CN117160157B

CN117160157B - Paint mist prefilter for second air passage of dry spray room

Info

Publication number: CN117160157B
Application number: CN202311452865.7A
Authority: CN
Inventors: 崔亚东; 丁勇刚; 白雪凤
Original assignee: Hangzhou Zhihe Coating Technology Co ltd
Current assignee: Hangzhou Zhihe Coating Technology Co ltd
Priority date: 2023-11-03
Filing date: 2023-11-03
Publication date: 2024-02-23
Anticipated expiration: 2043-11-03
Also published as: CN117160157A

Abstract

The invention discloses a paint mist prefilter for a second air passage of a dry spray booth, which mainly comprises a plurality of filter frames, a filter assembly, a bottom support frame, a bearing box and a side filter fiber layer, wherein the filter assembly is arranged on the bottom of the filter frame; a plurality of groups of filter fibers with the tops fixed and the bottoms capable of swinging freely are arranged in the upper area in the filter frame; a filter fiber layer is paved at the bottom of the bearing box; the bottom of the support frame is provided with a supporting point structure, and the periphery of the supporting point structure is provided with an umbrella-shaped covering piece; the filtering component capable of dynamically displacing comprises a thorn column and filtering fibers wound outside, and fixed thorns are arranged outside the thorn column, so that the filtering fibers are prevented from falling off or deforming after absorbing paint mist under the load; the method comprises the following steps of performing comprehensive universal design aiming at different working conditions of primer, colored paint and varnish; a protective bag at the periphery of the filter frame; the prefilter is arranged in the second air passage, so that the integral dry type filtering effect is improved, the burden of the rear section dry type filtering is reduced, the cleanliness of the second air passage is improved, the maintenance is reduced, and the filter can be reused.

Description

Paint mist prefilter for second air passage of dry spray room

Technical Field

The invention relates to the fields of automobiles, automobile parts and general industrial spraying equipment, in particular to a paint mist prefilter of a second air passage of a dry spray booth.

Background

The dry spray booth of the robot automatic coating line sequentially comprises a clean air supply chamber at the top, a dry paint spray booth, a first paint mist air mixing chamber, a second paint mist air passage, a dry spray booth air outlet, a dry filter device and an air pipe air inlet from top to bottom, is connected with a first fan through the air pipe air outlet, is subjected to constant temperature, constant humidity and purification treatment of a circulating air conditioning box, and is finally sent to the clean air supply chamber at the top of the spray booth through a second fan to form a complete closed circulation system, and the circulating air is subjected to secondary utilization, so that the energy consumption is most saved, but meanwhile, the technical requirement of the secondary utilized circulating air on dry filtration is higher, and the filtered circulating air is ensured to be cleaner. The total static pressure of the fan is about 3300pa, the wind resistance of each process section is different, the wind resistance comprises filtering consumable materials, the fan, a chamber body, heating, refrigerating, humidifying, dehumidifying, an air pipe, an elbow and the like, the resistance, the service life, the initial resistance, the final resistance and the pressure difference of a plurality of filtering sections are respectively different, the difference of the initial resistance and the final resistance of the dry type filtering device, namely the pressure difference range is about 900-1000pa, the pressure difference range before replacement is very large after initial installation to use, a plurality of dry type filtering devices are installed in each spray booth, the blocking conditions are respectively different, the service lives of the dry type filtering devices in a concentrated area under a robot and a non-concentrated area of air inlets and outlets of the spray booth are different, and the pressure difference change is multiple times. The dry paint mist is dynamically connected with the exhaust gas emission system, and the exhaust gas quantity with a certain proportion of about 5-10% of the total circulating air quantity of the spray booth is continuously emitted during production, so that the change of the air balance of the dry paint mist is large.

The spraying process of the robot automatic coating line generally comprises three spraying procedures of primer, colored paint and varnish, and independent dry spraying rooms are adopted respectively.

The national requirements for environmental protection are greatly improved, and in recent years, vehicle body coating lines are all sprayed by adopting dry spray houses and water paint. The robot automatic coating line newly built by high-end automobile part enterprises adopts dry spray houses and dry paint mist treatment technologies, and most of the robot automatic coating lines are sprayed by water paint, or the primer and the colored paint adopt water, and the varnish adopts solvent type. Compared with solvent type paint, the spray tool rotary cup or spray gun of water paint is very easy to block in the cleaning process, so that a large amount of solvent or pure water in the cleaning process is not smooth in the instant flowing down, or flows down after being sprayed, or leaks, so that the solvent type paint can leak into the space of the second air passage, or directly drifts into the dry type filter box along with high-pressure air, the paper dry type filter box is deformed, and liquid can directly leak to the workshop floor in severe cases, so that the environment is polluted, the solvent is discharged in an unorganized manner, and the environment-friendly risk is high.

The characteristic of different paints, the powder of the primer, the high viscosity of the colored paint, the hardness of the varnish after being solidified is no more than that of the varnish, and the varnish is adhered to an object and is difficult to clean and separate. The different paint characteristics have very different influences on the dry type filter box, and the adsorption effect, the filtering precision, the paint containing amount for adsorbing paint mist and the like are different. Different paint characteristics have different effects on the second vent. The primer powder is easy to form a thick paint slag powder layer in the second air passage, the paint slag powder is soft when being stepped on like flour, and can be deeply sunk, and the paint slag powder floats in the second air passage along with wind everywhere, so that more serious air environmental pollution of paint mist with pollution is continuously caused in the second air passage and the rear end. The varnish is hard after solidification, and any object in the second ventilation duct is easy to bond into a whole after contacting paint slag, so that the varnish is difficult to separate. And the time of each time or each week of line stop maintenance is short, maintenance operators are concentrated in the cleaning work with comprehensive high-efficiency rush time of the whole coating line, and the maintenance time of the second air passage of the dry spray booth can be seriously insufficient. In the second air passage of the dry spray booth of the existing many robot automatic coating lines, maintenance can be carried out in one or two months at regular intervals, even if the maintenance is carried out once with great force, pollution can be caused and gradually become more serious again in one or two days after the recovery production, no matter how much paint slag powder is accumulated in the second air passage, secondary pollution can be caused, and therefore, the long-term effect of cleaning maintenance in the second air passage carried out with great force is very little.

The paint mist treatment technology of the dry spray booth is gradually improved within five or six years from domestic rising, and the dry filter device can be replaced in part during online production. The most common in the prior art is to adopt a dry-type mobile trolley as a carrier, and to arrange six or eight general 485 dry-type filter paper boxes for dry-type paint mist filtering, wherein the dry-type mobile trolley and the dry-type filter paper boxes are used as a main ventilation duct of the dry-type paint mist together, and the peripheries of an air inlet and an air outlet of the dry-type mobile trolley are tightly pressed by sealing rubber strips and are respectively connected with an air outlet of a dry-type spray room and a circulating air pipe at the rear section. However, the adoption of the universal 485 dry type filter paper box has the advantages that the paper material is of a planar structure, a three-dimensional space is not formed, the paper is made into a sheet-shaped structure of honeycomb paper for improving the three-dimensional space, the sheet-shaped honeycomb paper has no strength, and under the action of high-pressure air, the water paint is easier to deform and collapse particularly, so that the filtration is invalid; the paper honeycomb paper box or the labyrinth paper box has poor filtering effect and very low paint containing amount of adsorbed paint mist, the paper filtering is combined with the second group of single-layer fiber filter layers with high density to improve the filtering precision, the dry paint mist filtering is easy to block in the use process of the low-efficiency filter paper box, the generated paint mist amount in unit time is fixed, if the paint mist cannot be quickly pumped away, the ventilation containing a large amount of paint mist particles is seriously blocked, the paint mist is further retained and falls to the inner bottom of the second air passage, the thicker paint mist powder is formed for a longer time, particularly turbulent flow is caused in the four corner areas, the dry filter box is suspended in the second air passage under the action of high-pressure circulating air, the polluted environment is more aggravated, or the burden of a part of the paint mist enters the dry filter box to increase the dry filter device, the dry filter box is more blocked, the service life is shortened, the replacement is more frequent, and the consumable cost is high; if paint mist in the second through air duct is too much, the cleanliness in the second through air duct is influenced, the stability of the whole air balance of the whole coating line dry type spray booth can be seriously influenced, and the qualification rate of products is further influenced.

In the practical application process of the dry spray booth, the second through-air duct cannot be maintained on line, paint residues in the second through-air duct can be completely removed only by comprehensively cleaning and maintaining the spray booth during line stopping, the cleaning period is long, and then a lot of paint residues are accumulated at the bottom quickly, so that the inner bottom of the second through-air duct of the spray booth is in a state of a lot of paint residues for a long time.

The powdery primer paint slag powder is taken as chemical dust to strongly stimulate respiratory systems, skin and the like in the cleaning process of the second ventilation duct, and has great occupational hazard.

The paint mist treatment chamber operation maintenance door of the dry spray room is arranged at the end position of the dry spray room in the length direction, is close to the ground, and is convenient for personnel to enter and exit.

In summary, there is no solution to the dry paint mist in the space of the second air passage of the dry spray booth in the prior art. The method is an absolute technical difficulty and pain point in the second air passage of all existing dry spray houses.

The glass fiber has extremely fluffy characteristics, and the fiber filaments are thin and long, the fiber filaments are many, staggered and longitudinally interwoven, the three-dimensional volume is large enough, the effect of absorbing paint mist is best, but the glass fiber supporting structure is the biggest technical difficulty.

The paint mist felt made of glass fibers is used as an early paint mist trapping method, but after paint mist is adsorbed by the paint mist felt, the glass fibers are manually and directly operated to cause great stimulation to the body, and a host factory is prohibited to directly use the whole paint mist adhesive for paint mist trapping, so that the technical application of the glass fibers in the filtration treatment of the paint mist in a dry spray booth is greatly limited. For this reason, the prior art does not have any prefilter technique or solution involving the use of glass fiber materials in the second ventilation duct of the dry spray booth. In the patent application No. 2023103312356.3, a paint mist prefilter module for a dry paint spray booth and a dry paint spray booth are disclosed, and the patent technology is applied in a first air mixing chamber of the dry paint spray booth and is different from a second air passage. The air flow of the first air mixing chamber is completely from top to bottom, and the passing direction is consistent. The bilateral inclined surface areas of the first air mixing chamber are symmetrically designed in the width direction, so that air flow is simpler; the prefilter module of the first air mixing chamber is closer to an overspray fog source generated by robot spraying in the dry type paint spraying chamber in the height direction; the effect of the first air mixing chamber is mainly that the air flow of the down overspray paint mist gradually narrows from the width of the spray chamber to the width range of the second air mixing channel for fully mixing air, so that the air speed difference in the plane of the inclined surface area of the first air mixing chamber is large. The prefilter modules are respectively arranged in the inclined surface areas on two sides of the first air mixing chamber, are whole glass fiber layers which are obliquely and planarly arranged along the length direction of the spray booth, and have certain ventilation property in the downward direction of air flow; the filter fibers of the prefilter module and the supporting pieces of the filter fibers are respectively designed into fixed structures and can be integrally disassembled; the whole structure of the prefilter module has large surface area and more complex replacement operation.

Disclosure of Invention

The invention aims to provide a dry paint mist prefilter of a second air passage in a dry spray room, which aims to solve the technical blind spot of never designing dry filtration in the second air passage of the dry spray room.

The action and principle of the prefilter of the second air passage of the dry spray booth and the prefilter module of the first air mixing chamber, the structure of the prefilter, the arrangement of the prefilter, the ventilation, the airflow direction, the paint adsorption quantity, the prefilter effect, the replacement of the prefilter and the like are all different.

The second air passage in the dry spray room is an asymmetric design of the single-side dry spray room wall plate and the opposite-side dry filter device, the wind direction is horizontally turned from top to bottom to 90 degrees for air outlet, and the design requirements on the air flow, the structure and the like of the prefilter of the second air passage are higher.

The technical aim of the invention is realized by the following technical scheme:

a paint mist prefilter for a second through-air duct of a dry spray booth disposed at an interior bottom of the second through-air duct, comprising:

the air flow of the second air passage is turned from top to bottom by 90 degrees and is horizontally connected with the air outlet;

A plurality of filter frames which are respectively adjacent in the transverse and longitudinal directions are arranged at the inner bottom of the second air passage along the length direction of the dry spray booth;

a plurality of groups of filter fibers I with fixed top parts and free swinging bottom parts along with wind are arranged above the filter frame;

the filter frame is internally provided with a plurality of filter components which are arranged in a staggered way and dynamically displace with wind;

further, the filtering frame is provided with an upright post, a cross beam and a longitudinal beam; an independent supporting frame is arranged at the bottom of the filtering frame; the filter frames are quickly connected by plastic connectors;

further, the first filter fibers are provided with a plurality of groups along the length direction of the cross beam of the filter frame; a certain gap is arranged between each group of first filter fibers; the longitudinal side surfaces of the periphery of the filter frame are provided with a first filter fiber layer; the first filter fiber is designed to be in a gradient from high to low from the opposite side of the air outlet of the first ventilating duct to the same side of the air outlet;

further, the filter assembly comprises a thorn column and a second filter fiber, wherein the second filter fiber is of a long-strip integral structure and is wound on the thorn column through a continuous spiral outside;

the thorn column is provided with a fixed thorn, and the second filter fiber is firmly connected to the thorn column through the fixed thorn; the whole body is not fallen off or deformed after the filter fiber and the thorn column absorb paint mist and gain weight;

Further, connecting pieces are respectively arranged between the two ends of the thorn column and the filtering frame; the connecting piece is flexibly connected, and the whole thorn column wound with the second filtering fiber can be dynamically displaced and changed under the influence of dynamic wind;

further, the cross-sectional area or the volume of the filter component and the second filter fiber are in equal proportion.

The filter components are arranged in the horizontal direction;

the center distances of the adjacent filter assemblies of the same horizontal layer are the same, and the cross-sectional areas and the volumes of the adjacent filter assemblies are the same;

the center distances of the filtering components of different horizontal layers in the space from top to bottom are gradually increased, and the cross-sectional area and the volume are respectively gradually increased;

the center distance between the adjacent filter assemblies on the same horizontal layer is not smaller than the center distance between the adjacent filter assemblies on the same horizontal layer above;

or (b)

The filter assembly is longitudinally arranged;

further, the heights of the first filter fibers and the upper edges of the filter assemblies on the opposite sides of the air outlet of the second air passage are not lower than the heights of the first filter fibers and the upper edges of the filter assemblies on the same side of the air outlet of the second air passage respectively;

the height of the upper edges of the first filter fibers and the filter assembly is designed to be an inclined plane or an arc shape from high to low from the opposite side of the air outlet of the second air passage to the same side of the air outlet, and the inclined plane or the arc shape is matched with the air flow direction of the second air passage;

Further, the support frame is provided with a bearing box and a supporting point structure;

the supporting point structure is at least provided with four groups, and the four corners of the filtering frame deviate from the central positions of the filtering frame and the bearing box by a certain distance;

a second filter fiber layer is paved at the bottom of the bearing box;

further, an umbrella-shaped covering part is arranged on the periphery of the supporting point structure, a cylindrical extension body with a certain height is connected below the umbrella-shaped covering part, the bottom of the cylindrical extension body is open, a certain gap is reserved between the bottom of the cylindrical extension body and the height direction of the second ventilation duct, and the shadow area of the covering part is far larger than the area of the supporting point structure.

Further, the filter frame and the filter fiber layer are coated with a protective bag with an integrated structure by the bottom surface and four side surfaces around the periphery;

the protective bag is provided with a five-face surrounding body with a bottom face and four side faces, and the top face is open;

extension sections are respectively arranged on the periphery of the top, and are connected with the cross beams and the longitudinal beams of the filter frame in parallel with the filter fibers;

the redundancy of the protective bag extension section is turned over outwards towards the filter frame;

the bottom of the protective bag and the bottom of the filter frame are supported on the supporting frame together;

The periphery of the opening on the top surface of the protective bag can be tensioned or tightened, and the opening is sealed.

Advantageous effects

In summary, by arranging a plurality of groups of dry paint mist prefilter devices in the second air passage of the dry spray booth, the beneficial effects are very obvious, and the following aspects are embodied:

1. after the paint slag powder of the second air passage is effectively adsorbed, the replacement operation can be timely carried out, so that serious paint accumulation and environmental pollution in the second air passage are reduced, and the cleanliness of the second air passage is ensured; meanwhile, cleaning and maintenance work of the bottom in the second through air channel is reduced, or the bottom in the second through air channel basically does not need to be cleaned.

2. The prefilter of the second ventilation duct is more beneficial to balancing and stabilizing the air flow, reducing turbulent flow in dead angle areas vertical to the opposite sides of the dry type filtration, being more beneficial to guiding the air flow to the dry type filtration air inlet at the fastest speed, and having remarkable functions of diversion, steady flow and current equalization.

3. The height above the filter components and the filter frames on the opposite sides of the dry type filter device is designed to be higher than the height above the filter components and the filter frames on the same side of the dry type filter device, and the height is matched and adapted with the direction of the air flow, so that the air flow is more beneficial to leading to the dry type filter device, and turbulence or retention is avoided.

4. The filter component can generate dynamic displacement under the action of dynamic paint mist wind through dynamic connection with the filter frame, primer paint slag absorbed by the filter component can be influenced to drop in the bearing box of the lower part in the dynamic displacement process, the most probable guarantee that the instant paint slag quantity of the filter component positioned in the upper region is the lowest, and the filter component is all sunk in the bearing box of the lower part and does not fly upwards for the second time, so that the load of entering the dry filter device along with air flow is reduced, and the dry filter device is further lightened.

5. The filter fiber that can swing at filter frame top, under the influence of power wind, but the free swing is based on the coating cloud air current dynamic change in the second ventilation duct, and its absorptive coating cloud falls the filter component of below with the coating cloud granule of filter fiber absorption under the influence of the power wind of next moment in, and in advancing into accepting the box again down, the burden of dry-type filter equipment can be alleviateed to the same reason.

6. Through the prefilter at the second ventilation duct, after effectual absorption coating cloud increased coating cloud bulk density, reduce dry-type coating cloud and to the dry-type filtration's of back road burden, extension dry-type filtration's life reduces dry-type filtration's change cycle, prefilter compares dry-type filtration's cost lower, and it is more convenient to change, and the comprehensive operation cost of dry-type filtration consumptive material is lower. 7. The prefilter of the second ventilation duct is suitable for different use environments and conditions of primer, color paint and varnish; the secondary pollution caused by paint slag of the primer powder can be effectively solved, the operation of difficult separation after the primer powder is adhered to paint is avoided, the replacement is convenient, and the efficiency is higher.

8. Aiming at priming paint or colored paint, the periphery of the prefilter of the second air passage is respectively adjacent to the longitudinal wall plate of the second air passage of the dry spray room or the adjacent prefilter, the filter frame is entirely covered with the inner surface area of the second air passage of the dry spray room, so that air leakage to the inner bottom of the second air passage is prevented; for varnish, a certain gap is arranged between the periphery of the prefilter of the second air passage and the longitudinal wall plate of the second air passage or the adjacent prefilter respectively, so that the phenomenon that the varnish is adhered, solidified and connected into a whole and is difficult to separate and disassemble due to the fact that the varnish is adsorbed after the varnish is tightly attached is avoided. Avoiding the difficulty in separation and disassembly caused by the fact that the varnish is adhered into a whole after being solidified immediately after absorbing varnish paint mist.

9. The dry paint mist wind descending from the robot paint spray booth is impacted on the pre-filtering device from top to bottom under the action of inertia force, filtering fibers capable of swinging freely in the pre-filtering device are extremely fluffy, after the filtering fibers absorb paint mist, the paint mist absorbed on the filtering fibers is scattered or falls downwards in the dynamic change process of the filtering fibers under the continuous influence of power wind, and then is absorbed on a filtering component below, and then is gradually deposited in a receiving box below after descending, and is blocked by the filtering component below, so that the paint mist can not be stirred up again by the power wind and is blown up to an inlet of the dry filtering device, and the paint mist can be effectively intercepted.

10. The prefilter and the filter frame of the second ventilation duct fully consider the ergonomics, and the outline dimension and the volume of the filter frame and the weight after paint mist absorption are convenient for manual transportation and operation; the filter frames are arranged in parallel, and are suitable for moving in and out for replacement through the operation maintenance door of the dry spray booth, and the operation is convenient.

11. Through the prefilter in the dry-type spray booth second vent, filter fiber of the same volume, or second vent and dry-type filter of the same volume, the absorptive coating cloud volume in second vent is greater than dry-type filter far away, and the prefilter in second vent belongs to fairly open ventilation zone from the direction and the position of arranging of air current, can not influence the wind speed and the pressure differential of the main vent of dry-type coating cloud, be different from dry-type filter in main vent, and the cross-section area and the volume of vent are limited, can block up main vent after adsorbing the coating cloud, and then cause the pressure differential to reduce, directly influence dry-type filter's life reduction.

12. The glass fiber that extremely fluffs adsorbs paint mist volume contrast summary, about 1 gram glass fiber adsorbs the dry-type paint mist granule more than 500-1000 gram, the second ventilation channel contrast dry-type filter equipment of dry-type spray booth belongs to the more front end of paint mist, the ventilation route is shorter, contain paint mist volume the biggest, adopt the prefilter in the second ventilation channel of dry-type spray booth, through the extremely fluffy glass fiber of the arrangement of the biggest, and not receive the restriction in space, can keep sufficient clearance between the glass fiber, do not influence the stable equilibrium of air current, make full use of space, filter and have the separation, more paint mist can be more effectively adsorbed.

13. Through set up the filter fiber layer at the peripheral side of filter frame periphery, the longitudinal side adsorbs lacquer sediment more, increases the coating cloud appearance weight in limited volume, improves filtration efficiency, reduces dry-type filtration's consumable cost.

14. The support frame that the bottom set up intensity is enough, and with dry-type filtration frame and protection bag components of a whole that can function independently setting. The paint residues adsorbed by the filter fibers above are subjected to percentage bearing through the bearing box above the supporting frame, so that the paint residues are prevented from falling into the second air passage, and the cleanliness of the second air passage is ensured at any time;

15. at least four groups of supporting point structures are arranged at the bottom of the supporting frame, so that the stability of the filtering frame after absorbing paint mist and being stressed is ensured; the supporting point structure is offset to the central position of the filtering frame by a certain distance at four corners of the filtering frame, so that the situation that the paint mist above is in direct contact or the airflow is in great quantity and the supporting point structure is contacted most quickly, and the adhesive varnish paint mist is difficult to separate from the bottom of the second through air duct is avoided.

16. The supporting point structure that support frame bottom set up adopts the mode of local point connection, under the prerequisite of guaranteeing structural strength, respectively with dry-type filtration frame and second vent channel's connection area minimum, avoid the whole back that adsorbs the coating cloud of prefilter, with the interior bottom adhesion of second vent channel difficult demolishs.

17. The supporting point structure is arranged at the bottom of the supporting frame, the umbrella-shaped covering piece is arranged outside the supporting point structure, and the shadow area of the umbrella-shaped covering piece is far larger than the area of the supporting point structure; the umbrella-shaped covering piece can effectively shield the pollution of the paint mist airflow above. The lower edge of the umbrella-shaped covering part of the supporting point structure is provided with a certain height distance with the inner bottom of the second through air duct, so that the umbrella-shaped covering part or the supporting point structure is prevented from being adhered with the second through air duct respectively after varnish paint mist is solidified, and the umbrella-shaped covering part or the supporting point structure is difficult to dismantle.

18. The thorn post of filter component is equipped with fixed thorn, and filter fiber is through fixed thorn firm connection on thorn post, and absorption coating cloud receives and does not drop or warp after heavy, guarantees filter component's stability, and filter fiber is on support piece thorn post at external connection, and the winding is convenient, need not inside packing, and efficiency is higher, more even, and the volume is more fluffy.

19. The peripheral protective bag of filter frame surrounds holistic filter frame, and the lacquer sediment is whole to be fallen in the protective bag, through appropriate compression or adjustment filter frame's volume, reduces prefilter's useless volume of danger, is convenient for carry or transport the operation through the protective bag by the manual work.

20. The protective bag that the filter frame periphery adopted, protective bag top opening part can tighten up, can seal after tightening up, prevent that primer or color paint from dropping paint slag powder or paint slag group in handling operation in-process, avoid polluting the environment, avoid manual operation to receive paint slag pollution, operational environment or operating condition are better.

21. The prefilter in the second ventilation duct of the dry spray booth adopts a plurality of groups of protective bags to be adjacently arranged along the length direction of the spray booth for blocking certain airflow, and paint mist airflow passes through the shortest path in the ventilation duct, so that the airflow is more stable relatively in the length direction of the dry spray booth, the mutual interference of the airflow in a concentrated area with the most paint mist generated under the dry spray booth robot and the airflow in a non-concentrated area under an air inlet and outlet of the spray booth or the middle area of the adjacent robot is avoided, the large change of wind robbing, cross wind, wind speed or wind pressure is avoided, the wind pressure, wind quantity and the maximum quantity of paint mist entering the corresponding dry filter are prevented from being influenced by the distance between the collected concentrated air inlet and the dry filter.

22. The dry type filter device is disposable, the dry type filter paper box has higher cost for dangerous waste treatment due to the fact that the weight of the dry type filter paper box is large, the protective bag is adopted at the periphery of the prefilter in the second ventilation duct, the quality is ultra-light, and the cost for dangerous waste treatment is lower.

Drawings

FIG. 1 is a schematic overall cross-sectional view of a second ventilation duct 1 of a dry spray booth according to the present invention

FIG. 2 is a schematic cross-sectional view of a second air passage 1 of a dry spray booth according to the prior art

FIG. 3 is a schematic axial view of a second air passage 1 of a dry spray booth according to the prior art

FIG. 4 is a side schematic view of a prior art dry travelling car axle according to the present invention

FIG. 5 is a schematic view of the overall profile of the filter frame 2 according to the present invention

FIG. 6 is a schematic axial view of a connection structure of a filter frame 2 according to the present invention

FIG. 7 is a schematic side view of a side by side of a plurality of filter frames 2 according to the present invention

FIG. 8 is a schematic axial side view of a filter fiber according to the present invention

FIG. 9 is a schematic view of the circumferential longitudinal filter fibers 5 according to the present invention taken along the opposite axis

FIG. 10 is a schematic axial view of a filter assembly 4 according to the present invention

FIG. 11 is a schematic axial view of a bottom receptacle 61 according to the present invention

FIG. 12 is a schematic diagram of a two-axis side view of a filter fiber layer of a cartridge according to the present invention

FIG. 13 is a schematic axial view of a protective bag 10 according to the present invention

FIG. 14 is a schematic axial view of a supporting point structure, umbrella-shaped cover and cylindrical extension body according to the present invention

Description of the figure:

second ventilation duct 1

Filter frame 2

Column 21

Cross beam 22

Longitudinal beam 23

Filter frame 25

Filter frame 26

Filter assembly 4

Bearing box 61

Supporting point structure 9

Protective bag 10

Thorn column 11

Umbrella cover 13

Fixing thorn 14

Air outlet 16

Cylindrical extension 17

Detailed Description

In order that the manner in which the above-recited features, advantages, objects and advantages of the invention are obtained, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The examples in the embodiments are intended to illustrate the present invention and are not to be construed as limiting the present invention.

Reference in the specification to "one embodiment" or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment itself can be included in at least one embodiment of the present patent disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

Referring to the drawings, a paint mist prefilter for a second air passage of a dry spray booth is disposed at an inner bottom of a second air passage 1 of the dry spray booth, comprising:

the air flow of the second air passage 1 is turned from top to bottom by 90 degrees and is horizontally connected with the air outlet 16;

A plurality of filter frames 2 which are respectively adjacent in the transverse and longitudinal directions are arranged at the inner bottom of the second air passage 1 along the length direction of the dry spray booth;

the filter frame 2 fully considers the ergonomics, and the outline dimension and the volume of the filter frame 2 and the weight after paint mist absorption are convenient for manual carrying operation; the filter frames 2 are arranged in parallel in groups, and are suitable for moving in, out and replacing through the operation maintenance door of the dry spray booth, and the operation is convenient.

In this embodiment, the filter frames 2 are respectively arranged in at least two groups along the width direction of the dry spray booth, the opposite sides close to the air outlet 16 are filter frames 25, the same sides close to the air outlet 16 are filter frames 26, the tops of the filter frames 25 are provided with planes and connected with inclined planes, the tops of the filter frames 26 are provided with inclined planes, the inclined planes of the filter frames 25 and the inclined planes of the filter frames 26 have the same angle, and the filter frames 25 and 26 are connected into a straight line after being overlapped with each other; the filter frames 2 are arranged in a plurality of groups along the length direction of the dry spray booth, and the filter frames 2 at the end of the dry spray booth are designed according to specific dimensions.

In the embodiment, the filtering frame 2 adopts a structure of quick connection of plastic parts and is fixedly connected with the round bar through a three-dimensional tee joint and a handle;

embodiment 2, filter frame 2 adopts the bearing structure of horizontal direction, adopts the bearing structure that has the recess, and with the bearing structure both ends head direct placement of horizontal direction in the recess, in the processing procedure is used as dangerously useless as the back, can convenient dismantlement or compress or fold, reduces prefilter's whole volume, and the prefilter of dismantlement or compression is whole to be loaded in protective bag 10.

In embodiment 3, the filter frames 2 adjacent to the primer and the color paint and the longitudinal wall plates of the filter frames 2 and the second air passage 1 of the dry spray booth are tightly connected without providing gaps, and the filter frames 2 are entirely distributed on the inner surface area of the second air passage 1 of the dry spray booth, so that air leakage to the inner bottom of the second air passage 1 is prevented.

In embodiment 4, a certain gap is provided between the adjacent filter frames 2 of the varnish and between the filter frames 2 and the longitudinal wall plates of the second ventilation duct 1 of the dry spray booth, so that the separation and disassembly are difficult due to the fact that the filter frames 2 are adhered, solidified and adhered into a whole by adsorbing varnish paint mist.

A plurality of groups of filter fibers I with fixed top parts and free swinging bottom parts along with wind are arranged above the inside of the filter frame 2;

in this embodiment, the top of the first filter fiber is horizontally connected and fixed with the cross beam 22 of the filter frame 2 in the length direction, and the connection is performed through the connection of the filter frame 2, so that the first filter fiber is ensured not to fall off.

The upper tops of the first filter fibers of two adjacent groups are connected into a straight line or an arc line to be matched with the air flow direction of the second air passage 1 at intervals, so that the stability of air flow is ensured.

The first filter fibers are of an integrated structure, a plurality of groups of longitudinal first filter fibers are respectively arranged at the top of each filter frame 2, and enough gaps are respectively arranged among the first filter fibers, so that the first filter fibers are not overlapped with each other under the blowing of paint mist power wind; the first filter fiber is not overlapped with the filter assembly 4 at the top of the filter frame 2, and has a certain interval, so that the first filter fiber is not bonded with the filter assembly 4 after adsorbing paint mist; the dry paint mist particles directly impact on the first filter fiber to be adsorbed under the inertia action of the power wind, or drop down onto the filter assembly 4 below from top to bottom under the continuous swing of the first filter fiber, and further drop down into the second filter fiber layer of the bearing box 61.

A plurality of filter assemblies 4 which are arranged in a staggered manner and dynamically displace with wind are arranged in the filter frame 2;

in this embodiment, the filter assemblies 4 arranged in each layer in the horizontal direction are on the same axis, the filter assemblies 4 arranged in each column in the horizontal direction are on the same axis, the distance between the filter assemblies 4 from top to bottom is gradually increased, the filter assemblies 4 adjacent in the horizontal direction or adjacent in the vertical direction are on the same oblique axis or are close to the same axis, the diameter of the filter assembly 4 arranged from top to bottom is not smaller than the diameter of the filter assembly 4 above. A filter frame 25 in which 5 groups of filter elements 4 and 9 groups of filter elements 4 are respectively disposed in the horizontal direction and the longitudinal direction; the filter frame 26 is provided with 2 groups of filter assemblies 4 in the horizontal direction and the longitudinal direction, respectively.

The filtering frame 2 is provided with upright posts 21, cross beams 22 and longitudinal beams 23; the bottom of the filter frame 2 is provided with a support frame which is independently connected;

in the embodiment, the support frame supports the filter frame 2;

the filter frame 2 is made of wood, bamboo or other nonmetallic materials with certain strength and hardness. The filter frame 2 is quickly connected by plastic connectors; the plastic connecting piece is connected by one or more of a three-dimensional tee joint, a three-dimensional four-way joint, a straight tee joint, a handle, an oblique tee joint, an oblique four-way joint and the like.

The first filter fibers are provided with a plurality of groups along the length direction of the cross beam 22 of the filter frame 2; a certain gap is arranged between each group of first filter fibers;

the first filter fiber is designed to be in a gradient from high to low from the opposite side of the air outlet 16 of the second air passage 1 to the same side of the air outlet 16;

the longitudinal side surfaces around the filter frame 2 are provided with a first filter fiber layer;

in this embodiment, the first filter fiber has a certain length, thickness and width, and is an integral structure. The first filter fibers are arranged in a plurality of groups, and the first filter fibers which are adjacent to each other in the front-back, left-right and up-down mode can not be overlapped under the influence of power wind. The first filter fiber is provided with a gradient and is matched with the airflow direction of the second ventilation duct 1.

The filter assembly 4 comprises a thorn column 11 and a second filter fiber, wherein the second filter fiber is of a long-strip integral structure and is wound on the thorn column 11 through a continuous spiral outside;

the spine 11 is provided with a fixing spine 14, and the second filter fiber is firmly connected to the spine 11 through the fixing spine 14; the filter fiber II and the thorn column 11 are effectively ensured not to fall off or deform integrally after absorbing paint mist and increasing weight, and the integral stability of the filter assembly 4 is improved.

In the embodiment, the thorn column 11 is of an integrated structure, and is made of plastic material, so that the strength is sufficient; the periphery of the thorn post 11 is provided with a fixed thorn 14, the thorn post 11 is provided with a vent hole, good ventilation is ensured, and the ventilation effect is not influenced after paint mist is adsorbed by the thorn post 11 body. The two intensities of a whole filter fiber of peripheral winding of thorn frame are higher, more even, and the volume is more fluffy, and the effect of adsorbing the coating cloud is better, and can realize automatic winding, avoids the manual work to fill the filter fiber to cylindric filter column inside, fills inhomogeneous, and stacks into a lump easily under the influence of power wind, and peripheral air leakage is extremely serious, loses the filter effect.

Connecting pieces are respectively arranged between the two ends of the thorn column 11 and the filter frame 2; the connecting piece is flexibly connected, and the whole thorn column 11 wound with the second filter fiber can be dynamically changed under the influence of dynamic wind;

in this embodiment, the dynamic change of the spike 11 and the second filter fiber causes the adsorbed paint mist to sink into the receiving box 61 below. The service life of the second filter fiber is prolonged, the cleanliness of the second ventilation duct 1 is guaranteed, and the pollution to the subsequent dry-type filter device is reduced.

The cross-sectional areas or volumes of the filter component 4 and the second filter fiber are in equal proportion;

The filter assembly 4 is arranged in a horizontal direction;

the center distances of the adjacent filter assemblies 4 in the same horizontal layer are the same, and the cross-sectional areas and the volumes are the same;

the center distance of the filter components 4 of different horizontal layers in the space from top to bottom is gradually increased, and the cross-sectional area and the volume are respectively gradually increased;

the center distance between the adjacent filter assemblies 4 on the same horizontal layer is not smaller than the center distance between the adjacent filter assemblies 4 on the same horizontal layer above;

or (b)

The filter assembly 4 is longitudinally arranged;

in this embodiment, the center points of the filter elements 4 are staggered vertically, and the oblique axes are close to one straight line.

In embodiment 5, the filter frame 25 is disposed at the top of the second ventilation duct 1 at the opposite side of the air outlet 16.

The heights of the upper edges of the second filter fibers and the filter assemblies 4 on the opposite sides of the air outlet 16 of the second air passage 1 are not lower than the heights of the upper edges of the second filter fibers and the filter assemblies 4 on the same side of the air outlet 16 of the second air passage 1 respectively;

the height of the upper edges of the second filter fibers and the filter assembly 4 is designed to be an inclined plane or an arc shape from high to low from the opposite side to the same side of the air outlet 16 of the second air passage 1, and the upper edges of the second filter fibers and the filter assembly are matched with the air flow direction of the second air passage 1;

In this embodiment, the inclined arrangement of the top of the filter component 4 at two sides of the second ventilation duct 1 may also adopt an arc arrangement, which is matched and adapted with the original airflow direction in the second ventilation duct 1, so as to be more beneficial for the airflow to lead to the dry filter device, and avoid generating turbulence or retention of the airflow in dead angle areas.

Each of the support frames is provided with a bearing box 61 and a supporting point structure 9;

at least four groups of supporting point structures 9 are arranged, and the four corners of the filter frame 2 and the receiving box 61 are offset to the center position of the filter frame 2 by a certain distance;

a filter fiber layer is paved at the bottom of the bearing box 61;

the bottom of each of the filter frames 2 is provided with a receiving box 61.

The direct contact of the paint mist above or the massive and rapid contact of the air flow with the supporting point structure 9 is avoided, so that the adhesive varnish paint mist is difficult to separate from the bottom in the second air passage 1.

In this embodiment, the supporting point structure 9 arranged at the bottom of the receiving box 61 adopts a local point connection mode, so that the connection area between the supporting point structure 9 and the dry type filtering frame 2 and the second through-air duct 1 is minimum on the premise of ensuring the connection strength, and the supporting point structure is prevented from being adhered to the inner bottom of the second through-air duct 1 and is not easy to detach after the whole pre-filtering device adsorbs paint mist.

In this embodiment, the second filtering fiber layer laid at the bottom of the receiving box 61 has a large thickness, the volume of the filtering fiber layer is large, the same density is lower, the filtering fiber layer is extremely fluffy, after paint slag falls into the fluffy second filtering fiber layer after falling down, the filtering fiber layer is blocked by a plurality of fiber yarns and cannot be raised again, paint mist particles are prevented from polluting the second ventilation duct again, and meanwhile, the paint absorbing capacity of the dry pre-filtering device is improved.

In this embodiment, the strength of the receiving box 61 is enough to perform percentage receiving on the paint slag adsorbed by the filter fiber 1 above, so as to prevent the paint slag from falling into the second air passage 1, and further ensure the cleanliness of the second air passage 1 at any time; the receiving box 61 may be a hollow plastic plate or a cardboard, or other nonmetallic material, covering the entire bottom surface of the receiving box 61.

The periphery of the supporting point structure 9 is provided with an umbrella-shaped covering piece 13, a cylindrical extension body 17 with a certain height is connected below the umbrella-shaped covering piece 13, the bottom of the cylindrical extension body 17 is opened, a certain gap is arranged between the bottom of the cylindrical extension body 17 and the height direction of the second ventilation duct 1, and the shadow area of the covering piece 13 is far larger than the area of the supporting point structure 9.

In the embodiment, the supporting point structure 9 arranged at the bottom of the receiving box 61 is provided with an umbrella-shaped covering part 13 outside, the upper part of the umbrella-shaped covering part 13 is opened for covering the outer diameter of the supporting point structure, the lower part is of an umbrella-shaped structure, and a cylindrical extension body 17 with a certain height is connected below the supporting point structure, so that the supporting point structure 9 is integrally covered; the shadow area of the cover 13 is much larger than the area of the support point structure 9; the umbrella-shaped covering piece 13 is provided with an opening and closing part which can cover the supporting point structure 9 and cover the whole surface, and the opening and closing part is overlapped in a large area; the umbrella-shaped covering piece 13 can effectively shield direct pollution of the paint mist airflow above. The lower edge of the umbrella-shaped covering part 13 is provided with a certain height distance with the inner bottom of the second through-air duct 1, so that the umbrella-shaped covering part 13 or the supporting point structure 9 is prevented from being adhered with the second through-air duct 1 respectively after varnish paint mist is solidified, and the umbrella-shaped covering part is difficult to dismantle. The umbrella-shaped covering 13 is made of plastic, paper or other nonmetallic materials.

The filter frame 2 and the filter fiber layer are coated with a protective bag 10 with an integrated structure on the bottom surface and four side surfaces around the periphery;

the protective bag 10 has a five-sided enclosure with a bottom surface and four sides, the top surface being open;

extension sections are respectively arranged on the periphery of the top, and are connected with the cross beam 22 and the longitudinal beam 23 of the filter frame 2 in parallel with the first filter fiber layer;

redundancy of the top extension of the protective bag 10 is turned outwards towards the filter frame 2;

the bottom of the protective bag 10 and the bottom of the filter frame 2 are supported on a supporting frame together;

the periphery of the opening on the top surface of the protective bag 10 can be tensioned or tightened, and the opening is sealed.

In the embodiment, the first filter fiber layer is arranged on the longitudinal side surface, adopts an integrated planar structure, is in a tetrahedron shape, and is opened on the longitudinal side surface; the first filter fiber layer is fixedly connected with the top of the filter frame 2; under the action of the power wind from top to bottom, paint mist particles impact on the first filter fiber layer of the whole surface; the integral structure of the filter fiber layer is higher in connection strength, and the filter fiber layer cannot droop or fall off after adsorbing paint mist; the paint slag is adsorbed on the longitudinal side surface more, the paint mist capacity weight is increased in the limited volume, the filtering efficiency is improved, and the integral cost of the dry type filtering consumable is reduced.

In this embodiment, the protective bag 10 surrounding the filter frame 2 surrounds the filter frame 2, and the filter frame 2 can be quickly disassembled or folded or completely falls into the protective bag 10 after compression, so that the hazardous waste volume of the prefilter is reduced, and the filter frame is convenient to carry or transport manually through the protective bag 10; the opening of the upper part of the protective bag 10 can be tightened, and after tightening, the protective bag can be sealed, so that the primer or the colored paint is prevented from dropping off paint slag powder or paint slag clusters in the process of carrying operation, the environment is prevented from being polluted, the paint slag pollution in the process of manual operation is avoided, and the working environment or the working condition is ensured to be better.

The prefilter who sets up in dry-type room second ventilation duct 1 spouts adopts multiunit protection bag 10 to arrange adjacently, carries out certain air current separation, and the stroke of air current in the ventilation duct shortens, more is favorable to in dry-type room length direction that spouts, it is relatively more stable to avoid producing the air current mutual interference of the concentrated region that paint mist is the biggest under the dry-type room robot and spout the regional non-concentrated region under room air inlet and outlet or the adjacent robot intermediate region, avoid robbing wind, cross wind, wind speed or wind pressure change big, avoid because of the concentrated exhaust pipe air inlet that gathers and dry filter device's distance far and near influence get into every dry filter device's wind pressure, wind speed, amount of wind, guarantee the biggest quick corresponding dry filter device of entering of paint mist.

In this embodiment, the protective bag 10 is made of plastic film or other nonmetallic material with flexibility.

In this embodiment, the protecting bag 10 is integrally wrapped outside the integral structure of the filtering frame 2, and the protecting bag 10 and the bottom of the filtering frame 2 are commonly supported above the supporting frame. The whole protective bag 10 covers the filter frame 2 and can be separated from the supporting frame, and is used for dangerous waste disposal. The supporting frame can be utilized for the second time.

In this embodiment, the first filter fiber layer, the second filter fiber and the second filter fiber layer are made of glass fiber materials, and keep the fluffy characteristics of the glass fibers.

Embodiment 6, the filtering frame 2 for priming paint connected by tee joint and grip, the filtering component 4, the receiving box 61 and all filtering fibers connected together, the prefilter of the integral structure except the supporting frame can be placed in a closed chamber body integrally, and the closed chamber body is provided with an access passage and a passage locking structure; by directly or indirectly shaking, swinging or vibrating the structure of the integral prefilter, all the paint slag powder adsorbed by the filter fibers can be vibrated to the inner bottom of the protective bag 10. After all the paint slag powder adsorbed by the filter fibers are fallen off, the filter fibers are all restored to the original state. Taking out the filter frame 2 and the whole of the internal structure together, and leaving all the paint slag powder in the protective bag 10, and transferring the protective bag 10 and the paint slag powder to a hazardous waste workshop as hazardous waste. The filter frame 2 and all the filter fibers of the prefilter can be reused after being sleeved with new protective bags 10, so that the consumable cost of the prefilter is saved. In the shaking or vibrating process, the paint slag powder is collected and transported in the sealed chamber body in a concentrated manner, so that the paint slag powder is quite convenient.

The protection bags are arranged in the whole inner bottom surface of the first ventilation channel, liquid injection, splashing, leakage and the like generated in the cleaning process of the robot spraying tool can be fully collected, and finally the protection bags are used as dangerous waste for collection and transportation, so that the second ventilation channel is prevented from being polluted, and cleaning work is reduced.

Through the comprehensive technical scheme that the pre-filtering device is arranged in the second air passage of the dry spray booth, the extremely fluffy characteristics of glass fibers and the optimal paint mist adsorption effect are utilized, the arrangement and the design of the multi-region multi-structure of the filter fibers 4, the filter fiber layer I, the filter fiber layer II and the filter fiber II are combined, the space is reasonably utilized, the multi-level combined type paint mist adsorption and filtration is adopted, the action of the dry paint mist wind descending from the robot spray booth on the inertia force is utilized, the trend of the air flow of the second air passage is optimized, the air flow of the second air passage is more beneficial to be stable and smooth, the air balance of the whole coating line is further ensured to be more stable, the product qualification rate is improved, the paint mist containing amount is increased, and the integral operation cost of dry filtration is reduced.

The prefilter of second ventilation duct compares dry-type filter equipment, and its space and ventilation nature are unrestricted, do not have pressure differential influence ventilation duct, and the effect of adsorbing the coating cloud is better, and need not sealed operation, and comprehensive dry-type consumptive material cost is lower.

The invention realizes that the dry type filtering technology is adopted for the first time in the second air passage of the dry type spray booth, fully considers the different use conditions of the primer, the colored paint and the varnish, the water paint and the solvent paint, and has more comprehensive overall technical scheme and better universality. The clean environment of the second ventilation channel can be effectively ensured, the replacement of the pre-passing device is convenient, the efficiency is higher, the secondary utilization technology of the priming paint or the colored paint can be considered, and the consumable cost of dry type filtration is greatly reduced.

The technical scheme of the invention actually brings very remarkable beneficial effects, and is unprecedented in the technical field of dry spray room paint mist filtering treatment.

In this document, the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", etc. refer to the directions or positional relationships based on those shown in the drawings, and are merely for clarity and convenience of description of the expression technical solution, and thus should not be construed as limiting the present invention. In this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a list of elements is included, and may include other elements not expressly listed.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A paint mist prefilter for a second through-air duct of a dry spray booth, arranged at an inner bottom of the second through-air duct (1), characterized by comprising:

the air flow of the second air passage (1) is turned from top to bottom by 90 degrees and is horizontally connected with the air outlet (16);

a plurality of filter frames (2) which are respectively adjacent in the transverse and longitudinal directions are arranged at the inner bottom of the second air passage (1) along the length direction of the dry spray booth;

a plurality of groups of filter fibers I with fixed top parts and free swinging bottom parts along with wind are arranged above the inside of the filter frame (2);

a plurality of filter components (4) which are arranged in a staggered way and dynamically displace with wind are arranged in the filter frame (2);

The filter assembly (4) comprises a thorn column (11) and a second filter fiber, wherein the second filter fiber is of a long-strip integral structure and is wound on the thorn column (11) through a continuous spiral outside;

the spine (11) is provided with a fixing spine (14), and the second filter fiber is firmly connected to the spine (11) through the fixing spine (14);

connecting pieces are respectively arranged between the two ends of the thorn column (11) and the filter frame (2); the connecting piece is flexibly connected, and the whole thorn column (11) wound around the second filter fiber can be dynamically changed under the influence of dynamic wind;

each supporting frame is provided with a bearing box (61) and a supporting point structure (9);

the periphery of the supporting point structure (9) is provided with an umbrella-shaped covering part (13), a cylindrical extension body (17) with a certain height is connected below the umbrella-shaped covering part (13), a certain gap is formed between the bottom of the cylindrical extension body (17) and the height direction of the second ventilation duct (1), and the shadow area of the covering part (13) is far larger than the area of the supporting point structure (9).

2. A paint mist prefilter for a second through-air duct of a dry spray booth according to claim 1, characterized in that the filter frame (2) is provided with uprights (21), cross members (22) and stringers (23); the bottom of the filter frame (2) is provided with a supporting frame which is independently connected.

3. A paint mist prefilter for a second through-air duct of a dry spray booth according to claim 2, characterized in that said filter fibers-are arranged in groups along the length of said cross beam (22) of said filter frame (2); a certain gap is arranged between each group of first filter fibers;

the first filter fiber is designed to be in a gradient from high to low from the opposite side of the air outlet (16) of the second air passage (1) to the same side of the air outlet (16);

the longitudinal side surfaces of the periphery of the filter frame (2) are provided with a first filter fiber layer.

4. A paint mist prefilter for a second through-air duct of a dry spray booth as defined in claim 1, wherein,

the cross-sectional area or the volume of the filter component (4) and the second filter fiber are in equal proportion;

the filter assembly (4) is arranged in a horizontal direction;

the center distances of the adjacent filter assemblies (4) of the same horizontal layer are the same, and the cross-sectional areas and the volumes are the same;

the center distance of the filtering components (4) of different horizontal layers in the space from top to bottom is gradually increased, and the cross-sectional area and the volume are respectively gradually increased;

the center distance between the adjacent filter assemblies (4) of the same horizontal layer is not smaller than the center distance between the adjacent filter assemblies (4) of the same horizontal layer above;

Or (b)

The filter assembly (4) is arranged longitudinally.

5. A paint mist prefilter for a second through-air duct of a dry spray booth as defined in claim 1, wherein,

the heights of the filter fibers I and the upper edges of the filter assemblies (4) on the opposite sides of the air outlet (16) of the second air passage (1) are not lower than the heights of the filter fibers I and the upper edges of the filter assemblies (4) on the same side of the air outlet (16) of the second air passage (1);

the height of the upper edges of the first filter fibers and the filter assembly (4) is designed to be an inclined plane or an arc shape from high to low from the opposite side of the air outlet (16) of the second air passage (1) to the same side of the air outlet (16), and the inclined plane or the arc shape is matched with the air flow direction of the second air passage (1).

6. A paint mist prefilter for a second through-air duct of a dry spray booth as defined in claim 1, wherein,

the supporting point structure (9) is at least provided with four groups, and four corners of the filtering frame (2) and the bearing box (61) deviate to the center position of the filtering frame (2) by a certain distance;

And a second filter fiber layer is paved at the inner bottom of the bearing box (61).

7. A paint mist prefilter for a second through-air duct of a dry spray booth as defined in claim 3, wherein,

the filter frame (2) and the filter fiber layer are a protective bag (10) with an integrated structure of surrounding bottom surfaces and four side surfaces;

the protective bag (10) is provided with a five-face surrounding body with a bottom face and four side faces, and the top face is open;

extension sections are respectively arranged on the periphery of the top, and are in parallel with the first filter fiber layer and are respectively connected with a cross beam (22) and a longitudinal beam (23) of the filter frame (2);

redundancy of the extension section of the protective bag (10) is turned outwards of the filter frame (2);

the bottom of the protective bag (10) and the bottom of the filter frame (2) are supported on a supporting frame together;

the periphery of the opening on the top surface of the protective bag (10) can be tensioned or tightened, and the opening is sealed.