Multi-stage screening equipment for coal gangue

Abstract

The utility model relates to the technical field of coal gangue screen subpackaging, in particular to coal gangue multi-stage screening equipment which comprises an equipment box, a vibration drive and a multi-stage screening mechanism. The multi-stage screening mechanism is arranged in the equipment box, elastically connected with one side of the equipment box through an elastic connecting piece and located between the elastic connecting piece and the vibration drive. The vibration driver is arranged on the other side of the equipment box and used for periodically pushing the multi-stage screening mechanism to conduct extrusion elastic connection in the horizontal direction. The vibration driver is arranged on the side face of the multi-stage screening mechanism to drive the multi-stage screening mechanism to reciprocate in the horizontal direction, so that coal gangue can be screened in a multi-stage mode in the horizontal reciprocating process of the multi-stage screening mechanism, and the actual screening requirement is met. Meanwhile, the multi-stage screening mechanism can be automatically rebounded after being compressed by vibration driving through the elastic connecting piece, the situation that the multi-stage screening mechanism is directly driven to reciprocate through vibration driving is avoided, and therefore the structural strength requirement is lowered, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of coal gangue screening and packaging, in particular to a coal gangue multi-stage screening device. Background Art

[0002] Gangue is a solid waste discharged during the coal mining and coal washing process. It is a black-gray rock with a low carbon content and harder than coal that accompanies the coal seam during the coal formation process. When using gangue, it is usually broken first, and then screened to obtain gangue of different specifications. For the screening of gangue powder, in most cases, the gangue crushed stone is screened through the vibrating screen of the screen plate. Because the screen plate has screen holes, it is convenient for fine materials smaller than the screen holes to pass through, and coarse materials larger than the screen holes cannot pass through, thereby realizing the screening of gangue stone.

[0003] In the existing coal gangue crushing equipment, for example, the Chinese invention patent application with publication number CN116689128A provides a coal gangue crushing and screening device, including a first screen and a second screen, wherein the first screen and the second screen are both through corresponding elastic parts so that the coal gangue on the top falls on the corresponding screen and then squeezes the elastic parts, and the elastic parts are used to drive the screen to float up and down reciprocatingly, thereby realizing the screening of the coal gangue on the screen.

[0004] On the one hand, the screening of coal gangue by the above method is inefficient, which may easily lead to the coal gangue feeding too fast, causing the screen to vibrate untimely or insufficiently, resulting in failure of coal gangue screening. At the same time, the vibration amplitude of the screen is small, and the coal gangue cannot be fully and effectively screened, thereby failing to meet actual screening needs. Utility Model Content

[0005] The utility model aims to provide a multi-stage screening device for coal gangue, so as to solve the problem of low screening efficiency of the existing coal gangue screening device.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A multi-stage screening device for coal gangue, comprising an equipment box, a vibration drive and a multi-stage screening mechanism;

[0008] The multi-stage screening mechanism is arranged in the equipment box, the multi-stage screening mechanism is elastically connected to one side of the equipment box through an elastic connecting piece, and the multi-stage screening mechanism is located between the elastic connecting piece and the vibration drive;

[0009] The vibration drive is arranged on the other side of the equipment box to periodically push the multi-stage screening mechanism to squeeze the elastic connecting piece in the horizontal direction.

[0010] It is further defined that the equipment box is divided into a screening chamber and a driving chamber on the left and right, the multi-stage screening mechanism and the elastic connecting part are both located in the screening chamber, the fixed end of the vibration drive is arranged in the driving chamber, and the output end of the vibration drive extends to the screening chamber and contacts with the multi-stage screening mechanism.

[0011] It is further defined that a lower hopper connected to the outside is provided at the top of the screening chamber, the lower hopper is opposite to the top of the multi-stage screening mechanism, and a collection box is provided at the bottom of the screening chamber, the collection box is opposite to the bottom of the multi-stage screening mechanism.

[0012] It is further defined that the multi-stage screening mechanism comprises a first screening frame, a second screening frame and a third screening frame which are sequentially arranged from top to bottom, and three open support plates are sequentially arranged from top to bottom in the screening chamber, and the open support plates are horizontally arranged;

[0013] The first screening frame, the second screening frame and the third screening frame are respectively slidably connected to the top of the corresponding opening support plate, the elastic connecting member is located above the corresponding opening support plate and is arranged in the same direction as the corresponding opening support plate, and the first screening frame, the second screening frame and the third screening frame are all connected to the screening chamber through the corresponding elastic connecting member.

[0014] It is further defined that a screening opening is provided on the open support plate, and the bottom of the first screening frame, the bottom of the second screening frame and the bottom of the third screening frame are respectively opposite to the screening openings on the corresponding open support plates;

[0015] The opening support plate is provided with a limiting slide groove, and the limiting slide groove is arranged in the same direction as the opening support plate; the bottom of the first screening frame, the bottom of the second screening frame and the bottom of the third screening frame are all provided with limiting sliding blocks matching the limiting slide groove.

[0016] It is further defined that the vibration drive comprises a rotation drive mechanism, a transmission belt and three vibration components arranged in sequence from top to bottom, and the vibration components comprise a transmission wheel, a deflection member and a roller;

[0017] The pushing end of the deflection member is rotatably connected to the roller, and the driving end of the deflection member is coaxially arranged with the transmission wheel; the driving end of any deflection member and the corresponding transmission wheel are connected to the output end of the rotary drive mechanism, and the transmission wheel connected to the output end of the rotary drive mechanism is transmission-connected to the remaining transmission wheels through a transmission belt;

[0018] The driving ends of the remaining deflection members and the corresponding transmission wheels are rotatably connected to the driving chamber via a rotating shaft;

[0019] The first screening frame, the second screening frame and the third screening frame are all located on one side of the corresponding deflecting member.

[0020] It is further defined that a box door is provided on one side of the screening chamber, the box door is engaged with the equipment box, a sealed inner bed is provided on the box door, the sealed inner bed is located in the screening chamber, the elastic connecting parts are connected to the box door through a connecting block, and the connecting block is located on the outside of the sealed inner bed.

[0021] It is further defined that the outer side of the vibration drive is provided with a protective cover, and the protective cover is located in the drive chamber and communicated with the screening chamber.

[0022] It is further defined that the multi-stage screening equipment for coal gangue also includes a dust suction mechanism, the fixed end of which is arranged on the outside of the equipment box, the dust suction end of which extends through the driving chamber to the screening chamber, and the dust suction end of the dust suction mechanism is close to the lower hopper.

[0023] It is further defined that the dust collection mechanism includes a dust collection box, a filter, a dust collection fan, a dust collection pipe and a dust collection hopper, and the dust collection box is provided with an exhaust port;

[0024] The dust hopper is connected to the dust box through a dust pipe. The dust box is arranged outside the equipment box. The filter and the dust fan are both arranged in the dust box. The filter is close to the dust pipe, and the dust fan is close to the exhaust port.

[0025] Compared with the prior art, the beneficial effects of the utility model are:

[0026] 1. The utility model arranges a vibration drive on the side of the multi-stage screening mechanism to drive it to reciprocate in the horizontal direction, so that the coal gangue can be screened in multiple stages during the horizontal reciprocating motion of the multi-stage screening mechanism, thereby improving the screening efficiency and ensuring sufficient screening to meet the actual screening needs; at the same time, the elastic connecting piece is used to make the multi-stage screening mechanism automatically rebound after being compressed by the vibration drive, thereby avoiding the reciprocating motion of the multi-stage screening mechanism directly driven by the vibration drive, thereby reducing the structural strength requirements and reducing costs.

[0027] 2. The utility model can prevent the dust generated in the process of gangue screening from spilling out by setting up a dust suction mechanism, avoid environmental pollution, and meet actual operation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the main cross-sectional structure of the utility model;

[0029] Figure 2 For this utility model Figure 1 The enlarged structural diagram at A in the middle;

[0030] Figure 3 This is a schematic diagram of the cross-sectional structure of the equipment box of the utility model from top view;

[0031] In the figure: 10-equipment box; 11-lower hopper; 12-collection box; 13-clamping groove; 20-vibration drive; 21-rotation drive mechanism; 22-transmission belt; 23-transmission wheel; 24-deflection member; 25-roller; 26-rotating shaft; 27-protective cover; 30-multi-stage screening mechanism; 31-first screening frame; 32-second screening frame; 33-third screening frame; 34-limiting slider; 40-screening chamber; 41-driving chamber; 50-opening support plate; 51-limiting slide; 60-elastic connecting piece; 70-box door; 71-sealed inner paving; 72-connecting block; 73-clamping block; 80-dust suction mechanism; 81-dust suction box; 82-filter; 83-dust suction fan; 84-dust suction pipe; 85-dust suction hopper; 86-exhaust port. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] See also Figures 1 to 3 The utility model provides an embodiment: a coal gangue multi-stage screening device for screening crushed coal gangue, comprising an equipment box 10, a vibration drive 20 and a multi-stage screening mechanism 30, wherein the multi-stage screening mechanism 30 and the vibration drive 20 are both arranged in the equipment box 10, the vibration drive 20 is used to periodically drive the multi-stage screening mechanism 30 to move in the horizontal direction, and the multi-stage screening mechanism 30 is elastically connected to the equipment box 10 through an elastic connecting piece 60, so that the elastic connecting piece 60 is compressed after the vibration drive 20 pushes the multi-stage screening mechanism 30 to move horizontally, and when the vibration drive 20 completes the horizontal movement of the multi-stage screening mechanism 30 and moves away from the multi-stage screening mechanism 30, the multi-stage screening mechanism 30 rebounds under the elastic action of the elastic connecting piece 60, thereby realizing a left and right vibration of the multi-stage screening mechanism 30; in this way, the vibration drive 20 periodically drives the multi-stage screening mechanism 30 to compress the elastic connecting piece 60, thereby realizing the vibration screening of coal gangue by the multi-stage screening mechanism 30.

[0034] Specifically, in order to facilitate the installation and maintenance of the interior of the equipment box 10, the interior of the equipment box 10 is partitioned into a screening chamber 40 and a driving chamber 41. The multi-stage screening mechanism 30 is arranged in the screening chamber 40, and the vibration drive 20 is arranged in the driving chamber 41. One end of the elastic connecting member 60 is connected to the side wall of the screening chamber 40, and the other end of the elastic connecting member 60 is connected to the multi-stage screening mechanism 30. The fixed end of the vibration drive 20 is connected to the inner wall of the driving chamber 41, and the other end of the vibration drive 20 passes through the driving chamber 41 and extends to the screening chamber 40, thereby realizing the periodic push of the multi-stage screening mechanism 30.

[0035] To further explain, the receiving end of the equipment box 10 is connected to the dropping end of the gangue crushing equipment, or the crushed gangue is periodically added to the receiving end of the equipment box 10, and the crushed gangue is added after one screening is completed, and the cycle is repeated; wherein a lower hopper 11 is arranged on the top of the equipment box 10 as the receiving end, and the bottom of the lower hopper 11 is located in the screening chamber 40 and is directly opposite to the top of the multi-stage screening mechanism 30, so as to facilitate the multi-stage screening mechanism 30 to receive the material; after the multi-stage screening mechanism 30 screens, the gangue at the bottom layer is collected in the aggregate box 12 located at the bottom of the screening chamber 40, so as to facilitate opening the screening chamber 40 to collect the gangue screened in the multi-stage screening mechanism 30 and the gangue in the aggregate box 12 to complete the multi-stage screening of the gangue.

[0036] Among them, the multi-stage screening mechanism 30 includes multiple screen frames, and the number of screen frames is three for example. The aperture of the screen in each screen frame increases from top to bottom. The screen frames specifically include a first screening frame 31, a second screening frame 32 and a third screening frame 33 arranged from top to bottom. The top of the first screening frame 31 is opposite to the lower hopper 11, and the bottom of the third screening frame 33 is opposite to the aggregate box 12. The coal gangue falling from the lower hopper 11 is screened by the first screening frame 31, leaving the coal gangue with the smallest particle size. The remaining coal gangue falls on the second screening frame 32 and then passes through the second screening frame 32 for screening, leaving the coal gangue with a slightly larger particle size, and the remaining coal gangue falls on the third screening frame 33; the coal gangue with the largest particle size is screened by the third screening frame 33 and falls into the aggregate box 12, and finally the four-stage screening of the crushed coal gangue is completed to obtain coal gangue with four particle size ranges.

[0037] Specifically, three open support plates 50 are arranged in the screening chamber 40 for supporting the corresponding screen frames; the open support plates 50 are arranged in the horizontal direction, and the three open support plates 50 are arranged in sequence from top to bottom, each screen frame is slidably arranged with the corresponding open support plate 50, the open support plate 50 is arranged at the bottom of the corresponding screen frame and is slidably connected thereto, the front and rear sides of the open support plate 50 are connected to the inner wall of the screening chamber 40, and the screen frame moves back and forth left and right, the elastic connecting member 60 is connected to the left side of the screening chamber 40, the elastic connecting member 60 is located above the corresponding open support plate 50, and the right side of the open support plate 50 is also connected to the right side of the screening chamber 40 to ensure the connection stability of the open support plate 50.

[0038] In order to ensure that the coal gangue after screening by the screen frame can fall into the screen frame of the lower layer, a screening opening is opened in the middle of the open support plate 50, and the screening opening is arranged horizontally on the left and right sides, so that the open support plate 50 is composed of two open support plates or the open support plate 50 is an n-type structure, and the open end of the open support plate 50 is located on the right side, opposite to the vibration drive 20, while avoiding the open support plate 50 blocking the movement of the output end of the vibration drive 20.

[0039] A limiting groove 51 is provided on the opening support plate 50, and there are two limiting grooves 51. The two limiting grooves 51 are respectively arranged on the front and rear sides of the opening support plate 50, and limiting sliders 34 matching the limiting grooves 51 are arranged on the front and rear sides of the bottom of the screen frame, so that the screen frame can slide back and forth left and right in the limiting grooves 51 on the opening support plate 50 through the limiting sliders 43.

[0040] To further explain, the vibration drive 20 includes a rotation drive mechanism 21, a transmission belt 22 and a vibration component. The rotation drive mechanism 21 drives one of the vibration components to rotate, and drives the remaining two vibration components to rotate through the transmission belt 22, so that the three vibration components can rotate synchronously.

[0041] The vibration assembly includes a transmission wheel 23, a deflection member 24 and a roller 25. The deflection member 24 is a shuttle plate, one end of the deflection member 24 is a driving end, and the other end of the deflection member 24 is a pushing end; the rotary drive mechanism 21 is arranged in the driving chamber 41, and the output end of the rotary drive mechanism 21 is connected to the driving end of any deflection member 24, preferably the deflection member 24 opposite to the first screening frame 31, and the transmission wheel 23 is also arranged on the output end of the rotary drive mechanism 21, and the deflection member 24 is preferably located on the outside of the transmission wheel 23; the other two deflection members 24 are arranged on the second screening frame 31. The right side of the material frame 32 and the right side of the third screening material frame 33 correspond to the position, and at this time, the two deflection members 24 are rotatably connected to the side wall of the driving chamber 41 through the rotating shaft 26, and a transmission wheel 23 is arranged on the rotating shaft 26. The three transmission wheels 23 are located in the same vertical plane, so that the two lower transmission wheels 23 are connected to the top transmission wheel 23 through the transmission belt 22. In order to ensure that the intermediate transmission wheel and the transmission belt 22 are in stable contact for transmission, tensioning wheels can be optionally arranged on the upper and lower sides and the left and right sides of the intermediate transmission wheel, so that the transmission belt 22 is in stable contact with the intermediate transmission wheel.

[0042] In actual operation, after the pushing end of the deflection member 24 rotates from the driving chamber 41 to the screening chamber 40, the roller 25 contacts the right side of the corresponding screen frame and pushes the screen frame to the left during the rotation of the deflection member 24, while squeezing the elastic connecting member 60. Subsequently, as the deflection member 24 continues to rotate, it passes through the screening opening on the corresponding open support plate 50, and the squeezing of the corresponding screen frame by the roller 25 is gradually released until the roller 25 leaves the screen frame, and the screen frame moves to the right under the action of the corresponding elastic connecting member 60, thereby realizing the left and right vibration of the screen frame; this cycle is repeated to realize the screening of coal gangue by the screen frame.

[0043] In order to increase the safety of the vibration drive 20 , a protective cover 27 is selected to be provided in the driving chamber 41 . The protective cover 27 is sleeved on the outside of the vibration drive 20 , and the left side of the protective cover 27 is connected to the screening chamber 40 to avoid hindering the rotation of the deflection member 24 .

[0044] To further explain, after the screening of the material of the crushed coal gangue is completed, in order to take out the coal gangue after multi-stage screening for the next screening, a box door 70 is selected to be set on one side of the equipment box 10, and the screened coal gangue can be collected by opening the box door 70; at this time, it is preferred to set the box door 70 on the left side of the equipment box 10, and the box door 70 and the equipment box 10 can be selectively snap-connected up and down and left and right, that is, a snap-connecting groove 13 is set on the equipment box 10, and a snap-connecting block 73 matching the snap-connecting groove 13 is set on the inner side of the box door 70, and a handle is set on the outer side of the box door 70 for easy opening and closing of the box door 70.

[0045] Specifically, the left side of the elastic connector 60 is detachably connected to the inner wall of the box door 70 , and after opening the box door 70 , the multi-stage screening mechanism 30 is pulled to move to the left, and then the elastic connector 60 is disassembled to take out the multi-stage screening mechanism 30 and the aggregate box 12 .

[0046] A sealed inner mat 71 is provided on the inner wall of the box door 70 to prevent dust leakage; the box door 70 is detachably connected to the corresponding elastic connecting piece 60 via a connecting block 72, and the connecting block 72 is located on the outer side of the sealed inner mat 71 to ensure the integrity of the sealed inner mat 71.

[0047] Further explanation, in order to reduce the accumulation of dust in the equipment box 10, a dust suction mechanism 80 is selected to be set in the equipment box 10, and the fixed end of the dust suction mechanism 80 is set on the outside of the equipment box 10. The dust suction end of the dust suction mechanism 80 is set in the transmission drive chamber 41 and extends to the screening chamber 40 to filter out the dust in the screening chamber 40.

[0048] Specifically, the dust collection mechanism 80 includes a dust collection box 81, a filter 82, a dust collection fan 83, a dust collection pipe 84 and a dust collection hopper 85, wherein the dust collection box 81 is provided with an exhaust port 86, the dust collection box 81 is arranged on the outside of the equipment box 10, the dust collection hopper 85 is arranged in the screening chamber 40 near the lower hopper 11, the dust collection hopper 85 is connected with the dust collection box 81 through the dust collection pipe 84, the filter 82 is arranged in the dust collection box 81 and close to the end of the dust collection pipe 84, the dust collection fan 83 is arranged in the dust collection box 81 and connected with the exhaust port 86, the filter 82 is arranged between the dust collection pipe 84 and the dust collection fan 83, and is used to filter the dust in the screening chamber 40 through the filter 82 and then discharge it to avoid environmental pollution.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-stage screening device for coal gangue, characterized in that: It comprises an equipment box (10), a vibration drive (20) and a multi-stage screening mechanism (30); The multi-stage screening mechanism (30) is arranged in the equipment box (10), the multi-stage screening mechanism (30) is elastically connected to one side of the equipment box (10) through an elastic connecting member (60), and the multi-stage screening mechanism (30) is located between the elastic connecting member (60) and the vibration drive (20); The vibration drive (20) is arranged on the other side of the equipment box (10) and is used to periodically push the multi-stage screening mechanism (30) to press the elastic connecting member (60) in the horizontal direction.

2. The multi-stage screening equipment for coal gangue according to claim 1, characterized in that: The equipment box (10) is divided into a screening chamber (40) and a driving chamber (41) on the left and right sides. The multi-stage screening mechanism (30) and the elastic connecting member (60) are both located in the screening chamber (40). The fixed end of the vibration drive (20) is arranged in the driving chamber (41). The output end of the vibration drive (20) extends to the screening chamber (40) and contacts the multi-stage screening mechanism (30).

3. The multi-stage screening equipment for coal gangue according to claim 2, characterized in that: The top of the screening chamber (40) is provided with a lower hopper (11) connected to the outside, and the lower hopper (11) is opposite to the top of the multi-stage screening mechanism (30). The bottom of the screening chamber (40) is provided with a collection box (12), and the collection box (12) is opposite to the bottom of the multi-stage screening mechanism (30).

4. The multi-stage screening equipment for coal gangue according to claim 3, characterized in that: The multi-stage screening mechanism (30) comprises a first screening frame (31), a second screening frame (32) and a third screening frame (33) which are arranged in sequence from top to bottom, and three opening support plates (50) are arranged in sequence from top to bottom in the screening chamber (40), and the opening support plates (50) are arranged horizontally; The first screening frame (31), the second screening frame (32) and the third screening frame (33) are respectively slidably connected to the top of the corresponding opening support plate (50), the elastic connecting member (60) is located above the corresponding opening support plate (50) and is arranged in the same direction therewith, and the first screening frame (31), the second screening frame (32) and the third screening frame (33) are all connected to the screening chamber (40) via the corresponding elastic connecting member (60).

5. The multi-stage screening equipment for coal gangue according to claim 4, characterized in that: The open support plate (50) is provided with a screening opening, and the bottom of the first screening frame (31), the bottom of the second screening frame (32) and the bottom of the third screening frame (33) are respectively opposite to the screening openings on the corresponding open support plate (50); The opening support plate (50) is provided with a limiting slide groove (51), and the limiting slide groove (51) is arranged in the same direction as the opening support plate (50); the bottom of the first screening frame (31), the bottom of the second screening frame (32) and the bottom of the third screening frame (33) are all provided with limiting sliding blocks (34) matching the limiting slide groove (51).

6. The multi-stage screening equipment for coal gangue according to claim 5, characterized in that: The vibration drive (20) comprises a rotation drive mechanism (21), a transmission belt (22) and three vibration components arranged in sequence from top to bottom, wherein the vibration components comprise a transmission wheel (23), a deflection member (24) and a roller (25); The pushing end of the deflection member (24) is rotationally connected to the roller (25), and the driving end of the deflection member (24) is coaxially arranged with the transmission wheel (23); the driving end of any deflection member (24) and the corresponding transmission wheel (23) are connected to the output end of the rotation drive mechanism (21), and the transmission wheel (23) connected to the output end of the rotation drive mechanism (21) is transmission-connected to the remaining transmission wheels (23) via a transmission belt (22); The driving ends of the remaining deflection members (24) and the corresponding transmission wheels (23) are rotatably connected to the driving chamber (41) via a rotating shaft (26); The first screening frame (31), the second screening frame (32) and the third screening frame (33) are all located on one side of the corresponding deflection member (24).

7. The multi-stage screening equipment for coal gangue according to claim 6, characterized in that: A door (70) is provided on one side of the screening chamber (40), the door (70) is snap-connected with the equipment box (10), a sealed inner layer (71) is provided on the door (70), the sealed inner layer (71) is located in the screening chamber (40), and the elastic connecting parts (60) are connected to the door (70) via a connecting block (72), and the connecting block (72) is located on the outside of the sealed inner layer (71).

8. The multi-stage screening equipment for coal gangue according to claim 7, characterized in that: The outer side of the vibration drive (20) is provided with a protective cover (27), and the protective cover (27) is located in the drive chamber (41) and communicated with the screening chamber (40).

9. The multi-stage screening equipment for coal gangue according to claim 8, characterized in that: The coal gangue multi-stage screening equipment further comprises a dust suction mechanism (80), wherein a fixed end of the dust suction mechanism (80) is arranged outside the equipment box (10), the dust suction end of the dust suction mechanism (80) passes through the driving chamber (41) and extends to the screening chamber (40), and the dust suction end of the dust suction mechanism (80) is close to the lower hopper (11).

10. The multi-stage screening equipment for coal gangue according to claim 9, characterized in that: The dust collection mechanism (80) comprises a dust collection box (81), a filter screen (82), a dust collection fan (83), a dust collection pipe (84) and a dust collection hopper (85); the dust collection box (81) is provided with an exhaust port (86); The dust hopper (85) is connected to the dust box (81) through a dust pipe (84); the dust box (81) is arranged outside the equipment box (10); the filter (82) and the dust fan (83) are both arranged inside the dust box (81); the filter (82) is close to the dust pipe (84); and the dust fan (83) is close to an exhaust port (86).

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