A polysilicon hydrogenation process silicon powder drying and pushing system and method

Abstract

The present invention discloses a polysilicon hydrogenation process silicon powder drying and pushing system and method, which includes a low-pressure silicon powder hopper, a low-pressure hopper dust collector, a high-pressure silicon powder hopper, and a high-pressure hopper dust collector; a circulation pipeline is connected between the top of the low-pressure silicon powder hopper and the low-pressure hopper dust collector; a circulation pipeline is connected between the top of the high-pressure silicon powder hopper and the high-pressure hopper dust collector; the bottom of the high-pressure silicon powder hopper is connected to a fluidized bed reactor through a high-pressure hopper feeding pipe. The present invention realizes low-pressure and high-temperature drying of silicon powder by setting a low-pressure silicon powder hopper, and realizes high-pressure pushing through a high-pressure silicon powder hopper, and realizes intermittent and multiple pushing according to the requirements of fluidized bed reaction. The low-pressure silicon powder hopper and the high-pressure silicon powder hopper operate separately to ensure the continuity of production.

Description

Technical Field

[0001] The present invention belongs to the field of polysilicon production, and particularly relates to a polysilicon hydrogenation process silicon powder drying and pushing system and method. Background Art

[0002] In the hydrogenation process stage of polysilicon production, silicon powder, silicon tetrachloride, and hydrogen are usually used as raw materials. Under the conditions of a catalyst, certain temperature and pressure, trichlorosilane is generated by reaction. As one of the raw materials, silicon powder is usually pressed into a fluidized bed for reaction by high-pressure hydrogen gas. Since the raw material silicon powder contains a certain amount of moisture, it needs to be dried before entering the fluidized bed.

[0003] The hydrogenation fluidized bed operates under high pressure and high temperature. Silicon powder contacts with hydrogen and silicon tetrachloride in the fluidized bed layer to undergo a chemical reaction. Different from gas materials, as a solid material, silicon powder needs to be intermittently fed according to consumption. The silicon powder raw material needs to go through repetitive operations from drying to entering the fluidized bed. Due to the involvement of pressure and temperature control, the actual operation is relatively complex, and manual operation is prone to errors and may cause safety accidents. Summary of the Invention

[0004] Object of the Invention: The technical problem to be solved by the present invention is to provide a polysilicon hydrogenation process silicon powder drying and pushing system aiming at the deficiencies of the prior art, so as to realize the safe, stable, and continuous operation of the silicon powder drying system.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A polysilicon hydrogenation process silicon powder drying and pushing system includes a silicon powder low-pressure hopper, a low-pressure hopper dust collector, a silicon powder high-pressure hopper, and a high-pressure hopper dust collector; a circulation pipeline is connected between the top of the silicon powder low-pressure hopper and the low-pressure hopper dust collector; a circulation pipeline is connected between the top of the silicon powder high-pressure hopper and the high-pressure hopper dust collector; the bottom of the silicon powder low-pressure hopper is connected to the silicon powder high-pressure hopper through a low-pressure hopper discharging pipe; the bottom of the silicon powder high-pressure hopper is connected to a fluidized bed reactor through a high-pressure hopper discharging pipe;

[0007] A silicon powder raw material pipe, a nitrogen introduction pipe, a steam coil, and a hot nitrogen introduction pipe are sequentially connected to the silicon powder low-pressure hopper;

[0008] A hot hydrogen introduction pipe is connected to the silicon powder high-pressure hopper.

[0009] Specifically, a first valve is provided on the silicon powder raw material pipe; a fifth valve is provided on the nitrogen introduction pipe; a second valve is provided on the low-pressure hopper discharging pipe;

[0010] A low-pressure hopper level gauge, a low-pressure hopper thermometer, and a low-pressure hopper pressure gauge are provided on the tank body of the silicon powder low-pressure hopper;

[0011] A fourth valve is provided on the hot nitrogen inlet pipe.

[0012] Specifically, the low-pressure silicon powder hopper is an externally coiled tube pressure tank. Both ends of the external coil are connected to a steam pipe and a condensate pipe. An eleventh valve is provided on the steam pipe.

[0013] Further, the circulation pipeline between the top of the low-pressure silicon powder hopper and the low-pressure hopper dust collector includes a low-pressure hopper pressure relief pipe connecting the low-pressure silicon powder hopper to the low-pressure hopper dust collector, and a first silicon powder return pipe connecting the bottom of the low-pressure hopper dust collector to the low-pressure silicon powder hopper; a seventh valve is provided on the low-pressure hopper pressure relief pipe, and an eighth valve is provided on the first silicon powder return pipe.

[0014] Further, a sixth valve is provided on the hot hydrogen inlet pipe; the bottom of the high-pressure silicon powder hopper is connected to the fluidized bed reactor through a high-pressure hopper feeding pipe, and a third valve is provided on the high-pressure hopper feeding pipe.

[0015] Specifically, a high-pressure hopper level gauge, a high-pressure hopper thermometer, and a high-pressure hopper pressure gauge are provided on the high-pressure silicon powder hopper tank body.

[0016] Further, the circulation pipeline between the top of the high-pressure silicon powder hopper and the high-pressure hopper dust collector includes a high-pressure hopper pressure relief pipe connecting the high-pressure silicon powder hopper to the high-pressure hopper dust collector, and a second silicon powder return pipe connecting the bottom of the high-pressure hopper dust collector to the high-pressure silicon powder hopper; a ninth valve is provided on the high-pressure hopper pressure relief pipe, and a tenth valve is provided on the second silicon powder return pipe.

[0017] Further, horizontal partitions are provided in the upper and middle parts of the low-pressure hopper dust collector and the high-pressure hopper dust collector. A group of sintered ceramic hollow columns are vertically installed downward from the lower end face of the partition as a filtering medium to intercept silicon powder in the gas.

[0018] Further, the bottoms of the low-pressure hopper dust collector and the high-pressure hopper dust collector are connected to the corresponding low-pressure silicon powder hopper and high-pressure silicon powder hopper through silicon powder return pipes, and the tops are respectively connected to an exhaust pipe and a nitrogen purge pipe.

[0019] Furthermore, the present invention also provides a method for baking and pushing silicon powder using the above system, including the following steps:

[0020] Step 1: Feed silicon powder raw materials into the low-pressure silicon powder hopper through the silicon powder raw material pipe. During the feeding process, connect the circulation pipeline between the low-pressure silicon powder hopper and the low-pressure hopper dust collector, and use the low-pressure hopper dust collector to filter and intercept the silicon powder. The intercepted silicon powder returns to the low-pressure silicon powder hopper again until the low-pressure silicon powder hopper reaches the set pressure and liquid level;

[0021] Step 2: Open the hot nitrogen inlet pipe and the steam coil, and use hot nitrogen and steam to bake the silicon powder in the low-pressure silicon powder hopper at the same time;

[0022] Step 3: Feed powder through the nitrogen pipe, send the silicon powder in the low-pressure silicon powder hopper into the high-pressure silicon powder hopper, connect the circulation pipeline between the high-pressure silicon powder hopper and the high-pressure hopper dust collector during the transportation process, use the high-pressure hopper dust collector to filter and intercept the silicon powder, and the intercepted silicon powder returns to the high-pressure silicon powder hopper until the high-pressure silicon powder hopper reaches the set pressure and liquid level;

[0023] Step 4: Use the hot hydrogen pipe to push the material, introduce hot hydrogen to boost the pressure, and push the silicon powder in the high-pressure silicon powder hopper into the fluidized bed reactor through the high-pressure hopper discharge pipe.

[0024] Beneficial effects:

[0025] 1. In the present invention, the low-pressure high-temperature drying of silicon powder is realized by setting the low-pressure silicon powder hopper, and the high-pressure material pushing is realized by the high-pressure silicon powder hopper. According to the requirements of the fluidized bed reaction, intermittent and multiple material pushing are realized. The low-pressure silicon powder hopper and the high-pressure silicon powder hopper operate separately to ensure the continuity of production.

[0026] 2. In the present invention, by controlling each step separately, the safe, stable and continuous operation of the system is realized. At the same time, manual and automatic operations can be set, and artificial intervention is used to avoid production abnormalities and secondary safety accidents caused by the malfunction of the automatic control instrument, providing a basis for realizing automatic material pushing.

[0027] 3. In the present invention, the recycling of silicon powder is realized by setting the low-pressure hopper dust collector and the high-pressure hopper dust collector. Description of the drawings

[0028] The following further specifically describes the present invention in conjunction with the drawings and specific embodiments, and the above and / or other advantages of the present invention will become clearer.

[0029] Figure 1 It is a schematic diagram of the overall structure of the silicon powder drying and pushing system for the polysilicon hydrogenation process.

[0030] Among them, each reference numeral represents respectively:

[0031] 10 Low-pressure silicon powder hopper; 101 Silicon powder raw material pipe; 102 Nitrogen pipe; 103 Hot nitrogen pipe; 104 Steam pipe; 105 Condensate pipe; 106 Low-pressure hopper pressure relief pipe; 107 Low-pressure hopper discharge pipe; 20 Low-pressure hopper dust collector; 201 First nitrogen purge pipe; 202 First silicon powder return pipe; 203 First exhaust pipe; 30 High-pressure silicon powder hopper; 301 Hot hydrogen pipe; 302 High-pressure hopper pressure relief pipe; 303 High-pressure hopper discharge pipe; 40 High-pressure hopper dust collector; 401 Second nitrogen purge pipe; 402 Second silicon powder return pipe; 403 Second exhaust pipe; 50 Fluidized bed reactor;

[0032] F1 First valve; F2 Second valve; F3 Third valve; F4 Fourth valve; F5 Fifth valve; F6 Sixth valve; F7 Seventh valve; F8 Eighth valve; F9 Ninth valve; F10 Tenth valve; F11 Eleventh valve; F12 Twelfth valve. Detailed implementation mode

[0033] The present invention can be better understood according to the following embodiments.

[0034] The structures, ratios, sizes, etc. shown in the accompanying drawings of the specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, terms such as "upper", "lower", "front", "rear", "middle", etc. cited in this specification are only for the convenience of clear narration and are not used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope under which the present invention can be implemented.

[0035] As Figure 1 As shown, the polysilicon hydrogenation process silicon powder drying and pushing system of the present invention includes a silicon powder low-pressure hopper 10, a low-pressure hopper dust collector 20, a silicon powder high-pressure hopper 30, and a high-pressure hopper dust collector 40; a circulation pipeline is connected between the top of the silicon powder low-pressure hopper 10 and the low-pressure hopper dust collector 20; a circulation pipeline is connected between the top of the silicon powder high-pressure hopper 30 and the high-pressure hopper dust collector 40; the bottom of the silicon powder high-pressure hopper 30 is connected to a fluidized bed reactor 50 through a high-pressure hopper feed pipe 303.

[0036] Among them, a silicon powder raw material pipe 101 and a nitrogen introduction pipe 102 are sequentially connected to the silicon powder low-pressure hopper 10; the bottom of the silicon powder low-pressure hopper 10 is connected to the silicon powder high-pressure hopper 30 through a low-pressure hopper feed pipe 107;

[0037] A first valve F1 is provided on the silicon powder raw material pipe 101; a fifth valve F5 is provided on the nitrogen introduction pipe 102; a second valve F2 is provided on the low-pressure hopper feed pipe 107;

[0038] A low-pressure hopper liquid level gauge L1, a low-pressure hopper thermometer T1, and a low-pressure hopper pressure gauge P1 are provided on the tank body of the silicon powder low-pressure hopper 10.

[0039] The silicon powder low-pressure hopper 10 is an external coil type pressure tank, and both ends of the external coil are connected to a steam pipe 104 and a condensate pipe 105, and an eleventh valve F11 is provided on the steam pipe 104.

[0040] The circulation pipeline between the top of the low-pressure hopper 10 for silicon powder and the low-pressure hopper dust collector 20 includes a low-pressure hopper pressure relief pipe 106 connecting the low-pressure hopper 10 for silicon powder to the low-pressure hopper dust collector 20, and a first silicon powder return pipe 202 connecting the bottom of the low-pressure hopper dust collector 20 to the low-pressure hopper 10 for silicon powder; a seventh valve F7 is provided on the low-pressure hopper pressure relief pipe 106, and an eighth valve F8 is provided on the first silicon powder return pipe 202.

[0041] A hot nitrogen introduction pipe 103 is also connected to the low-pressure hopper 10 for silicon powder, and a fourth valve F4 is provided on the hot nitrogen introduction pipe 103.

[0042] A hot hydrogen introduction pipe 301 is connected to the high-pressure hopper 30 for silicon powder, and a sixth valve F6 is provided on the hot hydrogen introduction pipe 301; the bottom of the high-pressure hopper 30 for silicon powder is connected to the fluidized bed reactor 50 through a high-pressure hopper blanking pipe 303, and a third valve F3 is provided on the high-pressure hopper blanking pipe 303.

[0043] A high-pressure hopper liquid level gauge L2, a high-pressure hopper thermometer T2, and a high-pressure hopper pressure gauge P2 are provided on the tank body of the high-pressure hopper 30 for silicon powder.

[0044] The circulation pipeline between the top of the high-pressure hopper 30 for silicon powder and the high-pressure hopper dust collector 40 includes a high-pressure hopper pressure relief pipe 302 connecting the high-pressure hopper 30 for silicon powder to the high-pressure hopper dust collector 40, and a second silicon powder return pipe 402 connecting the bottom of the high-pressure hopper dust collector 40 to the high-pressure hopper 30 for silicon powder; a ninth valve F9 is provided on the high-pressure hopper pressure relief pipe 302, and a tenth valve F10 is provided on the second silicon powder return pipe 402.

[0045] Horizontal partitions are provided in the upper and middle parts of the low-pressure hopper dust collector 20 and the high-pressure hopper dust collector 40. A group of sintered ceramic hollow columns are vertically installed on the lower end face of the partition as a filtering medium for intercepting silicon powder in the gas.

[0046] The bottoms of the low-pressure hopper dust collector 20 and the high-pressure hopper dust collector 40 are connected to the corresponding low-pressure hopper 10 for powder and the high-pressure hopper 30 for silicon powder through silicon powder return pipes, and the tops are respectively connected to exhaust pipes and nitrogen purge pipes.

[0047] The silicon powder raw material enters the low-pressure silicon powder hopper 10 through the silicon powder raw material pipe 101. The low-pressure silicon powder hopper 10 is an externally coiled tube pressure tank. The low-pressure silicon powder hopper 10 is provided with liquid level, temperature, and pressure monitoring points, and steam can be introduced into the coiled tube. The low-pressure silicon powder hopper dust collector 20 on the upper part of the low-pressure silicon powder hopper 10 is used to filter and intercept silicon powder when the low-pressure silicon powder hopper 10 receives silicon powder and relieves pressure. The intercepted silicon powder returns to the low-pressure silicon powder hopper again. After the silicon powder transportation is completed, hot nitrogen is introduced through the hot nitrogen pipe 103 to bake the silicon powder in the low-pressure hopper 10 simultaneously with steam. The hot nitrogen containing water vapor (referred to as: wet nitrogen) passing through the silicon powder layer is environmentally discharged after tail gas treatment; the silicon powder after baking enters the high-pressure silicon powder hopper 30.

[0048] The high-pressure silicon powder hopper 30 is provided with liquid level, temperature, and pressure monitoring points. The high-pressure silicon powder hopper dust collector 40 on the upper part of the high-pressure silicon powder hopper 30 is used to collect silicon powder. The collected silicon powder returns to the high-pressure silicon powder hopper 30 again. According to production needs, the silicon powder in the high-pressure silicon powder hopper 30 is pushed into the fluidized bed reactor 50 by introducing hot hydrogen through the hot hydrogen pipe 301 to increase the pressure. The low-pressure silicon powder hopper dust collector 20 and the high-pressure silicon powder hopper dust collector 40 are tanks installed with filter media bodies. An air inlet and an air outlet are respectively provided at the bottom and top of the dust collector. A horizontal partition is arranged in the upper middle part of the dust collector. Multiple sintered ceramic hollow columns are vertically installed downward from the partition end face. The hollow columns are filter media bodies. When the gas passes through, the silicon powder is intercepted on the ceramic columns. The powder-free gas enters the top gas collection cavity through the ceramic columns and then is discharged through the air outlet. The silicon powder on the outer wall of the ceramic column falls into the bottom of the dust collector after being back blown by nitrogen at the top of the dust collector and then returns to the hopper again.

[0049] The method for baking and pushing silicon powder using the above system includes the following steps:

[0050] Step 1: The low-pressure silicon powder hopper receives the silicon powder raw material. Confirm that the pressure P1 in the low-pressure silicon powder hopper is lower than 0.05 Mpa and the liquid level L1 is lower than 2%. Set the target values of P1 and L1, open the valve F1, close the valves F2 and F5. After receiving the valve opening signal, the valves F7 and F8 perform the opening action. The silicon powder enters the low-pressure silicon powder hopper through the pipeline. When L1 or P1 reaches the control point, the valve F1 performs the closing action. When P1 reaches the control point and L1 does not reach the control point, the system stands still until P1 meets the control requirements, and then the valve F1 performs the opening action. Repeat the above actions until L1 reaches the control point. After both P1 and L1 reach the control point, the valve F1 performs the closing action. After completing the valve actions, check the states of each control valve, and execute the closing of the valves F1, F2, F4, F5, and F11, and the opening states of the valves F7 and F8.

[0051] Step 2: Bake the powder. Confirm that valves F1, F2, F4, F5, and F11 are closed. Set the baking time. Valves F4 and F11 are opened (the steam condensate drain valve is normally open). Pass hot nitrogen and interlayer steam to bake the silicon powder raw material simultaneously. After the baking time reaches the set value, valves F4, F7, F8, and F11 are closed.

[0052] Step 3: Prepare for receiving material in the high-pressure silicon powder hopper. Confirm that valves F2, F3, F6, and F10 are closed and confirm that L2 is lower than 10%. Set the target value of P2. When the pressure P2 in the high-pressure silicon powder hopper is higher than the set value, valve F9 is opened, and valve F12 is slowly opened (the system sets different opening degrees according to the tank pressure). After the tank pressure is relieved to be lower than the set value of P2, valves F2, F3, F6, F10, and F12 are closed, and valve F9 remains open.

[0053] Step 4: Receive material in the high-pressure silicon powder hopper. Confirm that valves F2, F3, F6, F10, and F12 are closed. Set the target values of P1, L1, △P1 (P1 - P2), and T1. When T1 meets the conditions, the dried silicon powder can enter the high-pressure silicon powder hopper from the low-pressure silicon powder hopper. Valve F5 is opened. When P1 reaches the set value, valve F5 is closed, and valve F2 is opened. The dried silicon powder vertically enters the high-pressure silicon powder hopper from the low-pressure silicon powder hopper. When △P1 reaches the set value, valve F2 is closed. If L1 has not reached the set value at this time, valve F5 is slowly opened to 30% of the valve opening. When P1 reaches the set value, valve F5 is closed, and valve F2 is opened. After L1 reaches the set value, valve F2 is closed. It is set that valves F2 and F5 cannot be opened simultaneously.

[0054] Step 5: Prepare for pushing material in the high-pressure silicon powder hopper. Confirm that valves F2, F3, and F6 are closed and open F9 and F10. Set the low point and high point of P2 in the high-pressure silicon powder hopper and the replacement times. Use hot hydrogen to replace the nitrogen in the high-pressure silicon powder hopper completely. Slowly open valve F12 to 50% until it reaches the low point of P2, then close valve F12. Open valve F6 to 30% and fill the high-pressure silicon powder hopper with hot hydrogen. When the pressure reaches the high point of P2, close valve F6. Slowly open valve F12 to 50% until the pressure drops to the low point of P2 to complete the set replacement times; after the replacement, valves F2, F3, F6, F9, F10, and F12 remain closed.

[0055] Step Six: Pushing Material. Confirm that valves F2, F3, F6, F9, F10, and F12 are closed. Set the target values of the high point of △P2 (P2 - P3), the low point of △P2 (P2 - P3), and the pushing material weight (the pushing material weight is based on m = ρv, and the system implants the liquid level - mass quantitative value). Slowly open valve F6 to a valve opening of 30% to pressurize the high - pressure hopper. When the high point of △P2 (P2 - P3) reaches the set value, it means that the pushing material condition is met. Valve F6 is closed, and valve F3 is actuated to open. The system automatically pushes the material. After the pushing is completed, valve F3 is closed. During the pushing process, when the low point of △P2 is triggered, valve F3 automatically closes, and valve F6 is slowly opened to a valve opening of 30%. After the pressurization is completed, valve F3 is opened to continue pushing the material. The above actions can be repeated until the pushing is completed.

[0056] The present invention provides an idea and method for a polysilicon hydrogenation process silicon powder drying and pushing system and method. There are many specific methods and ways to implement this technical solution. The above - mentioned is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. Each component not clearly defined in this embodiment can be implemented by using the prior art.

Claims

1. A silicon powder drying and pushing system for polysilicon hydrogenation process, characterized in that, It includes a low-pressure hopper for silicon powder (10), a low-pressure hopper dust collector (20), a high-pressure hopper for silicon powder (30), and a high-pressure hopper dust collector (40); a circulation pipeline is connected between the low-pressure hopper for silicon powder (10) and the low-pressure hopper dust collector (20), and a circulation pipeline is connected between the top of the high-pressure hopper for silicon powder (30) and the high-pressure hopper dust collector (40); the bottom of the low-pressure hopper for silicon powder (10) is connected to the high-pressure hopper for silicon powder (30) through a low-pressure hopper discharging pipe (107); the bottom of the high-pressure hopper for silicon powder (30) is connected to a fluidized bed reactor (50) through a high-pressure hopper discharging pipe (303). A silicon powder raw material pipe (101), a nitrogen introducing pipe (102), a steam coil, and a hot nitrogen introducing pipe (103) are successively connected to the low-pressure hopper for silicon powder (10). A hot hydrogen introducing pipe (301) is connected to the high-pressure hopper for silicon powder (30). A first valve (F1) is provided on the silicon powder raw material pipe (101); a fifth valve (F5) is provided on the nitrogen introducing pipe (102); a second valve (F2) is provided on the low-pressure hopper discharging pipe (107). A low-pressure hopper liquid level gauge (L1), a low-pressure hopper thermometer (T1), and a low-pressure hopper pressure gauge (P1) are provided on the tank body of the low-pressure hopper for silicon powder (10). A fourth valve (F4) is provided on the hot nitrogen introducing pipe (103). The low-pressure hopper for silicon powder (10) is an external coil type pressure tank, and both ends of the external coil are connected to a steam pipe (104) and a condensate pipe (105), and an eleventh valve (F11) is provided on the steam pipe (104). The circulation pipeline between the top of the low-pressure hopper for silicon powder (10) and the low-pressure hopper dust collector (20) includes a low-pressure hopper pressure relief pipe (106) connecting the low-pressure hopper for silicon powder (10) to the low-pressure hopper dust collector (20), and a first silicon powder return pipe (202) connecting the bottom of the low-pressure hopper dust collector (20) to the low-pressure hopper for silicon powder (10); a seventh valve (F7) is provided on the low-pressure hopper pressure relief pipe (106), and an eighth valve (F8) is provided on the first silicon powder return pipe (202). A sixth valve (F6) is provided on the hot hydrogen introducing pipe (301); the bottom of the high-pressure hopper for silicon powder (30) is connected to the fluidized bed reactor (50) through a high-pressure hopper discharging pipe (303), and a third valve (F3) is provided on the high-pressure hopper discharging pipe (303). A high-pressure hopper liquid level gauge (L2), a high-pressure hopper thermometer (T2), and a high-pressure hopper pressure gauge (P2) are provided on the tank body of the high-pressure hopper for silicon powder (30). The circulation pipeline between the top of the high-pressure hopper for silicon powder (30) and the high-pressure hopper dust collector (40) includes a high-pressure hopper pressure relief pipe (302) connecting the high-pressure hopper for silicon powder (30) to the high-pressure hopper dust collector (40), and a second silicon powder return pipe (402) connecting the bottom of the high-pressure hopper dust collector (40) to the high-pressure hopper for silicon powder (30); a ninth valve (F9) is provided on the high-pressure hopper pressure relief pipe (302), and a tenth valve (F10) is provided on the second silicon powder return pipe (402).

2. The silicon powder drying and pushing system for polysilicon hydrogenation process according to claim 1, characterized in that, A horizontal partition is provided in the upper middle part of the low-pressure hopper dust collector (20) and the high-pressure hopper dust collector (40), and a filter medium is vertically installed downward from the lower end surface of the horizontal partition.

3. The silicon powder drying and pushing system for polysilicon hydrogenation process according to claim 2, characterized in that, The filter medium is a sintered ceramic hollow column.

4. The silicon powder drying and pushing system for polysilicon hydrogenation process according to claim 1, characterized in that, The bottoms of the low-pressure hopper dust collector (20) and the high-pressure hopper dust collector (40) are connected to the corresponding low-pressure silicon powder hopper (10) and high-pressure silicon powder hopper (30) through a silicon powder return pipe, and the exhaust pipe and the nitrogen purge pipe are respectively connected to the tops.

5. A method for silicon powder drying and pushing using the silicon powder drying and pushing system for polysilicon hydrogenation process according to claim 1, characterized in that, It includes: Silicon powder raw materials are transported to the low-pressure silicon powder hopper (10) through the silicon powder raw material pipe (101). During the transportation process, the circulation pipeline between the low-pressure silicon powder hopper (10) and the low-pressure hopper dust collector (20) is connected, and the low-pressure hopper dust collector (20) is used to filter and intercept the silicon powder. The intercepted silicon powder returns to the low-pressure silicon powder hopper (10) again until the low-pressure silicon powder hopper (10) reaches the set pressure and liquid level. Open the hot nitrogen lead pipe (103) and the steam coil, and use hot nitrogen and steam at the same time to dry the silicon powder in the low-pressure silicon powder hopper (10). Supply powder through the nitrogen lead pipe (102), and send the silicon powder in the low-pressure silicon powder hopper (10) into the high-pressure silicon powder hopper (30). During the transportation process, the circulation pipeline between the high-pressure silicon powder hopper (30) and the high-pressure hopper dust collector (40) is connected, and the high-pressure hopper dust collector (40) is used to filter and intercept the silicon powder. The intercepted silicon powder returns to the high-pressure silicon powder hopper (30) again until the high-pressure silicon powder hopper (30) reaches the set pressure and liquid level. Use the hot hydrogen lead pipe (301) to push the material, introduce hot hydrogen to increase the pressure, and push the silicon powder in the high-pressure silicon powder hopper (30) into the fluidized bed reactor (50) through the high-pressure hopper blanking pipe (303).

Images