Polycrystalline silicon powder production system
By introducing cyclone separators and negative pressure devices into the polysilicon powder production system, combined with multi-stage screening, the problems of uneven silicon powder particles and large numbers of tiny particles were solved, achieving the goal of efficient production and high-quality silicon powder.
Patent Information
- Application Number
- CN202422576584.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-23
AI Technical Summary
In the existing polysilicon powder production process, the silicon powder particles are uneven and contain a large number of tiny particles, resulting in low finished product yield, unstable fine powder content, and low unit production capacity, affecting product quality and production capacity.
A cyclone separator and a negative pressure device are introduced into the polysilicon powder production system to recover tiny particles through negative pressure. Combined with a screening device, multi-stage screening is performed to separate and recover particles whose particle size does not meet the standards, thereby improving screening efficiency and yield.
The yield rate and product quality of polysilicon powder have been improved, the unit production capacity has reached 2.5t/h, the content of tiny particles has been reduced, and the safety and efficiency of the production environment have been improved.
Smart Images
Figure CN223337820U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of silicon powder dust removal and recovery, and in particular to a polysilicon powder production system. Background Art
[0002] Silica fume is a fine, granular substance commonly used in industry. Primarily composed of silicon dioxide, it is an important inorganic material. Its primary raw material is silicon dioxide, a common natural mineral found in nature, such as quartz, glass, and silica sand. Silica fume is primarily composed of fine particles that have been subjected to high-temperature treatment and grinding. Its uniform particle size meets diverse application needs and is widely used in various fields.
[0003] Currently, with the continuous development of materials engineering and energy, the field of polysilicon technology is also undergoing continuous innovation and advancement. In the energy sector, the research and application of polysilicon solar cells will continue to promote the development of renewable energy and reduce dependence on traditional energy sources, while also placing stricter requirements on the quality of dust in the upstream raw material silicon powder.
[0004] However, existing methods for producing silicon powder have the following drawbacks: Commonly used equipment for producing silicon powder includes Raymond mills, roller mills, and disc mills. Based on the principle of pulverization, these methods employ extrusion pulverization. Because silicon powder requires varying particle sizes depending on demand, this results in uneven pulverization of silicon chunks, leading to a high concentration of tiny particles within the silicon powder. Specifically, in the current polysilicon powder production process, the yield of finished products is low, with the content of fine powder particles below 200 mesh ranging from 0.25% to 3.11%. This fluctuating and unstable fine powder content results in a high concentration of tiny particles within the silicon powder particles, and the unit production capacity only reaches 1.6 t / h, compromising product quality and capacity utilization, leading to frequent customer complaints. Summary of the Invention
[0005] One purpose of the present application is to disclose a polysilicon powder production system that can improve the quality of polysilicon powder.
[0006] Another object of the present application is to disclose a polysilicon powder production system to improve the efficiency of producing polysilicon powder.
[0007] To achieve the above objectives, the technical solution adopted in this application is: a polysilicon powder production system, including a screening device, a cyclone separator and a negative pressure device, the cyclone separator has an inlet, and a recovery pipe is arranged between the screening device and the inlet of the cyclone separator, the negative pressure device is used to make the air pressure in the recovery pipe lower than the air pressure of the screening device, so that the tiny particles in the screening device enter the cyclone separator through the recovery pipe under the action of negative pressure, the cyclone separator includes a first outlet located at the bottom and a second outlet located at the top, the first outlet is connected to the screening device so that the large-size particles separated by the cyclone separator enter the screening device, and the second outlet is connected to a recovery device, so that the small-size particles obtained by the cyclone separator are recovered by the recovery device.
[0008] Preferably, the screening device includes at least one square screen, the first outlet is connected to the feed port of the square screen, and the material bin of the square screen is connected to the recovery pipe.
[0009] As a preference, the discharge port of the square sieve is connected to a first storage bin.
[0010] Preferably, the screening device further comprises at least one circular screen, the feed port of the circular screen is connected to the discharge port of the square screen, and the silo of the circular screen is connected to the recovery pipe.
[0011] As a preference, the discharge port of the circular screen is connected to a second storage bin.
[0012] As a preferred embodiment, in any of the polysilicon powder production systems, the recovery device includes a recovery bin, the upper end of the recovery bin has a first interface and a second interface, the first interface is connected to the second outlet of the cyclone separator, the second interface is connected to a fan, and the lower end of the recovery bin has a discharge port.
[0013] As another preferred embodiment, a filtering device is provided in the recovery bin. After passing through the filtering device, the clean gas is discharged from the second interface and the particles are collected from the discharge port.
[0014] Further preferably, in any of the polysilicon powder production systems, the first outlet obtains particles with a particle size of not less than 45 μm.
[0015] Compared with the prior art, the present invention has the following advantages:
[0016] (1) The present invention installs a negative pressure device in the polysilicon powder production system so that the tiny particles in the screening device enter the cyclone separator through the recovery pipe under the action of negative pressure. The negative pressure device can help the cyclone separator to quickly recover the tiny particles, thereby improving the working efficiency of the polysilicon powder production system.
[0017] (2) The present invention adds a cyclone separator at the front end of the screening device, and absorbs the tiny particles in the system into the separator through negative pressure, and then separates and recovers particles with a mesh size of >325. The separation and recovery rate of finished particles in the range of 45-325 mesh (the index range for producing finished silicon powder) can reach more than 85%, which not only improves production efficiency, but also reduces the content index of tiny particles in silicon powder to within 0.1%. The unit production capacity reaches 2.5t / h, which improves the quality of silicon powder products and increases production capacity at the same time.
[0018] (3) The present invention provides a recovery device and a blower in the polysilicon powder production system, thereby helping to ensure the safety of workers and reducing dust pollution to the production environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural diagram of the present utility model.
[0020] In the figure: 10, screening device; 11, square screen; 110, square screen feed port; 111, square screen discharge port; 12, round screen; 120, round screen feed port; 121, round screen discharge port; 13, silo; 20, cyclone separator; 21, first inlet; 22, first outlet; 23, second outlet; 30, negative pressure device; 40, recovery device; 41, recovery bin; 410, first interface; 411, second interface; 412, filtering device; 413, discharge port; 42, fan; 43, dust bag; 50, recovery pipe. DETAILED DESCRIPTION
[0021] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.
[0022] In the description of this application, it should be noted that for directional words, such as the terms "center", "horizontal", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and so on, the directions and positional relationships indicated are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of this application.
[0023] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.
[0024] The terms "comprises" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, product or apparatus.
[0025] In the current polysilicon powder production process, the yield of finished products that meet the requirements is low, among which the content of fine powder particles below 200 mesh is in the range of 0.25%-3.11%, and the fine powder content index fluctuates greatly. This instability leads to a large number of tiny particles mixed in the silicon powder particles, and the unit production capacity only reaches 1.6t / h, which in turn affects product quality and production capacity.
[0026] In response to the problem that polysilicon powder produced by existing methods is mixed with many tiny particles and the quality of polysilicon powder products is low, the present application discloses a polysilicon powder production system. The system recovers the tiny particles of polysilicon powder produced by negative pressure during the production process to reduce the content of fine powder below 200 mesh, thereby improving the product quality of polysilicon powder. The present invention will be further described in detail in conjunction with the accompanying drawings and specific embodiments.
[0027] As attached Figure 1 As shown, this embodiment includes a screening device 10, a cyclone separator 20, a negative pressure device 30, a recovery device 40 and a recovery pipe 50. The cyclone separator 20 has a first inlet 21, a first outlet 22 and a second outlet 23. The first inlet 21 of the cyclone separator 20 is used to recover the tiny particles from each dust collecting point through the recovery pipe 50 under the action of the negative pressure of the negative pressure device 30 into the cyclone separator 20 for separation. The first outlet 22 of the cyclone separator 20 is used to separate the coarse particle silicon powder with a diameter of ≥45μm into the screening device 10 for further screening. The second outlet 23 of the cyclone separator 20 is used to discharge the tiny particle silicon powder with a diameter of <45μm from the cyclone separator 20. After being discharged, the tiny particles enter the recovery device 40 to improve the quality of the silicon powder product.
[0028] The recovery pipe 50 is arranged between the screening device 10 and the first inlet 21 of the cyclone separator 20. During the production process of polysilicon powder, the negative pressure device 30 is used to make the air pressure in the recovery pipe 50 lower than the air pressure of the screening device 10, so that the tiny particles in the screening device 10 enter the cyclone separator 20 through the recovery pipe 50 under the action of negative pressure. The negative pressure device 30 and the recovery pipe 50 help to collect and promote the recycling of tiny particles, thereby improving production efficiency and capacity.
[0029] The screening device 10 includes a square screen 11, a round screen 12 and a silo 13, wherein the square screen feed port 110 is connected to the first outlet 22 below the cyclone separator 20, the square screen 11 and the round screen 12 as well as the silo 13 below the round screen 12 are connected, and the silo 13 is used to collect the collected coarse silicon powder with a diameter ≥45μm. In addition, the fine silicon powder with a diameter of less than 45μm that enters the square screen 11 and the round screen 12 is further recovered into the cyclone separator 20 through the recovery pipe 50. After repeated multiple times, it is ensured that the fine particles of polysilicon powder are discharged into the recovery device 40, thereby improving the quality of the polysilicon powder product.
[0030] The square screen outlet 111 in the screening device 10 is connected to the circular screen feed port 120. During the polysilicon powder screening process, the square screen 11 is first used for preliminary screening, which can quickly remove larger particles, increase the processing capacity, and reduce the burden on the subsequent circular screen 12. At this time, the circular screen 12 is used for fine screening to ensure that polysilicon powder with higher purity and more uniform particle size is obtained, thereby improving the overall screening efficiency and the quality of the final product.
[0031] Recovery device 40 includes a recovery bin 41, a fan 42, and a dust bag 43. Recovery bin 41 has a first interface 410, a second interface 411, a filter 412, and a discharge port 413. First interface 410 is connected to second outlet 23 of cyclone separator 20. Fan 42 is connected to second interface 411 behind fan 42, which is used to discharge clean gas out of the production system. Filter 412 is used to filter fine dust particles with a diameter of less than 45 μm. After filtering, dust emission during polysilicon powder production can be reduced, dust concentration in the working environment can be lowered, operating conditions can be improved, and environmental pollution can be reduced. Dust bag 43 is connected below discharge port 413 of recovery bin 41, suitable for collecting tiny particles with a diameter of less than 45 μm, thereby further reducing dust emission and ensuring a safe working environment.
[0032] The particle size of the silicon powder obtained at the first outlet 22 below the cyclone separator 20 is ≥45 μm, ensuring that the particle size of the silicon powder obtained meets the production standards required by the finished product.
[0033] According to the connection between the various devices in the production system of this application, the operating steps of the polysilicon powder production system in this embodiment are as follows:
[0034] S10. The fine particles recovered from the front system of the crushing end and the crushing equipment end are followed by the square screen 11, the round screen 12, and the silo 13 of the back system to collect the fine particles. The particles enter the cyclone separator 20 for recovery through negative pressure;
[0035] S20. After the fine particles collected from the pipelines of each device enter the cyclone separator 20, the fine particle powder >325 mesh is collected by the cyclone separator 20 and discharged to the square screen 11 for swing screening and recovery. The screened product enters the round screen 12 for swing screening and then enters the silo 13 for subsequent packaging.
[0036] Combined with attachment Figure 1 As shown, the specific operating steps of the polysilicon powder production system in this embodiment are as follows:
[0037] First, the polysilicon powder fine particles recovered by the front system of the crushing end and the pulverizing equipment end and the fine particles collected by the square screen 11, the round screen 12 and the silo 13 of the rear system are fed into the cyclone separator 20 through the negative pressure device 30 and the recovery pipe 50. The cyclone separator 20 causes the internal dust-laden airflow to spirally move, and the polysilicon dust particles are separated by centrifugal force, gravity, etc., among which the coarse polysilicon powder particles with a particle size of ≥45μm enter the square screen feed from the first outlet 22 of the cyclone separator 20. Port 110, after being screened by the square sieve 11, the particles continue to enter the round sieve 12 for further screening. After double screening by the square sieve 11 and the round sieve 12, a portion of the finished polysilicon powder enters the silo 13 from the round sieve outlet 121 and is manually packaged and collected. The other portion of the polysilicon powder continues to pass through the negative pressure device 30 and enters the cyclone separator 20 from the recovery pipe 50 under negative pressure, and then undergoes a new round of screening until all the polysilicon powder is converted into high-value finished product powder, thereby achieving the effect of increasing production and improving quality. In addition, when the polysilicon powder passes through the cyclone separator, polysilicon powder particles with a particle size of less than 45 μm are discharged from the second outlet 23 of the cyclone separator 20, and then enter the recovery bin 41 through the first interface 410 of the recovery device 40. A filter device 412 is provided in the recovery bin 41. The polysilicon powder particles with a particle size of less than 45 μm after filtering by the filter device 412 are produced from the discharge port 413 below the recovery bin 41 and collected in the dust bag 43 for recovery. The clean gas is transferred from the second interface 411 of the recovery bin 41 to the fan 42 and discharged into the air.
[0038] In traditional bag dust collection systems, there are a large number of finished products with a size greater than 325 mesh, which are treated as low-value by-products. The present application adds a cyclone separator 20 at the front end of the screening device 10, which can absorb the tiny particles in the production system into the cyclone separator 20 through negative pressure and then separate and recover the particles with a size greater than 325 mesh. The separation and recovery rate of finished particles in the range of 45 mesh to 325 mesh (the index range for producing finished silicon powder) can reach more than 85%, which not only improves production efficiency, but also can reduce the content index of tiny particles in silicon powder to within 0.1%, so that the unit production capacity reaches 2.5t / h, thereby improving the quality of polysilicon powder products while increasing silicon powder production capacity.
[0039] The above describes the basic principles, main features, and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-described embodiments. The above-described embodiments and the specification merely illustrate the principles of the present application. Various changes and improvements may be made to the present application without departing from the spirit and scope of the present application. These changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the appended claims and their equivalents.
Claims
1. A polysilicon powder production system, comprising a screening device, characterized in that: It also includes a cyclone separator and a negative pressure device, the cyclone separator has an inlet, a recovery pipe is arranged between the screening device and the inlet of the cyclone separator, the negative pressure device is used to make the air pressure in the recovery pipe lower than the air pressure of the screening device, so that the tiny particles in the screening device enter the cyclone separator through the recovery pipe under the action of negative pressure, the cyclone separator includes a first outlet located at the bottom and a second outlet located at the top, the first outlet is connected to the screening device so that the large-size particles separated by the cyclone separator enter the screening device, and the second outlet is connected to a recovery device, so that the small-size particles obtained by the cyclone separator are recovered by the recovery device.
2. The polysilicon powder production system according to claim 1, characterized in that: The screening device includes at least one square screen, the first outlet is connected to the feed port of the square screen, and the material bin of the square screen is connected to the recovery pipeline.
3. The polysilicon powder production system according to claim 2, characterized in that: The discharge port of the square screen is connected to a first storage bin.
4. The polysilicon powder production system according to claim 2, characterized in that: The screening device further comprises at least one round screen, the feed port of the round screen is communicated with the discharge port of the square screen, and the material bin of the round screen is communicated with the recovery pipeline.
5. The polysilicon powder production system according to claim 4, characterized in that: The discharge port of the circular screen is connected to a second storage bin.
6. The polysilicon powder production system according to any one of claims 1 to 5, characterized in that: The recovery device includes a recovery bin, the upper end of the recovery bin has a first interface and a second interface, the first interface is connected to the second outlet of the cyclone separator, the second interface is connected to a fan, and the lower end of the recovery bin has a discharge port.
7. The polysilicon powder production system according to claim 6, characterized in that: A filtering device is provided in the recovery bin. After passing through the filtering device, the clean gas is discharged from the second interface and the particles are collected from the discharge port.
8. The polysilicon powder production system according to any one of claims 1 to 5, characterized in that: The first outlet obtains particles with a particle size of not less than 45 μm.