Slurry centrifugal equipment used in polycrystalline silicon production process

Abstract

The utility model provides a slag slurry centrifugal device used in a polycrystalline silicon production process, which comprises a floating platform placed on the ground and fixedly provided with a motor and a transmission part; and the output end of the motor drives a centrifugal machine part fixedly arranged on the floating platform through a transmission part, and is used for receiving the slag slurry and discharging filtered clear liquid and solid substances. The equipment can efficiently filter slag slurry, is simple in structure, high in automation degree, high in separation precision and simple to operate, and can greatly improve human efficiency and reduce energy consumption.

Description

Technical Field

[0001] The utility model relates to a slurry centrifugal equipment, in particular to a slurry centrifugal equipment used in the production process of polysilicon. Background Technique

[0002] The information provided in this part is only the background information related to the present disclosure, and it is not necessarily the prior art.

[0003] In the polysilicon industry, whether it is the improved Siemens method or the silane fluidized bed method for preparing polysilicon, slurry is generated during the process of hydrogenating and converting silicon tetrachloride into trichlorosilane. The slurry is a kind of slurry, and its main components include chlorosilane (liquid), silicon powder (solid), catalyst (copper chloride or other solid catalysts), etc.

[0004] The main purpose of slurry treatment is to recover chlorosilane in the slurry to reduce material loss in the whole production process. At present, there are two mainstream processes for slurry treatment in the industry. One is the sedimentation + drying process, that is, the slurry is subjected to liquid-solid separation in a sedimentation tank, the upper clear liquid is sent to the rectification process for recovery and treatment, and the lower material (solid content about 50%) enters the dryer to evaporate the volatile components in the material again to increase the solid content to more than 80%. The other is the vacuum drum filtration process, that is, using diatomite as a filter aid, making the liquid phase pass through the filter cake layer by using the pressure difference, and the solid phase (solid content more than 90%) is retained on the surface of the vacuum drum, and the solid material on the drum surface is continuously scraped off by a scraper to achieve the purpose of solid-liquid separation.

[0005] The existing process adopts the sedimentation + drying process or the vacuum drum filtration. The former process requires a large number of process equipment, the sedimentation separation pipeline is frequently blocked, and the downstream filter is frequently blocked due to the entrainment of silicon powder in the filtrate; the latter process has high energy consumption, the wet content of the filter residue of the vacuum drum filtration is large, the wearing parts of the auxiliary dynamic equipment consume a large amount, and the system is frequently overhauled.

[0006] It should be noted that the information disclosed in the above background technical part is only used to strengthen the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0007] Object of the Invention: The technical problem to be solved by the utility model is to provide a slurry centrifugal equipment used in the production process of polysilicon in view of the deficiencies of the prior art.

[0008] To solve the above technical problems, the utility model discloses a slurry centrifugal equipment used in the production process of polysilicon, including:

[0009] A floating platform placed on the ground, on which a motor and a transmission component are fixedly arranged; the output end of the motor drives a centrifuge component fixedly arranged on the floating platform through the transmission component;

[0010] The centrifuge component includes a hollow cylindrical outer shell horizontally arranged on the floating platform. One side of the hollow cylindrical outer shell is open, and the other side is closed. A machine cover is fixedly arranged on its open side;

[0011] A slurry feeding device for receiving slurry is fixedly arranged on the machine cover;

[0012] A hollow cylindrical drum is coaxially arranged inside the outer shell. One side of the drum close to the closed side of the outer shell is connected to the transmission component and is driven by it to rotate along the axial direction of the outer shell. The other side of the drum is open;

[0013] A scraper discharging device for scraping the solid substances attached to the inner side wall of the drum is arranged on the machine cover;

[0014] A silicon powder discharging component is arranged below the scraper discharging device, and one end of the silicon powder discharging component penetrates through the machine cover;

[0015] A filtrate siphon outlet for discharging the filtered clear liquid is arranged at the bottom of the outer shell.

[0016] Further, the scraper discharging device is fixedly arranged on the machine cover and includes:

[0017] An oil pressure driving device and a scraper fixedly connected thereto. The scraper is driven by the oil pressure driving device to approach or move away from the inner side wall of the top of the drum.

[0018] Further, the scraper discharging device further includes:

[0019] A scraper end position limit stop block and an end position proximity switch arranged at the end position of the scraper;

[0020] And an initial position proximity switch arranged at the initial position of the scraper.

[0021] Further, the silicon powder discharging component is a hollow cylindrical structure with both ends open, fixedly arranged on the machine cover, with the upper end arranged below the scraper discharging device and the lower end penetrating through the machine cover.

[0022] Further, a backflush port for inputting protective nitrogen into the inside of the outer shell is arranged on the side of the outer shell.

[0023] Further, the slurry feeding device includes:

[0024] A feed port connected to the upstream system. A distributor is arranged at one end of the feed port, and the distributor is arranged inside the drum, with a width less than or equal to the inner side of the drum, for evenly spreading the slurry on the inner side of the drum.

[0025] Further, the transmission component includes:

[0026] A bearing housing fixedly arranged outside the closed side of the housing. The bearing housing is of a hollow structure, in which a drive shaft is rotatably arranged. One end of the drive shaft is fixedly connected to the housing and rotates coaxially therewith, and the other end is connected to a transmission structure.

[0027] The transmission structure is fixedly arranged on the floating platform and transmits the output end of the motor to the drive shaft.

[0028] Further, the bottom of the floating platform is placed on the ground through shock absorbers.

[0029] Further, a filter cloth is arranged on the inner side of the drum.

[0030] Further, the filter cloth is 2000 - 3000 mesh.

[0031] Beneficial effects:

[0032] The utility model adopts a siphon centrifugal device, which can efficiently filter slurry. The device has a simple structure, high automation degree, high separation precision, and simple operation, and can greatly improve labor efficiency and reduce energy consumption. Specifically:

[0033] 1. The slurry is centrifugally separated through a horizontally arranged drum, reducing the solid content of the raw material slurry to less than 1% and the wet content to 5%. After centrifugal separation, the clear liquid is filtered and sent to the downstream process.

[0034] 2. Compared with the vacuum drum process, the utility model can directly replace the vacuum drum system, thereby reducing energy consumption.

[0035] 3. Compared with the sedimentation process, the utility model can replace the sedimentation process link, reduce equipment investment, and improve filtration efficiency. Description of the Drawings

[0036] The following further specifically describes the utility model in conjunction with the drawings and specific embodiments, and the above and / or other advantages of the utility model will become clearer.

[0037] Figure 1 It is a schematic cross-sectional view of the overall structure of the utility model.

[0038] Figure 2 It is a schematic view of the scraper unloading device.

[0039] Figure 3 It is a schematic external view of the overall structure of the utility model.

[0040] In the figure: 1. Scraper discharging device; 2. Rotary drum; 3. Machine cover; 4. Outer shell; 5. Bearing seat; 6. Transmission structure; 7. Floating platform; 8. Shock absorber; 9. Slurry feeding device; 10. Silicon powder discharging component; 11. Filtrate siphon outlet; 12. Spare port; 13. Backflush port; 14. Probe plate of level detector; 101. Limit stop for scraper end position; 102. Proximity switch for end position; 103. Proximity switch for initial position; 104. Initial position; 105. End position. Specific embodiments

[0041] The design concept of the present utility model is as follows:

[0042] The siphon centrifuge adopted in the present utility model is a horizontal installation continuous operation, intermittent discharging, filter type scraper discharging automatic centrifuge. It adopts an independently configured nitrogen filling protection system, uses 0.7 MPa nitrogen, which is reduced to 0.2 MPa after pressure reduction, and controls the nitrogen flow rate at 5 - 10 Nm3 / h. As Figure 3 shown, it enters the siphon centrifuge through the backflush port 13 and is used as protective nitrogen.

[0043] The upstream slurry material goes to the slurry tank, and the slurry is gravity-fed from the slurry tank to the slurry feeding device 9 of the horizontal siphon centrifuge through the control cut-off valve. As Figure 1 shown, through the distributor in the slurry feeding device 9, the slurry is evenly distributed on the surface of the rotary drum filter cloth. The chlorosilane clear liquid filtered by the siphon centrifuge enters the clear liquid tank, and the clear liquid is sent to the concentration unit for concentration. The filter residue is discharged to the hydrolysis tank for hydrolysis, and the sewage after hydrolysis is sent to the public works for treatment; the silicon powder-containing filtrate is cut to the overflow tank and returned to the slurry tank for re-treatment through the slurry pump. The specific principle of the slurry centrifugation equipment during use is as follows:

[0044] 1) Feeding

[0045] The slurry is evenly distributed on the inner side of the rotary drum wall through the distributor of the slurry centrifugation equipment. Under the action of centrifugal force, the chlorosilane passes through the filter cloth arranged on the inner side wall of the rotary drum 2 and is discharged to the clear liquid tank through the siphon port 11. The solid silicon powder is intercepted in the rotary drum 2. When the liquid touches the probe plate 14 of the level detector during the feeding process, the program automatically closes the valve to stop feeding.

[0046] 2) Dewatering

[0047] After feeding, the slurry centrifugation equipment performs a dewatering operation. The dewatering time is based on the dewatering performance of the material and the required moisture content. During the dewatering process, the speed of the rotary drum 2 is increased to the maximum to reduce the dewatering time.

[0048] 3) Discharging

[0049] When the solid moisture content in the slurry centrifugation equipment reaches the requirement, the scraper discharging device 1 acts to scrape off the solid material, and the material is sent to the downstream drying through the discharging port 10.

[0050] As Figure 2 shown, the scraper discharging device 1 drives the scraper stroke through a hydraulic system. The hydraulic system and the scraper are fixed on the machine cover 3. Open the hydraulic station, start the solenoid valve manually, and the scraper cylinder acts; when the scraper moves to the end limit stop 101, the scraper can be retracted.

[0051] After the silicon powder on the surface of the filter cloth is scraped off and discharged by the action of the scraper, the next batch of feeding operation is carried out.

[0052] The specific technical solution adopted by the present utility model is as follows:

[0053] A device suitable for slurry filtration, including a centrifuge and a clear liquid tank;

[0054] The centrifuge mainly consists of a scraper discharging device 1, a machine cover 3, a drum 2, a shaft seat group 5, a transmission structure 6, a vibration damping part, etc., and is used for filtering the polysilicon slurry transported by the upstream system;

[0055] The clear liquid tank is used to receive and store the clear liquid filtered by the slurry filtration device.

[0056] The centrifuge includes: a floating platform 7 placed on the ground through a shock absorber 8;

[0057] A motor is fixedly installed on the floating platform 7 and a transmission structure 6 connected to the output end of the motor, and the other end of the transmission structure 6 drives one end of the drive shaft in the bearing seat 5 to rotate.

[0058] A horizontally installed hollow cylindrical outer shell 4 is fixedly installed on the floating platform 7; one side of the outer shell 4 is closed and the other side is open; a bearing seat 5 is fixedly installed on the axis of the closed side of the outer shell 4, a drive shaft is rotatably arranged in the bearing seat 5, and a machine cover 3 is fixedly installed on the open side of the outer shell 4.

[0059] One end of the drive shaft is connected to the transmission structure 6, and the other end passes through the central through hole on the closed side of the outer shell 4 and is fixedly connected to the drum 2.

[0060] The drum 2 is a hollow cylindrical structure with one side open, is horizontally installed on one side of the drive shaft, and is driven by it to rotate coaxially.

[0061] The feed inlet of the centrifuge, that is, the slurry feeding device 9, is connected to the polysilicon slurry conveying pipeline of the upstream system, and the silicon slag slurry generated in the polysilicon production process is introduced into the centrifuge through the slurry feeding device 9 fixed on the machine cover 3 for separation and filtration;

[0062] The slurry feeding device 9 includes a distributor, the width of which is less than or equal to the inner side surface of the drum 2, and is used for evenly spreading the silicon slag slurry on the inner side surface of the drum 2.

[0063] A filter cloth is installed on the inner side of the drum 2.

[0064] The filter cloth is preferably 2000 - 3000 mesh.

[0065] A scraper discharging device 1 is fixedly installed on the machine cover 3, including: a scraper end position limit block 101, an end position proximity switch 102, and an initial position proximity switch 103. The hydraulic drive device drives the scraper to rotate for scraping the solid substances on the filter cloth.

[0066] At the end position 105 of the scraper, a corresponding scraper end position limit block 101 and an end position proximity switch 102 are provided. At the initial position 104 of the scraper, a corresponding initial position proximity switch 103 is provided.

[0067] A filtrate siphon outlet 11 is provided at the bottom of the outer shell 4 for discharging the filtered clear chlorosilane liquid. A spare port 12 is provided at the top of the outer shell 4. A backflush port 13 is provided on the side of the outer shell 4 for inputting the protective nitrogen into the interior of the outer shell 4.

[0068] A slurry level detector probe 14 is fixedly installed on the machine cover 3 for detecting the height of the slurry level inside the outer shell 4.

[0069] A silicon powder discharging component 10 is fixedly installed on the machine cover 3. The silicon powder discharging component 10 is of a hollow cylindrical structure, and the upper end is arranged below the scraper discharging device 1 for receiving the solid substances scraped by the scraper.

[0070] The present utility model provides an idea and method for a slag slurry centrifugal device in the polysilicon production process. There are many methods and ways to specifically implement this technical solution. The above - mentioned is only the preferred embodiment of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present utility model. Each component not clearly defined in this embodiment can be implemented by existing technologies.

Claims

1. A slurry centrifugation device for the polysilicon production process, characterized in that, Comprising: A floating platform (7) placed on the ground, on which a motor and transmission components are fixedly arranged; the output end of the motor drives a centrifuge component fixedly arranged on the floating platform (7) through the transmission components; The centrifuge component includes a hollow cylindrical outer shell (4) horizontally arranged on the floating platform (7), one side of the hollow cylindrical outer shell (4) is open and the other side is closed; a machine cover (3) is fixedly arranged on its open side; A slurry feeding device (9) for receiving slurry is fixedly arranged on the machine cover (3); A hollow cylindrical drum (2) is coaxially arranged inside the outer shell (4), one side of the drum (2) close to the closed side of the outer shell (4) is connected to the transmission component and is driven by it to rotate along the axial direction of the outer shell (4); the other side of the drum (2) is open; A scraper discharging device (1) for scraping solid substances attached to the inner side wall of the drum (2) is arranged on the machine cover (3); A silicon powder discharging component (10) is arranged below the scraper discharging device (1), and one end of the silicon powder discharging component (10) penetrates through the machine cover (3); A filtrate siphon outlet (11) for discharging filtered clear liquid is arranged at the bottom of the outer shell (4).

2. A slurry centrifugal device for the polysilicon production process according to claim 1, characterized in that, The scraper discharging device (1) is fixedly arranged on the machine cover (3) and includes: An oil pressure driving device and a scraper fixedly connected thereto, and the scraper is driven by the oil pressure driving device to approach or move away from the inner side wall of the top of the drum (2).

3. A slurry centrifugation device for polysilicon production according to claim 2, characterized in that, The scraper discharging device (1) further includes: A scraper end position limit stop block (101) and an end position proximity switch (102) arranged at the end position (105) of the scraper; And an initial position proximity switch (103) arranged at the initial position (104) of the scraper.

4. A slurry centrifugation device for the polysilicon production process according to claim 3, characterized in that, The silicon powder discharging component (10) is a hollow cylindrical structure with both ends open, fixedly arranged on the machine cover (3), the upper end is arranged below the scraper discharging device (1), and the lower end penetrates through the machine cover (3).

5. A slurry centrifugal device for polysilicon production according to claim 4, characterized in that, An anti - flush port (13) for inputting protective nitrogen into the interior of the outer shell (4) is arranged on the side of the outer shell (4).

6. The slurry centrifugal equipment for polysilicon production process according to claim 5, characterized in that, The slurry feeding device (9) includes: A feeding port connected to the upstream system, and a distributor is arranged at the other end of the feeding port, and the distributor is arranged inside the drum (2) with a width less than or equal to the inner side surface of the drum (2) for evenly spreading the slurry on the inner side surface of the drum (2).

7. A slurry centrifugal device for polysilicon production process according to claim 6, characterized in that, The transmission component includes: A bearing seat (5) fixedly arranged outside the closed side of the outer shell (4), the bearing seat (5) is a hollow structure, in which a driving shaft is rotatably arranged, one end of the driving shaft is fixedly connected to the outer shell (4) and rotates coaxially with it, and the other end is connected to a transmission structure (6); The transmission structure (6) is fixedly arranged on the floating platform (7) to transmit the output end of the motor to the driving shaft.

8. A slurry centrifugation device for polysilicon production process according to claim 7, characterized in that, The bottom of the floating platform (7) is placed on the ground through shock absorbers (8).

9. A slurry centrifugal device for the polysilicon production process according to claim 8, characterized in that, A filter cloth is arranged on the inner side surface of the drum (2).

10. A slurry centrifugation device for polysilicon production process according to claim 9, characterized in that, The filter cloth is 2000 - 3000 mesh.

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