Polysilicon material vacuum feeding machine
By combining a vacuum hopper, a feeding pipe, a crushing motor, and a cyclone separator, the problems of particle splashing and handling large pieces of material in vacuum feeders are solved, achieving efficient and low-cost polycrystalline silicon particle conveying.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Filing Date
- 2025-06-20
- Publication Date
- 2026-07-14
AI Technical Summary
Existing vacuum feeders reduce material conveying speed to avoid particle splashing, and the suction gun mechanism has difficulty handling large clumps of material, resulting in low conveying efficiency.
It employs components such as a vacuum hopper, a suction pipe, a sealed top cover, a crushing motor, and a cyclone separator to achieve efficient conveying and separation of particles through negative pressure suction, crushing, and gas-solid separation.
It improves material conveying efficiency, reduces cleaning and maintenance costs, and avoids particle waste and pipeline blockage.
Smart Images
Figure CN224492877U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of material transportation technology, and in particular relates to a vacuum feeder for polycrystalline silicon materials. Background Technology
[0002] Polycrystalline silicon is a form of elemental silicon. When molten elemental silicon solidifies under supercooled conditions, silicon atoms arrange themselves into many crystal nuclei in a diamond lattice. If these nuclei grow into grains with different crystal orientations, these grains combine to crystallize into polycrystalline silicon. In the production and processing of polycrystalline silicon, vacuum feeders are often used to transport granular polycrystalline silicon. A vacuum feeder is a dust-free, closed-loop pipeline conveying device that uses vacuum suction to transport granular and powdered materials. It utilizes the pressure difference between the vacuum and the ambient space to create gas flow within the pipeline, which in turn moves the powdered material, thus completing the powder transport. It has advantages such as simple maintenance, no dust pollution, low energy consumption, small size, and low noise, and is therefore widely used in various light and heavy industries such as chemical, pharmaceutical, food, metallurgy, building materials, and agriculture. However, it still has the following drawbacks in practical use:
[0003] Utility model CN221164962U discloses a vacuum feeding device suitable for polycrystalline silicon powder. The buffer silo includes an interconnected feeding silo and a discharging silo, with a buffer plate between them and a material leakage channel on the buffer plate. The discharge port of the vacuum feeder body passes through the top plate of the feeding silo via an extension tube and extends into the feeding silo. A vibration motor is installed on the buffer silo. The top plate of the feeding silo is a flexible plate, and the end of the extension tube that passes through the top plate has a flange, which is fixedly connected to the top plate. Vacuum feeders often require a structure to prevent particles from being discharged into the environment, thus avoiding environmental pollution and material waste. However, slowing down the material's movement speed reduces its conveying efficiency, while using a filter structure requires cleaning, increasing the cost and operating expenses of the vacuum feeder.
[0004] The invention patent with publication number CN111115273A discloses a suction gun mechanism for conveying powder in a vacuum feeder. The suction gun head has air supply pipes on both sides of its bottom. The top and bottom of each air supply pipe are connected to a guide pipe, and the top of the guide pipe is connected to an inlet pipe. The end of the inlet pipe away from the guide pipe is connected to an air filling device. Separating blocks are movably fitted on both sides of the inner cavity of each air supply pipe, and each separating block has a through groove. A connecting shaft is movably fitted between two separating blocks. The suction gun mechanism of the vacuum feeder uses the movement of a spring to shear agglomerated material to prevent blockage of the suction gun mechanism and the vacuum feeder's pipes. However, in actual use, larger agglomerated materials are difficult to shear within the suction gun mechanism and still require other devices to break them down to a suitable size before they can pass through the suction gun mechanism into the vacuum feeder, reducing material conveying efficiency. Utility Model Content
[0005] The purpose of this utility model is to provide a vacuum feeder for polycrystalline silicon materials. By using a vacuum hopper, a suction pipe, and a sealed top cover, it solves the problems of vacuum feeders that either reduce material conveying speed or require cleaning to avoid particle splashing, thus increasing the cost and operating expenses of the vacuum feeder. In addition, the suction gun mechanism is difficult to suck up large pieces of clump material, and other devices are still needed to break the large pieces of material to a suitable size before they can enter the vacuum feeder through the suction gun mechanism, which reduces the material conveying efficiency.
[0006] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:
[0007] This utility model is a vacuum feeding machine for polycrystalline silicon materials, including a vacuum hopper, a suction pipe and a sealed top cover. The suction pipe is provided at one end of the outer circumference of the vacuum hopper, and a feeding hopper is welded and fixed at one end of the suction pipe. A crushing motor is snapped onto the outer circumference of the suction pipe. A sealed top cover is snapped and fixed onto the top of the vacuum hopper. A vacuum pump is snapped through the top of the sealed top cover. A cyclone separator is snapped through the bottom of the vacuum pump. A filter tube is snapped through the bottom of the cyclone separator.
[0008] The feed hopper is large enough to suck up large areas of polycrystalline silicon particles. A pulverizing motor drives the rotation of a cutting blade inside the feed hopper, which cuts and pulverizes large polycrystalline silicon particles. This allows polycrystalline silicon particles of different sizes to quickly and smoothly enter the vacuum hopper, improving material conveying efficiency. A vacuum pump creates a vacuum in the cyclone separator and vacuum hopper, causing particles to be drawn into the vacuum hopper through the suction pipe under pressure difference. As the particles enter the vacuum hopper, a small amount of lighter particles and dust are carried by the airflow into the cyclone separator for gas-solid separation. The material and dust fall into the filter tube, eliminating the need for filtering the flowing air with a filter screen, thus reducing operating costs. After falling into the filter tube, the dust and a small amount of particles are separated, and a small amount of filtered particles are returned to the vacuum hopper, preventing waste of polycrystalline silicon particles.
[0009] Furthermore, a feed pipe is welded and fixed to the outer periphery of the vacuum hopper, a discharge pipe is welded through the center of the bottom of the vacuum hopper, and a shock-absorbing support frame is snapped and fixed around the bottom of the vacuum hopper.
[0010] The shock-absorbing support frame can prevent damage to the vacuum feeder caused by ground vibration. By drawing a vacuum into the vacuum hopper, polycrystalline silicon particles can quickly enter the vacuum hopper under the action of air pressure difference. The structure is simple and easy to operate. By opening the discharge pipe at regular intervals, the particles in the vacuum hopper can be quickly discharged.
[0011] Furthermore, a metal corrugated pipe is snapped and fixed at one end of the extraction pipe, and the metal corrugated pipe is located at the other end of the extraction pipe relative to the feed hopper. The other end of the metal corrugated pipe is snapped and fixed at one end of the feed pipe.
[0012] The feed hopper is large in size, which allows a large area of polycrystalline silicon particles to be inserted into the feed hopper, making it easier to quickly suck up a large number of polycrystalline silicon particles and improve the material conveying efficiency.
[0013] Furthermore, a transmission assembly is snapped onto one end of the crushing motor, the transmission assembly is snapped onto the outer circumference of the feeding pipe, a rotating rod is snapped onto one side of the transmission assembly, a cutting blade is snapped and fixed onto the outer circumference of the rotating rod, a screen is snapped and fixed onto one end of the feeding pipe, the screen is located at one end of the feeding hopper of the feeding pipe, the rotating rod is inserted through and inserted into one side of the screen, the cutting blade and one end of the rotating rod are inserted into the feeding hopper, and one end of the cutting blade is attached to one side of the screen;
[0014] The crushing motor drives the rotating rod and cutting blade to rotate through the transmission component, crushing and cutting large polycrystalline silicon particles. This avoids the slow conveying speed of larger polycrystalline silicon particles, improves the conveying efficiency of polycrystalline silicon particles, and screens the material to ensure that only particles of a certain size can enter the feeding pipe, thus avoiding blockage in the vacuum feeder.
[0015] Furthermore, an exhaust pipe is inserted through and snapped onto the outer circumference of the vacuum pump, the cyclone separator is inserted into the inner side of the vacuum hopper, an air extraction pipe is welded through and welded onto the top of the outer circumference of the cyclone separator, and a first solenoid valve is inserted through and snapped onto the bottom of the outer circumference of the cyclone separator.
[0016] The vacuum pump draws air from the vacuum hopper and cyclone separator, creating a relative vacuum within them. This allows polycrystalline silicon particles to quickly enter the vacuum hopper. After entering the hopper, a small amount of lighter particles and dust are carried by the airflow into the cyclone separator for gas-solid separation. The particles and dust then fall into the filter tube, eliminating the need for filtering the flowing air through a filter screen. This avoids the need for constant cleaning of the filter screen, reducing operating costs and ensuring efficient delivery without requiring a reduction in the vacuum pump's power.
[0017] Furthermore, a slag discharge pipe is welded through the bottom of the filter tube, a third solenoid valve is snapped through the outer circumference of the slag discharge pipe, the bottom of the slag discharge pipe is snapped through the bottom of the outer circumference of the vacuum hopper, a support guide frame is snapped through and fixed to the top of the filter tube, a dust filter bag is snapped through and snapped through the bottom of the support guide frame, a return pipe is snapped through and snapped through the bottom of the dust filter bag, a second solenoid valve is snapped through and snapped through the outer circumference of the return pipe, a vibration spring is snapped through and snapped through the outer circumference of the return pipe, the bottom of the vibration spring is snapped through and snapped into the bottom of the filter tube, and the bottom of the return pipe is inserted through and inserted into the bottom of the filter tube.
[0018] During vacuuming, the first solenoid valve opens while the second and third solenoid valves close, allowing dust and a small amount of polysilicon particles to fall into the dust filter bag. The vibration of the vacuum feeder causes the vibration spring and dust filter bag to vibrate, forcing the dust through the filter bag and into the slag discharge pipe. After a period of time, the second solenoid valve opens and the first solenoid valve closes, allowing the particles in the dust filter bag to flow back into the vacuum hopper through the return pipe, preventing waste of polysilicon particles. When dust removal is required, the first and second solenoid valves close and the third solenoid valve opens, allowing the dust to be quickly discharged through the slag discharge pipe. The filter tube has a simple structure, low cost, and can screen out and return polysilicon particles mixed with dust, improving the conveying efficiency of polysilicon particles and reducing the cost of the vacuum feeder.
[0019] This utility model has the following beneficial effects:
[0020] This invention solves the problems often encountered with vacuum feeders by incorporating a vacuum hopper and a sealed top cover. These problems include the need for structures to prevent particles from entering the environment, thus avoiding pollution and material waste. However, slowing down material movement reduces conveying efficiency, and using filter structures requires cleaning, increasing the cost and operating expenses of the vacuum feeder. Under negative pressure, polycrystalline silicon particles enter the vacuum hopper. A large number of particles fall to the bottom of the hopper under gravity and are periodically discharged. A small amount of smaller polycrystalline silicon particles and dust enter the cyclone separator with the airflow. The cyclone separator separates the gas and particles, allowing the particles and dust to fall into the filter tube. This eliminates the need for filtering the flowing air with a filter screen, avoiding the need for constant cleaning of filter screens and reducing operating costs. It also maintains the conveying efficiency without reducing the vacuum pump's power. Furthermore, the filter tube effectively separates dust and particles. By periodically closing the bottom of the cyclone separator and opening the bottom of the return pipe, particles can be returned, preventing waste of polycrystalline silicon particles.
[0021] This invention solves the problem of large lumps in vacuum feeders being difficult to cut by spring movement to prevent blockages in the suction gun mechanism and vacuum feeder pipes. In practice, these lumps require further processing to break them down to a suitable size, reducing material conveying efficiency. When suctioning polycrystalline silicon particles, the material enters the hopper under negative pressure. The larger hopper allows for the insertion of large polycrystalline silicon particles, while smaller particles pass through a screen into the vacuum hopper. Larger particles are crushed by a pulverizing motor-driven cutting blade and then pass through the screen into the suction pipe. This allows polycrystalline silicon particles of different sizes to enter the vacuum hopper quickly and smoothly, preventing slow movement of large particles and improving material conveying efficiency. Attached Figure Description
[0022] Figure 1 This is a structural rendering of the present invention;
[0023] Figure 2 This is a schematic diagram of the structure of this utility model;
[0024] Figure 3 This is a structural diagram of the vacuum hopper of this utility model;
[0025] Figure 4 This is a structural diagram of the material extraction tube of this utility model;
[0026] Figure 5This is a structural diagram of the sealing top cover and cyclone separator of this utility model;
[0027] Figure 6 This is a cross-sectional view of the filter tube of this utility model.
[0028] Figure label:
[0029] 1. Vacuum hopper; 101. Feed pipe; 102. Discharge pipe; 103. Shock-absorbing support frame; 2. Extraction pipe; 201. Feed hopper; 202. Crushing motor; 203. Transmission assembly; 204. Screen; 205. Metal corrugated pipe; 206. Rotating rod; 207. Cutting blade; 3. Sealed top cover; 301. Vacuum pump; 302. Cyclone separator; 303. Filter pipe; 304. Slag discharge pipe; 305. Air extraction pipe; 306. First solenoid valve; 307. Exhaust pipe; 308. Dust filter bag; 309. Return pipe; 310. Second solenoid valve; 311. Vibration spring; 312. Third solenoid valve; 313. Support guide frame. Detailed Implementation
[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.
[0031] Please see Figure 1-6 As shown, this utility model is a vacuum feeding machine for polycrystalline silicon materials, including a vacuum hopper 1, a suction pipe 2, and a sealing top cover 3. The suction pipe 2 is provided at one end of the outer peripheral surface of the vacuum hopper 1, and a feeding hopper 201 is welded and fixed at one end of the suction pipe 2. A crushing motor 202 is snapped onto the outer peripheral surface of the suction pipe 2. The sealing top cover 3 is snapped and fixed onto the top of the vacuum hopper 1. A vacuum pump 301 is snapped through the top of the sealing top cover 3. A cyclone separator 302 is snapped through the bottom of the vacuum pump 301. A filter pipe 303 is snapped through the bottom of the cyclone separator 302.
[0032] When conveying polycrystalline silicon particles, the vacuum pump 301 and the crushing motor 202 are started, and the feed hopper 201 is inserted into the polycrystalline silicon particles. The vacuum pump 301 evacuates the vacuum hopper 1, so that the polycrystalline silicon particles quickly enter the vacuum hopper 1 through the feed hopper 201 and the extraction pipe 2 under negative pressure. Large polycrystalline silicon particles are crushed and cut by the rotation of the cutting blade 207 driven by the crushing motor 202. After being cut to a suitable size, they enter the extraction pipe 2 through the screen 204. After the polycrystalline silicon particles enter the vacuum hopper 1, they fall to the bottom of the vacuum hopper 1 under the action of gravity. Very small polycrystalline silicon particles and dust enter the cyclone separator 302 with the airflow and are separated into gas and solid. The polycrystalline silicon particles and dust fall into the filter pipe 303. The first solenoid valve 306 is closed at regular intervals and the second solenoid valve 310 is opened so that the small amount of polycrystalline silicon particles filtered in the filter pipe 303 flows back into the vacuum hopper 1 through the return pipe 309.
[0033] Among them, such as Figure 1-4 As shown, a feed pipe 101 is welded and fixed to the outer periphery of the vacuum hopper 1, a discharge pipe 102 is welded through the center of the bottom of the vacuum hopper 1, and a shock-absorbing support frame 103 is snapped and fixed around the bottom of the vacuum hopper 1.
[0034] A metal corrugated pipe 205 is fixedly connected to one end of the extraction pipe 2. The metal corrugated pipe 205 is located at the other end of the extraction pipe 2 relative to the feed hopper 201. The other end of the metal corrugated pipe 205 is fixedly connected to one end of the feed pipe 101. A transmission component 203 is fixedly connected to one end of the crushing motor 202. The transmission component 203 is inserted through and fixed to the outer circumference of the extraction pipe 2. A rotating rod 206 is fixedly connected to one side of the transmission component 203. A cutting blade 207 is fixedly connected to the outer circumference of the rotating rod 206. A screen 204 is fixedly connected to one end of the extraction pipe 2. The screen 204 is located at one end of the feed hopper 201 of the extraction pipe 2. The rotating rod 206 is inserted through and inserted into one side of the screen 204. One end of the cutting blade 207 and the rotating rod 206 are inserted into the feed hopper 201. One end of the cutting blade 207 is attached to one side of the screen 204.
[0035] Polycrystalline silicon particles enter the feed hopper 201 under negative pressure. Small polycrystalline silicon particles pass through the screen 204 into the extraction pipe 2 and through the metal corrugated pipe 205 into the vacuum hopper 1. When large polycrystalline silicon particles enter the feed hopper 201, the crushing motor 202 drives the rotating rod 206 and the cutting blade 207 to rotate through the transmission component 203, crushing and cutting the polycrystalline silicon particles to a suitable size. The particles then pass through the screen 204 with the airflow. After entering the vacuum hopper 1, the polycrystalline silicon particles are discharged from the vacuum hopper 1 by opening the discharge pipe 102 at regular intervals.
[0036] Among them, such as Figure 1 , 2As shown in Figures 5 and 6, an exhaust pipe 307 is inserted and snapped through the outer circumference of the vacuum pump 301. A cyclone separator 302 is inserted into the inner side of the vacuum hopper 1. An extraction pipe 305 is welded through the top of the outer circumference of the cyclone separator 302. A first solenoid valve 306 is inserted and snapped through the bottom of the outer circumference of the cyclone separator 302. A slag discharge pipe 304 is welded through the bottom of the filter pipe 303. A third solenoid valve 312 is inserted and snapped through the outer circumference of the slag discharge pipe 304. The bottom of the slag discharge pipe 304 is inserted and snapped through the vacuum hopper 1. At the bottom of the outer periphery, a support guide frame 313 is snapped and fixed inside the top of the filter tube 303. A dust filter bag 308 is snapped through the bottom of the support guide frame 313. A return pipe 309 is snapped through the bottom of the dust filter bag 308. A second solenoid valve 310 is snapped through the outer periphery of the return pipe 309. A vibration spring 311 is snapped through the outer periphery of the return pipe 309. The bottom of the vibration spring 311 is snapped into the bottom of the filter tube 303. The bottom of the return pipe 309 is inserted through the bottom of the filter tube 303.
[0037] During the transport of polycrystalline silicon particles, the second solenoid valve 310 and the third solenoid valve 312 are closed and the first solenoid valve 306 is opened. The vacuum pump 301 is started to evacuate air from the vacuum hopper 1. The air carries the polycrystalline silicon particles into the vacuum hopper 1 through the extraction pipe 2. Dust and small polycrystalline silicon particles are carried into the extraction pipe 305 by the airflow and undergo gas-solid separation through the cyclone separator 302. The air is discharged through the exhaust pipe 307. Dust and a small amount of polycrystalline silicon particles fall onto the dust filter bag 30 along the support guide frame 313 under the action of gravity. Within 8, the vibration of the vacuum feeder drives the vibration spring 311 to vibrate, which in turn drives the dust filter bag 308 to vibrate, causing the dust to pass through the dust filter bag 308 and fall into the slag discharge pipe 304. After a certain period of time, the first solenoid valve 306 is closed and the second solenoid valve 310 is opened, allowing the polycrystalline silicon particles in the dust filter bag 308 to flow back into the vacuum hopper 1 through the return pipe 309. When it is necessary to clean the dust, the first solenoid valve 306 is closed and the third solenoid valve 312 is opened, allowing the dust to be discharged through the slag discharge pipe 304.
[0038] The specific working principle of this utility model is as follows: When it is necessary to transport polycrystalline silicon particles, the vacuum pump 301 and the crushing motor 202 are started, the second solenoid valve 310 and the third solenoid valve 312 are closed and the first solenoid valve 306 is opened. The vacuum pump 301 evacuates air from the vacuum hopper 1, making the vacuum hopper 1 relatively vacuum. Under the action of negative pressure, the polycrystalline silicon particles enter the feeding hopper 201. Small polycrystalline silicon particles pass through the screen 204 into the extraction pipe 2 and through the metal corrugated pipe 205 into the vacuum hopper 1. When large polycrystalline silicon particles enter the feeding hopper 201, the crushing motor 202 drives the rotating rod 206 and the cutting blade 207 to rotate through the transmission component 203, crushing and cutting the large polycrystalline silicon particles to a suitable size. The particles then pass through the screen 204 with the airflow. After entering the vacuum hopper 1, the large polycrystalline silicon particles fall into the vacuum under the action of gravity. At the bottom of hopper 1, small polycrystalline silicon particles and dust enter the exhaust pipe 305 with the airflow and are separated into gas and solid by the cyclone separator 302. The air is discharged through the exhaust pipe 307. Dust and a small amount of polycrystalline silicon particles fall into the dust filter bag 308 under the action of gravity along the support guide frame 313. The vibration of the vacuum feeder drives the vibration spring 311 to vibrate, which in turn drives the dust filter bag 308 to vibrate, causing the dust to pass through the dust filter bag 308 and fall into the slag discharge pipe 304. After a certain period of time, the first solenoid valve 306 is closed and the second solenoid valve 310 is opened, so that the polycrystalline silicon particles in the dust filter bag 308 flow back to the vacuum hopper 1 through the return pipe 309. When it is necessary to clean the dust, the first solenoid valve 306 is closed and the third solenoid valve 312 is opened, so that the dust is discharged through the slag discharge pipe 304. The discharge pipe 102 is opened at regular intervals to discharge the polycrystalline silicon particles in the vacuum hopper 1.
[0039] The above are merely preferred embodiments of the present utility model and do not limit the present utility model. Any modifications, equivalent substitutions, or improvements made to the technical solutions described in the foregoing embodiments, or to some of the technical features, shall fall within the protection scope of the present utility model.
Claims
1. A vacuum feeder for polycrystalline silicon materials, comprising a vacuum hopper (1), a feeding pipe (2), and a sealed top cover (3), characterized in that: The vacuum hopper (1) has a material extraction pipe (2) at one end of its outer periphery. A feeding hopper (201) is welded and fixed at one end of the material extraction pipe (2). A crushing motor (202) is snapped onto the outer periphery of the material extraction pipe (2). A sealing top cover (3) is snapped onto the top of the vacuum hopper (1). A vacuum pump (301) is snapped through the top of the sealing top cover (3). A cyclone separator (302) is snapped through the bottom of the vacuum pump (301). A filter pipe (303) is snapped through the bottom of the cyclone separator (302).
2. The vacuum feeding machine for polycrystalline silicon materials according to claim 1, characterized in that: The vacuum hopper (1) has a feed pipe (101) welded and fixed on its outer periphery, and a discharge pipe (102) is welded through the center of the bottom of the vacuum hopper (1). The vacuum hopper (1) has a shock-absorbing support frame (103) snapped and fixed around its bottom.
3. The vacuum feeder for polycrystalline silicon materials according to claim 2, characterized in that: One end of the extraction pipe (2) is fixedly connected to a metal corrugated pipe (205), which is located at the other end of the extraction pipe (2) relative to the feed hopper (201). The other end of the metal corrugated pipe (205) is fixedly connected to one end of the feed pipe (101) relative to the extraction pipe (2).
4. The vacuum feeder for polycrystalline silicon materials according to claim 1, characterized in that: One end of the crushing motor (202) is connected to a transmission assembly (203), which is connected to the outer circumference of the feeding pipe (2). A rotating rod (206) is connected to one side of the transmission assembly (203), and a cutting blade (207) is fixedly connected to the outer circumference of the rotating rod (206). A screen (204) is fixedly connected to one end of the feeding pipe (2), which is located at one end of the feeding hopper (201) of the feeding pipe (2). The rotating rod (206) is inserted through and inserted into one side of the screen (204). One end of the cutting blade (207) and the rotating rod (206) are inserted into the feeding hopper (201), and one end of the cutting blade (207) is attached to one side of the screen (204).
5. A vacuum feeder for polycrystalline silicon materials according to claim 1, characterized in that: The vacuum pump (301) has an exhaust pipe (307) inserted through and snapped onto its outer peripheral surface. The cyclone separator (302) is inserted into the inner side of the vacuum hopper (1). The top of the outer peripheral surface of the cyclone separator (302) is welded through and a suction pipe (305) is welded through and a first solenoid valve (306) is inserted through and snapped onto the bottom of the outer peripheral surface of the cyclone separator (302).
6. The vacuum feeder for polycrystalline silicon materials according to claim 1, characterized in that: The bottom of the filter tube (303) is welded with a slag discharge pipe (304). A third solenoid valve (312) is inserted through the outer circumference of the slag discharge pipe (304). The bottom of the slag discharge pipe (304) is inserted through the bottom of the outer circumference of the vacuum hopper (1). A support guide frame (313) is fixedly inserted into the top of the filter tube (303). A dust filter bag (308) is inserted through the bottom of the support guide frame (313). A return pipe (309) is inserted through the bottom of the dust filter bag (308). A second solenoid valve (310) is inserted through the outer circumference of the return pipe (309). A vibration spring (311) is inserted through the outer circumference of the return pipe (309). The bottom of the vibration spring (311) is inserted into the bottom of the filter tube (303). The bottom of the return pipe (309) is inserted through the bottom of the filter tube (303).