A silicon material cleaning system
By combining a fluidized bed system and nitrogen circulation with an electrostatic elimination unit, the problems of incomplete cleaning and chemical residues in polycrystalline silicon powder have been solved, achieving comprehensive cleaning and high-quality polycrystalline silicon powder production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- INNER MONGOLIA TONGWEI HIGH PURITY CRYSTAL SILICON CO LTD
- Filing Date
- 2025-04-11
- Publication Date
- 2026-05-29
AI Technical Summary
In the current polysilicon production process, the surface of powder with a thickness of less than 3mm has a high metal content, resulting in low selling price and limited application. Existing cleaning technologies also suffer from problems such as incomplete cleaning, chemical residues, and difficulty in drying.
A fluidized bed system combined with nitrogen or hot nitrogen purging and an electrostatic eliminator is used to perform all-round cleaning through physical means. Nitrogen circulation and electrostatic eliminators are used to remove surface impurities, achieving all-round cleaning and eliminating solvent residue.
It achieves comprehensive cleaning, eliminates solvent residue, improves the quality indicators of polycrystalline silicon powder, and ensures the drying environment and production quality.
Smart Images
Figure CN224294144U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of polysilicon production technology, and in particular to a silicon material cleaning system. Background Technology
[0002] During the production of polysilicon, powder particles smaller than 3mm are often found to have high surface metal content, resulting in low selling prices and limited applications. Aside from some silicon core production, most of this powder is sold at low prices. Current measures to reduce surface metal content in the powder, besides on-site cleanliness control and equipment material selection, lack effective control measures; they can only control the introduction of metal, not eliminate it entirely. Existing silicon cleaning technologies primarily involve acid washing, alkaline washing, and direct cleaning with ultrapure water. However, due to the small particle size, chemical and water washing suffer from the following problems: 1. Incomplete cleaning, leaving blind spots; 2. Chemical residues after washing; 3. The small size of silicon fragments and powder particles makes drying water trapped in the gaps between silicon particles difficult, and prolonged exposure during drying can easily lead to recontamination after cleaning; 4. Surface adsorption of dust and metal elements leads to excessive surface metal levels. Summary of the Invention
[0003] In view of the above situation and to overcome the defects of the prior art, the purpose of this utility model is to provide a silicon material cleaning system that solves the technical problems of incomplete cleaning of silicon fragments and silicon powder, chemical residues after cleaning, and poor removal of surface impurities.
[0004] To achieve the above objectives, this utility model provides the following technical solution:
[0005] A silicon material cleaning system includes: a fluidized bed; a circulation pipeline, one end of which is connected to the air outlet at the top of the fluidized bed and the other end of which is connected to the air inlet at the bottom of the fluidized bed; a dust removal unit, an induced draft fan, a heating unit, and an electrostatic elimination unit are sequentially arranged on the circulation pipeline along the gas flow direction; a nitrogen pipeline is connected to the circulation pipeline between the induced draft fan and the heating unit.
[0006] This invention uses nitrogen or hot nitrogen to purge and dry dried silicon material or wet silicon material after washing. Compared with existing water washing and chemical cleaning methods, this system uses physical means to clean the silicon material, achieving all-round cleaning and eliminating solvent residue. The nitrogen circulation ensures a good drying environment and production quality for the silicon material. At the same time, the use of an electrostatic eliminator to eliminate static electricity on the silicon material ensures that impurities adsorbed on the surface of the silicon material are removed, resulting in better removal of surface impurities and effectively improving quality indicators.
[0007] Optionally, the air outlet of the fluidized bed is connected to the inlet of the dust removal unit, the outlet of the dust removal unit is connected to the inlet of the induced draft fan, the outlet of the induced draft fan is connected to the inlet of the heating unit, and the static electricity elimination unit is disposed between the outlet of the heating unit and the air inlet of the fluidized bed.
[0008] Optionally, the dust removal unit includes a cyclone dust collector and a bag filter dust collector. The outlet of the fluidized bed is connected to the inlet of the cyclone dust collector, the outlet of the cyclone dust collector is connected to the inlet of the bag filter dust collector, and the outlet of the bag filter dust collector is connected to the inlet of the induced draft fan.
[0009] Optionally, a gas distribution plate is provided at the bottom of the fluidized bed.
[0010] Optionally, the heating unit may be an electromagnetic induction heater.
[0011] Optionally, one end of the nitrogen pipeline is connected to a nitrogen source, and the other end outlet is connected to the circulation pipeline and located in the section between the induced draft fan and the heating unit.
[0012] Optionally, the silicon material cleaning system also includes a feeding mechanism, the discharge end of which is connected to the fluidized bed feed inlet.
[0013] Optionally, the feeding mechanism is an inclined feeding belt conveyor.
[0014] Optionally, a material conveying mechanism is provided below the discharge port of the fluidized bed, and a finished product collection device is provided at the outlet end of the material conveying mechanism.
[0015] Optionally, the material conveying mechanism is a horizontally arranged unloading belt conveyor.
[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0017] 1. This invention uses nitrogen or hot nitrogen to purge and dry dry silicon material or wet silicon material after washing. Compared with existing water washing and chemical cleaning methods, this system uses physical means to clean the silicon material, achieving all-round cleaning and eliminating solvent residue. The nitrogen circulation formed ensures a good drying environment and production quality for the silicon material.
[0018] 2. The main reason for the low quality index is the adsorption of metal dust, metal elements, micro silicon powder and dust on the surface. This system uses an electrostatic eliminator to eliminate the static electricity of the silicon material, which can ensure that the impurities adsorbed on the surface of the silicon material are removed, and can better remove surface impurities, thus effectively improving the quality index. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the structure of this utility model.
[0021] Reference numerals in the attached drawings: 1. Fluidized bed; 2. Circulation pipeline; 3. Cyclone dust collector; 4. Bag dust collector; 5. Exhaust fan; 6. Heating unit; 7. Static electricity elimination unit; 8. Nitrogen pipeline; 9. Feeding mechanism; 10. Material conveying mechanism; 11. Finished product collection device. Detailed Implementation
[0022] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of this utility model application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.
[0023] In the description of the embodiments of this utility model application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "end", "side" etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, are only for the convenience of describing the embodiments of this utility model application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this utility model application.
[0024] In the embodiments of this utility model application, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model application according to the specific circumstances.
[0025] In the embodiments of this utility model application, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0026] The following disclosure provides many different implementations or examples for carrying out different structures of the embodiments of this utility model application. To simplify the disclosure of the embodiments of this utility model application, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of this utility model application. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of this utility model application; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.
[0027] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.
[0028] like Figure 1 As shown in the figure, the present invention provides a silicon material cleaning system, including: a fluidized bed 1, a circulation pipeline 2, a dust removal unit, an induced draft fan 5, a heating unit 6, and an electrostatic elimination unit 7.
[0029] One end of the circulation pipeline 2 is connected to the air outlet at the top of the fluidized bed 1, and the other end is connected to the air inlet at the bottom of the fluidized bed 1, forming a closed loop path.
[0030] The dust removal unit, the induced draft fan 5, the heating unit 6 and the static electricity elimination unit 7 are arranged sequentially on the circulation pipeline 2 along the gas flow direction. A nitrogen pipeline 8 is connected to the circulation pipeline 2 between the induced draft fan 5 and the heating unit 5. The nitrogen pipeline 8 is used to inject nitrogen into the fluidized bed 1.
[0031] Specifically, the fluidized bed 1 has an air outlet at the top and an air inlet at the bottom. The air outlet of the fluidized bed 1 is connected to the inlet of the dust removal unit, the outlet of the dust removal unit is connected to the inlet of the induced draft fan 5, the outlet of the induced draft fan 5 is connected to the inlet of the heating unit 6, and the static electricity elimination unit 7 is located between the outlet of the heating unit 6 and the air inlet of the fluidized bed 1.
[0032] Optionally, the dust removal unit includes a cyclone dust collector 3 and a bag filter dust collector 4. Specifically, the outlet of the fluidized bed 1 is connected to the inlet of the cyclone dust collector 3, the outlet of the cyclone dust collector 4 is connected to the inlet of the bag filter dust collector 3, and the outlet of the bag filter dust collector 3 is connected to the inlet of the induced draft fan 5. Using a two-stage dust removal system with both the cyclone dust collector 3 and the bag filter dust collector 4 can improve the system's dust removal efficiency, reduce dust emission concentration, and also reduce nitrogen consumption.
[0033] Optionally, heating unit 6 may employ an electromagnetic induction heater.
[0034] Optionally, the static elimination unit 7 is a static eliminator.
[0035] In one implementation scenario, when nitrogen (or hot nitrogen) passes through the bed from bottom to top, it suspends the silicon material, blows down the micro silicon powder and dust adsorbed on the surface of the broken silicon material and silicon powder, and draws them to the dust removal unit under the action of the induced draft fan 5. The cleaned broken silicon material and silicon powder are discharged from the other end of the fluidized bed 1.
[0036] Optionally, one end of the nitrogen pipeline 8 is connected to a nitrogen source, and the outlet of the other end is connected to the section between the induced draft fan 5 and the heating unit 6 in the circulation pipeline 2. When in use, nitrogen can be injected into the system through the nitrogen pipeline 8 to replace the air in the system with nitrogen. After use, the nitrogen in the system can also be recovered through the nitrogen pipeline 8.
[0037] Optionally, a gas distribution plate is provided at the bottom of the fluidized bed 1, which helps to improve cleaning efficiency.
[0038] Optionally, the silicon material cleaning system also includes a feeding mechanism 9, the discharge end of which is connected to the feed inlet of the fluidized bed 1.
[0039] Optionally, the feeding mechanism 9 is configured to transport crushed silicon material or silicon powder from a low position to a high position.
[0040] Optionally, the feeding mechanism 9 is an inclined feeding belt conveyor. In use, dry or washed silicon fragments or silicon powder containing water are fed into the feeding belt conveyor, which lifts the silicon material to the feed inlet of the fluidized bed.
[0041] Optionally, the silicon material cleaning system also includes a material conveying mechanism 10 located below the outlet of the fluidized bed 1, and a finished product collection device 11 located at the outlet end of the material conveying mechanism 10.
[0042] Optionally, the material conveying mechanism 10 is a horizontally arranged feeding belt conveyor. After being cleaned, the broken silicon material and silicon powder are discharged from the fluidized bed 1 and fall onto the feeding belt conveyor, which then transports the silicon material to the finished product collection device 11.
[0043] A method for cleaning silicon material: Dry or cleaned polycrystalline silicon fragments (less than 8mm) or silicon powder (particles or powders less than 3mm) are fed into a feeding mechanism 9, which lifts the silicon material to the inlet of a fluidized bed 1. Nitrogen or hot nitrogen is then introduced. As the nitrogen or hot nitrogen flows upwards through the fluidized bed, it suspends the silicon material, blowing off the micro-silicon powder and dust adsorbed on the surface of the fragments and powder. The dust-laden airflow is then filtered by a cyclone dust collector 3 and a bag filter 4 under the action of an induced draft fan 5. The purified nitrogen is recycled. The cleaned fragments and powder are discharged from the outlet of the fluidized bed. During the process, an electrostatic eliminator is activated to remove static electricity from the silicon material. This electrostatic eliminator eliminates static electricity, ensuring that impurities adsorbed on the surface of the silicon material are removed, thus improving the removal of adsorbed substances.
[0044] Any aspects not described in detail in this embodiment are techniques known in the art.
[0045] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.
Claims
1. A silicon material cleaning system, characterized in that, include: Fluidized bed; The circulation pipeline is connected at one end to the air outlet at the top of the fluidized bed and at the other end to the air inlet at the bottom of the fluidized bed. Along the gas flow direction, a dust removal unit, an induced draft fan, a heating unit, and an electrostatic elimination unit are sequentially installed on the circulation pipeline; A nitrogen pipeline is connected to the circulation pipeline between the induced draft fan and the heating unit.
2. The silicon material cleaning system according to claim 1, characterized in that, The air outlet of the fluidized bed is connected to the inlet of the dust removal unit, the outlet of the dust removal unit is connected to the inlet of the induced draft fan, the outlet of the induced draft fan is connected to the inlet of the heating unit, and the static electricity elimination unit is disposed between the outlet of the heating unit and the air inlet of the fluidized bed.
3. The silicon material cleaning system according to claim 1 or 2, characterized in that, The dust removal unit includes a cyclone dust collector and a bag filter dust collector. The outlet of the fluidized bed is connected to the inlet of the cyclone dust collector, the outlet of the cyclone dust collector is connected to the inlet of the bag filter dust collector, and the outlet of the bag filter dust collector is connected to the inlet of the induced draft fan.
4. The silicon material cleaning system according to claim 1, characterized in that, The fluidized bed is equipped with a gas distribution plate at its bottom.
5. The silicon material cleaning system according to claim 1, characterized in that, The heating unit uses an electromagnetic induction heater.
6. The silicon material cleaning system according to claim 1, characterized in that, One end of the nitrogen pipeline is connected to a nitrogen source, and the other end outlet is connected to the circulation pipeline and located in the section between the induced draft fan and the heating unit.
7. The silicon material cleaning system according to claim 1, characterized in that, The silicon material cleaning system also includes a feeding mechanism, the discharge end of which is connected to the fluidized bed feed inlet.
8. The silicon material cleaning system according to claim 7, characterized in that, The feeding mechanism is an inclined feeding belt conveyor.
9. The silicon material cleaning system according to claim 1, characterized in that, A material conveying mechanism is provided below the discharge port of the fluidized bed, and a finished product collection device is provided at the outlet end of the material conveying mechanism.
10. The silicon material cleaning system according to claim 9, characterized in that, The material conveying mechanism is a horizontally arranged unloading belt conveyor.