JPH0866655A - Air cleaner in coating film drying oven - Google Patents

Abstract

PURPOSE: To make a life cycle of removing a gum component from circulating air long, also to make filtering efficiency high and to enable to clean by easily taking the device off. CONSTITUTION: In an air cleaner in a coating film drying oven, a filter 14 having at least two sheets of metallic plates 15, 16 provided with many numbers of air passing-through holes 17, 18 arranged so as not to be mutually superposed is, installed in a circulation system for circulating air in the oven into a hot air generator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cleaning device for removing vaporized tar components from paints, inks or adhesives contained in the air in a coating film drying furnace.

[0002]

2. Description of the Related Art In a coating film drying oven, all paints, adhesives, and inks produce solid elements that become tars, the amount of which is related to the chemical composition of the resin used. As an example, regarding the amount of tar generated in painting an automobile body, Masaharu Nishimura, “Painting Engineering 29, [4], 161 (1)
949) ”is shown in Table 1.

[0003]

[Table 1]

The main components that become tars are low molecular weight or unreacted components contained in resins for paints, inks and adhesives, and part of resins for paints, inks and adhesives due to hot air. Oxidatively decomposed volatiles, such as those that should originally be used as a two-component paint, are coated with another compound so that the reactive crosslinking agent does not react at low temperature in order to make it a one-component type for work. This is when the blocking agent is vaporized when the blocking agent is dissociated by heat in the film drying furnace to be cured and dried.

A typical example of vaporization of the blocking agent is a thermally dissociated isocyanate blocking agent found in cationic electrodeposition paints and the like.

[0006] These components are vaporized and oxidatively polymerized while adhering to the furnace wall, or decomposed, and apparently dark brown or black brown oil is deposited in the form of a plate.

The components heated and vaporized in the furnace adhere to low temperature parts such as the entrance and exit of the furnace body and the exhaust duct, and are deposited as oily or plate-like particles, which eventually fall or scatter. This was the cause of so-called defective dust in the coating film. As a countermeasure against this, a method of burning the air in the furnace with an afterburner or cleaning the inside of the furnace at an extremely high frequency to remove the accumulated tar is adopted.

[0008]

However, the method of burning the air in the furnace by the afterburner in order to remove the tar has a problem of high fuel consumption.

A method of cleaning the inside of the furnace at high frequency is as follows:
So-called dirty, bitter, and odorous 3K work not only compels the worker to perform painstaking work, but the powder that was peeled off during cleaning floats again in the furnace, and again adheres to the inside of the furnace body after cleaning, causing dust defects again. As a result, the cleaning effect was not necessarily high.

An object of the present invention is to provide an air cleaning device in a coating film drying furnace which has a long life cycle for removing tar components from circulating air, has high filtration efficiency, and can be easily removed and cleaned. .

Another object of the present invention is to provide an air cleaning device in a coating film drying furnace which has a higher filtration efficiency.

[0012]

In order to achieve the above object, the present invention has at least two metal plates provided with a large number of air passage holes in a circulation system for circulating air in a furnace to a hot air generator.
The filters are arranged so that the air passage holes do not overlap each other.

In order to achieve the above object, the present invention provides a collar at least around the inflow side of the circulating air in the air passage hole of each of the metal plates, and further, the circulation in each of the metal plates. A metal mesh is attached to the surface on the air inflow side and the surface other than the air passage hole.

[0014]

In the present invention, the filter is installed in the circulation system for circulating the air in the furnace to the hot air generator. This filter has at least two metal plates with many air passage holes,
The air passage holes are arranged so as not to overlap each other.

Thus, the circulating air sent from the coating film drying furnace to the hot air generator passes through the air passage holes provided in the metal plate of the filter in a zigzag shape. At this time, the circulating air contacts the surface of the metal plate, the tar component of the circulating air adheres to and is captured on the surface of the metal plate, and the filtered clean air is fed to the hot air generator.

Therefore, according to the present invention, the tar component can be efficiently removed from the circulating air circulated to the hot air generator through the circulation system, and since the filter is formed of the perforated plate, the tar component is removed. The life cycle can be maintained for a long time, and each metal plate can be easily removed and cleaned to be used in a clean state.

As a result, it is possible to always clean the air in the furnace and prevent the coating film from being defective in dust.

Further, in the present invention, the collar is formed at least around the inflow side of the circulating air in the air passage hole of each metal plate. As a result, after the circulating air comes into contact with the surface of the metal plate, it does not immediately enter the air passage hole, but once hits the collar to generate a turbulent air flow.

As a result, the chances of the circulating air coming into contact with the surface of each metal plate are greatly increased, so that the tar component in the air in the furnace can be removed more efficiently.

Further, according to the present invention, the surface of each of the metal plates on the inflow side of the circulating air, and the surface other than the air passage hole,
A metal mesh is attached.

As a result, the circulating air is passed in a zigzag manner between at least two metal plates having a large number of air passage holes, and the tar component is adhered to and removed from the surface of each metal plate.
By allowing the circulating air to directly contact the metal mesh and capturing and removing the tar component, the tar component can be more efficiently removed.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. FIG. 1 is a vertical sectional side view of a coating film drying furnace using both near infrared rays and hot air, and FIG. 2 is installed in a hot air circulation system. FIG. 3 is a schematic view of a filter box incorporating a filter, and FIG. 3 is an exploded enlarged perspective view of a filter portion.

The coating film drying furnace shown in FIG. 1 has a furnace body 1, a trolley conveyor 3 in which a hanger 4 is suspended and supported, near-infrared irradiation devices 6 and 7, a hot air generator 8, and hot air in the furnace. A circulation system for circulating the generator 8 is configured.

The furnace body 1 is formed in a substantially chevron shape by connecting one half and the other half, which are symmetrically formed, with a connecting portion 2. Further, the furnace body 1 has a furnace body carry-in section A, a furnace body effective section B that follows the furnace body carry-in section A, and a furnace body carry-out section C that further follows the furnace body effective section B. Note that P1, P2, P3, P4, and P5 in FIG. 1 indicate points for explaining the operation.

The trolley conveyor 3 suspends an article 5 to be coated on a hanger 4, and sends the article 5 to the next step through a furnace body loading section A, a furnace body effective section B, and a furnace body unloading section C. It is mounted like.

The near-infrared irradiation devices 6 and 7 are installed in the effective part B of the furnace body at a predetermined interval, and irradiate near-infrared rays to the article 5 suspended and moved by the hanger 4,
I try to dry the coating.

The hot air generator 8 generates hot air and supplies it from the bottom of the furnace body 1 to the effective furnace body B through the hot air duct 9.

The circulation system for circulating the air in the furnace to the hot air generator 8 includes a circulation duct 10, a filter box 11 and
A circulation fan 12 is provided. The circulation duct 10 takes in the furnace air from the ceiling portion of the furnace body effective portion B near the furnace body unloading portion C and sends it to the filter box 11.

The filter box 11 is designed to remove the tar component from the circulating air sent from the circulating duct 10 by a filter, and its specific structure and operation will be described in detail later.

The circulation fan 12 positively sends the clean air filtered by the filter in the filter box 11 to the hot air generator 8. By the way, the filter box 11 is provided with a door 13, a filter 14, a cooling fan 25, and a cooling air outlet pipe 27.

As shown in FIG. 1, the door 13 is attached so as to be openable and closable via a hinge so that the filter 13 can be replaced or inspected by opening the door 13.

The filter 14 includes a first metal plate 15 and a first metal mesh 2 as shown in FIGS.
One unit and a plurality of units of the second metal plate 16 and the second metal mesh 22 are stacked and built in the filter box 11.

The first and second metal plates 15 and 16 are, for example, aluminum plates that are lightweight and easy to process, and are formed in a square shape having a thickness of 1 mm and a side of 500 mm, for example.

On the first and second metal plates 15 and 16,
Air passage holes 17 and 18 are formed.

The air passage holes 17 and 18 are, for example, a square having a side of about 70 mm as a basic shape, and are formed in a rectangular shape of an appropriate size in a margin portion.
For example, 30 metal plates 15 and 16 are provided so that their positions are shifted so that they do not overlap each other. as a result,
The first and second metal plates 15 and 16 have air passage holes 17,
The total surface area excluding 18 is about 103000 mm ² .

Collars 19 and 20 are integrally formed around the air passage holes 17 and 18 on both the inflow side and the outflow side of the circulating air 28 in the first and second metal plates 15 and 16. There is. Each of the collars 19 and 20 has, for example, a height of 1
It is formed to 0 to 20 mm.

The first and second metal meshes 21 and 2
2 has a thickness of, for example, 10 mm, the first metal mesh 21 is provided with a window 23 that fits outside the collar 19 of the first metal plate 15, and the second metal mesh 22 is provided.
Is provided with a window 24 that fits outside the collar 20 of the second metal plate 16.

The first metal mesh 21 is detachably attached to the surface of the first metal plate 15 on the inflow side of the circulating air 28 through the collar 19 and the window 23.
A second metal mesh 22 is detachably attached to the surface of the second metal plate 16 on the inflow side of the circulating air 28 via the collar 20 and the window 24.

The unit of the first metal plate 15 and the first metal mesh 21 and the unit of the second metal plate 16 and the second metal mesh 22 are, for example, 30 to 50 mm.
In this embodiment, seven sets are stacked at regular intervals and housed in the filter box 11.

As shown in FIG. 1, the cooling fan 25 sends cooling air into the filter box 11 via a cooling pipe 26 to cool the filter 14.

As can be seen from FIG. 1, the cooling air outlet pipe 27 is designed to feed the air after the filter cooling as the primary air of the hot air generator 8.

Next, the operation of the coating film drying furnace and the air cleaning device according to the above-mentioned embodiment will be described.

In this embodiment, as a typical paint having a large amount of generation of tar, an object to be coated with a cationic electrodeposition paint will be described as an example.

First, hot air is generated by the hot air generator 8,
Hot air is supplied from the bottom of the furnace body effective portion B in the furnace body 1 through the hot air duct 9 to warm up the inside of the furnace body 1. Also,
The near-infrared lamps of the near-infrared irradiation devices 6 and 7 are turned on and stand by for the entry of the article to be coated 5.

On the other hand, the object is preliminarily coated with a cationic electrodeposition paint, and the object 5 to be coated is hung and supported by the hanger 4 of the trolley conveyor 3, and the trolley conveyor 3 causes the furnace body loading section of the furnace body 1 to hang up. Then, it is moved to the furnace body effective portion B and the furnace body unloading portion C.

While moving the article to be coated 5 to the furnace body carry-in section A, the furnace body effective section B and the furnace body carry-out section C, the coating film is dried in a hot air atmosphere, and then the near infrared ray irradiation device 6, The coating material 5 is irradiated with near infrared rays from 7 to dry the coating film from the inside.

On the other hand, the furnace body unloading section C in the furnace body effective section B
A part of the air in the furnace is taken out as circulating air from the ceiling portion near the circulating duct 10 and the circulating air is guided to the filter box 11 from the circulating duct 10 and is filtered by the filter 14 housed in the filter box 11. After being filtered and purified, it is sent to the hot air generator 8 by the circulation fan 12, heated, and reused.

From the coating film heated in the furnace body effective part B, the solvent in the coating material is first vaporized at a relatively low temperature, and then the blocking agent is vaporized at a dissociation temperature of about 140 to 150 ° C. Further, at a high temperature of 170 to 180 ° C., a low molecular weight resin is vaporized by the urethane reaction and dispersed and floated in the air in the furnace. P shown in FIG. 1 in the vicinity of the connecting portion 2 of B, the furnace body unloading portion C
1, P2, P4 and P5 are contacted with each other to remove heat and become a liquid tar and adhere.

Further, when the in-furnace air in the effective furnace body B which is circulated for reuse passes through the circulation duct 10 having a relatively low temperature, part of the tar component contained in the in-furnace air is partially removed. It mainly attaches around P3 at the entrance.

It is difficult to prevent the generation of tars themselves in view of the components of the paint, and it is also difficult to prevent the tars from adhering to the furnace wall owing to the structure of the coating film drying furnace.

Therefore, when the object 5 to be coated is heated and dried in the furnace body 1, the concentration of the vaporized tar component increases,
To prevent a large amount of tar from adhering to the furnace wall, peeling off and floating, and adhering to the object to be coated 5 and causing dust defects, deteriorating the working environment and releasing foul odor and pollution to the outside. Efficient removal of the causative tar component and reduction of the absolute amount of tar production are the main points of problem solving.

Therefore, in this embodiment, when circulating the air in the furnace, the circulating air 28 is fed into the filter box 11 through the circulation duct 10.

In the filter box 11, a unit of the first metal plate 15 and the first metal mesh 21,
The filter 14 in which, for example, seven sets of the second metal plate 16 and the unit of the second metal mesh 22 are stacked is installed.

Then, the first and second metal plates 15 and 1
6 are provided with a large number of air passage holes 17 and 18, respectively. Further, the air passage holes 17 and 18 provided in the first and second metal plates 15 and 16 are arranged so as not to overlap with each other, and each air passage A collar 1 is provided around the passage holes 17 and 18.
9 and 20 are formed.

As a result, the circulating air 28 sent into the filter box 11 comes into contact with the first metal mesh 21 to capture the tar component, and adheres to the surface of the first metal plate 15 to cause the tar component. Are removed.

Next, the circulating air 28 is supplied to the first metal plate 15
Through a large number of air passage holes 17 which are provided on the first side and are surrounded by the collar 19 and flow toward the unit side of the second metal plate 16 and the second metal mesh 22. Here, the air passage hole 18 provided in the second metal plate 16 and the first metal plate 15
Since it is arranged so as not to overlap the air passage hole 17 provided in the first metal plate 15, the circulating air 28 flowing out from the air passage hole 17 provided in the first metal plate 15 is provided in the second metal plate 16. It does not directly pass through the created air passage hole 18 but flows in a zigzag shape.

Therefore, the circulating air 28 flowing out from the air passage hole 17 provided in the first metal plate 15 comes into contact with the second metal mesh 22 to trap the tar component, and the second metal plate 16 is also caught. After the tar component has been removed by contacting the surface of the first metal plate 15 and the first metal plate 15 and the first metal plate 15 through the plurality of air passage holes 18 provided in the second metal plate 16 and surrounded by the collar 20. It flows to the unit side of the mesh 21.

By repeating the above operation, seven sets of the first metal plate 15 and the first metal mesh 2 are formed.
While passing through the first unit and the second metal plate 16 and the second metal mesh 22, the tar component contained in the circulating air 28 is extremely efficiently removed, and the purified circulating air 28 is a circulating fan. It is positively sent to the hot air generator 8 by 12, heated again, and reused.

During the purification of the circulating air 28 in the filter 14, cold air is sent into the filter box 11 through the cooling fan 25 and the cooling pipe 26, and the cold air causes the first and second metal plates 15, 15 of the filter 14 to flow. 16 and the first and second metal meshes 21 and 22 are cooled,
The filtration function is maintained. Further, the cooling air after cooling the first and second metal plates 15 and 16 and the first and second metal meshes 21 and 22 in the filter box 11 is supplied to the hot air generator 8 through the cooling air outlet pipe 27. It is guided and used as the primary air of the hot air generator 8.

The first and second metal plates 1 of the filter 14
5, 16 and first and second metal meshes 21, 22
When the tar component adheres to and is deposited on the door, the door 13 attached to the filter box 11 is opened, and the first and second metal plates 15 and 16 and the first and second metal mesh 2 are attached.
1 and 2 are removed, and the first and second metal plates 15 and 16 and the first and second metal mesh 2 are removed by using a solvent, for example.
The filtration function is restored by cleaning the 1, 2 and the like. After that, it is put in the filter box 11 again, the door 13 is closed, and it is reused.

The collars 19 and 20 are formed around the air passage holes 17 and 18 of the first and second metal plates 15 and 16, respectively, and the first and second metal meshes 21 and 22 are omitted. In that case, immediately after the circulating air 28 comes into contact with the surfaces of the first and second metal plates 15 and 16, the air passage holes 17 and
Without entering 18, the turbulence is generated by hitting the collars 19 and 20 once.

As a result, the chances of the circulating air 28 coming into contact with the surfaces of the first and second metal plates 15, 16 are greatly increased, and in this case as well, the tar component in the furnace air is efficiently removed. be able to.

Further, in this embodiment, in addition to hot air as a heating source for the article 5 to be coated, it can be applied to a coating film drying oven using another heating source instead of the near infrared ray irradiation device.

Furthermore, the first and second metal plates 15 and 16 of the filter 14, the air passage holes 17 and 18, the collars 19 and 2, respectively.
The shapes of 0 and the first and second metal meshes 21 and 22 are not limited to the rectangles shown in the drawings, but may be other polygonal shapes or circular shapes.

Further, it goes without saying that the unit of the first metal plate 15 and the first metal mesh 21 and the unit of the second metal plate 16 and the second metal mesh 22 are not limited to 7 sets. The stacking interval can also be set arbitrarily according to the circulating air amount and the like.

[0067]

In the invention described in claim 1 of the present invention described above, at least two metal plates provided with a large number of air passage holes are provided in the circulation system for circulating the air in the furnace to the hot air generator.
Since the filters are installed so that the air passage holes do not overlap with each other, the circulating air sent from the coating film drying furnace to the hot air generator passes through the air passage holes provided in the metal plate of the filter in a zigzag shape. At this time, however, the circulating air contacts the surface of the metal plate, the tar component of the circulating air adheres to and is captured by the surface of the metal plate, and the filtered clean air is fed to the hot air generator.

As a result, there is an effect that the tar component can be efficiently removed from the circulating air circulated to the hot air generator through the circulation system, and since the filter is formed by the perforated plate, the life for removing the tar component is increased. It has the effect of keeping the cycle for a long time, and has the effect that each metal plate can be easily removed and cleaned to be used in a clean state. Therefore, the air in the furnace can be constantly cleaned and the coating film can be prevented from being defective in dust. There are possible effects.

In the invention according to claim 2 of the present invention,
A collar is formed at least around the inflow side of the circulating air in the air passage hole of each metal plate, and after the circulating air comes into contact with the surface of the metal plate, it does not immediately enter the air passage hole, but hits the collar once. As a result of generating the turbulent air flow, the chances that the circulating air comes into contact with the surface of each metal plate is greatly increased, so that the tar component in the air in the furnace can be removed more efficiently.

Further, in the invention according to claim 3 of the present invention, a metal mesh is attached to the surface of each of the metal plates on the side where the circulating air is injected, and the surface other than the air passage hole, and the air passage hole is formed. Circulating air is passed in zigzag between at least two metal plates provided in large numbers, and the action of adhering and removing the tar component on the surface of each metal plate and the circulating air directly contacting the metal mesh to trap the tar component By the synergistic action with the action of removing the resin, the tar component can be removed more efficiently.

[Brief description of drawings]

FIG. 1 is a partially longitudinal side view showing an embodiment of an air cleaning apparatus of the present invention and a coating film drying furnace to which the air cleaning apparatus is attached.

FIG. 2 is a schematic diagram of a filter box that incorporates a filter that is an essential part of the present invention.

FIG. 3 is an exploded enlarged perspective view of a filter portion that is a main part of the present invention.

[Explanation of symbols]

 1 ... Furnace main body of coating film drying furnace A ... Furnace body loading section B ... Furnace body effective section C ... Furnace body unloading section 3 ... Trolley conveyor for coating object 4 ... Hanger 5 ... Coating object 6, 7 ... Close Infrared irradiation device 8 ... Hot air generator 9 ... Hot air duct 10 ... Circulation duct 11 ... Filter box 12 ... Circulation fan 14 ... Filter 15, 16 ... First and second metal plates 17, 18 ... Air passage holes 19, 20 ... Color 21, 22 ... First and second metal mesh 28 ... Circulating air

Claims (3)

[Claims] 1. A coating film drying furnace in which the air in the furnace is circulated to a hot air generator through a circulation system, heated and reused,
At least two metal plates provided with a large number of air passage holes are installed in the circulation system, and a filter is arranged so that the air passage holes do not overlap each other. apparatus. 2. The air cleaning apparatus in the coating film drying furnace according to claim 1, wherein a collar is formed at least around the inflow side of the circulating air in the air passage hole of each metal plate. 3. The coating according to claim 1, wherein a metal mesh is attached to a surface of each of the metal plates on the inflow side of the circulating air and a surface other than the air passage hole. Air cleaning device in the film drying furnace.