A screening system for screening seed crystals in a size seed crystal

Abstract

The utility model provides a kind of screening system for screening size seed crystal in seed crystal, comprising: for storing seed crystal raw material seed crystal raw material tank (1), the discharge outlet of the seed crystal raw material tank (1) is connected with the feed inlet of seed crystal product sieve (3) for screening large particle;The discharge outlet of the seed crystal product sieve (3) is connected with the feed inlet of seed crystal sorting machine (5) by seed crystal discharging adjusting valve (4), and large particle discharge outlet is sent to seed crystal finished product tank (6) to be stored after being sorted by the seed crystal sorting machine (5), and silicon powder and small particle size seed crystal are sent to dust collector (8) to carry out dust removal treatment by small particle discharge outlet.

Description

Technical Field

[0001] This utility model relates to a screening system, and more particularly to a screening system for screening seed crystals of different sizes in seed crystals. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] After the silane fluidized bed method produces granular polycrystalline silicon seed crystals and grinds them into finished products, the product particle size range is wide, with a size range between 200-1000 micrometers in D(32) particle size. Because the size range is too large, it cannot meet the size requirements of the fluidized bed, which is not conducive to the production process control of the fluidized bed. It is easy to cause a large size range of granular silicon products, resulting in a large number of small-diameter granular silicon products.

[0004] Currently, there is a lack of a practical screening system.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0006] Purpose of the invention: The technical problem to be solved by this utility model is to provide a screening system for screening seed crystals of different sizes, addressing the shortcomings of the existing technology.

[0007] To solve the above-mentioned technical problems, this utility model discloses a sieving system for separating seed crystals of different sizes, comprising:

[0008] A seed crystal raw material tank is used to store seed crystal raw materials. The outlet of the seed crystal raw material tank is connected to the inlet of a seed crystal product sieve used to screen out large particles. The outlet of the seed crystal product sieve is connected to the inlet of a seed crystal sorting machine through a seed crystal feeding regulating valve. Large-diameter seed crystals formed after sorting by the seed crystal sorting machine are sent to a seed crystal finished product tank for storage through the large particle outlet. Silicon powder and small-diameter seed crystals are sent to a dust collector for dust removal treatment through the small particle outlet.

[0009] Furthermore, the bottom of the seed crystal raw material tank is equipped with a seed crystal raw material tank scale for weighing.

[0010] Furthermore, the bottom of the seed crystal finished product tank is equipped with a seed crystal finished product tank scale for weighing.

[0011] Furthermore, the seed crystal sorting machine includes:

[0012] The shell is hollow and cylindrical, with a closed top and a seed crystal inlet in the center. The seed crystal inlet is connected to a material distribution pipe for dispersing and distributing the material. An upward air duct is fitted over the material distribution pipe. The bottom opening of the air duct is connected to the upper end of the seed crystal discharge pipe. The lower end of the seed crystal discharge pipe extends out of the bottom of the shell and is connected to a large-diameter seed crystal outlet. A nitrogen inlet for inputting nitrogen gas is provided on the bottom side of the shell.

[0013] Furthermore, an upper flange cover is detachably installed on the top of the housing, and the seed crystal inlet is located at the center of the upper flange cover.

[0014] Furthermore, the fabric tube has a hollow cylindrical structure with an opening at the top and is installed at the bottom of the upper flange cover;

[0015] The fabric tube is coaxially arranged with the housing;

[0016] The lower part of the side wall of the fabric tube has a feeding hole.

[0017] Furthermore, a support frame is fixed on the inner wall of the housing, and the air duct is installed on the support frame;

[0018] The air duct is a hollow cylindrical structure, coaxially installed with the fabric distribution pipe, and sleeved on the outside of the fabric distribution pipe;

[0019] The top of the air duct has an opening, and the height of the opening is not lower than the discharge hole;

[0020] The bottom opening of the air duct is connected to the top of the seed crystal discharge pipe;

[0021] The bottom of the air duct is lower than the bottom of the fabric distribution pipe;

[0022] An air outlet is provided on the side wall of the air duct in the area below the bottom of the fabric tube.

[0023] Furthermore, an outlet is provided on the outer wall of the housing corresponding to the lower part of the annular cavity formed between the inner wall of the housing and the outer wall of the duct, for discharging small-diameter seed crystals and silicon powder.

[0024] Furthermore, the feeding hole is opened obliquely downward from the inner side wall of the feeding tube to the outer side wall;

[0025] The air outlet is opened obliquely upward from the outer wall of the air duct towards the inner wall.

[0026] Furthermore, the bottom surface of the upper flange cover is fixed with an internal coating, a casting, or a single crystal component;

[0027] The inner wall of the shell is also provided with an internal coating, casting, or single crystal.

[0028] Beneficial effects:

[0029] 1. The system designed in this utility model reduces the range of seed crystal particle size, meets the requirements of fluidized bed process control and reduces the yield of small particles in the finished granular silicon product, ensuring that the particle size range of the finished granular silicon product is small and the particle size is uniform.

[0030] 2. The system designed in this utility model does not introduce other impurities during the seed crystal processing. Attached Figure Description

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0032] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0033] Figure 2 This is a schematic diagram of the overall structure of the seed crystal sorting machine.

[0034] In the diagram, 1 is the seed crystal raw material tank; 2 is the seed crystal raw material tank weighing scale; 3 is the seed crystal product screen; 4 is the seed crystal feeding regulating valve; 5 is the seed crystal sorting machine; 6 is the seed crystal finished product tank; 7 is the seed crystal finished product tank weighing scale; and 8 is the dust collector.

[0035] 501 is the seed crystal inlet; 502 is the upper flange cover; 503 is the material distribution pipe; 504 is the internal coating, casting part or single crystal part; 505 is the air duct; 506 is the support frame; 507 is the vent outlet; 508 is the seed crystal discharge pipe; 509 is the large-diameter seed crystal outlet; 510 is the nitrogen inlet; 511 is the shell; 531 is the discharge hole; 551 is the vent hole; 552 is the upper opening. Detailed Implementation

[0036] The overall concept of this utility model is as follows:

[0037] 1. Use air classification for sieving to reduce the range of seed crystal size;

[0038] 2. Reduce the output ratio of small particles in fluidized bed production;

[0039] 3. Reduce the impact of small-diameter seed crystals on the fluidized bed.

[0040] The specific technical solution of this utility model is as follows: Figure 1 As shown, a sieving system for separating seed crystals of different sizes includes:

[0041] Seed crystal raw material tank 1 is used to store seed crystal raw materials. Seed crystal raw material tank 1 is equipped with a seed crystal raw material tank scale 2 at the bottom. The discharge port of seed crystal raw material tank 1 is connected to the inlet of seed crystal product screen 3.

[0042] The seed crystal product screen 3 is used to filter large particles. The discharge port of the seed crystal product screen 3 is connected to the inlet of the seed crystal sorter 5 through the seed crystal feeding regulating valve 4, so that the filtered seed crystals are sent to the seed crystal sorter 5 for sorting.

[0043] After sorting, large-diameter seed crystals, silicon powder, and small-diameter seed crystals are formed. The large-diameter seed crystals are sent to the seed crystal finished product tank 6 through the large particle outlet for storage, while the silicon powder and small-diameter seed crystals are sent to the dust collector 8 through the small particle outlet for dust removal treatment.

[0044] The bottom of the seed crystal finished product tank 6 is equipped with a seed crystal finished product tank scale 7.

[0045] Among them, seed crystal sorting machine 5, such as Figure 2 As shown, it includes:

[0046] The hollow cylindrical shell 511 has a detachable upper flange cover 502 on the top. The upper flange cover 502 has a seed crystal inlet 501 in the center for inputting the seed crystals to be sorted.

[0047] The lower part of the upper flange cover 502 is equipped with a feeding pipe 503. The feeding pipe 503 is a hollow cylindrical structure, which is coaxially installed with the shell 511. Its bottom is closed and its top opening is the same size as the seed crystal inlet 501.

[0048] The lower part of the side wall of the feeding tube 503 is provided with a feeding hole 531, through which the seed crystal to be sorted passes through the feeding hole 531 and enters the outside of the feeding tube 503.

[0049] A support frame 506 is fixed on the inner wall of the housing 511, and an air duct 505 is installed on the support frame 506.

[0050] The air duct 505 is a hollow cylindrical structure, coaxially installed with the material distribution pipe 503, and sleeved on the outside of the material distribution pipe 503. The top opening, i.e. the upper opening 552 of the air duct 505, is not lower than the material discharge hole 531, and the bottom opening is connected to the seed crystal discharge pipe 508.

[0051] The bottom of the air duct 505 is lower than the bottom of the fabric distribution pipe 503. An air outlet 551 is provided on the side wall of the air duct 505 in the area lower than the bottom of the fabric distribution pipe 503.

[0052] The bottom of the housing 511 is closed, and a nitrogen inlet 510 is provided on the lower side for introducing nitrogen for purging.

[0053] The bottom center of the housing 511 has a large-diameter seed crystal outlet 509, which is connected to the seed crystal discharge pipe 508 for discharging large-diameter seed crystals.

[0054] An annular cavity is formed between the housing 511 and the air duct 505. An vent outlet 507 is provided on the outer side wall of the lower housing 511 to discharge small-diameter seed crystals and silicon powder.

[0055] The material discharge hole 531 is opened obliquely downward from the inner wall of the material distribution pipe 503 to the outer wall, and the air outlet 551 is opened obliquely upward from the outer wall of the air duct 505 to the inner wall.

[0056] The upper flange cover 502 is fixed to the ground with an internal coating, casting or monocrystalline component 504 to prevent dust accumulation.

[0057] The inner wall of the housing 511 is also provided with an internal coating, casting or single crystal 504.

[0058] In use, the seed crystals are released from the raw material tank 1 by controlling the opening of valve 4. The feeding speed of the seed crystals is controlled by valve 4. The seed crystals are filtered by the product screen 3 to remove large particles. The seed crystals enter the material distribution pipe 503 inside the sorting machine 5. The seed crystals pass through the feeding hole 531 of the material distribution pipe 503 and enter the air duct 505. The pressure and flow rate of nitrogen entering through the bottom nitrogen inlet 510 are adjusted to control the pressure and flow rate of the air outlet 551 of the air duct 505, which is made of wear-resistant materials such as polyurethane / monocrystalline. The nitrogen blows the silicon powder and small-diameter seed crystals out of the upper opening of the air duct through the upward-sloping air outlet 551. The large-diameter seed crystals fall under the action of gravity and enter the seed crystal discharge pipe 508 for discharge, entering the bottom finished product tank 6. The silicon powder and small-diameter seed crystals blown out of the upper opening of the air duct are discharged through the vent outlet 507 and enter the dust collector 8.

[0059] This utility model provides a concept and method for a sieving system for separating seed crystals of different sizes. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. All components not explicitly stated in this embodiment can be implemented using existing technology.

Claims

1. A sieving system for separating seed crystals of different sizes, characterized in that, include: A seed crystal raw material tank (1) is used to store seed crystal raw materials. The outlet of the seed crystal raw material tank (1) is connected to the inlet of the seed crystal product screen (3) used to screen out large particles. The outlet of the seed crystal product screen (3) is connected to the inlet of the seed crystal sorting machine (5) through the seed crystal feeding regulating valve (4). The large-diameter seed crystals formed after sorting by the seed crystal sorting machine (5) are sent to the seed crystal finished product tank (6) for storage through the large particle outlet. Silicon powder and small-diameter seed crystals are sent to the dust collector (8) for dust removal treatment through the small particle outlet.

2. The sieving system for separating large and small seed crystals in seed crystals according to claim 1, characterized in that, The bottom of the seed crystal raw material tank (1) is equipped with a seed crystal raw material tank scale (2) for weighing.

3. A sieving system for separating large and small seed crystals in seed crystals according to claim 1, characterized in that, The bottom of the seed crystal finished product tank (6) is equipped with a seed crystal finished product tank scale (7) for weighing.

4. A sieving system for separating large and small seed crystals in seed crystals according to claim 1, characterized in that, The seed crystal sorting machine (5) includes: A hollow cylindrical shell (511) is provided, with the top of the shell (511) closed and a seed crystal inlet (501) in the center. The seed crystal inlet (501) is connected to a material distribution pipe (503) for dispersing and distributing the material below. The material distribution pipe (503) is covered with an upward air supply duct (505). The bottom opening of the air supply duct (505) is connected to the upper end of the seed crystal discharge pipe (508). The lower end of the seed crystal discharge pipe (508) extends out of the bottom of the shell (511) and is connected to the large-diameter seed crystal outlet (509). A nitrogen inlet (510) for inputting nitrogen gas is provided on the bottom side of the shell (511).

5. A sieving system for separating large and small seed crystals in seed crystals according to claim 4, characterized in that, The top of the housing (11) is detachably fitted with an upper flange cover (502), and the seed crystal inlet (501) is located at the center of the upper flange cover (502).

6. A sieving system for separating large and small seed crystals in seed crystals according to claim 5, characterized in that, The fabric tube (503) is a hollow cylindrical structure with an opening at the top and is installed at the bottom of the upper flange cover (502); The fabric tube (503) is coaxially arranged with the housing (511); The lower part of the side wall of the fabric tube (503) is provided with a feeding hole (531).

7. A sieving system for separating large and small seed crystals in seed crystals according to claim 6, characterized in that, A support frame (506) is fixed on the inner wall of the housing (511), and the air duct (505) is installed on the support frame (506); The air duct (505) is a hollow cylindrical structure, coaxially installed with the fabric distribution pipe (503), and sleeved on the outside of the fabric distribution pipe (503); The top of the air duct (505) is provided with an upper opening (552), and the height of the upper opening (552) is not lower than that of the discharge hole (531); The bottom opening of the air duct (505) is connected to the top of the seed crystal discharge pipe (508); The bottom of the air duct (505) is lower than the bottom of the fabric distribution pipe (503); An air outlet (551) is provided on the side wall of the air duct (505) in the area below the bottom of the fabric tube (503).

8. A sieving system for separating large and small seed crystals in seed crystals according to claim 7, characterized in that, An vent outlet (507) is provided on the outer wall of the housing (511) corresponding to the lower part of the annular cavity formed between the inner wall of the housing (511) and the outer wall of the air duct (505) for discharging small-diameter seed crystals and silicon powder.

9. A sieving system for separating large and small seed crystals in seed crystals according to claim 8, characterized in that, The feeding hole (531) is opened obliquely downward from the inner side wall of the feeding tube (503) to the outer side wall; The air outlet (551) is opened obliquely upward from the outer side wall of the air duct (505) towards the inner side wall.

10. A sieving system for separating large and small seed crystals in seed crystals according to claim 9, characterized in that, The bottom surface of the upper flange cover (502) is fixed with an internal coating, a casting, or a single crystal component (504); The inner wall of the shell (511) is also provided with an internal coating, casting or single crystal (504).

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