CN220283885U - Sludge low-temperature belt drier - Google Patents

Abstract

The utility model belongs to the technical field of sludge treatment and specifically relates to a sludge low temperature area desiccator is related to, it is including setting up the organism in the baking house, be provided with the division board in the organism, the division board is divided into drying chamber and clean room with organism inner chamber, organism is close to drying chamber one side and is provided with the circulating fan who is used for introducing the drying chamber with gas, be provided with the net belt assembly that supplies the mud to place in the drying chamber, division board is kept away from net belt assembly one end and is provided with the gas passage that is used for intercommunication drying chamber and clean room, the gas passage inner wall is provided with plate filter, organism is close to clean room one side and is provided with the condenser that is used for giving gas heating, the gas outlet and the air inlet intercommunication of circulating fan of condenser, be provided with filter gas's dust collector in the clean room, the condenser is close to dust collector one side and is provided with dehydrating unit. The dust removal effect of desiccator can be optimized to this application.

Description

Sludge low-temperature belt drier

Technical Field

The application relates to the technical field of sludge treatment, in particular to a sludge low-temperature belt dryer.

Background

The desiccator is mainly used for dehydrating sludge, and removing most of water content from the sludge through the actions of infiltration or evaporation and the like. The desiccator is usually arranged in a drying room, and the inner wall of the drying room adopts a heat insulation material, so that the temperature of gas in the drying room is higher than the temperature outside the drying room, thereby meeting the temperature required by the desiccator for drying sludge. For example, in order to ensure a better drying effect, the air speed of the air source heat pump belt dryer is increased under the condition of a certain air supply temperature, so that the drying time can be shortened. However, excessive wind speed can cause a large amount of dust, dust can adhere to the surfaces of the fin type evaporator and the fin type condenser along with the flow of gas, the air passage between fins is blocked, the heat exchange effect is affected, and high-temperature alarm shutdown of a unit can be caused when the air flow is severe.

If the traditional plate filter, bag filter or pulse filter cartridge dust collector and other devices are adopted, the small dust interception effect is limited. And the gas with higher humidity is easy to form dew on the surface of the condenser, and forms moist dust or sludge together with dust intercepted on the surface of the condenser to block the condenser, so that the dust removal effect of the drier on the gas is poor, and the situation needs to be improved.

Disclosure of Invention

In order to optimize the dust removal effect of the desiccator, the application provides a sludge low-temperature belt desiccator.

The application provides a mud low temperature belt desiccator adopts following technical scheme:

the utility model provides a mud low temperature belt desiccator, includes the organism that sets up in the baking house, be provided with the division board in the organism, the division board will organism inner chamber divide into drying chamber and clean room, the organism is close to drying chamber one side is provided with and is used for introducing gas circulating fan in the drying chamber, be provided with in the drying chamber and supply the net belt subassembly that mud was placed, the division board is kept away from net belt subassembly one end is provided with and is used for the intercommunication drying chamber with the gas passage of clean room, the gas passage inner wall is provided with plate filter, the organism is close to clean room one side is provided with the condenser that is used for giving gas heating, the gas outlet of condenser with circulating fan's air inlet intercommunication, be provided with filter gas's dust collector in the clean room, the condenser is close to dust collector one side is provided with dehydrating unit.

By adopting the technical scheme, the machine body is arranged in the drying room, and the temperature in the drying room is higher than the outside temperature, so that the heat preservation effect is achieved. The separator divides the inner cavity of the machine body into a drying chamber and a purifying chamber, the circulating fan sucks hot gas heated by the condenser into the drying chamber, the hot gas dries sludge on the mesh belt assembly, and part of dust is generated in the process of heating and dehydrating the sludge; the hot gas and the dust are mixed to form mixed gas, the mixed gas enters a purifying chamber after filtering out large-particle dust through a plate filter, and then small-particle dust is filtered out through a dust removing device in the purifying chamber; after the purified gas flows to a dehumidifying device for dehumidification, the purified gas is further heated by a condenser and is sucked into a drying room through a circulating fan, so that the gas in the drying room is recycled; the scheme in this application is through the double-deck filtration of plate filter and dust collector to gas to by condenser heating gas after the dehydrating unit drying gas, improved the great gaseous condition of leading dust blocking on the condenser of humidity to optimize the dust removal effect of desiccator.

Optionally, the dust collector including set up in the basin of clean room bottom, set up in the clean room and with the spray set spare of basin intercommunication, set up in spray set spare with plastics packing layer between the basin, spray set spare to plastics packing layer surface spraying water forms the water film that is used for absorbing the dust.

By adopting the technical scheme, the spraying component absorbs water in the water tank, water is sprayed on the plastic filler layer to form a water film, dust-containing gas is contacted with the water film, and after small particle dust is fused with the water film, the water with the dust flows into the water tank; according to the scheme, dust with small particles in the gas can be filtered, and the dust removal effect of the gas in the desiccator is improved.

Optionally, the spray assembly is including set up in the organism outer wall be close to basin one side and with the water pump of basin intercommunication, one end set up in on the water pump and the other end set up in pipeline in the clean room, set up in the pipeline is close to atomizer on one side of the plastics packing layer.

Through adopting above-mentioned technical scheme, spray the water in the subassembly through water pump extraction basin, transport plastics packing layer top with water through the pipeline, spray on plastics packing layer after the rethread atomizer atomizes water, form the form of water film, adsorb gas dust, improve gaseous degree of purification.

Optionally, the dehumidification device includes set up in spray subassembly be close to defogging piece of condenser one side, set up in the condenser is close to the evaporimeter of defogging piece one side.

Through adopting above-mentioned technical scheme, the great gas of humidity passes the defogging piece, consumes the moisture in the gas, and the rethread evaporimeter carries out cooling treatment to the gas, separates out the moisture in the gas, further reduces the humidity of gas, and the moisture of separating out flows to basin one side through the action of gravity.

Optionally, the defogging piece including set up in spray the subassembly be close to the folded plate defroster of condenser one side, set up in folded plate defroster is close to the silk screen defroster of evaporimeter one side.

By adopting the technical scheme, the demister adopts the combination of the folded plate demister and the silk screen demister, the folded plate demister is formed by combining a plurality of corrugated plates, when gas with high humidity passes through the corrugated plates at a certain speed, due to inertial impact of the gas, liquid drops are separated from the surfaces of the corrugated plates when colliding with the corrugated plates, so that the demisting effect is achieved; when the gas passes through the silk screen of the silk screen demister, the liquid drops touch the silk screen and are adhered or adsorbed, and the liquid drops fall under the action of gravity; the scheme in this application, the great gas of humidity is got rid of the moisture of macroparticle earlier through folded plate defroster, and the moisture of rethread wire mesh defroster with the macroparticle is got rid of, improves gaseous dehumidification effect.

Optionally, the guipure subassembly includes along the first guipure and the second guipure that the vertical direction of desiccation room set up side by side, first guipure is close to circulating fan one side with the organism inner wall constitutes the first chamber that holds that supplies mud to place, first guipure with clearance between the second guipure constitutes the second chamber that holds that supplies mud to place.

Through adopting above-mentioned technical scheme, first guipure and second guipure are used for the business turn over of mud, and the hot air of the circulating fan of being convenient for lets in heats the stoving to the mud on first guipure and the second guipure.

Optionally, the first mesh belt and the second mesh belt are both mesh structures, and the first mesh belt and the second mesh belt are both rotationally connected with the inner wall of the drying chamber.

Through adopting above-mentioned technical scheme, first guipure and second guipure are established to the network structure, and the flow of the gas of being convenient for accelerates the mummification of mud, and first guipure and second guipure are all connected with the rotation of mummification indoor wall, the business turn over of mud of being convenient for.

Optionally, the organism includes confession the purification unit that dust collector placed, confession the drying portion that the guipure subassembly placed, set up in the drying portion is close to the wind-guiding portion of circulating fan one side, wind-guiding portion is loudspeaker form, the length that wind-guiding portion is close to circulating fan one side is less than the length that wind-guiding portion kept away from circulating fan one side.

Through adopting above-mentioned technical scheme, wind-guiding portion is loudspeaker form, leads the steam of circulating fan's introduction for the gas blows to the guipure subassembly more even, promotes the efficiency of sludge drying.

In summary, the present application includes at least one of the following beneficial technical effects:

1. according to the scheme, through double-layer filtering of the gas by the plate filter and the dust removing device and heating of the gas by the condenser after the gas is dried by the dehumidifying device, the situation that dust is blocked on the condenser by the gas with high humidity is improved, so that the dust removing effect of the drier is optimized;

2. the spraying assembly absorbs water in the water tank, water is sprayed on the plastic packing layer to form a water film, and after dust-containing gas contacts with the water film, small particle dust fuses with the water film and water with the dust flows into the water tank; according to the scheme, dust with small particles in the gas can be filtered, and the dust removal effect of the gas in the desiccator is improved.

Drawings

FIG. 1 is a schematic diagram of the wind direction flow of a sludge low-temperature belt dryer in an embodiment of the application;

fig. 2 is a cross-sectional view of a sludge low-temperature belt dryer according to an embodiment of the present application.

Reference numerals illustrate:

1. a body; 2. a partition plate; 3. a drying chamber; 4. a clean room; 5. a circulating fan; 6. a mesh belt assembly; 7. a panel filter; 8. a condenser; 9. a dust removal device; 10. a dehumidifying device; 11. a water tank; 12. a spray assembly; 13. a plastic filler layer; 14. a water pump; 15. a pipe; 16. an atomizing nozzle; 17. a defogging member; 18. an evaporator; 19. a folded plate demister; 20. a wire mesh mist eliminator; 21. a first mesh belt; 22. a second mesh belt; 23. a first accommodation chamber; 24. a second accommodation chamber; 25. a purifying section; 26. a drying part; 27. an air guide part; 28. and (5) a drying room.

Detailed Description

The present application is described in further detail below.

The embodiment of the application discloses a sludge low-temperature belt dryer. Referring to fig. 1 and 2, the air conditioner comprises a machine body 1 arranged in a drying room 28, wherein the drying room 28 covers the machine body 1, so that an effect of heat preservation is achieved, and air is recycled in the drying room 28. The inside of the machine body 1 is fixedly provided with a partition plate 2, the inner cavity of the machine body 1 is divided into a drying chamber 3 and a purifying chamber 4 through the partition plate 2, the drying chamber 3 is used for drying sludge, and the purifying chamber 4 is used for purifying gas. A circulating fan 5 is arranged on one side of the machine body 1, which is close to the drying chamber 3, the circulating fan 5 sucks hot gas from the outside of the machine body 1 into the drying chamber 3 and dries sludge, a net belt component 6 is arranged in the drying chamber 3, and the net belt component 6 is rotationally connected with the inner wall of the drying chamber 3 for the inlet and outlet of the sludge. The partition plate 2 is provided with a gas channel, the gas channel and the net belt assembly 6 are not located on the same horizontal plane and are located below the net belt assembly 6, powder and gas are easy to mix due to the process of drying sludge by hot gas, and a plate filter 7 is arranged on the inner wall of the gas channel, so that large particulate matters in the gas can be filtered out. The filtered gas enters the purifying chamber 4, the dust removing device 9 is arranged in the purifying chamber 4, and the dust removing device 9 filters small particle dust in the gas. A condenser 8 for heating the gas is arranged on one side of the machine body 1 close to the purifying chamber 4, an air outlet of the condenser 8 is communicated with an air inlet of the circulating fan 5, and the hot gas heated by the condenser 8 enters the drying chamber 3 from the circulating fan 5. Since the hot gas takes away a lot of moisture when drying the sludge, a dehumidifying device 10 for removing moisture in the gas is installed between the condenser 8 and the dust removing device 9 in the purifying chamber 4, and the gas is dried first and then heated.

In this application embodiment, the desiccator uses hot gas to dry earth back gas contains a large amount of dust, and gas humidity reaches 60%, and the dust that easily forms the wet dust with the interception at condenser 8 surface blocks up condenser 8. According to the scheme, hot gas sequentially passes through the mesh belt assembly 6, the plate filter 7, the dust removing device 9 and the dehumidifying device 10 and then is heated by the condenser 8, and the heated gas is sucked into the drying chamber 3 through the circulating fan 5. Part of dust is generated in the heating and dehydrating process of the sludge, the gas and the dust are mixed to form turbid gas, and the turbid gas firstly filters large-particle dust through the plate filter 7 and then enters the purifying chamber 4. The gas is first removed by dust collector 9 in clean room 4, and the gas after dust removal is dried by dehumidifier 10, and then further heated by condenser 8. The double-layer filtering of the plate filter 7 and the dust removing device 9 is adopted to improve the purification degree of the gas, and the dehumidification device 10 is used for drying the gas, so that the gas with high humidity is easy to block internal equipment after dust combination, and the effect of optimizing the dust removal of the drier is achieved.

The filter material of the plate filter 7 can be made of high-quality polyester synthetic fibers, and has a long service life, a fluffy and gradually dense fiber structure, large air quantity and high dust capacity, and the service life of the middle-efficiency filter at the rear end of the plate filter is effectively prolonged. The filter screen of the plate filter 7 can be one of a galvanized net, a filter screen, a stainless steel net and a plastic spraying net, so that the strength of the plate filter 7 is enhanced. The outer frame of the plate filter 7 can adopt one of an aluminum frame, a galvanized frame and a stainless steel frame, so that the hardness of the plate filter 7 is further enhanced, and the plate filter 7 is difficult to deform, crack and twist in normal operation.

Referring to fig. 2, the machine body 1 includes a purifying part 25, a drying part 26 and an air guiding part 27, the purifying part 25 is internally placed for the dust removing device 9 of the purifying room 4, the drying part 26 is internally placed for the net belt assembly 6 of the drying room 3, the air guiding part 27 is fixed on one side of the drying part 26 close to the circulating fan 5, the air guiding part 27 is used for guiding hot air sucked by the circulating fan 5 to one side of the net belt assembly 6, the air guiding part 27 is horn-shaped for enabling the air to flow to the net belt assembly 6 more uniformly, and the length of the air guiding part 27 on one side close to the circulating fan 5 is smaller than that of the air guiding part 27 on one side far away from the circulating fan 5.

In this embodiment, organism 1 divides inside functional area through purifying part 25, drying part 26 and wind-guiding portion 27, and drying part 26 is used for drying mud, and purifying part 25 is used for purifying the tail gas after drying mud for gaseous cyclic utilization reduces the influence to surrounding environment, and wind-guiding portion 27 designs into loudspeaker form, and wind-guiding portion 27 supplies circulating fan 5 to place in narrow mouth one side of wind-guiding portion 27, and wind-guiding portion 27 is loudspeaker form, and the hot gas of being convenient for introducing circulating fan 5 plays the guide effect, makes the hot gas more even act on mud, accelerates the efficiency of drying mud.

Referring to fig. 1 and 2, the mesh belt assembly 6 includes a first mesh belt 21 and a second mesh belt 22, the first mesh belt 21 and the second mesh belt 22 are juxtaposed in a vertical direction of an inner wall of the drying chamber 3, a first accommodating chamber 23 in which sludge is placed is formed between one side of the first mesh belt 21 close to the circulating fan 5 and the inner wall of the machine body 1, and a second accommodating chamber 24 in which sludge is placed is formed by a gap between the first mesh belt 21 and the second mesh belt 22. And the first mesh belt 21 and the second mesh belt 22 are designed into a mesh structure, so that hot gas sucked by the circulating fan 5 uniformly flows between the first mesh belt 21 and the second mesh belt 22, and in order to improve the efficiency of sludge transportation, the first mesh belt 21 and the second mesh belt 22 are both rotatably connected with the inner wall of the drying chamber 3.

In this application embodiment, first guipure 21 and second guipure 22 not only play the effect that supplies mud to place, and first guipure 21 and second guipure 22 are connected with desiccation room 3 inner wall rotation moreover, and the business turn over of mud of being convenient for like the drawer, and first guipure 21 and second guipure 22 are established to the network structure, and the gas of being convenient for flows between first guipure 21 and second guipure 22, accelerates the desiccation of mud.

Referring to fig. 1 and 2, the dust removing device 9 includes a water tank 11, a spray assembly 12, and a plastic packing layer 13. The water tank 11 is arranged at the bottom of the purifying chamber 4, the spraying assembly 12 is arranged at the middle part of the purifying chamber 4, and the plastic packing layer 13 is arranged between the spraying assembly 12 and the water tank 11. After the spray assembly 12 is communicated with the water tank 11, the sucked water is sprayed to the surface of the plastic packing layer 13 to form a water film shape. When the dust-containing gas contacts with the water film, the small-particle dust and the water film are fused and then drop into the water tank 11. Spray assembly 12 includes a water pump 14, a conduit 15, and an atomizer 16. The water pump 14 is fixed on one side of the outer wall of the machine body 1, which is close to the water tank 11, the water pump 14 is communicated with the water tank 11, one end of the pipeline 15 is installed on the water pump 14, the other end of the pipeline 15 is arranged in the purifying chamber 4, and the atomizing nozzle 16 is installed on one side of the pipeline 15, which is close to the plastic packing layer 13. After the water pump 14 sucks water in the water tank 11, the water is transported to the upper side of the plastic packing layer 13 through the pipeline 15, and then atomized through the atomizing nozzle 16 and sprayed on the plastic packing layer 13 to form a water film for adsorbing small particle dust.

In this application embodiment, water pump 14 absorbs water in the basin 11, transports the top of plastics packing layer 13 through the water pipe with water, sprays on plastics packing layer 13 after atomizing through atomizer 16 with water atomization, forms the form of water film, and the gas that contains dirt contacts the back with the water film, and after small granule dust and the water film fused, the water flow that takes the dust goes into in the water tank 11 to reach the effect of purifying gas.

Because the sludge is easy to produce harmful gas pollutants such as ammonia gas, hydrogen sulfide and the like in the heating and drying process. The deodorizing agent such as citric acid, caustic soda flakes and the like can be added into the water tank 11, and the spraying assembly 12 sprays water mixed with the deodorizing agent in the water washing process and then is mixed with gas, so that harmful gas pollutants are absorbed and purified.

The plastic filler layer 13 is made of plastic filler, the plastic filler is developed on the basis of soft filler and semi-soft filler, and has the advantages of the soft filler and the semi-soft filler, the structure is a double-ring large plastic ring, and the hydroformylation fiber or polyester yarn is pressed on the ring of the ring, so that fiber bundles are uniformly distributed; the inner ring is snowflake-shaped plastic branches, so that the film can be hung, and bubbles can be effectively cut and are widely used for sewage and wastewater treatment engineering.

Referring to fig. 1 and 2, the dehumidifying apparatus 10 includes a mist eliminator 17 and an evaporator 18, wherein the mist eliminator 17 includes a flap mist eliminator 19 and a wire mesh mist eliminator 20. The evaporator 18 is installed and is close to defogger 17 one side at condenser 8, and folded plate defroster 19 is installed and is close to condenser 8 one side at spray assembly 12, and wire mesh defroster 20 is installed and is close to evaporator 18 one side at folded plate defroster 19. The gas with higher humidity firstly removes the water of large particles through the folded plate demister 19, then removes the water of small particles through the wire mesh demister 20, and then flows to the evaporator 18, and the water in the gas is separated out through the temperature reduction of the evaporator 18.

In this embodiment, the great gas of humidity separates large granule moisture earlier through folded plate defroster 19, and rethread wire mesh defroster 20 separates small granule moisture, consumes the moisture in the gas. Then the gas is cooled by the evaporator 18, the water in the cooled gas is further separated out, the separated water flows to one side of the water tank 11 by gravity, the gas is dried,

the folded plate demister 19 is formed by combining a plurality of corrugated plates, and gas or liquid passes through the corrugated plates, so that suspended particles and liquid drops in the gas or liquid are condensed into liquid on the corrugated plate sections, and then flow to the bottom along the surfaces of the corrugated plates, and finally the demisting purpose is achieved. The wire mist eliminator 20 is typically constructed of a set of wire mesh or plastic fiber mesh materials having various pore sizes and degrees of sieving to effectively filter out particles and droplets of various sizes. As the gas or liquid flows through the screen mist eliminator 20, suspended particles and droplets therein are caught on the mesh, while clean gas or liquid passes along the screen for mist elimination purposes.

The implementation principle of the sludge low-temperature belt dryer is as follows: the drier equipment is arranged in the drying room 28, and the inner wall of the drying room 28 is made of heat insulation materials, so that the temperature in the drying room 28 is higher than the outside temperature, and the hot gas in the drying room 28 can support the drier to dry the sludge. The hot gas sequentially passes through the mesh belt assembly 6, the plate filter 7, the dust removing device 9 and the dehumidifying device 10, is heated by the condenser 8, and is sucked into the drying chamber 3 by the circulating fan 5. The circulating fan 5 sucks hot gas heated by the condenser 8 into the drying chamber 3, and the hot gas dries sludge on the mesh belt assembly 6. Part of dust is generated in the heating and dehydrating process of the sludge, the gas and the dust are mixed to form turbid gas, and the turbid gas firstly filters large-particle dust through the plate filter 7 and then enters the purifying chamber 4. The gas is firstly removed by the dust removing device 9 from the small-particle dust in the purifying chamber 4, the gas after the dust removal is dried by the dehumidifying device 10, and then the gas is further heated by the condenser 8, so that the gas reaches the temperature of drying the sludge. The scheme in this application is through the double-deck filtration of plate filter 7 and dust collector 9 to gas to and the dehumidification device 10 is by condenser 8 heating gas again after the drying gas, has improved the great gaseous condition of taking the dust to block up on condenser 8 of humidity, thereby optimizes the dust removal effect of desiccator.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims (8)

1. The utility model provides a mud low temperature belt desiccator, includes organism (1) that sets up in the baking house, a serial communication port, be provided with division board (2) in organism (1), division board (2) will organism (1) inner chamber partition is drying chamber (3) and clean room (4), organism (1) are close to drying chamber (3) one side is provided with and is used for introducing gas circulation fan (5) in drying chamber (3), be provided with in drying chamber (3) and supply net belt assembly (6) that mud was placed, division board (2) are kept away from net belt assembly (6) one end is provided with and are used for the intercommunication drying chamber (3) with the gas passage of clean room (4), the gas passage inner wall is provided with plate filter (7), organism (1) are close to clean room (4) one side is provided with condenser (8) that are used for giving the gas heating, condenser (8) with the air inlet intercommunication of circulation fan (5), be provided with filter gas outlet (9) in clean room (4), dust collector (9) are close to one side dust collector (10).

2. The sludge low-temperature belt dryer according to claim 1, wherein the dust removing device (9) comprises a water tank (11) arranged at the bottom of the purifying chamber (4), a spraying assembly (12) arranged in the purifying chamber (4) and communicated with the water tank (11), and a plastic packing layer (13) arranged between the spraying assembly (12) and the water tank (11), and the spraying assembly (12) sprays water to the surface of the plastic packing layer (13) to form a water film for absorbing dust.

3. The sludge low-temperature belt dryer according to claim 2, wherein the spraying assembly (12) comprises a water pump (14) arranged on one side of the outer wall of the machine body (1) close to the water tank (11) and communicated with the water tank (11), a pipeline (15) with one end arranged on the water pump (14) and the other end arranged in the purifying chamber (4), and an atomization nozzle (16) arranged on one side of the pipeline (15) close to the plastic filler layer (13).

4. The sludge low-temperature belt dryer according to claim 2, wherein the dehumidifying device (10) comprises a demister (17) arranged on one side of the spray assembly (12) close to the condenser (8), and an evaporator (18) arranged on one side of the condenser (8) close to the demister (17).

5. The sludge low-temperature belt dryer according to claim 4, wherein the demister (17) comprises a folded plate demister (19) arranged on one side of the spray assembly (12) close to the condenser (8), and a wire mesh demister (20) arranged on one side of the folded plate demister (19) close to the evaporator (18).

6. The sludge low-temperature belt dryer according to claim 1, wherein the mesh belt assembly (6) comprises a first mesh belt (21) and a second mesh belt (22) which are arranged in parallel along the vertical direction of the drying chamber (3), a first accommodating chamber (23) for placing sludge is formed by one side, close to the circulating fan (5), of the first mesh belt (21) and the inner wall of the machine body (1), and a second accommodating chamber (24) for placing sludge is formed by a gap between the first mesh belt (21) and the second mesh belt (22).

7. The sludge low-temperature belt dryer as claimed in claim 6, wherein the first mesh belt (21) and the second mesh belt (22) are both mesh structures, and the first mesh belt (21) and the second mesh belt (22) are both rotatably connected with the inner wall of the drying chamber (3).

8. The sludge low-temperature belt dryer according to claim 1, wherein the machine body (1) comprises a purifying part (25) for placing the dust removing device (9), a drying part (26) for placing the net belt assembly (6), and an air guide part (27) arranged on one side of the drying part (26) close to the circulating fan (5), the air guide part (27) is horn-shaped, and the length of the air guide part (27) close to one side of the circulating fan (5) is smaller than the length of the air guide part (27) away from one side of the circulating fan (5).