Silica powder blanking system

Abstract

The embodiment of the utility model provides a silicon powder blanking system, the system comprises a silicon powder receiving tank, a first silicon powder filter and a nitrogen access part, the silicon powder receiving tank comprises a first part, a second part and a third part, the first part is arranged at the top of the silicon powder receiving tank, and the first part is at least provided with a first gas outlet; the second part is arranged below the first part, the second part is communicated with the first part, the second part is at least provided with a first nitrogen access port, the third part is arranged below the second part, the third part is communicated with the second part, and the third part is at least provided with a second nitrogen access port; a first air inlet of the first silicon powder filter is connected with a first air outlet of the silicon powder receiving tank; the nitrogen access component is communicated with the first nitrogen access port and the second nitrogen access port, so that nitrogen is filled into the silicon powder receiving tank for nitrogen replacement, the nitrogen in the silicon powder receiving tank enters the first silicon powder filter through the first gas outlet, the micro-aerobic dew point in the silicon powder can be fully replaced, and the nitrogen consumption is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polysilicon production, and in particular to a silicon powder discharging system. BACKGROUND

[0002] Polysilicon is a key material for manufacturing semiconductor devices and solar cells. With the growing global demand for renewable energy, especially the rise of solar power generation, the demand for polysilicon continues to increase. The silicon powder discharging system based on the polysilicon cold hydrogenation process is an important link in the production process of polysilicon. In the production process of polysilicon, silicon powder, as one of the raw materials, needs to be accurately controlled in terms of speed and quantity when added to the reactor.

[0003] In the related art, after the silicon powder receiving tank receives the silicon powder, hot nitrogen gas is used for replacement, the hot nitrogen gas enters from the top of the silicon powder receiving tank, and the pressure is released from the top. This hot nitrogen gas replacement method cannot completely replace the silicon powder in the conical part of the silicon powder receiving tank. CONTENT OF THE UTILITY MODEL

[0004] The embodiment of the present application provides a silicon powder discharging system, which improves the replacement efficiency in the silicon powder receiving tank by changing the entering path of nitrogen gas in the silicon powder receiving tank.

[0005] The silicon powder discharging system provided by the embodiment of the present application comprises a silicon powder receiving tank, a first silicon powder filter and a nitrogen gas access component.

[0006] The silicon powder receiving tank receives at least silicon powder from a front component, and the silicon powder receiving tank comprises a first part, a second part and a third part.

[0007] The first part is arranged at the top of the silicon powder receiving tank, and the first part is provided with at least a first gas outlet; the second part is arranged below the first part, the second part is in communication with the first part, and the second part is provided with at least a first nitrogen gas access port; and the third part is arranged below the second part, the third part is in communication with the second part, and the third part is provided with at least a second nitrogen gas access port.

[0008] The gas inlet of the first silicon powder filter is connected with the first gas outlet of the silicon powder receiving tank.

[0009] The nitrogen gas access component is in communication with the first nitrogen gas access port and the second nitrogen gas access port, so that nitrogen gas is filled into the silicon powder receiving tank for nitrogen replacement, and the nitrogen gas in the silicon powder receiving tank enters the first silicon powder filter through the first gas outlet.

[0010] In a possible implementation, the silicon powder discharging system further comprises a three-way valve, and the first part further comprises a third nitrogen gas access port.

[0011] The input end of the three-way valve is connected with the nitrogen gas access component, and the first output end of the three-way valve is connected with the third nitrogen gas access port.

[0012] The second output end of the three-way valve is connected to the first nitrogen inlet and the second nitrogen inlet through pipes respectively.

[0013] In a possible implementation, the first pipeline is provided with a wear-resistant lining.

[0014] In a possible implementation, the wear-resistant lining is a wear-resistant ceramic lining.

[0015] In a possible implementation, the silicon powder feeding system further comprises a silicon powder feeding tank and a second silicon powder filter, wherein the silicon powder feeding tank is connected to the silicon powder discharge end of the silicon powder receiving tank.

[0016] The second inlet of the second silicon powder filter is connected to the second outlet of the silicon powder feeding tank through a single cut-off valve.

[0017] In a possible implementation, the silicon powder feeding system further comprises a first cut-off valve, which is arranged on the pressure relief bus of the second silicon powder filter.

[0018] In a possible implementation, the silicon powder feeding system further comprises a second cut-off valve, one end of which is connected to the nitrogen inlet part, and the other end of which is connected to the input end of the three-way valve.

[0019] In a possible implementation, the silicon powder feeding system further comprises a ball valve, one end of which is connected to the nitrogen inlet part, and the other end of which is connected to the first nitrogen inlet and the second nitrogen inlet respectively.

[0020] In a possible implementation, the first nitrogen inlet is provided in a plurality of first nitrogen inlets arranged along the height direction of the silicon powder receiving tank.

[0021] In a possible implementation, the first nitrogen inlet, the second nitrogen inlet, the third nitrogen inlet and the first outlet are each provided with an independently controlled control valve.

[0022] The silicon powder feeding system provided by the embodiments of the present application realizes the change from single-point nitrogen input to multi-point nitrogen input, and realizes the change from top hot nitrogen replacement adjustment to middle and bottom hot nitrogen replacement, so that the micro-oxygen dew point in the silicon powder can be fully replaced, and the nitrogen consumption can be saved. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments consistent with the application and, together with the description, further serve to explain the principles of the application.

[0024] Figure 1 A structural schematic diagram of a silicon powder discharging system provided by the present application;

[0025] Figure 2 Another structural schematic diagram of a silicon powder discharging system provided by the present application.

[0026] Legend of reference signs:

[0027] 1 - silicon powder receiving tank; 2 - first silicon powder filter; 3 - nitrogen access component;

[0028] 11 - first part; 111 - first gas outlet; 112 - third nitrogen access;

[0029] 113 - silicon powder access; 132 - first silicon powder discharge outlet;

[0030] 21 - first gas inlet; 22 - first pipeline; 23 - fourth shut-off valve;

[0031] 12 - second part; 121 - first nitrogen access;

[0032] 13 - third part; 131 - second nitrogen access;

[0033] 4 - three-way valve; 5 - silicon powder feeding tank; 51 - second gas outlet;

[0034] 52 - hydrogen access; 6 - second silicon powder filter;

[0035] 61 - second gas inlet; 7 - single shut-off valve;

[0036] 62 - first shut-off valve; 8 - second shut-off valve; 9 - ball valve.

[0037] The specific embodiments of the present application have been shown through the above-described drawings, and will be described in more detail hereinafter. These drawings and written description are not intended to restrict the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0038] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The description of the exemplary embodiments is intended to apply to any embodiment of the application, unless specified otherwise. Accordingly, when the same, similar or like components are functionally equivalent in the different drawings, they are designated by the same reference numerals. The following exemplary embodiments described in the following exemplary embodiments are not representative of all embodiments consistent with the present application. Rather, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims. The exemplary embodiments will be described in detail herein with reference to the attached drawings. The description of the exemplary embodiments is intended to apply to any embodiment of the application, unless specified otherwise. Accordingly, when the same, similar or like components are functionally equivalent in the different drawings, they are designated by the same reference numerals. The following exemplary embodiments described in the following exemplary embodiments are not representative of all embodiments consistent with the present application. Rather, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims.

[0039] The specific application scenario of the silicon powder discharging system in the present application is a polysilicon cold hydrogenation process scenario.

[0040] In combination with the above scenario, it can be known that in the related art, the nitrogen gas inlet of the silicon powder receiving tank 1 is generally arranged at the top, the nitrogen gas outlet of the silicon powder receiving tank 1 is also arranged at the top, and the structure of the silicon powder receiving tank 1 itself is a long structure. The in-out gas at the top can cause incomplete hot nitrogen replacement in the silicon powder receiving tank 1, resulting in waste of nitrogen gas.

[0041] The silicon powder discharging system provided in the present application adjusts the arrangement position and number of the nitrogen gas inlets of the silicon powder receiving tank 1 in the silicon powder discharging system, improves the replacement efficiency of the silicon powder receiving tank 1, and reduces the waste of nitrogen gas.

[0042] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific examples. The following specific examples can be combined with each other, and the same or similar concepts or processes can not be described again in some examples. The embodiments of the present application will be described below with reference to the drawings.

[0043] Figure 1 The structure schematic diagram of the silicon powder discharging system provided in the present application is shown in FIG. 1. As shown in FIG. 1, the system includes a silicon powder receiving tank 1, a first silicon powder filter 2, and a nitrogen gas access component 3. Figure 1

[0044] The silicon powder receiving tank 1 receives at least silicon powder from a front component.

[0045] In some implementable modes, the silicon powder of the silicon powder discharging system is sent from the previous process to the silicon powder receiving tank 1 through a pneumatic conveying system.

[0046] The silicon powder receiving tank 1 includes a first part 11, a second part 12, and a third part 13.

[0047] The first part 11 is arranged at the top of the silicon powder receiving tank 1, and the first part 11 is provided with at least a first gas outlet 111.

[0048] The second part 12 is arranged below the first part 11, the second part 12 is in communication with the first part 11, and the second part 12 is provided with at least a first nitrogen gas inlet 121.

[0049] The third part 13 is arranged below the second part 12, the third part 13 is in communication with the second part 12, and the third part 13 is provided with at least a second nitrogen gas inlet 131.

[0050] The first gas inlet 21 of the first silicon powder filter 2 is connected with the first gas outlet 111 of the silicon powder receiving tank 1.

[0051] ​Nitrogen enters the silicon powder receiving tank 1 from the first nitrogen inlet 121 and the second nitrogen inlet 131, and is discharged from the silicon powder receiving tank 1 through the first gas outlet 111.

[0052] In some possible implementations, the first part 11 of the silicon powder receiving tank 1 adopts a circular structure.

[0053] The second part 12 adopts a cylindrical body, and the top of the cylindrical body is connected to the bottom of the circular structure.

[0054] The third part 13 adopts an inverted conical structure, and the top of the inverted conical structure is connected to the bottom of the cylindrical body.

[0055] The silicon powder inlet 113 is arranged at the top of the circular structure, and is used to receive the silicon powder from the previous process.

[0056] The first nitrogen inlet 121 is arranged on the sidewall of the cylindrical body. The first nitrogen inlet 121 is in communication with the nitrogen inlet component 3, so as to receive the nitrogen from the nitrogen inlet component 3 for nitrogen replacement.

[0057] The second nitrogen inlet 131 is arranged at a middle position of the inverted conical structure. The second nitrogen inlet 131 is in communication with the nitrogen inlet component 3, so as to receive the nitrogen from the nitrogen inlet component 3 for nitrogen replacement.

[0058] In some possible implementations, the second nitrogen inlet 131 is arranged at a position lower than the middle of the inverted conical structure. The second nitrogen inlet 131 is in communication with the nitrogen inlet component 3, so as to receive the nitrogen from the nitrogen inlet component 3 for nitrogen replacement.

[0059] The first gas outlet 111 is arranged at the top of the circular structure. The first gas outlet 111 is connected to the first gas inlet 21 of the first silicon powder filter 2, so as to release the pressure of the silicon powder receiving tank 1, discharge the nitrogen in the silicon powder receiving tank 1, and facilitate the next nitrogen filling.

[0060] The nitrogen inlet component 3 is in communication with the first nitrogen inlet 121 and the second nitrogen inlet 131. Nitrogen enters the silicon powder receiving tank 1 through the first nitrogen inlet 121 and the second nitrogen inlet 131, and is replaced in the silicon powder receiving tank 1. Then, the replaced nitrogen enters the first silicon powder filter 2 through the first gas outlet 111.

[0061] The above replacement of oxygen in the silicon powder receiving tank 1 reduces the oxygen content below the combustible dust explosion limit threshold, and eliminates the risk of combustion and explosion of the silicon powder.

[0062] The sufficient replacement of nitrogen can effectively ensure that the oxygen content in the silicon powder meets the requirements, avoid the reaction of oxygen and subsequent introduced hydrogen, and prevent external pollutants from entering and ensure the cleanliness of the silicon powder.

[0063] By setting the nitrogen inlet at different positions of the silicon powder receiving tank 1, the multi-path distribution of the nitrogen inlet, the avoidance of local dead angles, and the improvement of the replacement thoroughness.

[0064] In a possible implementation, the first nitrogen inlet 121 is provided as several first nitrogen inlets 121 arranged along the height direction of the silicon powder feeding tank 5.

[0065] By providing several first nitrogen inlets 121, the nitrogen inlets of the silicon powder receiving tank 1 can be increased, and the first nitrogen inlets 121 are arranged in the middle, which facilitates the diffusion and replacement of nitrogen in the silicon powder receiving tank 1 and improves the replacement efficiency.

[0066] With reference to Figure 1 , the first nitrogen inlet 121 is provided as two first nitrogen inlets 121 arranged on the sidewall of the silicon powder receiving tank 1.

[0067] In some embodiments, the first silicon powder filter 2 further comprises a nitrogen outlet arranged at the top of the first silicon powder filter 2, and the nitrogen outlet is connected to an external nitrogen recovery device.

[0068] In a possible implementation, the silicon powder discharging system further comprises a three-way valve 4, and the first part 11 further comprises a third nitrogen inlet 112.

[0069] The input end of the three-way valve 4 is connected to the nitrogen inlet component 3, and the first output end of the three-way valve 4 is connected to the third nitrogen inlet 112.

[0070] The second output end of the three-way valve 4 is connected to the first nitrogen inlet 121 and the second nitrogen inlet 131 through pipelines.

[0071] With reference to Figure 1 , the top of the first part 11 is provided with the third nitrogen inlet 112. The third nitrogen inlet 112 is connected to the nitrogen inlet component 3, and the third nitrogen inlet 112 is configured to receive nitrogen.

[0072] The nitrogen inlet component 3 is connected to the input end of the three-way valve 4, the first output end of the three-way valve 4 is connected to the third nitrogen inlet 112, and the second output end of the three-way valve 4 is connected to the first nitrogen inlet 121 and the second nitrogen inlet 131.

[0073] By controlling the state of the three-way valve 4 to adjust the on-off state of the nitrogen inlet of the silicon powder receiving tank 1, flexible control of the nitrogen input is realized.

[0074] In a possible implementation, the silicon powder receiving tank 1 and the first silicon powder filter 2 are connected through a first pipeline 22, and the first pipeline 22 is provided with a wear-resistant lining.

[0075] In the related art, a vent hand valve and a fourth shut-off valve 23 are arranged between the silicon powder receiving tank 1 and the first silicon powder filter 2 for controlling whether the two are communicated, but the gas discharged from the silicon powder receiving tank 1 inevitably carries silicon powder, the silicon powder is in contact with the inside of the vent hand valve and rubs against it, and the vent hand valve is always in an open state, losing the switching function.

[0076] Therefore, in the above-mentioned embodiments, the vent hand valve is adjusted to the first pipeline 22, and the lining of the first pipeline 22 is set to a wear-resistant lining, thereby prolonging the service life of the first pipeline 22.

[0077] In some embodiments, the lining of the shut-off valve herein can be provided with a wear-resistant lining to prolong the service life of the equipment.

[0078] In some possible embodiments, the lining of other valves involved in the embodiments of the present application can be provided with a wear-resistant lining.

[0079] In a possible embodiment, the wear-resistant lining is a wear-resistant ceramic lining. The ceramic lining is bonded to the base body through a sintering or inlaying process to ensure mechanical strength and wear resistance.

[0080] By replacing the vent hand valve with the first pipeline 22 with a wear-resistant ceramic lining, the risk of wear and leakage can be avoided, the frequency of replacing worn valves is reduced, the replacement cycle is prolonged, the frequency of shutdown maintenance is reduced, and the risk of silicon powder escaping or gas pollution caused by valve leakage is eliminated.

[0081] In a possible embodiment, the silicon powder discharging system further comprises a silicon powder feeding tank 5 and a second silicon powder filter 6, wherein the silicon powder feeding tank 5 is connected to the silicon powder discharge end of the silicon powder receiving tank 1; and the silicon powder is placed in the silicon powder feeding tank 5 after being replaced by nitrogen.

[0082] A third shut-off valve (not shown in the figure) is arranged between the top of the silicon powder feeding tank 5 and the first silicon powder discharge port 132 of the bottom of the silicon powder receiving tank 1 for controlling the silicon powder in the silicon powder receiving tank 1 to enter the silicon powder feeding tank 5.

[0083] Referring to Figure 2 , the silicon powder feeding tank 5 further comprises a hydrogen inlet 52 for filling hydrogen into the silicon powder feeding tank 5.

[0084] The hydrogen inlet 52 is arranged in the middle and top of the silicon powder feeding tank 5 to perform cold hydrogen replacement in the silicon powder feeding tank 5.

[0085] The silicon powder feeding tank 5 further comprises a hot hydrogen inlet arranged at the bottom of the silicon powder feeding tank 5.

[0086] The silicon powder feeding tank 5 further comprises a second silicon powder discharge outlet arranged at the bottom of the silicon powder feeding tank 5 and connected with the reactor.

[0087] The silicon powder in the silicon powder feeding tank 5 is replaced by cold hydrogen, and hot hydrogen is used as a pushing gas to push the silicon powder into the reactor for reaction.

[0088] The second gas inlet 61 of the second silicon powder filter 6 is connected with the second gas outlet 51 of the silicon powder feeding tank 5 through the single cut-off valve 7.

[0089] In order to avoid damage to the filter element of the second silicon powder filter 6 caused by pressure relief impact, the pressure difference between the silicon powder feeding tank 5 and the second silicon powder filter 6 cannot be too large, so the double cut-off valve between the silicon powder feeding tank 5 and the second silicon powder filter 6 in the related art loses its setting function.

[0090] It should be noted that the single cut-off valve 7 mentioned above refers to a valve with only one closing element to control the flow of fluid. When it is necessary to close the fluid, this single closing element moves to a position completely blocking the pipeline.

[0091] The double cut-off valve refers to a valve system composed of two independent closing elements. The two closing elements are usually installed in series on the same pipeline, and each closing element can independently close the fluid flow.

[0092] By replacing the double cut-off valve with the single cut-off valve 7, the on-off control between the silicon powder feeding tank 5 and the second silicon powder filter 6 can be met, and the waste of complex components can be avoided. Moreover, the installation and maintenance of components are simpler.

[0093] Setting the single cut-off valve 7 can reduce unnecessary losses. By controlling the pressure difference between the silicon powder feeding tank 5 and the second silicon powder filter 6 through the single cut-off valve 7, complex operations can be reduced.

[0094] The top of the second silicon powder filter 6 is further connected with a nitrogen recovery device to avoid leakage of nitrogen and other recovered gases.

[0095] The bottom of the second silicon powder filter 6 is provided with an opening connected with a waste contact tank for receiving remaining solid residues.

[0096] In a possible implementation, the silicon powder feeding system further comprises a first cut-off valve 62 arranged on the pressure relief bus of the second silicon powder filter 6.

[0097] By arranging the first cut-off valve 62 on the pressure relief bus of the second silicon powder filter 6, the flexibility of operation can be improved, the maintenance cost can be reduced, and the safety can be improved.

[0098] In a possible implementation, the silicon powder discharging system further comprises a second shutoff valve 8, one end of the second shutoff valve 8 being connected to the nitrogen access component 3, and the other end being connected to the input end of the three-way valve 4.

[0099] With reference to Figure 1 , the second shutoff valve 8 is arranged on the side of the three-way valve 4 close to the nitrogen access component 3, and whether the nitrogen enters the silicon powder receiving tank 1 can be controlled through the second shutoff valve 8. This improves the flexibility of operation and reduces maintenance costs.

[0100] In a possible implementation, with reference to Figure 2 , the silicon powder discharging system further comprises a ball valve 9, one end of the ball valve 9 being connected to the nitrogen access component 3, and the other end of the ball valve 9 being connected to the first nitrogen inlet 121 and the second nitrogen inlet 131 respectively.

[0101] With reference to Figure 2 , one end of the ball valve 9 is connected between the nitrogen access component 3 and the second shutoff valve 8.

[0102] The pipe junction where the nitrogen input ends of the first nitrogen inlet 121 and the second nitrogen inlet 131 are defined as a first connection position, and the other end of the ball valve 9 is connected between the second output port of the three-way valve 4 and the first connection position.

[0103] By arranging the ball valve 9, when the second shutoff valve 8 or the three-way valve 4 malfunctions, the silicon powder receiving tank 1 can be filled with nitrogen through the ball valve 9, which improves the flexibility of operation and the fault tolerance of the silicon powder discharging system.

[0104] In a possible implementation, the first nitrogen inlet 121, the second nitrogen inlet 131, the third nitrogen inlet 112, and the first gas outlet 111 are each provided with an independently controlled control valve.

[0105] By arranging corresponding control valves at the first nitrogen inlet 121, the second nitrogen inlet 131, the third nitrogen inlet 112, and the first gas outlet 111, the entire silicon powder discharging system can be controlled not only through the valves on the pipes, but also individually controlled at each port. This greatly improves the flexibility of operation of the silicon powder discharging system.

[0106] In a possible implementation, a control valve is arranged at the silicon powder inlet 113 for controlling whether the silicon powder enters the silicon powder receiving tank 1.

[0107] The silicon powder discharging system provided by the embodiment of the application realizes the change from single-point nitrogen gas input to multi-point nitrogen gas input, and realizes the change from top heat nitrogen replacement adjustment to middle and bottom heat nitrogen replacement, so that the micro-oxygen dew point in the silicon powder can be fully replaced, and the nitrogen gas consumption is saved.

[0108] The silicon powder discharging operation of the silicon powder discharging system in the embodiment of the application is as follows:

[0109] The raw material silicon powder is transported to the silicon powder receiving tank 1 by nitrogen gas, and when the silicon powder receiving tank 1 reaches the maximum receiving capacity, the silicon powder is stopped.

[0110] The fourth cut-off valve 23 between the silicon powder receiving tank 1 and the first silicon powder filter 2 is closed. Then, the silicon powder receiving tank 1 is pressurized by using the nitrogen gas access component 3, and when the first preset pressure is reached, the fourth cut-off valve 23 between the silicon powder receiving tank 1 and the first silicon powder filter 2 is opened.

[0111] When the gas pressure in the silicon powder receiving tank 1 is uniform, the drying is replaced by re-pressurization and depressurization.

[0112] When it is determined that the silicon powder feeding tank 5 is empty and the pressure has been depressurized to the minimum, the nitrogen gas access inlet in the silicon powder receiving tank 1 is opened to ensure that the pressure of the silicon powder receiving tank 1 is higher than the second preset pressure of the silicon powder feeding tank.

[0113] Then, the third cut-off valve between the silicon powder receiving tank 1 and the silicon powder feeding tank 5 is opened, and the silicon powder is transferred to the silicon powder feeding tank 5.

[0114] After confirming that all the silicon powder in the silicon powder receiving tank 1 is transferred to the silicon powder feeding tank 5, the third cut-off valve is closed, the communication relationship between the hydrogen gas access inlet and the hydrogen gas is opened, the silicon powder feeding tank 5 is pressurized to the third preset pressure, the single cut-off valve 7 between the silicon powder feeding tank 5 and the second silicon powder filter 6 is opened, the silicon powder feeding tank 5 and the second silicon powder filter 6 are equalized in pressure, the re-pressurization and depressurization replacement is repeated, and the first cut-off valve 62 on the depressurization pipeline of the silicon powder feeding tank 5 is closed.

[0115] For the above-mentioned preset pressure value, the person skilled in the art can set it according to the actual working condition, and the preset pressure value does not affect the essential content of the technical solution of the present application. The optimized silicon powder feeding system proposed in the embodiment of the present application sets the first nitrogen inlet 121 on the second part 12 of the silicon powder receiving tank 1, sets the second nitrogen inlet 131 on the third part 13, and discharges nitrogen gas through the first gas outlet 111 set on the first part 11, and realizes the adjustment of the hot nitrogen replacement from the top to the middle and the bottom, realizes the change from single-point nitrogen input to multi-point nitrogen input, and improves the nitrogen replacement efficiency.

[0116] By replacing the venting hand valve with the first pipeline 22 with a wear-resistant lining, the risk of valve wear is avoided, and the safety of the system is increased.

[0117] The nitrogen replacement method in the embodiment of the present application is beneficial to the qualification of the silicon powder micro-oxygen silicon powder dew point; the reduced nitrogen usage and valve replacement frequency reduce the maintenance cost and facilitate promotion.

[0118] Finally, it should be noted that: after considering the specification and practicing the utility model disclosed herein, the person skilled in the art will easily think of other embodiments of the utility model. The present utility model is intended to cover any variations, uses or adaptations of the present utility model, which follow the general principles of the present utility model and include common knowledge or conventional technical means in the technical field not disclosed by the present utility model, and is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present utility model is only limited by the appended claims.

Claims

1. A silicon powder dosing system, characterized in that include: A silicon powder receiving container, wherein the silicon powder receiving container receives at least silicon powder from the pre-processor; the silicon powder receiving container comprises: The first part is located at the top of the silicon powder receiving tank, and the first part is provided with at least a first air outlet; The second part is located below the first part and is connected to the first part; the second part is at least provided with a first nitrogen inlet. The third part is located below the second part and is connected to the second part. The third part is provided with at least a second nitrogen inlet. A first silicon powder filter, wherein the first air inlet of the first silicon powder filter is connected to the first air outlet of the silicon powder receiving tank; A nitrogen inlet component is connected to the first nitrogen inlet and the second nitrogen inlet to fill the silicon powder receiving tank with nitrogen for nitrogen replacement. The nitrogen gas in the silicon powder receiving tank enters the first silicon powder filter through the first gas outlet.

2. The silicon powder dispensing system of claim 1, wherein It also includes a three-way valve, and the first part also includes a third nitrogen inlet; The input end of the three-way valve is connected to the nitrogen inlet component, and the first output end of the three-way valve is connected to the third nitrogen inlet. The second output end of the three-way valve is connected to the first nitrogen inlet and the second nitrogen inlet via pipelines.

3. The silicon powder dispensing system of claim 2, wherein, The silicon powder receiving tank and the first silicon powder filter are connected by a first pipeline, which is provided with a wear-resistant lining.

4. The silicon powder dispensing system of claim 3, wherein The wear-resistant liner is made of wear-resistant ceramic.

5. The silicon powder dispensing system according to any one of claims 1 to 4, wherein Also includes: A silicon powder feeding tank, wherein the silicon powder feeding tank is connected to the silicon powder discharge end of the silicon powder receiving tank; The second silicon powder filter has its second air inlet connected to the second air outlet of the silicon powder feed tank via a single shut-off valve.

6. The silicon powder dispensing system of claim 5, wherein, It also includes a first shut-off valve, which is located on the pressure relief bus of the second silicon powder filter.

7. The silicon powder dispensing system of any of claims 2-4, wherein, It also includes a second shut-off valve, one end of which is connected to the nitrogen inlet component, and the other end is connected to the input end of the three-way valve.

8. The silicon powder dispensing system of claim 7, wherein, It also includes a ball valve, one end of which is connected to the nitrogen inlet component, and the other end of which is connected to the first nitrogen inlet and the second nitrogen inlet, respectively.

9. The silicon powder dispensing system of any of claims 2-4, wherein, The first nitrogen inlet is configured to be a plurality of such inlets, which are arranged along the height direction of the silicon powder receiving tank.

10. The silicon powder dispensing system of claim 2, wherein, Each of the first nitrogen inlet, the second nitrogen inlet, the third nitrogen inlet, and the first outlet is equipped with an independently controlled control valve.

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