Silicon powder separation and recovery device

Abstract

The utility model discloses a silica powder separating and recycling device which comprises a dust remover, an induced draft fan and an ash storage moving barrel, an air inlet of the induced draft fan is connected with one end of a pipeline through a bent pipe, the other end of the pipeline is connected with an air outlet of the dust remover, and an ash outlet in the bottom of an ash bin of the dust remover is connected with one end of an ash discharging pipe through a star-shaped ash discharging valve. The other end of the ash discharging pipe is movably connected with an inlet of the ash storage moving barrel through a flange, and a plurality of electric discharging valves are arranged on the ash discharging pipe; an explosion-proof valve is arranged on an air inlet of the dust remover; an explosion venting sheet is arranged on the side surface of the dust remover; contacts of the air pressure monitor are arranged on one side, close to the dust remover, of the air inlet of the dust remover and one side, close to the dust remover, of the pipeline And an ash bin of the dust remover is provided with a contact of the thermodetector. The device has the advantages that the dust remover filters and recycles silicon powder under negative pressure, and continuous dust removal, recycling and transferring after accumulation to a certain degree can be realized. The temperature measuring instrument monitors the temperature of the ash bin of the dust remover, timely treatment is achieved, and safety accidents are avoided; and an explosion venting sheet and an explosion-proof valve are arranged to improve the safety.

Description

Technical fields:

[0001] This utility model relates to the field of polysilicon production, specifically to a silicon powder separation and recycling device. Background technology:

[0002] Monocrystalline silicon, produced from electronic-grade polycrystalline silicon, is a fundamental material for the electronics and information industry, serving as a raw material for the production of large-scale integrated circuits, semiconductor discrete components, and power electronic devices. Currently, over 70% of polycrystalline silicon production processes internationally utilize the modified Siemens process. The Siemens process, also known as the trichlorosilane hydrogen reduction process, is a method for generating polycrystalline silicon through a chemical reaction within a reduction furnace.

[0003] In the process of preparing polycrystalline silicon rods, in addition to the main product silicon rods, byproducts such as silicon tetrachloride, dichlorosilane, and hydrogen chloride are generated in the reduction furnace. At the same time, silicon powder is inevitably generated and adheres to the bell base, electrodes, and other equipment of the reduction furnace. The characteristic of the modified Siemens process for producing polycrystalline silicon is that the silicon rods produced in the reduction furnace are produced in intermittent batches. After each batch of silicon rods is disassembled, the silicon cores must be reassembled before production can continue. Therefore, cleaning and recycling silicon powder is a very important part of the production process.

[0004] Existing equipment for cleaning silicon powder, such as portable small vacuum cleaners, requires multiple cleanings indoors, each requiring the emptying of silicon powder. This results in problems with continuous use or continuous recycling of the cleaned silicon powder. During production, a large amount of silicon powder is recovered, and multiple transfers are inconvenient. Furthermore, after silicon powder is recycled, it still contains trace amounts of chlorosilane. If stored indoors, excessive accumulation of chlorosilane can cause static electricity to be generated during movement, which can lead to combustion and poses a significant safety hazard. Utility model content:

[0005] The purpose of this invention is to provide a silicon powder separation and recycling device.

[0006] This utility model is implemented by the following technical solution:

[0007] A silicon powder separation and recycling device includes a dust collector, an induced draft fan, and a mobile ash storage bin. The air inlet of the induced draft fan is connected to one end of a pipe via a bend, and the other end of the pipe is connected to the air outlet of the dust collector. The air outlet of the induced draft fan is connected to an exhaust chimney via a silencer.

[0008] The ash outlet at the bottom of the ash hopper of the dust collector is connected to one end of the ash discharge pipe via a star-shaped ash discharge valve. The other end of the ash discharge pipe is movably connected to the inlet of the ash storage mobile bucket via a flange. Multiple electric discharge valves are provided on the ash discharge pipe.

[0009] The dust collector is equipped with an explosion-proof valve at its air inlet.

[0010] The dust collector is equipped with a venting diaphragm on its side;

[0011] The air inlet of the dust collector and the side of the pipe near the dust collector are both equipped with contacts for a pressure monitoring instrument.

[0012] The dust collector has a temperature measuring device contact point on one side of the ash hopper;

[0013] A housing is placed above the contact point of the thermometer and fixed on the ash hopper of the dust collector. One end of the housing has an inlet, and the other end is connected to a bend through a cooling pipe. A valve is provided on the cooling pipe, and a one-way valve is provided on the cooling pipe between the valve and the bend.

[0014] Preferably, the dust collector has multiple inspection holes on its top, multiple filter bags are provided inside the dust collector between the air inlet and the air outlet, and an air collection bag is fixed on the outside of the dust collector. The air collection bag is connected to the blow pipe above the filter bags through multiple pulse solenoid valves.

[0015] Advantages of this utility model: The induced draft fan of this application creates negative pressure in the dust collector, which can filter the gas containing silicon powder. The silicon powder settles to the bottom of the ash silo and can finally be recovered into the mobile ash storage bin. This allows for continuous dust removal and recovery, and the dust can be transferred after accumulating to a certain level.

[0016] The air pressure monitoring instrument is designed to monitor the air pressure changes at the air inlet and outlet of the dust collector. If the two pressures are equal or have a small difference, it indicates that the dust collector is functioning normally under negative pressure. If the pressure difference is large, it indicates that the dust collector is not functioning normally and needs to be cleaned in a timely manner.

[0017] The temperature measuring instrument monitors the temperature of the dust collector's ash hopper. When too much silicon powder accumulates in the ash hopper, or when trace amounts of chlorosilane in the silicon powder ignite due to other reasons, the abnormal temperature can be detected in time and dealt with promptly to avoid safety accidents. At the same time, protective devices such as explosion relief discs are used to relieve pressure in case of possible combustion and explosion inside the dust collector, and explosion-proof valves are used to block the propagation of possible combustion and explosion inside the dust collector, thereby improving safety.

[0018] A separate casing is installed, and an induced draft fan creates negative pressure inside the casing, allowing low-temperature air to circulate. This air then cools the outside of the dust collector's ash hopper through heat exchange, reducing the risk of internal combustion caused by high external temperatures. Attached image description:

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0021] In the diagram: 1. Exhaust fan; 2. Bend; 3. Pipe; 4. Dust collector; 4.1. Inspection hole; 4.2. Filter bag; 4.3. Air collection bag; 4.4. Pulse solenoid valve; 4.5. Pulse jet pipe; 5. Silencer; 6. Exhaust chimney; 7. Rotary rotary valve; 8. Ash discharge pipe; 9. Electric discharge valve; 10. Ash storage moving bucket; 11. Explosion-proof valve; 12. Explosion relief disc; 13. Air pressure monitor; 14. Thermometer; 15. Housing; 16. Cooling pipe; 17. Valve; 18. Check valve. Detailed implementation method:

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] like Figure 1 As shown, a silicon powder separation and recycling device includes a dust collector 4, an induced draft fan 1, and a ash storage mobile bin 10. The air inlet of the induced draft fan 1 is connected to one end of a pipe 3 through a bend 2, and the other end of the pipe 3 is connected to the air outlet of the dust collector 4. The air outlet of the induced draft fan 1 is connected to an exhaust chimney 6 through a silencer 5. The silencer 5 can reduce noise.

[0024] The induced draft fan 1 draws in air, creating negative pressure inside the bend 2, pipe 3, and dust collector 4. The dust collector 4 can then draw in dust through the air inlet, and the air drawn in by the induced draft fan 1 is discharged from the exhaust chimney 6.

[0025] The ash outlet at the bottom of the ash hopper of the dust collector 4 is connected to one end of the ash discharge pipe 8 via a star-shaped ash discharge valve 7. The other end of the ash discharge pipe 8 is connected to the inlet of the ash storage mobile bucket 10 via a flange. The ash discharge pipe 8 is equipped with multiple electric discharge valves 9. The star-shaped ash discharge valve 7, also called a star-shaped discharger, is a special discharge device. It is mainly used at the discharge port under negative pressure to transport materials through a rotating impeller and to play a sealing role to prevent air from being sucked in from the discharge port during pneumatic conveying, thus ensuring the normal discharge of the discharger. In this application, air is prevented from being sucked in from the ash discharge pipe 8 by the ash hopper of the dust collector 4.

[0026] The silicon powder filtered out by the dust collector 4 falls into the ash hopper of the dust collector 4. The star-shaped ash discharge valve 7 is opened, and the silicon powder can fall into the ash discharge pipe 8. The star-shaped ash discharge valve 7 is closed, and multiple electric feeding valves 9 are opened in sequence, so that the silicon powder is finally stored in the ash storage mobile bucket 10. The ash storage mobile bucket 10 can be separated from the ash discharge pipe 8 and moved and unloaded by the universal wheels at the bottom.

[0027] The dust collector 4 is equipped with an explosion-proof valve 11 at its air inlet. The explosion-proof valve 11 is a passive safety device that blocks the spread of explosions through physical isolation. It is mainly used in industrial pipeline systems. The dust accumulated in the dust collector 4 in this application, as well as the chlorosilane, have the risk of being flammable and explosive.

[0028] The dust collector 4 is provided with a rupture disc 12 on its side. The rupture disc 12 is also called a rupture disc, explosion-proof disc, or explosion-proof membrane. It uses the rupture of the diaphragm to relieve pressure. After the pressure is relieved, the container is forced to stop operating. In this application, the pressure can be relieved when a combustion or explosion occurs inside the dust collector 4.

[0029] The air pressure monitoring device 13 is installed on the side of the air inlet of the dust collector 4 and the side of the pipe 3 near the dust collector 4. The air pressure monitoring device 13 monitors the air pressure changes at the air inlet and outlet of the dust collector 4. When the two pressures are equal or the difference is within a preset appropriate range, it indicates that the negative pressure in the dust collector 4 is normal for dust removal. When the pressure difference is large and exceeds the preset maximum value, it indicates that there is no negative pressure in the dust collector 4 and it cannot remove dust normally. This indicates that the filter bag 4.2 is blocked and needs to be cleaned.

[0030] The induced draft fan 1 is a variable frequency fan, which can adjust and control the air force according to the pressure difference between the air inlet and the air outlet of the dust collector 4.

[0031] The dust collector 4 has a contact point of a thermometer 14 on one side of the ash hopper. The thermometer 14 monitors the temperature of the ash hopper of the dust collector 4. When too much silicon powder is deposited in the ash hopper, or when trace amounts of chlorosilane in the silicon powder are burned due to other reasons, the abnormal temperature is detected in time and can be dealt with in time to avoid safety accidents.

[0032] A housing 15 is placed above the contact of the thermometer 14 and fixed on the ash hopper of the dust collector 4. One end of the housing 15 has an inlet, and the other end is connected to the bend 2 through the cooling pipe 16. A valve 17 is provided on the cooling pipe 16, and a one-way valve 18 is provided on the cooling pipe 16 between the valve 17 and the bend 2. The one-way valve 18 prevents the air coming out of the dust collector 4 from entering the cooling pipe 16.

[0033] By opening valve 17, the induced draft fan 1 can create negative pressure inside the cooling pipe 16 and the casing 15, allowing low-temperature air to circulate. This heat exchange cools the outer perimeter of the dust collector 4's ash hopper, reducing the risk of internal combustion caused by high external temperatures.

[0034] The dust collector 4 has multiple inspection holes 4.1 on its top, which facilitate the inspection and replacement of filter bags 4.2. Inside the dust collector 4, there are multiple filter bags 4.2 between the air inlet and the air outlet. A gas collection bag 4.3 is fixed on the outside of the dust collector 4. The gas collection bag 4.3 provides a back-blowing air source. The gas collection bag 4.3 is connected to the blowpipe 4.5 above the filter bags 4.2 through multiple pulse solenoid valves 4.4. The pulse solenoid valves 4.4 control the blowpipe 4.5 at intervals to back-blow and clean the filter bags 4.2.

[0035] Working Principle: When this utility model is in use, the induced draft fan 1 is started, and negative pressure is generated in the dust collector 4 through the bend 2 and pipe 3. Gas carrying silica powder enters the dust collector 4 through the air inlet. The silica powder is filtered and separated by the filter bags 4.2 and settles to the bottom of the ash hopper. The separated silica powder is discharged into the ash discharge pipe 8 through the star-shaped ash discharge valve 7, and then recovered into the ash storage mobile bucket 10 by the electric discharge valve 9. The clean airflow after filtering the dust is drawn out by the induced draft fan 1 and discharged to a safe location through the exhaust chimney 6.

[0036] The filter bag 4.2 is continuously backflushed by gas controlled by the pulse solenoid valve 4.4, so that the filter bag 4.2 can be used continuously and normally.

[0037] The air pressure monitor 13 monitors the air pressure changes at the air inlet and outlet of the dust collector 4. When the two pressures are equal or the difference is within a preset appropriate range, it indicates that the negative pressure inside the dust collector 4 is normal for dust removal. When the pressure difference is large and exceeds the preset maximum value, it indicates that there is no negative pressure inside the dust collector 4 and it cannot remove dust normally, indicating that the filter bag 4.2 is blocked and needs to be cleaned. The induced draft fan 1 is a variable frequency fan, which can adjust and control the air force according to the pressure difference between the air inlet and outlet of the dust collector 4.

[0038] The thermometer 14 monitors the temperature of the ash hopper of the dust collector 4. When too much silicon powder is deposited in the ash hopper, or when trace amounts of chlorosilane in the silicon powder burn due to other reasons, the abnormal temperature is detected in time and can be dealt with promptly to avoid safety accidents. At the same time, protective devices such as explosion relief discs 10 and explosion-proof valves 11 are used. The former relieves pressure in case of possible combustion and explosion in the dust collector 4, and the latter blocks the propagation of possible combustion and explosion in the dust collector 4.

[0039] When valve 17 is opened, the induced draft fan 1 can create negative pressure inside the cooling pipe 16 and the casing 15, allowing low-temperature air to circulate. This heat exchange cools the outside of the dust collector 4's ash hopper, reducing the risk of internal combustion caused by high external temperatures. When chlorosilane burns inside the ash hopper, the temperature measuring instrument 14 below the casing 15 will still detect it.

[0040] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A silicon powder separation and recovery device, characterized by comprising: It includes a dust collector, an induced draft fan, and a mobile ash storage bin. The air inlet of the induced draft fan is connected to one end of a pipe via a bend, and the other end of the pipe is connected to the air outlet of the dust collector. The air outlet of the induced draft fan is connected to an exhaust chimney via a silencer. The ash outlet at the bottom of the ash hopper of the dust collector is connected to one end of the ash discharge pipe via a star-shaped ash discharge valve. The other end of the ash discharge pipe is movably connected to the inlet of the ash storage mobile bucket via a flange. Multiple electric discharge valves are provided on the ash discharge pipe. The dust collector is equipped with an explosion-proof valve at its air inlet. The dust collector is equipped with a venting diaphragm on its side; The air inlet of the dust collector and the side of the pipe near the dust collector are both equipped with contacts for a pressure monitoring instrument. The dust collector has a temperature measuring device contact point on one side of the ash hopper; A housing is placed above the contact point of the thermometer and fixed on the ash hopper of the dust collector. One end of the housing has an inlet, and the other end is connected to a bend through a cooling pipe. A valve is provided on the cooling pipe, and a one-way valve is provided on the cooling pipe between the valve and the bend.

2. The device for separating and recovering silicon powder according to claim 1, characterized in that: The dust collector has multiple inspection holes on its top. Inside the dust collector, there are multiple filter bags between the air inlet and the air outlet. An air collection bag is fixed on the outside of the dust collector. The air collection bag is connected to the blow pipe above the filter bags through multiple pulse solenoid valves.

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