Silicon powder collecting device and using method thereof

Abstract

The invention discloses a silicon powder collecting device and a using method thereof, and relates to the technical field of polycrystalline silicon production, the silicon powder collecting device comprises a collecting tank used for collecting silicon powder, and the collecting tank is provided with a pressure detector and a discharging valve; the molecular sieve is communicated with the collecting tank, and the molecular sieve is used for cooling the reduction tail gas and intercepting silicon powder in the reduction tail gas; the ton bag vehicle is provided with a weighing module, and the ton bag vehicle is communicated with the collecting tank; the central control system is in signal connection with the pressure detector, the discharging valve and the ton bag vehicle, and the central control system is used for controlling the discharging valve to be opened and closed according to a pressure threshold value obtained by the pressure detector so as to control the conduction state between the collecting tank and the ton bag vehicle. And the central control system triggers a replacement signal after the weighing module detects that the ton bag vehicle reaches the preset load capacity. The silicon powder collecting device provided by the invention can realize full-process automatic collection of silicon powder and ton bag replacement.

Description

Technical Field

[0001] This application relates to the technical field of polysilicon production, and particularly to a silicon powder collection device and a method for using the same. Background Art

[0002] In the process of polysilicon production, a large amount of high-temperature fine silicon powder is carried by the reduction tail gas and needs to be treated by a recovery system. In the prior art, the collection of silicon powder mainly relies on manual operation: two people are required to cooperate (one person operates and one person monitors).

[0003] However, when manually replacing the ton bags, the silicon powder is easily spilled, resulting in environmental pollution, equipment corrosion and personnel health problems; at the same time, the efficiency of manually handling the ton bags is low and there are safety hazards. Summary of the Invention

[0004] In view of the above problems, the embodiments of this application provide a silicon powder collection device and a method for using the same, realizing the full-process automatic collection of silicon powder and the replacement of ton bags.

[0005] To achieve the above object, the embodiments of this application provide the following technical solutions:

[0006] In a first aspect, the embodiments of this application provide a silicon powder collection device, which includes:

[0007] A collection tank for collecting silicon powder, on which a pressure detector and a discharge valve are provided;

[0008] A molecular sieve connected to the collection tank, which is used to cool the reduction tail gas and intercept the silicon powder in the reduction tail gas;

[0009] A ton bag cart with a weighing module, which is connected to the collection tank;

[0010] A central control system, which is signal-connected to the pressure detector, the discharge valve and the ton bag cart. The central control system is used to control the opening and closing of the discharge valve according to the pressure threshold obtained by the pressure detector, so as to control the conduction state between the collection tank and the ton bag cart, and the central control system triggers a replacement signal after the weighing module detects that the ton bag cart reaches the preset load.

[0011] As a possible implementation manner, the molecular sieve has a first air inlet and a first air outlet, and the collection tank is provided with a second air inlet and a second air outlet, and the collection tank is connected to the first air outlet of the molecular sieve through the second air inlet.

[0012] As a possible implementation manner, the collection tank is provided with a nitrogen inlet, which is connected to the second air inlet, and the nitrogen inlet is used to convey nitrogen to the molecular sieve for back blowing and cleaning.

[0013] As a possible implementation manner, the weighing module of the ton bag vehicle is signal-connected to the central control system. A control panel is provided on the ton bag vehicle, and the control panel is signal-connected to the central control system. An audible and visual alarm unit is integrated on the control panel. When the weight of the ton bag on the ton bag vehicle reaches the set value, the central control system controls the closing of the blanking valve and triggers the audible and visual alarm unit to emit an audible and visual alarm signal.

[0014] As a possible implementation manner, the ton bag vehicle is detachably connected to the collection tank through a connecting member.

[0015] As a possible implementation manner, the connecting member is an electromagnetic lock. The electromagnetic lock includes a lock base, the lock base is fixed on the collection tank, an electromagnet is embedded in the lock base, the electromagnet has a moving iron core, and a retractable lock tongue is connected to the moving iron core; the ton bag vehicle has a lock groove, which is correspondingly arranged with the lock tongue;

[0016] The central control system controls the on-off of the circuit of the electromagnet. When the electromagnet is energized, the electromagnet drives the lock tongue to extend and insert into the lock groove of the ton bag vehicle; when the electromagnet is de-energized, the lock tongue retracts, so that the ton bag vehicle can move relative to the collection tank.

[0017] As a possible implementation manner, control buttons are integrated on the control panel, and the control buttons are signal-connected to the central control system. The control buttons are used to trigger the central control system to control the fixing or separation of the ton bag vehicle and the collection tank.

[0018] As a possible implementation manner, the ton bag vehicle includes a vehicle body and a ton bag. A first flange is provided on the vehicle body, and a convex buckle is provided on the first flange. The ton bag has a discharge port, and a second flange is fixedly provided on the discharge port. The second flange has a card slot. The vehicle body and the ton bag are flange-connected through the cooperation of the convex buckle and the card slot.

[0019] The silicon powder collection device provided by the embodiments of the present application at least has the following beneficial effects:

[0020] The high-temperature reduction tail gas is cooled and the fine silicon powder is intercepted by an external molecular sieve. The opening and closing of the automatic blanking valve are controlled by the differential pressure control in the silicon powder collection tank. A ton bag trolley equipped with automatic weighing, electric drive and anti-spillage design is used to realize the full-process automatic collection of silicon powder and the replacement of ton bags. The present invention effectively eliminates the need for manual intervention, significantly improves the operation efficiency, avoids equipment corrosion and health problems caused by the spillage of silicon powder, reduces the loss of compressor filters and energy consumption costs, and provides a safe, efficient and environmentally friendly silicon powder recovery solution for polysilicon production.

[0021] Second aspect, the present application provides a method for using a silicon powder collection device, where the silicon powder collection device is the silicon powder collection device provided by any technical solution of the first aspect, and the method for using includes the following steps:

[0022] The reduction tail gas sequentially passes through the molecular sieve and the collection tank. The molecular sieve reduces the tail gas temperature to below 50°C and intercepts more than 90% of the silicon powder in the reduction tail gas.

[0023] When the pressure in the collection tank reaches 0.5 MPa, the central control system triggers the opening of the blanking valve, and the silicon powder falls into the ton bag of the ton bag truck.

[0024] The ton bag truck monitors the weight of the ton bag in real time through the weighing module. When it reaches 1 ton, the blanking valve is closed, and a replacement signal is sent to the central control system.

[0025] The ton bag truck is controlled to transfer through the control panel.

[0026] As a possible implementation manner, a nitrogen inlet is provided on the collection tank, and the molecular sieve is cleaned by back blowing through the nitrogen inlet. The back blowing pressure is 0.3 - 0.5 MPa, and it lasts for 5 - 10 minutes.

[0027] In addition to the technical problems solved by the embodiments of the present application, the technical features constituting the technical solutions, and the beneficial effects brought by these technical features of the technical solutions described above, the other technical problems that the sorting system provided by the embodiments of the present application can solve, the other technical features included in the technical solutions, and the beneficial effects brought by these technical features will be further described in detail in the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic structural diagram of the silicon powder collection device provided by the embodiment of the present application.

[0030] Description of the reference numerals:

[0031] 100. Collection tank;

[0032] 110. Pressure detector;

[0033] 120. Blanking valve;

[0034] 130. Second air inlet;

[0035] 140. Second air outlet;

[0036] 150. Nitrogen inlet;

[0037] 200. Molecular sieve;

[0038] 210. First air inlet;

[0039] 220. First air outlet;

[0040] 300. Tonne bag truck;

[0041] 310. Control panel;

[0042] 400. Connector. Detailed implementation manners

[0043] As described in the background art, during the polysilicon production process, the reduction tail gas carries a large amount of high-temperature fine silicon powder, which needs to be processed by a recovery system. In the prior art, the collection of silicon powder mainly relies on manual operation: it requires two people to cooperate (one person operates and one person monitors).

[0044] However, when manually replacing the tonne bag, the silicon powder is easily spilled, resulting in environmental pollution, equipment corrosion and personnel health problems; at the same time, the efficiency of manually handling the tonne bag is low and there are safety hazards.

[0045] In view of the above technical problems, the silicon powder collection device provided in the embodiments of the present application cools the high-temperature reduction tail gas and intercepts the fine silicon powder through an external molecular sieve, combines the differential pressure control in the silicon powder collection tank to open and close the automatic blanking valve, and uses a tonne bag trolley equipped with automatic weighing, electric drive and anti-spill design to realize the full-process automatic collection of silicon powder and the replacement of tonne bags.

[0046] The present invention effectively eliminates the need for manual intervention, significantly improves the operation efficiency, avoids equipment corrosion and health problems caused by the spillage of silicon powder, and at the same time reduces the loss of compressor filters and energy consumption costs, providing a safe, efficient and environmentally friendly silicon powder recovery solution for polysilicon production.

[0047] In order to make the above objects, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0048] Reference Figure 1, the silicon powder collection device provided by the embodiment of the present application includes: a collection tank 100 for collecting silicon powder, on which a pressure detector 110 and a blanking valve 120 are provided; a molecular sieve 200 connected to the collection tank 100, and the molecular sieve 200 is used to cool the reduction tail gas and intercept the silicon powder in the reduction tail gas; a ton bag truck 300 with a weighing module, and the ton bag truck 300 is connected to the collection tank 100; a central control system, which is signal-connected to the pressure detector 110, the blanking valve 120 and the ton bag truck 300. The central control system is used to control the opening and closing of the blanking valve 120 according to the pressure threshold obtained by the pressure detector 110 to control the conduction state between the collection tank 100 and the ton bag truck 300, and the central control system triggers a replacement signal after the weighing module detects that the ton bag truck 300 reaches the preset load capacity.

[0049] In this way, the external molecular sieve 200 is used to cool the high-temperature reduction tail gas and intercept the fine silicon powder. The differential pressure control in the silicon powder collection tank 100 is combined to automatically control the opening and closing of the blanking valve 120, and a ton bag trolley equipped with automatic weighing, electric drive and anti-leakage design is adopted to realize the full-process automatic collection of silicon powder and ton bag replacement. The present invention effectively eliminates the need for manual intervention, significantly improves the operation efficiency, avoids equipment corrosion and health problems caused by the spillage of silicon powder, and at the same time reduces the loss of compressor filters and energy consumption costs, providing a safe, efficient and environmentally friendly silicon powder recovery solution for polysilicon production.

[0050] In some embodiments, the molecular sieve 200 has a first air inlet 210 and a first air outlet 220. The collection tank 100 is provided with a second air inlet 130 and a second air outlet 140. The collection tank 100 is connected to the first air outlet 220 of the molecular sieve 200 through the second air inlet 130.

[0051] For example, the first air outlet 220 of the molecular sieve 200 is connected to the second air inlet 130 of the collection tank 100 through a flange pipe, ensuring that the tail gas passes through the filtration of the molecular sieve 200 and the secondary sedimentation of the collection tank 100 in sequence, and then is discharged from the second air outlet 140 of the collection tank 100. The silicon powder content in the purified tail gas can be lower than 0.1%. The two-stage filtration design (molecular sieve 200 + collection tank 100) can significantly improve the recovery rate of silicon powder.

[0052] Exemplarily, the collection tank 100 is a cylindrical tank body, on which a pressure detector 110 (i.e., a pressure gauge) is provided at the top, and an automatic blanking valve 120 is installed at the bottom of the collection tank 100. The tank body receives the tail gas treated by the molecular sieve 200 through the second air inlet 130, and the second air outlet 140 discharges the purified tail gas; the molecular sieve 200 is externally placed on the collection tank 100, the first air inlet 210 of the molecular sieve 200 is connected to the reduction tail gas pipeline, and the first air outlet 220 is connected to the second air inlet 130 of the collection tank 100 through a pipeline.

[0053] The molecular sieve 200 is made of high-temperature resistant ceramic material, with a pore diameter of 5 - 10 μm, which can intercept more than 90% of the fine silicon powder, and at the same time reduce the tail gas temperature from 200 °C to below 50 °C; a weighing module (such as a high-precision electronic scale) is provided at the bottom of the ton bag truck 300, and the top of the ton bag truck 300 can be docked with the discharge valve 120 of the collection tank 100 through a connecting piece. The weighing module monitors the weight of the ton bag in real time and transmits the data to the central control system.

[0054] The central control system is integrated with a PLC controller, which receives the pressure signal of the pressure detector 110 (the threshold can be set to 0.5 MPa) and the ton bag weight signal (the threshold can be set to 1 ton). When the pressure exceeds the limit, the central control system opens the discharge valve 120 to discharge silicon; when the ton bag is full, the discharge valve 120 is closed and a ton bag replacement signal is triggered.

[0055] In this way, the external molecular sieve 200 reduces the tail gas temperature and the heat load of downstream equipment. The central control system fully automatically controls the silicon discharge and ton bag replacement, reducing the labor cost. The dual-threshold control of pressure and weighing avoids pipeline blockage and silicon powder overflow.

[0056] In some embodiments, a nitrogen inlet 150 is provided on the collection tank 100. The nitrogen inlet 150 is connected to the second air inlet 130 and is used to convey nitrogen to the molecular sieve 200 for backwashing and cleaning.

[0057] Further, the nitrogen inlet 150 of the collection tank 100 is connected to the second air inlet 130 through a three-way valve. Exemplarily, the backwashing and cleaning process is as follows: The molecular sieve 200 can trigger backwashing after running for 24 hours or when the pressure difference reaches 0.6 Mpa. The central control system opens the valve of the nitrogen inlet 150 and blows the molecular sieve 200 in the reverse direction at a pressure of 0.4 MPa for 5 minutes to remove the adsorbed fine silicon powder.

[0058] In this way, the resistance of the molecular sieve 200 is restored to 95% of the initial value, and its service life is extended to more than 2 years. Nitrogen backwashing avoids the blockage of the molecular sieve 200, reduces the shutdown and maintenance frequency, and the automated backwashing process reduces the problem of manual operation.

[0059] In some embodiments, the weighing module of the ton bag truck 300 is signal-connected to the central control system. A control panel 310 is provided on the ton bag truck 300. The control panel 310 is signal-connected to the central control system. An audible and visual alarm unit is integrated on the control panel 310. When the ton bag weight of the ton bag truck 300 reaches the set value, the central control system controls the discharge valve 120 to close and triggers the audible and visual alarm unit to send out an audible and visual alarm signal.

[0060] Exemplarily, the control panel 310 of the bulk bag truck 300 integrates a touch screen and an audible and visual alarm unit (LED indicator and buzzer). When the weighing module detects that the weight of the bulk bag reaches 1 ton, the central control system sends a closing instruction to the control panel 310, and the feeding valve 120 closes immediately; the audible and visual alarm unit is activated, the buzzer sounds 3 times, and the red light flashes continuously until the operator confirms the signal.

[0061] In this way, real-time alarm reminder avoids overloading of bulk bags, and the human-machine interaction interface simplifies the operation process.

[0062] In some embodiments, the bulk bag truck 300 is detachably connected to the collection tank 100 through a connecting member.

[0063] In some embodiments, the connecting member is an electromagnetic lock. The electromagnetic lock includes a lock base fixed on the collection tank 100. An electromagnet is embedded in the lock base. The electromagnet has a moving iron core, and a retractable lock tongue is connected to the moving iron core; the bulk bag truck 300 has a lock groove corresponding to the lock tongue; the central control system controls the on / off of the circuit of the electromagnet. When the electromagnet is powered on, the electromagnet drives the lock tongue to extend and insert into the lock groove of the bulk bag truck 300; when the electromagnet is powered off, the lock tongue retracts, so that the bulk bag truck 300 can move relative to the collection tank 100.

[0064] Exemplarily, the lock base is fixed at the bottom of the collection tank 100, with an electromagnet and a moving iron core built in, and the lock tongue is connected to the end of the moving iron core; a lock groove is provided at the top of the bulk bag truck 300, and the inner wall of the groove is designed with an inclined surface to guide the insertion of the lock tongue. The operator presses the "Lock" button set on the control panel 310, and the central control system supplies power to the electromagnet, and the lock tongue extends and snaps into the lock groove; when the "Unlock" button is pressed, the electromagnet is powered off, and the spring return mechanism drives the lock tongue to retract, and the bulk bag truck 300 can move.

[0065] In this way, the electromagnetic lock can be locked / unlocked with one key, avoiding manual handling of bulk bags; the mechanical interlock design ensures connection stability.

[0066] In some embodiments, control buttons are integrated on the control panel 310, and their signals are connected to the central control system. The control buttons are used to trigger the central control system to control the fixation or separation of the bulk bag truck 300 and the collection tank 100.

[0067] In some embodiments, the bulk bag truck 300 includes a vehicle body and a bulk bag. A first flange is provided on the vehicle body, and a raised buckle is provided on the first flange. The bulk bag has a discharge port, and a second flange is fixedly provided on the discharge port. The second flange has a card slot, and the vehicle body and the bulk bag are flange-connected through the cooperation of the raised buckle and the card slot.

[0068] Specifically, the first flange is welded to the top of the vehicle body, and there are 4 radial protruding buckles at the edge. The cross-section of the buckle is trapezoidal; the second flange is fixed to the discharge port of the ton bag, and an L-shaped slot is opened at the edge with a slot depth of 10 mm. When connecting, align the ton bag flange with the vehicle body flange and rotate it clockwise by 30°. The buckle slides into the horizontal section of the slot to achieve mechanical locking. In this way, a flange quick-release structure between the collection tank 100 and the ton bag vehicle 300 is realized, which is relatively convenient.

[0069] In a second aspect, an embodiment of the present application provides a method for using a silicon powder collection device, where the silicon powder collection device is the silicon powder collection device provided in any embodiment of the first aspect. The method for using includes the following steps:

[0070] The reduction tail gas passes through the molecular sieve and the collection tank in sequence. The molecular sieve reduces the temperature of the tail gas to below 50°C and intercepts more than 90% of the silicon powder in the reduction tail gas. That is to say, the above process is the reduction tail gas treatment stage. The reduction tail gas (the temperature can be 200°C) enters the molecular sieve, is cooled to below 50°C, and about 90% of the fine silicon powder is intercepted. The remaining tail gas enters the collection tank, and the coarse silicon powder settles at the bottom of the tank;

[0071] When the pressure in the collection tank reaches 0.5 MPa, the central control system triggers the opening of the discharge valve, and the silicon powder falls into the ton bag in the ton bag vehicle. This process is the silicon discharge control stage;

[0072] The ton bag vehicle uses the weighing module to monitor the weight of the ton bag in real time. When it reaches 1 ton, the discharge valve is closed, and a replacement signal is sent to the central control system; the ton bag vehicle is controlled to move through the control panel.

[0073] Specifically, the operator can press the "Separation" button on the control panel. The ton bag vehicle moves to a safe area, and the trailer transports the full ton bag away. After installing a new ton bag, press the "Fix" button, and the ton bag vehicle resets and locks.

[0074] In this way, the full-process automation significantly reduces the silicon discharge time per shift and saves labor costs. At the same time, direct contact between personnel and silicon powder is avoided throughout the process, which allows for better investment in work in other areas, greatly improves work efficiency, and protects the health of personnel. Using this method to discharge silicon is friendly to the on-site environment.

[0075] In some embodiments, the collection tank is provided with a nitrogen inlet, and the molecular sieve is cleaned by backblowing through the nitrogen inlet. The backblowing pressure is 0.3 - 0.5 MPa and lasts for 5 - 10 minutes. For example, the backblowing pressure is 0.5 MPa and lasts for 5 minutes.

[0076] In more examples, the molecular sieve is cleaned by backblowing through the nitrogen inlet, the backblowing pressure is 0.3 MPa, and it lasts for 10 minutes.

[0077] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present application.

[0078] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0079] In the present application, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0080] In the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0081] The embodiments or implementation manners in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0082] It should be noted that the embodiments referred to as "one embodiment", "an embodiment", "exemplary embodiments", "some embodiments", etc. in the specification may include specific features, structures or characteristics, but not every embodiment necessarily includes the specific feature, structure or characteristic. In addition, such phrases do not necessarily refer to the same embodiment. Further, when combining a specific feature, structure or characteristic with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure or characteristic in combination with other embodiments, whether explicitly or implicitly described.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A silicon powder collecting device, characterized in that: include: A collecting tank, used to collect silicon powder, wherein the collecting tank is provided with a pressure detector and a discharge valve; A molecular sieve connected to the collecting tank, the molecular sieve is used to cool the reduction tail gas and intercept silicon powder in the reduction tail gas; A ton bag truck has a weighing module, and the ton bag truck is connected to the collection tank; The central control system is connected to the pressure detector, the unloading valve and the ton bag truck signal. The central control system is used to control the opening and closing of the unloading valve according to the pressure threshold obtained by the pressure detector to control the conduction state between the collection tank and the ton bag truck, and the central control system triggers a replacement signal after the weighing module detects that the ton bag truck has reached a preset load.

2. The silicon powder collecting device according to claim 1, characterized in that: The molecular sieve has a first air inlet and a first air outlet, the collecting tank is provided with a second air inlet and a second air outlet, and the collecting tank is connected to the first air outlet of the molecular sieve through the second air inlet.

3. The silicon powder collecting device according to claim 2, characterized in that: The collecting tank is provided with a nitrogen inlet, which is communicated with the second air inlet and is used to transport nitrogen to the molecular sieve for backwash cleaning.

4. The silicon powder collecting device according to any one of claims 1 to 3, characterized in that: The weighing module of the ton bag truck is connected to the central control system signal. The ton bag truck is provided with a control panel, and the control panel signal is connected to the central control system. The control panel is integrated with an audible and visual alarm unit. When the weight of the ton bags on the ton bag truck reaches a set value, the central control system controls the unloading valve to close and triggers the audible and visual alarm unit to send out an audible and visual alarm signal.

5. The silicon powder collecting device according to any one of claims 1 to 3, characterized in that: The ton bag truck is detachably connected to the collection tank via a connecting piece.

6. The silicon powder collecting device according to claim 5, characterized in that: The connecting piece is an electromagnetic lock, which includes a lock base, which is fixed on the collection tank, and an electromagnet is embedded in the lock base, which has a moving iron core, and a retractable lock tongue is connected to the moving iron core; the ton bag truck has a lock slot, which is arranged corresponding to the lock tongue; The central control system controls the on and off of the circuit of the electromagnet. When the electromagnet is energized, the electromagnet drives the lock tongue to extend and insert into the lock slot of the ton bag truck; when the electromagnet is de-energized, the lock tongue retracts so that the ton bag truck can move relative to the collection tank.

7. The silicon powder collecting device according to claim 6, characterized in that: The control panel is integrated with control buttons, whose signals are connected to the central control system. The control buttons are used to trigger the central control system to control the fixing or separation of the ton bag truck and the collection tank.

8. The silicon powder collecting device according to any one of claims 1 to 3, characterized in that: The ton bag truck includes a vehicle body and ton bags, the vehicle body is provided with a first flange, the first flange is provided with a protruding buckle, the ton bag has a discharge port, a second flange is fixedly provided on the discharge port, the second flange has a slot, the vehicle body and the ton bag are connected by matching flanges of the protruding buckle and the slot.

9. A method for using a silicon powder collecting device, characterized in that: The silicon powder collecting device is the silicon powder collecting device according to any one of claims 1 to 8, and the method of using the device comprises the following steps: The reduced tail gas passes through the molecular sieve and the collecting tank in sequence, and the molecular sieve reduces the tail gas temperature to below 50° C. and intercepts more than 90% of the silicon powder in the reduced tail gas; When the pressure in the collection tank reaches 0.5 MPa, the central control system triggers the unloading valve to open, and the silicon powder falls into the ton bag of the ton bag truck; The ton bag truck monitors the weight of the ton bag in real time through the weighing module, closes the unloading valve when the weight reaches 1 ton, and sends a replacement signal to the central control system; The transfer of the ton bag truck is controlled by the control panel.

10. The method of use according to claim 9, characterized in that: The collecting tank is provided with a nitrogen inlet, and the molecular sieve is back-flushed and cleaned through the nitrogen inlet, with a back-flushing pressure of 0.3-0.5 MPa for 5-10 minutes.

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