fixedly connected to a horizontal plate. An arc-shaped helical tooth plate is fixedly connected to the side wall of the horizontal plate. The side wall of the arc-shaped helical tooth plate is slidably and sealingly connected to the inner wall of the circular groove. The arc-shaped helical tooth plate is located near the liquid inlet pipe. A through groove is opened on the side wall of the first groove located above, near the arc-shaped helical tooth plate. The side wall of the arc-shaped helical tooth plate fits against the inner wall of the through groove. A helical gear is fixedly connected above the side wall of the rotating shaft.
10. The integrated multi-stage adsorption and impurity removal device for polycrystalline silicon preparation according to claim 1, characterized in that: The boron content after treatment by the first adsorption component is ≤50ppb, the boron content after treatment by the second adsorption component is ≤20ppb, and the boron content after treatment by the distillation secondary column is ≤10ppb. The first adsorption component consists of two shells connected in parallel, one of which is in operation and the other is in standby. The second adsorption component consists of five shells connected in parallel, three of which are in operation and the other two are in standby.