Silicon powder feeding structure and polycrystalline silicon cold hydrogenation system

Abstract

This application provides a silicon powder feeding structure and a polycrystalline silicon cold hydrogenation system. The silicon powder feeding structure includes a feeding device and a nitrogen supply device. The feeding device has a material chamber and an air inlet, an air outlet, and a feeding port connecting the material chamber. External silicon powder can be supplied to the material chamber. The nitrogen supply device is connected to the air inlet and can introduce nitrogen gas into the material chamber through the air inlet. The introduced nitrogen gas carries out the air inside the material chamber and replaces the air inside the material chamber with nitrogen gas. After the air inside the material chamber is replaced with nitrogen gas, silicon powder is then supplied into the material chamber. The feeding device can feed the material to the reactor for hydrogenation reaction. Since the silicon powder feeding structure also includes a separation device, the separation device can separate nitrogen gas from the mixed gas. The separated nitrogen gas can be reintroduced into the nitrogen supply device for recycling. Therefore, nitrogen gas recycling can be achieved, avoiding waste of nitrogen resources.

Description

Technical Field

[0001] This application relates to the field of polysilicon production technology, and in particular to a silicon powder feeding structure and a polysilicon cold hydrogenation system. Background Technology

[0002] The core task of the polycrystalline silicon cold hydrogenation system is to convert silicon tetrachloride (SiCl4), a byproduct generated during the polycrystalline silicon production process, into trichlorosilane (SiHCl3), thereby achieving efficient utilization and recycling of silicon resources.

[0003] The polycrystalline silicon cold hydrogenation system requires adding silicon powder to the fluidized bed reactor through a silicon powder tank. To prevent the silicon powder from oxidizing inside the silicon powder tank, the air in the silicon powder tank needs to be replaced with nitrogen before adding the silicon powder. During the replacement process, nitrogen is simply introduced into the silicon powder tank to drive the air out of the tank.

[0004] To ensure that all the air in the silicon powder tank is expelled, a large amount of nitrogen needs to be introduced into the silicon powder tank during the replacement process. However, the introduced nitrogen will generally be discharged into the atmosphere along with the air, resulting in a waste of nitrogen resources and an increase in the operating cost of the polycrystalline silicon cold hydrogenation system. Utility Model Content

[0005] This application provides a silicon powder feeding structure and a polycrystalline silicon cold hydrogenation system to solve the technical problem that the polycrystalline silicon cold hydrogenation system is prone to nitrogen resource waste during the silicon powder supply process, which leads to an increase in the operating cost of the polycrystalline silicon cold hydrogenation system.

[0006] On one hand, this application provides a silicon powder feeding structure, including:

[0007] The feeding device is provided with a material chamber, and an air inlet, an air outlet and a feed inlet communicating with the material chamber. The material chamber is used to store silicon powder, and the feed inlet is used to connect to the reactor and supply silicon powder to the reactor.

[0008] A nitrogen supply device, connected to the air inlet, is used to supply nitrogen gas into the material chamber through the air inlet, so as to drive the gas in the material chamber to be discharged through the air outlet.

[0009] A separation device, connected to the nitrogen supply device and the gas outlet, is used to separate nitrogen gas from the gas discharged from the gas outlet and return the separated nitrogen gas to the nitrogen supply device.

[0010] In some embodiments, the separation device includes a packed absorption tower having an exhaust port and an adsorption chamber with adsorption packing. The adsorption chamber is connected to the exhaust port and is used to receive gas discharged from the exhaust port. The adsorption packing is used to adsorb gases other than nitrogen in the adsorption chamber. The exhaust port is connected to the adsorption chamber and is used to discharge the gas adsorbed by the adsorption packing. The nitrogen supply device is connected to the exhaust port.

[0011] In some embodiments, the nitrogen supply device includes a nitrogen buffer tank, which is connected to the separation device and the air inlet, for storing the nitrogen separated by the separation device and supplying the stored nitrogen to the air inlet.

[0012] In some embodiments, the nitrogen supply device further includes a nitrogen heat exchanger, which is connected to the nitrogen buffer tank and the air inlet, and is used to heat the nitrogen gas supplied from the nitrogen buffer tank to the air inlet.

[0013] In some embodiments, the feeding device includes a silicon powder receiving tank and a silicon powder feeding tank. The material chamber, the air inlet, and the air outlet are all disposed in the silicon powder receiving tank. The silicon powder feeding tank is connected to the silicon powder receiving tank and is used to receive silicon powder from the silicon powder receiving tank. The feeding port is disposed in the silicon powder feeding tank.

[0014] In some embodiments, the silicon powder feeding structure further includes a silicon powder filter, which is connected to the gas outlet and the separation device, and is used to filter silicon powder in the gas passing through the gas outlet to the separation device.

[0015] In some embodiments, the silicon powder filter is also connected to the nitrogen supply device, and the gas inside the silicon powder filter can be replaced by nitrogen introduced through the nitrogen supply device.

[0016] On the other hand, this application provides a polycrystalline silicon cold hydrogenation system, comprising:

[0017] Reactor;

[0018] A silicon powder feeding structure is connected to the reactor and is used to feed silicon powder into the reactor;

[0019] A reaction gas supply structure is connected to the reactor and is used to supply reaction gas to the reactor;

[0020] A polycrystalline silicon forming structure is connected to the output end of the reactor for forming polycrystalline silicon through the products of the reactor.

[0021] In some embodiments, the reaction gas supply structure includes a hydrogen supply device, a silicon tetrachloride supply device, and a heating pipeline. The hydrogen supply device and the silicon tetrachloride supply device are connected to the heating pipeline for supplying hydrogen and silicon tetrachloride to the heating pipeline. The heating pipeline is connected to the reactor for heating the hydrogen and silicon tetrachloride and supplying them to the reactor.

[0022] In some embodiments, the polycrystalline silicon forming structure includes a silicon powder recovery pipeline, a condenser tower, a slurry treatment pipeline, and a polycrystalline silicon forming pipeline. The silicon powder recovery pipeline is connected to the reactor and is used to separate silicon powder from the reactor product. The condenser tower is connected to the silicon powder recovery pipeline and is used to condense the reactor product after silicon powder separation. Both the slurry treatment pipeline and the polycrystalline silicon forming pipeline are connected to the condenser tower. The slurry treatment pipeline is used to treat the slurry formed by the condenser tower, and the polycrystalline silicon forming pipeline is used to treat the condensate formed by the condenser tower, so that the condensate is reduced to form polycrystalline silicon.

[0023] The silicon powder feeding structure and polycrystalline silicon cold hydrogenation system provided in this application include a feeding device and a nitrogen supply device. The feeding device has a material chamber, and an air inlet, an air outlet, and a feed port connecting the material chamber. External silicon powder can be supplied to the material chamber. The nitrogen supply device is connected to the air inlet and can introduce nitrogen gas into the material chamber through the air inlet. The introduced nitrogen gas carries away the air inside the material chamber and fills the material chamber, replacing the air inside with nitrogen gas. After the air inside the material chamber is replaced with nitrogen gas, silicon powder is then supplied into the material chamber, so that the silicon powder is in a nitrogen environment to prevent silicon powder oxidation. The feeding device can be connected to the reactor through the feed port, and the feed gas can be supplied to the reactor through the feed port. The silicon powder feeding structure is equipped with a separation device connected to the nitrogen supply device and the gas outlet. During the nitrogen replacement process, the nitrogen-containing gas mixture exiting through the gas outlet enters the separation device, which separates the nitrogen from the mixture. The separated nitrogen can then be recycled back into the nitrogen supply device. Therefore, by incorporating a separation device, the silicon powder feeding structure can achieve nitrogen recycling, avoiding the waste of nitrogen resources and significantly reducing nitrogen consumption during the feeding process of the polycrystalline silicon cold hydrogenation system, thereby lowering the operating cost of the polycrystalline silicon cold hydrogenation system. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0025] Figure 1 This is a schematic diagram of the silicon powder feeding structure provided in the embodiments of this application;

[0026] Figure 2 This is a schematic diagram of the structure of the polycrystalline silicon cold hydrogenation system provided in the embodiments of this application.

[0027] Labels for each item in the figure:

[0028] 10—Feeding device; 11—Silicon powder receiving tank; 12—Silicon powder feeding tank;

[0029] 20—Nitrogen supply device; 21—Nitrogen buffer tank; 22—Nitrogen heat exchanger;

[0030] 30—Separation device; 31—Packed absorption tower;

[0031] 40—Silicon powder filter; 50—Reactor; 60—Silicon powder feeding structure;

[0032] 70—Reaction gas supply structure; 71—Hydrogen supply device; 72—Silicon tetrachloride supply device; 73—Heating pipeline; 731—Multiphase flow heat exchanger; 732—Vaporizer; 733—Feed heater; 734—First heat exchanger; 735—Second heat exchanger; 736—Electric heater;

[0033] 80—Polycrystalline silicon forming structure; 81—Silicon powder recovery pipeline; 811—Cyclone separator; 812—Silicon powder filter; 813—Silicon powder collection tank; 82—Condensation tower; 83—Slurry treatment pipeline; 831—Slurry collection tank; 832—Slurry filter; 84—Polycrystalline silicon forming pipeline; 841—Eight-stage condensation module; 842—Distillation module; 843—Reduction module.

[0034] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0035] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0036] This application provides a silicon powder feeding structure for use in a polycrystalline silicon cold hydrogenation process. In the polycrystalline silicon cold hydrogenation process, silicon powder needs to be added to the fluidized bed reactor during the reaction. Before adding silicon powder, the air in the silicon powder tank needs to be replaced with nitrogen. In traditional processes, the nitrogen discharged during the replacement process is usually directly discharged, resulting in a waste of nitrogen resources.

[0037] To address the technical problem of nitrogen resource waste during the silicon powder supply process in polycrystalline silicon cold hydrogenation systems, which leads to increased operating costs, the silicon powder feeding structure provided in this application enables the recycling of nitrogen resources, thereby avoiding nitrogen resource waste.

[0038] It should be noted that the silicon powder feeding structure described in this application is used in, but not limited to, polycrystalline silicon cold hydrogenation systems, and can also be used in any process system that requires silicon powder as a reaction raw material. For ease of explanation, this application takes the application of the silicon powder feeding structure in a polycrystalline silicon cold hydrogenation system as an example. The principle of the silicon powder feeding structure applied to other process systems is essentially the same as that applied to the polycrystalline silicon cold hydrogenation system, and will not be elaborated here.

[0039] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0040] To better understand this application, the following is combined with... Figures 1 to 2 The technical solution of this application is described in detail below:

[0041] like Figure 1 and 2 As shown in the figure, the silicon powder feeding structure provided in this embodiment includes a feeding device 10, a nitrogen supply device 20, and a separation device 30. The feeding device 10 has a material chamber, and an air inlet, an air outlet, and a feeding port connected to the material chamber. The material chamber is used to store silicon powder, and the feeding port is used to connect to the reactor 50 and supply silicon powder to the reactor 50. The nitrogen supply device 20 is connected to the air inlet and is used to supply nitrogen gas into the material chamber through the air inlet to drive the gas in the material chamber to be discharged through the air outlet. The separation device 30 is connected to the nitrogen supply device 20 and the air outlet and is used to separate the nitrogen gas in the gas discharged from the air outlet and return the separated nitrogen gas to the nitrogen supply device 20.

[0042] Specifically, the silicon powder feeding structure includes a feeding device 10 and a nitrogen supply device 20. The feeding device 10 has a material chamber, and an air inlet, an air outlet, and a feed inlet connecting the material chamber. External silicon powder can be supplied to the material chamber. The nitrogen supply device 20 is connected to the air inlet and can introduce nitrogen gas into the material chamber through the air inlet. The introduced nitrogen gas carries out the air inside the material chamber and fills the material chamber, replacing the air inside the material chamber with nitrogen gas. After the air inside the material chamber is replaced with nitrogen gas, silicon powder is then supplied into the material chamber, so that the silicon powder is in a nitrogen environment to prevent silicon powder oxidation. The feeding device 10 can be connected to the reactor 50 through the feed inlet and feeds the silicon powder into the reactor 50 for processing. In the hydrogenation reaction, the silicon powder feeding structure is also equipped with a separation device 30, which is connected to the nitrogen supply device 20 and the gas outlet. During the nitrogen replacement process, the nitrogen-containing mixed gas passing through the gas outlet will enter the separation device 30. The separation device 30 can separate the nitrogen from the mixed gas. The separated nitrogen can be fed back into the nitrogen supply device 20 for recycling. Therefore, by setting the separation device 30, the silicon powder feeding structure can realize the recycling of nitrogen, avoid the waste of nitrogen resources, and significantly reduce the nitrogen consumption during the feeding process of the polycrystalline silicon cold hydrogenation system, thereby reducing the operating cost of the polycrystalline silicon cold hydrogenation system.

[0043] Understandably, the feeding device 10 can be a single storage tank for temporarily storing silicon powder, or a combination of multiple connected storage tanks.

[0044] In some embodiments, such as Figure 1 and 2 As shown, the feeding device 10 includes a silicon powder receiving tank 11 and a silicon powder feeding tank 12. A material chamber, an air inlet, and an air outlet are all located in the silicon powder receiving tank 11. The silicon powder feeding tank 12 is connected to the silicon powder receiving tank 11 and is used to receive silicon powder from the silicon powder receiving tank 11. A feed port is located in the silicon powder feeding tank 12. Specifically, the feeding device 10 has two combined tank structures: the silicon powder receiving tank 11 and the silicon powder feeding tank 12. The silicon powder receiving tank 11, by having a material chamber, an air inlet, and an air outlet, can be specifically used to create a nitrogen environment to receive external silicon powder, ensuring the silicon powder is not oxidized in the nitrogen environment. The silicon powder feeding tank 12 can serve as a transition tank for supplying silicon powder to the reactor 50, receiving the silicon powder received by the silicon powder receiving tank 11. The silicon powder feeding tank 12 can be filled with the reaction gas required for the reaction in the reactor 50 or set as a vacuum tank to supply silicon powder into the reactor 50.

[0045] In this embodiment, the nitrogen supply device 20 needs to perform three nitrogen supply cycles on the silicon powder receiving tank 11. Through three nitrogen supply cycles, the air inside the receiving tank can be effectively replaced.

[0046] Understandably, the silicon powder feed tank 12 can be a storage tank filled with the reaction gas required for the hydrogenation reaction in the reactor 50, or a vacuum tank, to prevent irrelevant gases from entering the reactor 50 during the process of supplying silicon powder to the reactor 50 and affecting the hydrogenation reaction in the reactor 50.

[0047] To prevent other gases from entering the reactor 50 along with the silicon powder feeder 12, in this embodiment, the silicon powder feeder 12 is a vacuum tank.

[0048] Understandably, the nitrogen supply device 20 can be any device that can receive gas and supply nitrogen to the feeding device 10. For example, the nitrogen supply device 20 can be a gas storage tank, a compressor, a nitrogen generator, or other devices.

[0049] In some embodiments, such as Figure 1 and 2 As shown, the nitrogen supply device 20 includes a nitrogen buffer tank 21, which is connected to the separation device 30 and the air inlet. The nitrogen buffer tank 21 stores the nitrogen separated by the separation device 30 and directs the stored nitrogen to the air inlet. Specifically, the nitrogen buffer tank 21 receives the nitrogen separated by the separation device 30, providing buffering and temporary storage for the nitrogen, thereby ensuring a stable supply of nitrogen to the material chamber.

[0050] Understandably, the nitrogen buffer tank 21 can be connected to the air inlet via a pipe, or to any other device with a connection channel.

[0051] In some embodiments, such as Figure 1 and 2 As shown, the nitrogen supply device 20 also includes a nitrogen heat exchanger 22, which is connected to the nitrogen buffer tank 21 and the air inlet, and is used to heat the nitrogen gas supplied from the nitrogen buffer tank 21 to the air inlet. Specifically, the nitrogen heat exchanger 22 can heat the nitrogen gas before it is supplied into the material chamber through the air inlet, causing the nitrogen molecules to move violently, increasing the diffusion rate of nitrogen gas in the material chamber, thereby quickly expelling the air in the material chamber and rapidly filling the material chamber, improving the replacement efficiency.

[0052] Understandably, the nitrogen heat exchanger 22 can be any heat exchange device capable of heating nitrogen.

[0053] Understandably, the separation device 30 can be any separation equipment capable of separating nitrogen from air. For example, the separation device 30 can be a membrane separation device, which relies on the differences in the solubility and diffusion coefficients of different gases in the membrane to achieve gas separation due to their different permeation rates. When the mixed gas is subjected to a pressure difference across the membrane, gases with relatively fast permeation rates, such as oxygen and carbon dioxide, permeate through the membrane and are enriched on the permeate side, while gases with relatively slow permeation rates, such as nitrogen, remain on the retention side and are enriched, thereby achieving the purpose of separating the mixed gas. The separation device 30 can also be an air separation nitrogen generator, which compresses and filters natural air to remove impurities, then heats and cools the air until different elements reach their boiling points and are then separated.

[0054] In some embodiments, such as Figure 1 and 2 As shown, the separation device 30 includes a packed absorption tower 31, which has an exhaust port and an adsorption chamber with adsorption packing. The adsorption chamber is connected to the exhaust port to receive the gas discharged from the exhaust port. The adsorption packing is used to supply gases other than nitrogen in the adsorption chamber. The exhaust port is connected to the adsorption chamber to discharge the gas adsorbed by the adsorption packing. The nitrogen supply device 20 is connected to the exhaust port. Specifically, during the nitrogen replacement process, the mixed gas discharged from the exhaust port will enter the adsorption chamber. When the mixed gas flows through the adsorption packing, other gases in the mixed gas, except for nitrogen, will be adsorbed by the adsorption packing, while the nitrogen that is not adsorbed by the adsorption packing will be discharged from the exhaust port to the nitrogen supply device 20, thereby achieving the separation of nitrogen from the mixed gas.

[0055] In this embodiment, under high pressure conditions, the adsorbent (such as carbon molecular sieve) in the packed absorption tower 31 has a strong adsorption capacity for impurities such as oxygen, carbon dioxide and water vapor, but a weak adsorption capacity for nitrogen.

[0056] When air passes through the adsorption tower, oxygen, carbon dioxide, and water vapor are adsorbed by the adsorbent, while nitrogen is discharged through the adsorption tower outlet, forming high-purity nitrogen.

[0057] The specific adsorption process is as follows: the gas discharged from the outlet is first compressed to a certain pressure (usually 7-8 bar). The compressed air enters the adsorption chamber containing the adsorption packing material. Under high pressure, the adsorption sites on the surface of the adsorption packing material are occupied by impurities such as oxygen, while nitrogen is enriched due to its weaker adsorption capacity.

[0058] To improve separation efficiency, in this embodiment, the packed absorption tower 31 includes two or more tower bodies, one tower for adsorption and the other tower for desorption, and multiple tower bodies work alternately to ensure a continuous supply of nitrogen.

[0059] In this embodiment, the exhaust port of the packed absorber 31 is connected to the nitrogen buffer tank 21.

[0060] In some embodiments, such as Figure 1 and 2 As shown, the silicon powder feeding structure also includes a silicon powder filter 40, which is connected to the gas outlet and the separation device 30. The silicon powder filter 40 is used to filter the silicon powder in the gas flowing from the gas outlet to the separation device 30. Specifically, all gas discharged from the gas outlet enters the silicon powder filter 40. The gas carries some silicon powder with it as it exits the gas outlet. The silicon powder filter 40 filters the silicon powder carried in the gas. The gas after filtering the silicon powder enters the separation device 30 for nitrogen separation, while the silicon powder re-enters the feeding chamber. This avoids waste of silicon powder and prevents contamination of the separation device 30 by the silicon powder.

[0061] To prevent the silicon powder inside the silicon powder filter 40 from being oxidized, in some embodiments, the silicon powder filter 40 is also connected to a nitrogen supply device 20, and the gas inside the silicon powder filter 40 can be replaced by nitrogen gas supplied by the nitrogen supply device 20. Specifically, by connecting to the nitrogen supply device 20, the silicon powder filter 40 can also replace the gas inside by the nitrogen gas supplied by the nitrogen supply device 20, and the gas discharged through the silicon powder filter 40 will enter the separation device 30, effectively preventing the silicon powder in the silicon powder filter 40 from being oxidized.

[0062] In this embodiment, the silicon powder filter 40 is connected to the nitrogen heat exchanger 22.

[0063] This application also provides a polycrystalline silicon cold hydrogenation system, such as... Figure 2 As shown, the reactor includes a reactor 50, a silicon powder feeding structure 60, a reaction gas supply structure 70, and a polycrystalline silicon forming structure 80. The silicon powder feeding structure 60 is connected to the reactor 50 and is used to feed silicon powder into the reactor 50. The reaction gas supply structure 70 is connected to the reactor 50 and is used to supply reaction gas into the reactor 50. The polycrystalline silicon forming structure 80 is connected to the output end of the reactor 50 and is used to form polycrystalline silicon through the products of the reactor 50.

[0064] Specifically, the polycrystalline silicon cold hydrogenation system comprises a reactor 50, a silicon powder feeding structure 60, a reaction gas supply structure 70, and a polycrystalline silicon forming structure 80. During the hydrogenation reaction, the silicon powder feeding structure 60 supplies silicon powder into the reactor 50, and the reaction gas supply structure 70 supplies the hydrogen and silicon tetrachloride required for the reaction into the reactor 50. Under process conditions of a temperature of 565-590℃, a pressure of 2.5-2.9 MPa, and using copper chloride as a catalyst, a hydrogenation reaction occurs in the reactor 50, generating a mixed gas of chlorosilanes such as trichlorosilane, silicon tetrachloride, and dichlorosilane. The polycrystalline silicon forming structure 80 processes the mixed gas generated in the reactor 50 to ultimately produce the product polycrystalline silicon.

[0065] In some embodiments, such as Figure 2As shown, the reaction gas supply structure 70 includes a hydrogen supply device 71, a silicon tetrachloride supply device 72, and a heating pipe 73. The hydrogen supply device 71 and the silicon tetrachloride supply device 72 are connected to the heating pipe 73 to supply hydrogen and silicon tetrachloride to the heating pipe 73. The heating pipe 73 is connected to the reactor 50 to heat the hydrogen and silicon tetrachloride and then supply them into the reactor 50. Specifically, during the reaction gas supply process, the hydrogen supply device 71 supplies hydrogen to the heating pipe 73, and the silicon tetrachloride supply device 72 supplies silicon tetrachloride to the heating pipe 73. The hydrogen and silicon tetrachloride are heated by the heating pipe 73 before being supplied into the reactor 50, thus realizing the supply of reaction gas.

[0066] In this embodiment, the hydrogen supplied by the hydrogen supply device 71 includes reduction byproduct hydrogen generated during the reduction process of polycrystalline silicon forming structure 80, synthesis byproduct hydrogen generated as a byproduct during chemical synthesis, and unreacted circulating hydrogen in the hydrogenation system.

[0067] In this embodiment, as Figure 2 As shown, the heating pipeline 73 is sequentially equipped with a multiphase flow heat exchanger 731, a vaporizer 732, a feed heater 733, a first heat exchanger 734, a second heat exchanger 735, and an electric heater 736. The hydrogen supply device 71 and the silicon tetrachloride supply device 72 are connected to the multiphase flow heat exchanger 731. The hydrogen supply device 71 and the silicon tetrachloride supply device 72 first supply hydrogen and silicon tetrachloride into the multiphase flow heat exchanger 731 for preheating. Then, the vaporizer 732 vaporizes the hydrogen and silicon tetrachloride, which is then fed into the feed heater 733 for heating. Finally, the hydrogen and silicon tetrachloride are sequentially heated by the first heat exchanger 734, the second heat exchanger 735, and the electric heater 736 before being fed into the reactor 50. This preheating provides the hydrogen and silicon tetrachloride with a suitable temperature for the hydrogenation reaction, ensuring the smooth progress of the reaction.

[0068] In some embodiments, such as Figure 2 As shown, the polycrystalline silicon forming structure 80 includes a silicon powder recovery pipeline 81, a condenser tower 82, a slurry treatment pipeline 83, and a polycrystalline silicon forming pipeline 84. The silicon powder recovery pipeline 81 is connected to the reactor 50 and is used to separate silicon powder from the product of the reactor 50. The condenser tower 82 is connected to the silicon powder recovery pipeline 81 and is used to condense the product of the reactor 50 after the silicon powder separation. The slurry treatment pipeline 83 and the polycrystalline silicon forming pipeline 84 are both connected to the condenser tower 82. The slurry treatment pipeline 83 is used to treat the slurry formed by the condenser tower 82, and the polycrystalline silicon forming pipeline 84 is used to treat the condensate formed by the condenser tower 82, so that the condensate is reduced to form polycrystalline silicon.

[0069] Specifically, the mixed gas of trichlorosilane, silicon tetrachloride, and dichlorosilane formed by the hydrogenation reaction in reactor 50 first enters silicon powder recovery pipeline 81. After unreacted silicon powder is recovered through silicon powder recovery pipeline 81, it is introduced into condenser tower 82. Condenser tower 82 cools and washes the mixed gas. The slurry formed by the mixture of residual silicon powder and high-boiling substances is discharged to slurry treatment pipeline 83. The slurry is then further processed by the slurry treatment pipeline. The condensate from the top of condenser tower 82 enters polycrystalline silicon formation pipeline 84, and finally, the condensate is reduced to form polycrystalline silicon.

[0070] In this embodiment, as Figure 2 As shown, the silicon powder recovery pipeline 81 is equipped with a cyclone separator 811 and a silicon powder filter 812. Both the cyclone separator 811 and the silicon powder filter 812 are connected to a silicon powder collection tank 813. The silicon powder recovery pipeline 81 is connected to the first heat exchanger 734 and the second heat exchanger 735. The high-temperature mixed gas generated by the reaction in the reactor 50 first enters the second heat exchanger 735. The mixed gas products transfer heat to the hydrogen and silicon tetrachloride reaction gas entering the second heat exchanger 735 before entering the first heat exchanger. The heat exchanger 734 transfers heat to the hydrogen and silicon tetrachloride reaction gas entering the first heat exchanger 734, and then enters the cyclone separator 811. The cyclone separator separates silicon powder from the mixed gas product and then passes it into the silicon powder collection tank 813 for collection. The mixed gas product processed by the cyclone separator is then passed into the silicon powder filter 812 to further filter out the silicon powder in the product. The filtered silicon powder is then passed into the silicon powder collection tank 813 for collection. Finally, the mixed gas after separating the silicon powder is passed into the condenser tower 82 for condensation.

[0071] In this embodiment, as Figure 2 As shown, the slurry treatment pipeline 83 is equipped with a slurry collection tank 831 and a slurry filter 832. After the slurry is collected by the slurry collection tank 831, the larger slurry particles are filtered through the slurry filter 832. Finally, the filtered slurry is treated through the treatment process.

[0072] In this embodiment, as Figure 2 As shown, the polysilicon forming pipeline 84 is equipped with an eight-stage condensation module 841, a distillation module 842, and a reduction module 843. The polysilicon forming pipeline 84 is connected to a multiphase flow heat exchanger 731. The condensate formed by condensation enters the multiphase flow heat exchanger 731, where it exchanges heat with hydrogen and silicon tetrachloride supplied by the hydrogen supply device 71 and the silicon tetrachloride supply device 72. After condensation, it enters the eight-stage condensation module 841 to obtain crude trichlorosilane. The crude trichlorosilane is sent to the distillation module 842 for distillation and purification. The purified trichlorosilane is finally reduced by hydrogen in the reduction module 843 to produce polysilicon.

[0073] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0074] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A silicon powder feed structure, characterized by, include: The feeding device is provided with a material chamber, and an air inlet, an air outlet and a feed inlet communicating with the material chamber. The material chamber is used to store silicon powder, and the feed inlet is used to connect to the reactor and supply silicon powder to the reactor. A nitrogen supply device, connected to the air inlet, is used to supply nitrogen gas into the material chamber through the air inlet, so as to drive the gas in the material chamber to be discharged through the air outlet. A separation device, connected to the nitrogen supply device and the gas outlet, is used to separate nitrogen gas from the gas discharged from the gas outlet and return the separated nitrogen gas to the nitrogen supply device.

2. The silicon powder feed structure of claim 1, wherein The separation device includes a packed absorption tower, which has an exhaust port and an adsorption chamber with adsorption packing. The adsorption chamber is connected to the exhaust port and is used to receive the gas discharged from the exhaust port. The adsorption packing is used to adsorb gases other than nitrogen in the adsorption chamber. The exhaust port is connected to the adsorption chamber and is used to discharge the gas adsorbed by the adsorption packing. The nitrogen supply device is connected to the exhaust port.

3. The silicon powder feeding structure as described in claim 1, characterized in that, The nitrogen supply device includes a nitrogen buffer tank, which is connected to the separation device and the air inlet. The nitrogen buffer tank is used to store the nitrogen separated by the separation device and to supply the stored nitrogen to the air inlet.

4. The silicon powder feeding structure as described in claim 3, characterized in that, The nitrogen supply device also includes a nitrogen heat exchanger, which is connected to the nitrogen buffer tank and the air inlet, and is used to heat the nitrogen gas supplied from the nitrogen buffer tank to the air inlet.

5. The silicon powder feeding structure according to any one of claims 1-4, characterized in that, The feeding device includes a silicon powder receiving tank and a silicon powder feeding tank. The material chamber, the air inlet and the air outlet are all located in the silicon powder receiving tank. The silicon powder feeding tank is connected to the silicon powder receiving tank and is used to receive silicon powder from the silicon powder receiving tank. The feeding port is located in the silicon powder feeding tank.

6. The silicon powder feeding structure according to any one of claims 1-4, characterized in that, It also includes a silicon powder filter, which is connected to the gas outlet and the separation device, and is used to filter silicon powder in the gas passing through the gas outlet to the separation device.

7. The silicon powder feeding structure as described in claim 6, characterized in that, The silicon powder filter is also connected to the nitrogen supply device, and the gas inside the silicon powder filter can be replaced by nitrogen introduced through the nitrogen supply device.

8. A polycrystalline silicon cold hydrogenation system, comprising: Reactor; The silicon powder feeding structure as described in any one of claims 1-7, wherein the silicon powder feeding structure is connected to the reactor and is used to feed silicon powder into the reactor; A reaction gas supply structure is connected to the reactor and is used to supply reaction gas to the reactor; A polycrystalline silicon forming structure is connected to the output end of the reactor for forming polycrystalline silicon through the products of the reactor.

9. The polycrystalline silicon cold hydrogenation system as described in claim 8, characterized in that, The reaction gas supply structure includes a hydrogen supply device, a silicon tetrachloride supply device, and a heating pipeline. The hydrogen supply device and the silicon tetrachloride supply device are connected to the heating pipeline for supplying hydrogen and silicon tetrachloride to the heating pipeline. The heating pipeline is connected to the reactor for heating the hydrogen and silicon tetrachloride and supplying them to the reactor.

10. The polycrystalline silicon cold hydrogenation system as described in claim 8, characterized in that, The polycrystalline silicon forming structure includes a silicon powder recovery pipeline, a condenser tower, a slurry treatment pipeline, and a polycrystalline silicon forming pipeline. The silicon powder recovery pipeline is connected to the reactor and is used to separate silicon powder from the reactor product. The condenser tower is connected to the silicon powder recovery pipeline and is used to condense the reactor product after silicon powder separation. Both the slurry treatment pipeline and the polycrystalline silicon forming pipeline are connected to the condenser tower. The slurry treatment pipeline is used to treat the slurry formed by the condenser tower, and the polycrystalline silicon forming pipeline is used to treat the condensate formed by the condenser tower, so that the condensate is reduced to form polycrystalline silicon.

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