A cold hydrogenated silicon powder nitrogen recovery system

Abstract

This invention provides a nitrogen recovery system for cold hydrogenated silicon powder, including a silicon powder receiving tank, a low-pressure gas-solid separation buffer tank, a compressor, and a high-pressure gas-solid separation buffer tank. One end of the low-pressure gas-solid separation buffer tank is connected to the silicon powder receiving tank, and the other end is connected to the high-pressure gas-solid separation buffer tank. The compressor is located between the low-pressure and high-pressure gas-solid separation buffer tanks, and a filter is located between the silicon powder receiving tank and the low-pressure gas-solid separation buffer tank. The filter performs initial filtration of the nitrogen carrying the silicon powder, and the nitrogen is further separated in the low-pressure gas-solid separation buffer tank using the principle of centrifugal sedimentation. Subsequently, the compressor pressurizes the nitrogen and introduces it into the high-pressure gas-solid separation buffer tank. The nitrogen blown out from the top of the buffer tank meets the requirements and is used for silicon powder transportation. The recovery system recycles the nitrogen, saves nitrogen resources, and reduces the manufacturing cost of polysilicon.

Description

Technical Field

[0001] This utility model relates to the field of nitrogen conveying technology for silicon powder, and in particular to a nitrogen recovery system for cold hydrogenated silicon powder. Background Technology

[0002] Currently, the polysilicon industry generally uses nitrogen gas at pressures of 0.3 to 0.6 MPa to transport silicon powder. The silicon powder is transported by nitrogen gas to the silicon powder silo at the highest position. A large amount of nitrogen gas is required during the transportation process. It takes 100 to 150 cubic meters of nitrogen gas to transport 1 ton of silicon powder. The nitrogen gas after transporting the silicon powder is directly discharged into the atmosphere.

[0003] Nitrogen released into the atmosphere contains a small amount of silicon powder, which will cause environmental pollution. Furthermore, this portion of nitrogen has a high content and large volume. Direct release will result in a lack of nitrogen in the silicon powder conveying system, thus requiring the re-installation of nitrogen generation equipment, which wastes resources and increases the cost of polysilicon production. Utility Model Content

[0004] This invention addresses the problems of environmental pollution, resource waste, and increased polysilicon production costs caused by the direct emission of nitrogen during the transport of cold hydrogenated silicon powder in existing technologies, by providing a nitrogen recovery system for cold hydrogenated silicon powder.

[0005] The technical solution adopted in this utility model is:

[0006] A nitrogen recovery system for cold hydrogenated silicon powder includes:

[0007] Silicon powder receiving tank, used to receive silicon powder transported by nitrogen;

[0008] A low-pressure gas-solid separation buffer tank is connected at one end to the silicon powder receiving tank;

[0009] The compressor is connected at one end to the low-pressure gas-solid separation buffer tank.

[0010] A high-pressure gas-solid separation buffer tank is connected to the compressor.

[0011] Furthermore, the other end of the high-pressure gas-solid separation buffer tank is connected to the silicon powder receiving tank.

[0012] Furthermore, it also includes:

[0013] A filter is disposed between the silicon powder receiving tank and the low-pressure gas-solid separation buffer tank.

[0014] Furthermore, it also includes:

[0015] A silicon powder storage tank is connected to the silicon powder receiving tank.

[0016] Furthermore, the silicon powder storage tank is connected to a filter.

[0017] Furthermore, the silicon powder storage tank is connected to a low-pressure gas-solid separation buffer tank.

[0018] Furthermore, the silicon powder storage tank is connected to the silicon powder output end of the high-pressure gas-solid separation buffer tank.

[0019] Furthermore, the silicon powder storage tank is connected to the outlet of the high-pressure gas-solid separation buffer tank.

[0020] The beneficial effects of this utility model are:

[0021] The nitrogen carrying silicon powder is initially filtered by a filter. The nitrogen is further separated in a low-pressure gas-solid separation buffer tank by centrifugal sedimentation. The nitrogen is then pressurized by a compressor and introduced into a high-pressure gas-solid separation buffer tank. The nitrogen blown out from the top of the buffer tank meets the requirements and is used for silicon powder transportation. The recovery system recycles the nitrogen, saving nitrogen resources and reducing the manufacturing cost of polysilicon. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0023] Figure 1 This is a schematic diagram of the structure of the cold hydrogenated silicon powder nitrogen recovery system of this utility model.

[0024] Marked in the image:

[0025] 100. Nitrogen recovery system; 101. Silicon powder receiving tank; 102. Filter; 103. Low-pressure gas-solid separation buffer tank; 104. Compressor; 105. High-pressure gas-solid separation buffer tank; 106. Silicon powder storage tank. Detailed Implementation

[0026] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model 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 of this utility model.

[0027] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this invention.

[0028] The embodiments of the utility model will now be described in detail with reference to the accompanying drawings.

[0029] This embodiment provides a nitrogen recovery system for cold hydrogenated silicon powder, which solves the problems of environmental pollution, resource waste, and increased polysilicon production costs caused by the direct emission of nitrogen during the transportation of cold hydrogenated silicon powder into the air. The system recovers and recycles the nitrogen, achieving the goals of cost reduction, efficiency improvement, and environmental cleanliness.

[0030] Reference Figure 1 The nitrogen recovery system 100 for cold hydrogenated silicon powder includes a silicon powder receiving tank 101, a filter 102, a low-pressure gas-solid separation buffer tank 103, a compressor 104, a high-pressure gas-solid separation buffer tank 105, and a silicon powder storage tank 106. One end of the silicon powder receiving tank 101 is connected to the filter 102, and the other end of the filter 102 is connected to the low-pressure gas-solid separation buffer tank 103. One end of the compressor 104 is connected to the low-pressure gas-solid separation buffer tank 103, and the other end is connected to the high-pressure gas-solid separation buffer tank 105.

[0031] Nitrogen gas transports silicon powder to the silicon powder receiving tank 101 at the highest position. The nitrogen gas exiting the receiving tank 101 is passed into the filter 102, which removes the silicon powder carried in the nitrogen gas, thus improving the purity of the nitrogen gas. Subsequently, the nitrogen gas is passed from the filter 102 into the low-pressure gas-solid separation buffer tank 103. Utilizing the principle of centrifugal sedimentation, the nitrogen gas rotates in the low-pressure gas-solid separation buffer tank 103, generating a strong centrifugal force. Solids with greater inertia are thrown against the inner wall of the buffer tank, further separating the silicon powder that was not fully filtered out by the filter 102 from the nitrogen gas. The nitrogen gas is then blown out from the top of the low-pressure gas-solid separation buffer tank 103, while the silicon powder remains at the bottom of the low-pressure gas-solid separation buffer tank 103, further purifying the nitrogen gas. At the same time, the nitrogen gas also serves as a buffer within the low-pressure gas-solid separation buffer tank 103.

[0032] The purified nitrogen enters the compressor 104 from the low-pressure gas-solid separation buffer tank 103. After being pressurized by the compressor, the nitrogen enters the high-pressure gas-solid separation buffer tank 105 through the outlet of the compressor 104. The centrifugal force generated by the high flow rate further separates the silicon powder carried in the nitrogen, and the nitrogen is also buffered in the high-pressure gas-solid separation buffer tank 105.

[0033] A silicon powder storage tank 106 is also connected between the silicon powder receiving tank 101 and the high-pressure gas-solid separation buffer tank 105. At the same time, the silicon powder storage tank 106 is also connected to the filter 102 and the low-pressure gas-solid separation buffer tank 103 respectively. The silicon powder filtered and deposited by the filter 102, the low-pressure gas-solid separation buffer tank 103 and the high-pressure gas-solid separation buffer tank 104 is periodically transported to the silicon powder storage tank 106 to realize the recycling of silicon powder.

[0034] After three filtration separations, the nitrogen gas exiting from the top of the high-pressure gas-solid separation buffer tank 105 has reached the required purity. Therefore, a portion of the nitrogen gas is incorporated into the nitrogen pipeline network, another portion is used for silicon powder transportation, and a third portion is used to transport the silicon powder in the silicon powder storage tank 106 to the silicon powder receiving tank 101. Then, the nitrogen gas enters the filter 102 from the outlet of the silicon powder receiving tank 101 for another round of filtration and purification, achieving a cycle of reuse.

[0035] Nitrogen gas transports silicon powder to silicon powder receiving tank 101. Then, the nitrogen gas enters filter 102 from the outlet of silicon powder receiving tank 101. Filter 102 filters and separates the silicon powder carried in the nitrogen gas. The filtered silicon powder is transported to silicon powder storage tank 106 for recycling. The purified nitrogen gas is introduced into low-pressure gas-solid separation buffer tank 103 from the outlet of filter 102.

[0036] Inside the low-pressure gas-solid separation buffer tank 103, the principle of centrifugal sedimentation is used to make the nitrogen gas rotate and generate a strong centrifugal force. The silicon powder with a large inertia is thrown against the inner wall of the buffer tank, further separating the silicon powder that was not fully filtered out by the filter 102 from the nitrogen gas. The nitrogen gas is blown out from the top of the low-pressure gas-solid separation buffer tank 103, while the silicon powder remains at the bottom of the low-pressure gas-solid separation buffer tank 103. The silicon powder remaining at the bottom is periodically discharged into the silicon powder storage tank 106.

[0037] Then, nitrogen gas is pressurized by compressor 104 and introduced into high-pressure gas-solid separation buffer tank 105. The centrifugal force generated by the high flow rate further separates the silicon powder carried in the nitrogen gas, and the silicon powder is discharged into silicon powder storage tank 106 for subsequent recycling. The purity of the nitrogen gas exiting from the top of high-pressure gas-solid separation buffer tank 105 meets the requirements. Therefore, a portion of the nitrogen gas is incorporated into the nitrogen pipeline network, another portion is used for silicon powder transportation, and a third portion is used to transport the silicon powder in silicon powder storage tank 106 to silicon powder receiving tank 101. Finally, the nitrogen gas enters filter 102 from the outlet of silicon powder receiving tank 101 for another round of filtration and purification. These steps achieve the recycling of nitrogen gas without external discharge, reducing the cost of polysilicon production.

[0038] The above embodiments are merely a more detailed description of the present utility model. For those skilled in the art, modifications or equivalent substitutions can still be made to the technical solutions in the foregoing embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model patent.

Claims

1. A nitrogen recovery system for cold hydrogenated silicon powder, characterized in that, include: Silicon powder receiving tank, used to receive silicon powder transported by nitrogen; A low-pressure gas-solid separation buffer tank is connected at one end to the silicon powder receiving tank; The compressor is connected at one end to the low-pressure gas-solid separation buffer tank. A high-pressure gas-solid separation buffer tank is connected to the compressor.

2. The nitrogen recovery system for cold hydrogenated silicon powder according to claim 1, characterized in that: The other end of the high-pressure gas-solid separation buffer tank is connected to the silicon powder receiving tank.

3. The nitrogen recovery system for cold hydrogenated silicon powder according to claim 1, characterized in that, Also includes: A filter is disposed between the silicon powder receiving tank and the low-pressure gas-solid separation buffer tank.

4. The nitrogen recovery system for cold hydrogenated silicon powder according to claim 3, characterized in that, Also includes: A silicon powder storage tank is connected to the silicon powder receiving tank.

5. The nitrogen recovery system for cold hydrogenated silicon powder according to claim 4, characterized in that: The silicon powder storage tank is connected to the filter.

6. The nitrogen recovery system for cold hydrogenated silicon powder according to claim 4, characterized in that: The silicon powder storage tank is connected to the low-pressure gas-solid separation buffer tank.

7. The nitrogen recovery system for cold hydrogenated silicon powder according to claim 4, characterized in that: The silicon powder storage tank is connected to the silicon powder output end of the high-pressure gas-solid separation buffer tank.

8. The nitrogen recovery system for cold hydrogenated silicon powder according to claim 6, characterized in that: The silicon powder storage tank is connected to the outlet of the high-pressure gas-solid separation buffer tank.

Images