CN211444298U

CN211444298U - Slag collecting device

Info

Publication number: CN211444298U
Application number: CN201922128777.7U
Authority: CN
Inventors: 刘李梦; 谢娟; 卢燕
Original assignee: Luonan Huanyayuan Copper Co ltd
Current assignee: Luonan Huanyayuan Copper Co ltd
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2020-09-08
Anticipated expiration: 2029-12-02

Abstract

The utility model discloses a slag collecting device relates to slag treatment facility technical field. The slag collection device comprises a slag collection chamber, a first conveyor belt, first baffles arranged on two sides of the conveyor belt, a dust chamber, a slag inlet arranged at the top end of the dust chamber, a dust hood arranged on the first conveyor belt and connected between the two first baffles, a feeding cavity for conveying slag formed between the dust hood and the first conveyor belt, and a dust collection pipe arranged on the dust hood and communicated with the feeding bin and the dust chamber; the clean room top is equipped with atomizer, is located the atomizer below in the clean room and is provided with the second conveyer belt, has seted up a plurality of holes of permeating water on the second conveyer belt, and the second conveyer belt below is provided with the waste water collecting vat, communicates between slag collecting chamber and the clean room, and the waste residue after the second conveyer belt will remove dust is carried to the slag collecting chamber in. The utility model has the advantages that the dust generated in the slag collecting process can not enter the environment and pollute the air.

Description

Slag collecting device

Technical Field

The utility model belongs to the technical field of slag treatment facility technique and specifically relates to a slag collection device is related to.

Background

In some industries such as metallurgy, thermal power generation, boiler plants and the like, coal plays a vital role. Coal, when burned, produces coal ash and coal slag, which require periodic disposal.

Chinese patent No. CN206782766U discloses a returned slag collecting device, which comprises a conveyor belt and a recovery trolley located below the output end of the conveyor belt; the conveying belt is positioned below the waste discharge port, first baffle plates are arranged on two sides of the body of the conveying belt, and an output end of the conveying belt is provided with a downward bent inclined edge; the recycling trolley comprises a walking trolley and a hopper arranged on the walking trolley through four stand columns, the cross section of the hopper is of a semi-elliptical structure, first idler wheels are arranged on the stand columns, two first sliding grooves are formed in positions corresponding to the bottom sides of the hopper, and the hopper is fixed on the hopper through the first idler wheels and the sliding grooves and can slide back and forth along the sliding grooves.

The prior art solutions in the above patents have the following drawbacks: because a large amount of coal ash is mixed in the cinder, the cinder on the conveyor belt can generate a part of dust in the transportation process, and when the cinder falls into the hopper from the inclined edge, more dust can be generated due to the impact of the cinder and the hopper, so that the returned cinder collecting device can generate a large amount of dust and pollute air in the use process.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exists, the utility model aims to provide a slag collecting device, its dust that has the slag and collect the in-process and produce can not get into environment, contaminated air's advantage.

The above object of the present invention can be achieved by the following technical solutions: a slag collecting device comprises a slag collecting chamber, a first conveyor belt and first baffles arranged on two sides of the conveyor belt respectively, and is characterized by further comprising a dust removing chamber, wherein a slag inlet is formed in the position, close to the output end of the first conveyor belt, of the dust removing chamber, one end of the first conveyor belt extends into the slag inlet, a dust removing cover is arranged on the first conveyor belt and connected between the two first baffles, a feeding cavity for conveying slag is formed between the dust removing cover and the first conveyor belt, a dust suction pipe communicated with the feeding cavity is arranged on the dust removing cover, an air suction fan is arranged on one side of the dust removing chamber, an air suction port of the air suction fan is communicated with the dust suction pipe, and an air outlet of the air suction fan is communicated with the dust removing chamber; the clean room top is equipped with the atomizer with the water pipe intercommunication, it is provided with the second conveyer belt to be located atomizer below level in the clean room, a plurality of holes of permeating water have been seted up on the second conveyer belt, it is provided with the waste water collecting vat to be located the second conveyer belt below in the clean room, communicate between slag collecting room and the clean room, the waste residue after the second conveyer belt will remove dust is carried to the slag collecting room in.

By adopting the technical scheme, after the slag is fed into the inlet of the first conveyor belt, a large amount of floating dust is generated in the feeding cavity, and the dust is sucked into the dust suction pipe and is fed into the dust removal chamber under the action of the air exhaust fan; when the slag of the first conveyor belt falls into the dust removing chamber, a large amount of dust is generated, and the dust fed in along with the dust suction pipe is rapidly removed under the action of water mist sprayed by the atomizing nozzle. And the slag after dust removal enters the slag collecting chamber through the second conveyor belt, and water generated by the atomizing nozzle penetrates through the slag after dust removal and enters the wastewater collecting tank from the water permeable holes. The design enables dust generated in the slag conveying and collecting processes to be treated in the dust removing chamber, so that the slag collecting device has the advantages that the dust generated in the slag collecting process cannot enter the environment and pollute the air.

The present invention may be further configured in a preferred embodiment as: the dust hood is provided with a jacket, a cavity is formed between the jacket and the dust hood, the dust hood is provided with a plurality of dust suction holes, and the dust suction pipes are communicated with the cavity.

Through adopting above-mentioned technical scheme, the effectual dust absorption area who increases the dust excluding hood for the dust that gets into in the feeding chamber all can be followed the dust absorption hole and got into in the cavity in the optional position of first conveyer belt, is sent into the clean room and handles, very big reinforcing the dust throughput in the feeding chamber.

The present invention may be further configured in a preferred embodiment as: the input end of the feeding cavity close to the first conveyor belt is hinged with a second baffle, and the second baffle completely covers the inlet of the feeding cavity.

Through adopting above-mentioned technical scheme, when the pan feeding end of first conveyer belt sent into the slag, the slag can promote the second baffle and rotate towards the income slag notch to normally get into the feeding intracavity. At the moment, the second baffle basically shields the inlet of the feeding cavity, so that dust is effectively reduced from entering the environment from the inlet of the feeding cavity, and the dust treatment effect in the feeding cavity is further enhanced.

The present invention may be further configured in a preferred embodiment as: the first conveyor belt is obliquely and downwards arranged towards the slag inlet.

By adopting the technical scheme, the slag on the first conveyor belt can be subjected to a downward sliding force which is parallel to the surface of the first conveyor belt and faces the slag inlet, and under the transmission action of the conveyor belt, the slag can enter the dust removing chamber more quickly and thoroughly, so that the blocking condition of the slag at the slag inlet can be effectively avoided; simultaneously, because the second baffle covers the entry in feeding chamber and first conveyer belt is gone into the slope of cinder notch and is set up downwards, is not influenced when second baffle is gone into cinder notch one end and is rotated towards, has guaranteed that the slag can normally be fed, and the second baffle is restricted by the conveyer belt when the entry in feeding chamber rotates, and the effectual dust that has prevented the feeding intracavity promotes the second baffle and gets into the environment. Therefore, the inclined arrangement of the first conveyor belt is beneficial to conveying the slag and more thoroughly treating the dust in the feeding cavity.

The present invention may be further configured in a preferred embodiment as: the intercommunication has the extrusion room between room is collected to clean room and slag, be equipped with the transport chamber between the room is collected to extrusion room and slag, the second conveyer belt stretches into the transport intracavity through the extrusion room, be located the extrusion conveyer belt that the second conveyer belt top was equipped with the slope and sets up in the extrusion room, the extrusion conveyer belt sets up downwards towards the slope of transport chamber, leave the clearance between extrusion conveyer belt minimum and the second conveyer belt.

Through adopting above-mentioned technical scheme, wet slag after the dust removal gets into the extrusion chamber under the effect of second conveyer belt, and the wet slag that gets into the extrusion chamber is located between second conveyer belt and the extrusion conveyer belt, because the extrusion conveyer belt sets up downwards towards the slope of transport chamber, and the extrusion force that wet slag received is bigger and bigger, has effectually detached a large amount of moisture that mix with in the wet slag, more is favorable to the subsequent processing of slag. The compacted wet slag has smaller volume, and after entering the slag collection chamber through the conveying cavity, the collection space of the slag collection chamber is effectively saved; meanwhile, the compacted wet slag can hardly generate dust, so that the method is more environment-friendly.

The present invention may be further configured in a preferred embodiment as: the top of second conveyer belt is located the entrance level in extrusion room and is provided with the brush roll of perpendicular to second conveyer belt direction of motion, the brush roll includes the pivot and locates a plurality of brush boards on the pivot perisporium, the brush board extends and each brush board is radial setting around the pivot along pivot generating line direction, be equipped with the first motor of drive brush roll along the opposite direction pivoted with the direction of rotation of second conveyer belt outside the dust chamber.

Through adopting above-mentioned technical scheme, under the combined action of brush roll and second conveyer belt, the wet slag that is located on the second conveyer belt all can be scraped into the extrusion chamber by the brush board, and effectual wet slag speed of sending out in having promoted the clean room has avoided the wet slag in clean room bottom to pile up the jam problem that probably causes.

The present invention may be further configured in a preferred embodiment as: be equipped with slag reducing mechanism between second conveyer belt and the income cinder notch in the dust removal chamber, slag reducing mechanism is including mutually supporting the first crushing roller and the second crushing roller that use and the equal level set up and drive first crushing roller and second crushing roller pivoted drive assembly in opposite directions.

Through adopting above-mentioned technical scheme, under drive assembly's effect, first crushing roller and second crushing roller rotate in opposite directions, make the slag that gets into the clean room all can be smashed to certain size, avoid some great metal infusible matters that exist in the slag to get into between second conveyer belt and the extrusion conveyer belt, because the too big belt that causes of volume damages.

The present invention may be further configured in a preferred embodiment as: the driving assembly comprises a first gear, a second gear and a second motor, the first gear is coaxially connected with the axis of the first crushing roller, the second gear is coaxially connected with the axis of the second crushing roller, the shaft lever is connected with the circle center of the first gear, the first gear is meshed with the second gear, and the first gear, the second gear and the second motor are all arranged outside the dust chamber.

By adopting the technical scheme, under the action of the motor, the first gear and the second gear rotate in opposite directions, so that the first crushing roller and the second crushing roller rotate in opposite directions to realize the crushing effect of the slag; the first gear, the second gear and the second motor which are arranged outside the dust removing chamber are prevented from being in direct contact with slag and water, and the dust removing device is safer and more durable.

To sum up, the utility model discloses a beneficial technological effect does:

1. the slag is basically in a closed state in the conveying process by arranging the dust hood and the second baffle and is difficult to enter the environment, and dust generated in the slag collecting process can not enter the environment and pollute the air by further designing the dust suction pipe and the atomizing spray head.

2. Through setting up slag reducing mechanism, effectual great slag is smashed, has further promoted the dust treatment effect that the slag produced, has got rid of a large amount of moisture that contains in the wet slag a little through setting up the extrusion conveyer belt, compresses tightly the dust on the slag simultaneously, the effectual dust removal effect that has promoted.

Drawings

FIG. 1 is a schematic view of the slag collection apparatus;

FIG. 2 is a perspective view taken along the line A-A in FIG. 1;

fig. 3 is a partially enlarged schematic view of a portion B in fig. 2.

Reference numerals: 1. a slag collection chamber; 2. a dust chamber; 3. a first conveyor belt; 4. a first baffle plate; 5. a slag inlet; 6. a dust hood; 7. a jacket; 8. a feed cavity; 9. a dust collection pipe; 10. an air exhaust fan; 11. an atomizing spray head; 12. a second conveyor belt; 13. water permeable holes; 14. a wastewater collection tank; 15. a dust collection hole; 16. a second baffle; 17. a pressing chamber; 18. extruding the conveyor belt; 19. a brush roll; 191. a rotating shaft; 192. brushing the board; 193. a first motor; 20. a slag crushing device; 201. a first crushing roller; 202. a second crushing roller; 21. a drive assembly; 211. a first gear; 212. a second gear; 213. a second motor; 22. a delivery lumen; 23. a third conveyor belt.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1 and 2, for the utility model discloses a slag collecting device, including clean room 2, slag collecting room 1, first conveyer belt 3 and weld respectively at the first baffle 4 of conveyer belt both sides, the income cinder notch 5 of 2 open-top rectangles in clean room, the one end of first conveyer belt 3 stretches into in the cinder notch 5. In order to remove dust generated when the slag is conveyed on the first conveyor belt 3, a dust hood 6 (refer to fig. 3) with an arc-shaped cross section is arranged on the first conveyor belt 3, the dust hood 6 is welded between the top ends of the two first baffles 4, a feeding cavity 8 for conveying the slag is formed between the dust hood 6 and the first conveyor belt 3, a dust suction pipe 9 communicated with the feeding cavity 8 is arranged on the dust hood 6, an air exhaust fan 10 is placed on one side of the dust chamber 2, an air suction port of the air exhaust fan 10 is communicated with the dust suction pipe 9, and an air outlet of the air exhaust fan 10 is communicated with the dust chamber 2. In order to effectively increase the dust absorption area of the dust hood 6, dust entering the feeding cavity 8 can enter a cavity from the dust absorption hole 15 at any position of the first conveyor belt 3, the dust hood 6 is welded with the jacket 7, a cavity is formed between the jacket 7 and the dust hood 6, the dust hood 6 is provided with a plurality of circular dust absorption holes 15, and the dust absorption pipe 9 is communicated with the cavity.

Referring to fig. 2, further, a second baffle 16 is hinged to the feeding cavity 8 near the input end of the first conveyor belt 3, and the second baffle 16 completely covers the inlet of the feeding cavity 8, so that when the slag is fed into the feeding end of the first conveyor belt 3, the slag can push the second baffle 16 to normally enter the feeding cavity 8, and the second baffle 16 can basically shield the inlet of the feeding cavity 8, thereby effectively reducing dust entering the environment from the inlet of the feeding cavity 8, and enhancing the dust treatment effect in the feeding cavity 8. Preferably, the first conveyor belt 3 can be obliquely arranged downwards towards the slag inlet 5, so that the second baffle 16 is not affected when rotating towards one end of the slag inlet 5, normal feeding of slag is ensured, the second baffle 16 is limited by the conveyor belt when rotating towards the inlet of the feeding cavity 8, and dust in the feeding cavity 8 is effectively prevented from pushing the second baffle 16 to enter the environment; meanwhile, the slag on the inclined first conveyor belt 3 is acted by a downward sliding force, so that the slag can enter the dust removal chamber 2 more conveniently.

When the slag of first conveyer belt 3 falls into clean room 2 in, can produce a large amount of dusts, in order to detach clean room 2 and come from the dust absorption dust pipe 9 dust of carrying, install evenly distributed and with eight atomizer 11 of water pipe intercommunication on 2 tops of clean room, lie in atomizer 11 below horizontal installation in clean room 2 and have second conveyer belt 12, a plurality of circular shape hole 13 of permeating water has been seted up on second conveyer belt 12, lie in second conveyer belt 12 below in clean room 2 and placed waste water collecting vat 14, communicate between slag collecting room 1 and the clean room 2, waste residue after second conveyer belt 12 will remove dust is carried to slag collecting room 1 in. Under the action of water mist sprayed by the atomizing nozzles 11, the dust is rapidly removed, the dedusted slag enters the slag collection chamber 1 through the second conveyor belt 12, and water generated by the atomizing nozzles 11 penetrates through the dedusted slag and enters the wastewater collection tank 14 from the water permeable holes 13 for recycling. In this embodiment, the dust outlet of the dust suction pipe 9 is arranged below the second conveyor belt 12, so that the rising air containing dust can be fully contacted with the next water, and the dust in the air can be collected more thoroughly.

In order to further improve the dust removal effect, remove a large amount of moisture contained in the slag and facilitate the collection of the slag, a squeezing chamber 17 is communicated between the dust removal chamber 2 and the slag collection chamber 1, a conveying chamber 22 is arranged between the squeezing chamber 17 and the slag collection chamber 1, the second conveyor belt 12 extends into the conveying chamber 22 through the squeezing chamber 17, a squeezing conveyor belt 18 is obliquely installed above the second conveyor belt 12 in the squeezing chamber 17, the squeezing conveyor belt 18 is obliquely and downwards placed towards the conveying chamber 22, and a gap is reserved between the lowest point of the squeezing conveyor belt 18 and the second conveyor belt 12. The wet slag after dust removal enters the extrusion chamber 17 under the action of the second conveyor belt 12, the wet slag entering the extrusion chamber 17 is positioned between the second conveyor belt 12 and the extrusion conveyor belt 18, and the extrusion conveyor belt 18 is obliquely arranged downwards towards the conveying cavity 22, so that the extrusion force applied to the wet slag is larger and larger, a large amount of moisture mixed in the wet slag is effectively removed, and the subsequent treatment of the slag is facilitated. The compacted wet slag has smaller volume and effectively saves the collection space of the slag collection chamber 1 after entering the slag collection chamber 1 through the conveying cavity 22; meanwhile, the compacted wet slag can hardly generate dust, so that the method is more environment-friendly. In the present embodiment, in order to completely separate the slag collection chamber 1 from the clean room 2 and prevent the wet slag from carrying a large amount of moisture into the slag collection chamber 1, the slag collection chamber 1 is disposed on one side of the clean room 2 in the axial direction of the second conveyor belt 12, the slag collection chamber 1 is disposed below the second conveyor belt 12, a third conveyor belt 23 is installed below the discharge end of the second conveyor belt 12 at the bottom in the conveying chamber 22, and one end of the third conveyor belt 23 extends into the slag collection chamber 1.

Referring to fig. 1 and 2, in order to enable wet slag on the second conveyor belt 12 to rapidly enter the extrusion chamber 17, effectively increase the sending speed of the wet slag in the dust chamber 2, and avoid the problem of blockage caused by accumulation of the wet slag at the bottom end of the dust chamber 2, a brush roller 19 perpendicular to the movement direction of the second conveyor belt 12 is horizontally installed at an inlet of the extrusion chamber 17 above the second conveyor belt 12, the brush roller 19 includes a rotating shaft 191 and six brush plates 192 located on the periphery of the rotating shaft 191, the brush plates 192 are welded to the rotating shaft 191 along the generatrix direction of the rotating shaft 191 and are radial, and a first motor 193 for driving the brush roller 19 to rotate along the direction opposite to the rotation direction of the second conveyor belt 12 is installed outside the dust chamber 2.

Because of some of the larger metal infusions present in the slag, belt damage may result if these larger volumes of solid impurities enter between the second conveyor belt 12 and the extrusion conveyor belt 18. Therefore, the slag crushing device 20 is installed between the second conveyor belt 12 and the slag inlet 5 in the dust chamber 2, the slag crushing device 20 comprises a first crushing roller 201 and a second crushing roller 202 which are mutually matched for use and are all horizontally arranged, and a driving assembly 21 for driving the first crushing roller 201 and the second crushing roller 202 to rotate oppositely, and the first crushing roller 201 and the second crushing roller 202 are both connected with the inner wall of the dust chamber 2 through shaft rods in a rotating mode. The driving assembly 21 comprises a first gear 211 coaxially welded with the axis of the first crushing roller 201, a second gear 212 coaxially connected with the axis of the second crushing roller 202, and a second motor 213 with a shaft rod welded with the center of the first gear 211, the first gear 211 and the second gear 212 are engaged with each other, and the first gear 211, the second gear 212 and the second motor 213 are all placed outside the dust chamber 2. To sum up, the utility model has the advantages that the dust generated in the slag collecting process can not enter the environment and pollute the air.

The implementation principle of the embodiment is as follows: when waste residue is collected, the first conveyor belt 3, the second conveyor belt 12, the extrusion conveyor belt 18, the third conveyor belt 23, the first motor 193, the second motor 213 and the first motor 193 are started, then, slag is fed into the inlet of the feeding cavity 8, and dust generated by the slag entering the feeding cavity 8 is fed into the dust removal chamber 2 through the dust suction pipe 9; the slag introduced into the dust chamber 2 is rapidly dusted by the water sprayed from the atomizing nozzle 11, and then introduced between the first crushing roller 201 and the second crushing roller 202 to be crushed. The crushed wet slag falls on the second conveyor belt 12, and is fed into the pressing chamber 17 under the combined action of the brush roller 19 and the second conveyor belt 12 before being fed to the brush roller 19. The wet slag fed into the pressing chamber 17 is subjected to the action of the pressing conveyor 18 to remove a large amount of water from the wet slag, the removed water enters the wastewater collection tank 14, and the wet slag after water removal then falls onto the third conveyor 23 to be fed into the slag collection chamber 1.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. The utility model provides a slag collecting device, includes slag collecting chamber (1), first conveyer belt (3) and sets up first baffle (4) in the conveyer belt both sides respectively, its characterized in that still includes clean room (2), the output that clean room (2) are close to first conveyer belt (3) is equipped with into cinder notch (5), the one end of first conveyer belt (3) stretches into in cinder notch (5), be provided with dust excluding hood (6) on first conveyer belt (3), dust excluding hood (6) are connected between two first baffle (4), form feed cavity (8) of carrying the slag between dust excluding hood (6) and first conveyer belt (3), be equipped with dust absorption pipe (9) with feed cavity (8) intercommunication on dust excluding hood (6), clean room (2) one side is equipped with air exhaust fan (10), the induction port and the dust absorption pipe (9) intercommunication of air exhaust fan (10), the air outlet of the air exhaust fan (10) is communicated with the dust chamber (2); dust removal room (2) top is equipped with atomizer (11) with the water pipe intercommunication, it is provided with second conveyer belt (12) to lie in atomizer (11) below level in dust removal room (2), a plurality of holes (13) of permeating water have been seted up on second conveyer belt (12), it is provided with waste water collecting tank (14) to lie in second conveyer belt (12) below in dust removal room (2), communicate between slag collection room (1) and dust removal room (2), waste residue after second conveyer belt (12) will remove dust is carried to slag collection room (1) in.

2. The slag collecting device according to claim 1, characterized in that the dust hood (6) is provided with a jacket (7), a cavity is formed between the jacket (7) and the dust hood (6), the dust hood (6) is provided with a plurality of dust suction holes (15), and the dust suction pipe (9) is communicated with the cavity.

3. Slag collection device according to claim 1, characterized in that the feed chamber (8) is hinged, close to the input end of the first conveyor belt (3), with a second baffle (16), the second baffle (16) completely covering the inlet of the feed chamber (8).

4. Slag collection device according to claim 3, characterized in that the first conveyor belt (3) is arranged obliquely downwards towards the slag inlet (5).

5. The slag collecting device according to claim 4, characterized in that a squeezing chamber (17) is communicated between the dust removing chamber (2) and the slag collecting chamber (1), a conveying chamber (22) is arranged between the squeezing chamber (17) and the slag collecting chamber (1), the second conveyor belt (12) extends into the conveying chamber (22) through the squeezing chamber (17), an obliquely arranged squeezing conveyor belt (18) is arranged above the second conveyor belt (12) in the squeezing chamber (17), the squeezing conveyor belt (18) is obliquely and downwardly arranged towards the conveying chamber (22), and a gap is reserved between the lowest point of the squeezing conveyor belt (18) and the second conveyor belt (12).

6. The slag collecting device according to claim 5, characterized in that a brush roller (19) perpendicular to the moving direction of the second conveyor belt (12) is horizontally arranged above the second conveyor belt (12) at the inlet of the squeezing chamber (17), the brush roller (19) comprises a rotating shaft (191) and a plurality of brush plates (192) arranged on the peripheral wall of the rotating shaft (191), the brush plates (192) extend along the generatrix direction of the rotating shaft (191) and the brush plates (192) are radially arranged around the rotating shaft (191), and a first motor (193) for driving the brush roller (19) to rotate along the direction opposite to the rotating direction of the second conveyor belt (12) is arranged outside the dust chamber (2).

7. The slag collection apparatus according to claim 6, wherein a slag crusher (20) is disposed in the dust chamber (2) between the second conveyor (12) and the slag inlet (5), and the slag crusher (20) comprises a first crushing roller (201) and a second crushing roller (202) which are horizontally disposed and cooperate with each other, and a driving assembly (21) for driving the first crushing roller (201) and the second crushing roller (202) to rotate in opposite directions.

8. The slag collecting device according to claim 7, wherein the driving assembly (21) comprises a first gear (211) coaxially connected with the axial center of the first crushing roller (201), a second gear (212) coaxially connected with the axial center of the second crushing roller (202), and a second motor (213) with a shaft connected with the center of the first gear (211), wherein the first gear (211) and the second gear (212) are engaged with each other, and the first gear (211), the second gear (212) and the second motor (213) are all arranged outside the dust chamber (2).