CN212446454U

CN212446454U - Self-cleaning slurry pressure filter for kitchen garbage

Info

Publication number: CN212446454U
Application number: CN202020898180.0U
Authority: CN
Inventors: 朱青
Original assignee: Guorun Environmental Engineering Changzhou Co Ltd
Current assignee: Guorun Environmental Engineering Changzhou Co Ltd
Priority date: 2020-05-25
Filing date: 2020-05-25
Publication date: 2021-02-02
Anticipated expiration: 2030-05-25

Abstract

The utility model relates to a self-cleaning slurry filter press for kitchen garbage, which comprises a frame, wherein a workbench is arranged on the frame, a feeding chamber, a separating chamber and a discharging chamber which are sequentially communicated are arranged on the workbench, a feeding hole is arranged at the top of the feeding chamber, a discharging chamber communicated with the separating chamber is also arranged at the bottom of the separating chamber on the workbench, a screening net cylinder is rotatably connected in the separating chamber, and the two axial ends of the screening net cylinder are arranged to be open and respectively communicated with the feeding chamber and the discharging chamber; stirring shafts are arranged in the feeding chamber and the separation chamber in a penetrating manner, the stirring shafts are coaxially arranged in the screening net barrel, and feeding screws are arranged on the outer side wall of the stirring shaft in the feeding chamber; the workbench is also provided with a driving motor for driving the stirring shaft to rotate; still be provided with a plurality of blowback shower nozzles along a screening net section of thick bamboo axial evenly distributed in the both sides of screening net section of thick bamboo axial in the separator, the blowback shower nozzle is linked together with the outside air-blast device of separator, the utility model discloses have and carry out self-cleaning's effect to a screening net section of thick bamboo.

Description

Self-cleaning slurry pressure filter for kitchen garbage

Technical Field

The utility model belongs to the technical field of kitchen garbage processing equipment's technique and specifically relates to a kitchen garbage is with automatically cleaning thick liquid pressure filter is related to.

Background

The kitchen waste refers to perishable organic waste such as discarded fruit and vegetable and food leftovers, melon and fruit peels in daily life of a family, has the characteristics of high water content, high salt content, high oil content and the like, and is not suitable for direct landfill or incineration disposal. Therefore, a pretreatment process for removing the filtrate from the kitchen waste is required to separate the filtrate from the kitchen waste to obtain dry kitchen waste residues, which facilitates the next treatment process.

Chinese patent No. CN107497583A discloses a kitchen waste crushing device capable of separating solid and liquid, which belongs to the field of domestic waste recycling treatment and comprises a shell, a crushing rod, a discharge port, a cover plate, a base and a liquid discharge pipe; the shell is horizontally arranged above the base, and a crushing cavity and a sewage cavity are arranged in the shell; the base is arranged under the shell, and the shell is fixedly connected with the base through the supporting column; the top of the shell is provided with a feeding device, and the left end of the shell is provided with a cover plate; the rotating shaft is horizontally arranged on the central line of the crushing cavity, and the left end of the rotating shaft penetrates through the cover plate through a bearing and is connected with the transmission device; the feeding tank is fixedly arranged at the top of the left side of the shell, the crushing motor is arranged in the feeding tank through a fixing frame, and a guide cone is fixedly arranged at the top end of the crushing motor;

in the above scheme, the crushing motor arranged in the feeding device provides power for the rotation of the crushing rotating shaft, and the crushing rotating shaft drives the rotary blade and the fixed blade to rotate relatively, so that the kitchen garbage is pre-crushed. Liquid in the kitchen waste is filtered by arranging the filter screen below the rotating shaft, and the dry residue of the kitchen waste is discharged from the discharge port, so that solid-liquid separation of the kitchen waste is realized; however, in the above scheme, in the long-term use process, the filter screen is blocked due to the impurities with small particle sizes in the kitchen waste, so that the filtrate in the kitchen waste cannot be filtered sufficiently, and the dehydration treatment effect of the kitchen waste is reduced. Therefore, there is a need for a solid-liquid separation apparatus for kitchen waste, which can self-clean the filter screen, to improve the solid-liquid separation effect of the kitchen waste.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a kitchen garbage solid-liquid separation machine which can self-clean the filter screen.

The above technical purpose of the present invention can be achieved by the following technical solutions: a self-cleaning slurry filter press for kitchen waste comprises a rack, wherein a workbench is arranged on the rack, a feeding chamber, a separating chamber and a discharging chamber which are sequentially communicated are arranged on the workbench, a feeding hole is formed in the top of the feeding chamber, a discharging chamber communicated with the separating chamber is further arranged at the bottom of the separating chamber on the workbench, a screening net cylinder is further rotatably connected in the separating chamber, and two axial ends of the screening net cylinder are provided with openings and are respectively communicated with the feeding chamber and the discharging chamber; stirring shafts are further arranged in the feeding chamber and the separating chamber in a penetrating manner, the stirring shafts are coaxially arranged in the screening net barrel, and a feeding screw is further arranged on the outer side wall of the stirring shaft in the feeding chamber; the workbench is also provided with a driving motor for driving the stirring shaft to rotate; and a plurality of back-blowing nozzles which are uniformly distributed along the axial direction of the screening net barrel are also arranged on the two axial sides of the screening net barrel in the separation chamber, and the back-blowing nozzles are communicated with a blowing device outside the separation chamber.

By adopting the technical scheme, kitchen waste is added from the feeding port and moves into the separation chamber under the pushing of the feeding screw, and the kitchen waste is dehydrated in the separation chamber; after the primary solid-liquid separation treatment process of the kitchen waste is finished, starting the equipment to idle the equipment; then start the air-blast device, the air-blast device carries high-pressure draught to the blowback shower nozzle, and the blowback shower nozzle sprays high-pressure draught to screening net section of thick bamboo outer wall to this blows off the kitchen garbage residue that adheres to on the screening net section of thick bamboo inner wall, prevents that these kitchen garbage residues from blockking up the screening net section of thick bamboo, causes the influence to the dehydration process of next time.

The present invention may be further configured in a preferred embodiment as: horizontal gas guide pipes parallel to the axial direction of the screening net cylinder are arranged in the separation chamber in a sliding and penetrating mode on two axial sides of the screening net cylinder; the horizontal air guide pipes are communicated with a plurality of arc-shaped air guide pipes which are uniformly distributed along the axial direction of the screening net cylinder; the back-blowing spray head is communicated with one side of the arc-shaped air duct close to the screening net barrel; the horizontal air guide pipe is arranged on the workbench and is connected with a movable rod of the driving cylinder along the axial direction of the screening net barrel, one end of the horizontal air guide pipe, which is positioned outside the separation chamber, is also communicated with a blowing device.

Through adopting above-mentioned technical scheme, drive actuating cylinder and drive horizontal air duct along the axial reciprocating motion of screening net section of thick bamboo, horizontal air duct drives the blowback shower nozzle and moves at screening net section of thick bamboo axial, can fully get rid of the surplus rubbish residue in kitchen on the screening net section of thick bamboo lateral wall like this.

The present invention may be further configured in a preferred embodiment as: the screening net cylinder is arranged in an installation pipe, the installation pipe penetrates through the separation chamber and is rotatably connected with the separation chamber, and one end, close to the feeding chamber, of the installation pipe is rotatably connected with the feeding chamber; the outer side wall of the mounting pipe between the feeding chamber and the separating chamber is also provided with a gear ring, and the workbench is also provided with a gear driving mechanism which is matched with the gear ring to drive the mounting pipe to rotate; the side wall of the installation pipe in the separation chamber is arranged into a grid.

By adopting the technical scheme, the gear driving mechanism is matched with the gear ring to drive the mounting pipe to rotate, and the mounting pipe drives the screening net cylinder to rotate; the side wall of the installation pipe positioned in the separation chamber is provided with a grid, so that the filtrate in the kitchen garbage can be conveniently discharged.

The present invention may be further configured in a preferred embodiment as: and a plurality of flow guide scrapers are further arranged on the outer side wall of the stirring shaft in the separation chamber.

Through adopting above-mentioned technical scheme, the water conservancy diversion scraper blade plays the stirring and the transport effect to the rubbish from cooking, when driving the rubbish from cooking and carrying out the rotation dehydration, still drives the rubbish from cooking and removes to the discharge chamber direction, and finally the rubbish from cooking is dry the sediment and is discharged from the discharge chamber.

The present invention may be further configured in a preferred embodiment as: the back flushing nozzle is obliquely arranged towards the direction of the discharging chamber.

Through adopting above-mentioned technical scheme, not only can reduce the volume that kitchen garbage filtrating enters into the blowback shower nozzle, the blowback shower nozzle sprays high-pressure draught to the discharge chamber direction moreover, can make like this from the kitchen garbage residue that drops on the screening net section of thick bamboo inner wall to the discharge chamber direction removal, is convenient for arrange the sediment.

The present invention may be further configured in a preferred embodiment as: the air blowing device comprises an air inlet pipe, heat exchange equipment communicated with the air inlet pipe, an air blower communicated with the heat exchange equipment and an exhaust pipe communicated with the air blower; one end of the air inlet pipe, which is far away from the heat exchange equipment, is communicated with two air inlet branch pipes, and the two air inlet branch pipes are respectively communicated with horizontal air guide pipes on two sides of the screening net cylinder; one end of the exhaust pipe, which is far away from the air blower, is communicated with a first exhaust branch pipe and a second exhaust branch pipe, the first exhaust branch pipe is communicated with the discharge chamber, and the second exhaust branch pipe is communicated with the separation chamber.

By adopting the technical scheme, the heat exchange equipment heats air, then the heated air is conveyed to the two horizontal air guide pipes through the air inlet pipe and the two air inlet branch pipes, and finally the heated air is sprayed to the outer wall of the screening net barrel from the back flushing sprayer; the hot-air can be weathered the moist rubbish residue from cooking on the screening net section of thick bamboo, reduces the adhesion force of rubbish residue from cooking to the screening net section of thick bamboo, and the rubbish residue from cooking of being convenient for drops, improves abluent effect. Hot air entering the separation chamber and the discharge chamber is sucked into the blowing device again by the two air draft branch pipes for heating, and then is conveyed into the horizontal air duct by the air inlet pipe for utilization, so that the cyclic utilization of hot air is realized; not only keeps the temperature of hot air, but also reduces the emission of toxic and harmful gases.

The present invention may be further configured in a preferred embodiment as: and an air treatment device is communicated between the blower and the exhaust pipe.

By adopting the technical scheme, the air treatment equipment can carry out dehumidification, filtration, purification and other treatments on sucked hot air, can keep the dryness of hot air and improve the cleaning effect on the screening net cylinder; and toxic and harmful components in the gas can be filtered.

The present invention may be further configured in a preferred embodiment as: one end of the separation chamber, which is close to the discharge chamber, is connected with a partition plate, and the separation chamber is separated from the discharge chamber through the partition plate; the partition plate is provided with a mounting hole, and one end of the mounting pipe close to the discharge chamber is rotatably connected in the mounting hole; the edge of the top of the mounting hole in the discharging chamber is also provided with a guide plate, and one end of the guide plate, which is far away from the mounting hole, is obliquely arranged downwards; the first air draft branch pipe is communicated with the top of the discharging chamber.

By adopting the technical scheme, the dry kitchen waste residues are pushed by the flow guide scraper plate and finally enter the discharge chamber, and under the action of centrifugal force, the dry kitchen waste residues can be scattered around because of no restriction of the screening net barrel after entering the discharge chamber; the deflector can prevent that kitchen garbage from flying to the top of ejection of compact room, prevents that kitchen garbage from being inhaled in the air-blast device by first convulsions branch pipe.

The present invention may be further configured in a preferred embodiment as: a filter screen is further arranged in the first air draft branch pipe at the position communicated with the discharge chamber, and an opening of the communicated position of the second air draft branch pipe and the separation chamber is arranged downwards.

By adopting the technical scheme, the filter screen can prevent some light kitchen garbage dry residues from being sucked into the blowing device by the first air draft branch pipe, and the light kitchen garbage dry residues can reduce the heat exchange efficiency of the heat exchange equipment when entering the heat exchange equipment.

To sum up, the utility model discloses a following at least one useful technological effect:

1. through the arrangement of the air blowing device and the back blowing spray head, the effect of cleaning the screening net barrel can be achieved;

2. through the arrangement of the driving cylinder, the horizontal air guide pipe and the arc-shaped air guide pipe, the effect of fully blowing off kitchen waste residues on the inner wall of the screening net cylinder can be achieved;

3. the back-blowing nozzle inclines towards the direction of the discharging chamber and the flow guide scraper plate is arranged, so that the effect of pushing the blown-off dry kitchen waste residues towards the direction of the discharging chamber can be achieved;

4. through the arrangement of the guide plate and the filter screen, the effect of preventing the dry kitchen waste residues from being sucked into the air blowing device can be achieved.

Drawings

FIG. 1 is a schematic view showing the overall structure of the self-cleaning solid-liquid separator for kitchen waste;

FIG. 2 is a schematic view of the internal structure of the separation chamber of the self-cleaning solid-liquid separator for kitchen waste;

FIG. 3 is a schematic sectional view showing the overall structure of the self-cleaning solid-liquid separator for kitchen waste.

In the figure, 1, a frame; 2. a work table; 3. a feed chamber; 4. a separation chamber; 5. a discharge chamber; 6. a liquid outlet chamber; 7. a stirring shaft; 71. a feed screw; 72. a diversion scraper blade; 8. screening the net barrel; 9. installing a pipe; 10. a ring gear; 11. a partition plate; 12. mounting holes; 121. a guide plate; 13. an air inlet branch pipe; 131. an air inlet pipe; 14. a heat exchange device; 15. a blower; 16. an air treatment device; 17. an exhaust pipe; 171. a first exhaust branch pipe; 172. a second air draft branch pipe; 18. a filter screen; 19. a driving cylinder; 20. a horizontal airway tube; 21. an arc-shaped air duct; 22. and a blowback nozzle.

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 surplus rubbish in kitchen is with automatically cleaning thick liquid pressure filter, including frame 1, be provided with workstation 2 in the frame 1, be provided with feed chamber 3, separation chamber 4 and the play feed chamber 5 that communicates in proper order on the workstation 2, the feed inlet has been seted up at the 3 tops of feed chamber, still is provided with the play liquid chamber 6 that is linked together with separation chamber 4 in the bottom of separation chamber 4 on the workstation 2. A mounting pipe 9 penetrates through the separating chamber 4, the mounting pipe 9 is rotatably connected with the separating chamber 4, and one end, close to the feeding chamber 3, of the mounting pipe 9 is rotatably connected with the feeding chamber 3; a screening net cylinder 8 is fixed inside the separation chamber 4 through the mounting pipe 9, and the side wall of the mounting pipe 9 in the separation chamber 4 is provided with a grid; the outer side wall of the mounting pipe 9 between the feeding chamber 3 and the separating chamber 4 is also fixed with a gear ring 10, and the workbench 2 is also provided with a gear driving mechanism which is matched with the gear ring 10 to drive the mounting pipe 9 to rotate.

Referring to fig. 2 and 3, a stirring shaft 7 penetrates through the feeding chamber 3 and the separating chamber 4, a shaft seat is further arranged on the side, away from the feeding chamber 3, of the discharging chamber 5 on the rack 1, and one end, close to the discharging chamber 5, of the stirring shaft 7 is rotatably connected with the shaft seat; and a driving motor for driving the stirring shaft 7 to rotate is further installed at one end, close to the feeding chamber 3, of the machine frame 1. The outer side wall of the stirring shaft 7 in the feeding chamber 3 is connected with a feeding screw 71 which pushes kitchen garbage to move into the separation chamber 4; the outer side wall of the stirring shaft 7 positioned in the separation chamber 4 is connected with a plurality of flow guide scrapers 72, the flow guide scrapers 72 can drive the kitchen waste to rotate in the screening net barrel 8, and liquid in the kitchen waste is filtered by using centrifugal force; the diversion scraper 72 also plays a role in conveying and pushing the dry kitchen waste residues into the discharging chamber 5.

Referring to fig. 2, horizontal air ducts 20 axially parallel to the screening net cylinder 8 are slidably arranged in the separation chamber 4 at two axial sides of the screening net cylinder 8, and the horizontal air ducts 20 are located in the separation chamber 4 and are also communicated with a plurality of arc-shaped air ducts 21. Arc air duct 21 is along 8 axial evenly distributed of screening net section of thick bamboo, and the one side intercommunication that is close to screening net section of thick bamboo 8 on the arc air duct 21 has a plurality of blowback shower nozzles 22, and blowback shower nozzle 22 sets up towards 5 direction slopes of ejection of compact room. In the axial direction of the screening net cylinder 8, two driving cylinders 19 are further installed on one side, close to the feeding chamber 3, of the separation chamber 4 on the workbench 2, piston rods of the two driving cylinders 19 are fixedly connected with one end, located outside the separation chamber 4, of the horizontal air guide pipe 20, and the two driving cylinders 19 respectively drive the two horizontal air guide pipes 20 to move along the axial direction of the screening net cylinder 8.

Referring to fig. 1, a blower device is further arranged on the frame 1 below the workbench 2, and the blower device comprises an air inlet pipe 131, a heat exchange device 14 communicated with the air inlet pipe 131, an air blower 15 communicated with the heat exchange device 14, an air treatment device 16 communicated with the air blower 15, and an exhaust pipe 17 communicated with the air treatment device 16; one end of the air inlet pipe 131, which is far away from the heat exchange device 14, is communicated with two air inlet branch pipes 13, and the two air inlet branch pipes 13 are respectively communicated with the horizontal air ducts 20 on the two sides of the screening net cylinder 8; one end of the exhaust pipe 17, which is far away from the blower 15, is communicated with a first exhaust branch pipe 171 and a second exhaust branch pipe 172, the first exhaust branch pipe 171 is communicated with the top of the discharge chamber 5, and the second exhaust branch pipe 172 is communicated with the separation chamber 4 and is downward in opening at the communicated part.

Referring to fig. 2 and 3, a partition plate 11 is connected to one end of the separation chamber 4 close to the discharging chamber 5, and the separation chamber 4 is separated from the discharging chamber 5 by the partition plate 11; the partition plate 11 is provided with a mounting hole 12, and one end of the mounting pipe 9 close to the discharging chamber 5 is rotatably connected in the mounting hole 12; the edge of the top of the mounting hole 12 in the discharging chamber 5 is also provided with a guide plate 121, and one end of the guide plate 121 far away from the mounting hole 12 is arranged in a downward inclined manner; a filter screen 18 is arranged in the first air draft branch pipe 171 and communicated with the discharging chamber 5; this prevents the dry kitchen waste from being sucked into the blower unit by the first branch air draft tube 171, causing the blower unit to be clogged and affecting the heating efficiency of the heat exchange apparatus 14.

The implementation principle of the embodiment is as follows: kitchen waste is added from the feeding port, the kitchen waste is pushed by the feeding screw 71 to move into the separation chamber 4, and the kitchen waste is pushed and dehydrated in the separation chamber 4. After the primary dehydration treatment process of the kitchen waste is finished, starting the equipment to idle the equipment; then start the air-blast device, the air-blast device carries high-pressure draught to in the blowback shower nozzle 22, and blowback shower nozzle 22 sprays high-pressure draught to the outer wall of screening net section of thick bamboo 8 to this blows off the adnexed kitchen garbage residue on the inner wall of screening net section of thick bamboo 8, prevents that these kitchen garbage residues from blockking up screening net section of thick bamboo 8, causes the influence to the dehydration process of next time. In the cleaning process, the driving cylinder 19 drives the blowback nozzle 22 to move along the axial direction of the screening net cylinder 8, and the mounting pipe 9 drives the screening net cylinder 8 to rotate, so that the screening net cylinder 8 can be better cleaned.

The embodiment of this specific implementation mode is the preferred embodiment of the present invention, not limit according to this the utility model discloses a protection scope, so: all equivalent changes made according to the structure, shape and principle of the utility model are covered within the protection scope of the utility model.

Claims

1. The utility model provides a kitchen is automatically cleaning thick liquid pressure filter for rubbish, includes frame (1), be provided with workstation (2) in frame (1), be provided with feed chamber (3), separation chamber (4) and play feed chamber (5) that communicate in proper order on workstation (2), the feed inlet has been seted up at feed chamber (3) top, still be provided with in the bottom of separation chamber (4) on workstation (2) with play liquid room (6) that separation chamber (4) are linked together, its characterized in that: a screening net cylinder (8) is further rotatably connected in the separation chamber (4), and two axial ends of the screening net cylinder (8) are provided with openings and are respectively communicated with the feeding chamber (3) and the discharging chamber (5); stirring shafts (7) are further arranged in the feeding chamber (3) and the separating chamber (4) in a penetrating manner, the stirring shafts (7) are coaxially arranged in the screening net barrel (8), and feeding screws (71) are further arranged on the outer side wall of the stirring shafts (7) in the feeding chamber (3); the workbench (2) is also provided with a driving motor for driving the stirring shaft (7) to rotate; and a plurality of back-blowing nozzles (22) which are uniformly distributed along the axial direction of the screening net barrel (8) are further arranged on two axial sides of the screening net barrel (8) in the separation chamber (4), and the back-blowing nozzles (22) are communicated with a blowing device outside the separation chamber (4).

2. The filter press of claim 1, wherein the filter press comprises: horizontal air ducts (20) which are parallel to the axial direction of the screening net cylinder (8) are arranged in the separation chamber (4) in a sliding and penetrating mode on two axial sides of the screening net cylinder (8); the horizontal air guide pipes (20) are communicated with a plurality of arc-shaped air guide pipes (21), and the arc-shaped air guide pipes (21) are uniformly distributed along the axial direction of the screening net cylinder (8); the blowback spray head (22) is communicated with one side of the arc-shaped air duct (21) close to the screening net barrel (8); the horizontal air duct (20) is arranged on the workbench (2) and moves along the axial direction of the screening net cylinder (8), the end, located outside the separation chamber (4), of the horizontal air duct (20) is connected with a movable rod of the driving cylinder (19), and the end, located outside the separation chamber (4), of the horizontal air duct (20) is communicated with a blowing device.

3. The filter press of claim 2, wherein the filter press comprises: the screening net barrel (8) is arranged in an installation pipe (9), the installation pipe (9) penetrates through the separation chamber (4) and is rotatably connected with the separation chamber (4), and one end, close to the feeding chamber (3), of the installation pipe (9) is rotatably connected with the feeding chamber (3); the outer side wall of the mounting pipe (9) between the feeding chamber (3) and the separating chamber (4) is also provided with a gear ring (10), and the workbench (2) is also provided with a gear driving mechanism which is matched with the gear ring (10) to drive the mounting pipe (9) to rotate; the side wall of the installation pipe (9) in the separation chamber (4) is arranged into a grid.

4. The filter press of claim 3, wherein the filter press comprises: the outer side wall of the stirring shaft (7) in the separation chamber (4) is also provided with a plurality of flow guide scrapers (72).

5. The filter press of claim 4, wherein the filter press comprises: the blowback spray head (22) is obliquely arranged towards the direction of the discharging chamber (5).

6. The filter press of claim 5, wherein the filter press comprises: the air blowing device comprises an air inlet pipe (131), heat exchange equipment (14) communicated with the air inlet pipe (131), an air blower (15) communicated with the heat exchange equipment (14) and an exhaust pipe (17) communicated with the air blower (15); one end of the air inlet pipe (131) far away from the heat exchange equipment (14) is communicated with two air inlet branch pipes (13), and the two air inlet branch pipes (13) are respectively communicated with horizontal air guide pipes (20) on two sides of the screening net cylinder (8); one end of the exhaust pipe (17) far away from the air blower (15) is communicated with a first exhaust branch pipe (171) and a second exhaust branch pipe (172), the first exhaust branch pipe (171) is communicated with the discharge chamber (5), and the second exhaust branch pipe (172) is communicated with the separation chamber (4).

7. The filter press of claim 6, wherein the filter press comprises: and an air treatment device (16) is communicated between the blower (15) and the exhaust pipe (17).

8. The filter press of claim 7, wherein the filter press comprises: one end of the separation chamber (4) close to the discharge chamber (5) is connected with a partition plate (11), and the separation chamber (4) is separated from the discharge chamber (5) through the partition plate (11); a mounting hole (12) is formed in the partition plate (11), and one end, close to the discharging chamber (5), of the mounting pipe (9) is rotatably connected into the mounting hole (12); the edge of the top of the mounting hole (12) in the discharging chamber (5) is also provided with a guide plate (121), and one end of the guide plate (121) far away from the mounting hole (12) is arranged in a downward inclined manner; the first air draft branch pipe (171) is communicated with the top of the discharging chamber (5).

9. The filter press of claim 8, wherein the filter press comprises: a filter screen (18) is further arranged in the first air draft branch pipe (171) at the position communicated with the discharging chamber (5), and an opening of the communicated position of the second air draft branch pipe (172) and the separating chamber (4) is downward arranged.