JPS6362265B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating machine, particularly a so-called continuous coating machine. Continuous coating machines generally have a cabinet or booth in which the product is transported and paint or other material is sprayed from nozzles located above the cabinet. Any sprayed material that does not deposit on the product is collected and recycled.

One of the common problems with this type of paint sprayer is:
The goal is to maintain oversprayed paint and solvents in the cabinet so that they do not escape through the product access ports. These ports are not closed during spraying to prevent airborne spray material and/or solvent from escaping through these ports. The problem is complicated by the fact that the moving product creates an air stream that tends to blow excess paint and solvent out of the cabinet.

In the past, some continuous coating machines were designed to take out the air inside the booth using an exhaust device. The exhaust system includes a filter or other component to extract oversprayed paint before it is released to the atmosphere. Although this type of device solves the above problem, it inherently creates other problems. That is, this type of device reduces the effectiveness of the device in reducing the proportion of paint applied to the product.
Additionally, in the case of solvent-based paints, a significant amount of atomized solvent is extracted from the booth, making it difficult to maintain the solvent in the saturated air within the booth. Such air is desirable to prevent oversprayed material from accumulating inside the booth.

In the past, in order to prevent excess spray material from escaping from the outlet and inlet of the sprayer, it has been common practice to locate inlets around the outlet and inlet and connect them to an exhaust system. The exhaust system is adapted to remove air contained in the sprayed material from the air. This conventional example relies on water flow within the exhaust system to slow down the exhaust flow from the inlet and outlet. However, this device has some drawbacks. One of these was that the ventilation flow from the inlet and outlet was easily overwhelmed by external drafts and vortices, creating a swirling force of the spraying air away from the sprayer and into the atmosphere. Another disadvantage is that prior art systems create a continuous, high volume air flow from the booth to the exhaust system because it is difficult to keep the paint or solvent saturated within the cabinet.

Therefore, the main object of the present invention is to provide a continuous coating machine that can eliminate the above-mentioned drawbacks of the prior art.

In particular, it is an object of the present invention to provide a coating machine that is more efficient in coating work than those used hitherto.

Another object of the present invention is to provide a booth in which sprayed material is prevented from escaping through its inlets and outlets under any conditions of use.

Yet another object of the present invention is to provide a continuous coating machine that not only prevents leakage of excess spray material into the atmosphere, but also reduces the amount of air extracted from the booth. By reducing the amount of air extracted from the booth, the atmosphere inside the booth can be easily controlled and maintained at a saturated or semi-saturated state, preventing the solvent in the oversprayed material from drying out. This will promote its recovery and recycling.

A continuous coating machine capable of accomplishing each of the above objectives consists of a cabinet or booth having an exit port extending outwardly from both the product inlet and outlet. This inlet/outlet is connected to an exhaust system including an exhaust fan. The fan draws in atmospheric air in sufficient quantities and at sufficient velocity to effectively form a barrier to the exit of oversprayed material. The structure of the entrance is
Most of the air drawn in to form the barrier is air outside the booth.
As a result, airflow obstruction within the booth is minimized and the utilization of the sprayed material is maximized.

In a preferred embodiment, an airflow nozzle is provided within each port to provide a curtain of airflow toward the cabinet. Airflow reduces the amount of paint or spray material that is airborne. These escape from the sprayer cabinet into the inlet and exit ports, keeping the interior of the cabinet at or near saturation.

In addition to the above-mentioned advantages, the sprayer according to the present application has the advantage that it can operate with lower total horsepower compared to conventional devices. In prior art systems, water flow was used to create a negative pressure that prevented oversprayed material from exiting the booth outlet and inlet. Whenever water has been used to direct air volumes from adjacent parts of the product inlet and outlet, the equipment has required very high horsepower to pump large amounts of water and create a suitable air flow. I couldn't do it. It has been found that in the device according to the present invention, the removal of liquid from the exhausted gas is achieved more efficiently and with lower horsepower than in the prior art.

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

1 to 5 show preferred embodiments of the continuous coating machine according to the present invention. This paint machine 1
0 consists of a booth or cabinet 11 with entrances and exits 12 and 13 on both sides. Entrance/exit sections extend laterally from opposite sides of the booth through which the product to be applied is accessed. Entrance/exit part 1
2 and 13 are communicated to the atmosphere through duct arrangements 15 and 16. Intake fans 17 and 18 are provided in the middle thereof, respectively.

The booth 11 has a pair of side walls 20 and 21, a downwardly sloping bottom wall 22, a ceiling wall 23, and an end wall 26.
and 27. A slot 24 is formed at the top of the ceiling wall 23 to allow a conveyor support hook 25 to pass therethrough. end wall 2
6 is similarly formed with a slot 28 to allow conveyor support hooks to pass therethrough. The end walls 26 and 27 also include an inlet 30 and an outlet 31.
is formed, through which products suspended from the hook 25 can be put into or taken out of the booth.

Slot 24 in the ceiling wall and slot 28 in the end wall
are closed by overlapping flexible strips 29, allowing intrusion of hooks 25 but preventing overspray and air leaking into or out of the booth through the slots. In the embodiment shown in FIGS. 1-5, paint or other application material is supplied from a reservoir, not shown, through a hydraulic pump to a rotating nozzle 35 mounted on a rotating arm 36. In the embodiment shown in FIGS. Paint is delivered to the arm from a reservoir under high pressure and is applied as an atomized spray from a nozzle. Unapplied paint falls onto the bottom wall 22 of the booth and is removed from the siphon port 38 by the cleaning pump before returning to the main pump reservoir.

Here, the booth includes a conveyor device for transporting the product, a rotating nozzle, a paint supply source, a collection and coating device, etc., all of which are known.
It does not constitute the main part of this application. Rather, the booth comprising the inlet/outlet ports 12 and 13 and the ducting devices 15 and 16 which prevent the escape of the air containing the spray paint is the essential part of the present application.

Since the two entrance/exit sections 12 and 13 are symmetrical, only one entrance/exit section 12 adjacent to the entrance section 30 of the booth will be described in detail. The other entrance/exit section 13 surrounds the exit section 31 and is connected to the opposite end 27 of the booth.
is attached to. The entry/exit section 12 acts as an enclosed passageway through which the products are admitted into the booth 11. The entrance/exit part is a pair of end walls 4
0 and 41, a ceiling wall 42 and a bottom wall 43. Each of these walls maintains a sealing effect and booth 11
is attached to the end wall 26 of.

A slot 42a is formed in the ceiling wall 42 in the longitudinal direction to facilitate the operation of the hook 25 through the opening. In booth passageway 48, slot 42a is closed by overlapping flexible strips extending across the slot. This strip allows conveyor hook ingress, but serves to prevent overspray and air from escaping through the slot to the atmosphere, and also to prevent air from entering the doorway through slot 42a.

The central portion of each sidewall 40 and 41 of the doorway tapers outwardly from the portion adjacent the outer end 47, thereby creating a rectangular air gap on each side of the doorway. A collection passage 48 is formed. The passage 48 is constituted by outwardly flared side walls 45 and 46, non-flared side walls 49 and 50, a ceiling wall 42, and a bottom wall 43. Each rectangular passage 48 is
It is connected by funnel-shaped conduits 52 and 53 to circular ducts 54 and 55, respectively. conduit 5
2 and 53 are rectangular on the inlet side connected to passage 48 and circular on the inlet side connected to conduits 54 and 55.

2, 3 and 5, it can be seen that there is a means for creating an air curtain 108 within each doorway. This air curtain 108 is created by pressurized air released from holes or slots 112 in conduit 109. Slots 112 are aligned to create an air flow located between passageway 48 and the interior surface of cabinet 11.

These conduits 109 follow the cross-sectional silhouette of the port opening. Slot 112 in conduit 109
acts to create an air curtain 108 that forms a predetermined angle inwardly with respect to the booth.
The air flow within the air curtain 108 is directed through the conduit 1
09 is regulated and varied by an air pressure controller 110 located in an air line 111 supplying air pressure. By appropriately adjusting the controller 110 to balance the pressures at each inlet and outlet, the inside of the booth can be slightly pressurized. This reduces the amount of paint and solvent contained in the air exiting the booth 11, which is discharged into the passageway 48 and further removed from the booth 11.
It is kept at a state of saturation similar to that of the atmosphere.

At the outer end, the side walls 40 and 4 of the doorway
1 has an outwardly extending flange 56, which forms an extension of the side wall. This flange extends at approximately 45 DEG to the vertical plane of the side wall and serves to direct the airflow at the outer opening of the doorway.

As is clear from FIGS. 1, 2, and 4, the ducts 54 and 55 extend substantially horizontally, but strictly speaking, they are inclined slightly downward. The inner ends of the ducts 54 and 55 are connected to the vertical portions of the expansion chambers 74 and 75, which extend upwardly on the sides of the cabinet 11 to form a buffle box 78 and ducts 58 and 59. There is. The upper ends of each duct 58 and 59 are joined at a joint 60 and connected to the exhaust fan 17. When the fan 17 is in operation, air flows through the outer end 47.
through the passageway 48 as indicated by the arrow 65 and is directed through the conduit 54, the expansion chamber 75, the baffle box 78 and the conduit 59 to the duct arrangement. As will be discussed in more detail below, this airflow forms a flow barrier at the outer end of the inlet/outlet that prevents overspray and solvent from escaping from the cabinet 11.

The coating machine shown in FIGS. 1-5 can be used to apply either dry powder material or wet liquid paint to products passing through the cabinet 11. The spraying machine shown here is primarily intended for the use of wet paint or liquid spray material and is therefore equipped with a device for removing the liquid. This removal device extracts paint or spray material contained in the exhaust air before it is released to the atmosphere. At this end, each duct 54
and 55 includes a spray nozzle 70.
Liquid is injected through it to form a liquid scrubber 71 within each duct 54 and 55. This scrubber 71 is effective in capturing the air contained within the particles, which causes them to be discharged from the duct through outlet 73 into a tank (not shown).

The expansion chambers 74 and 75 are approximately the same size as the duct 5.
4 and 55.

A downwardly bent deflection plate 76 is provided inside the expansion chambers 74 and 75. This deflection plate is slightly wider than the diameter of the ducts 54 and 55;
The cross-sectional area is such that a deflection plate at least equal to the area of the duct can pass through. By combining a downwardly bent deflection plate and an expansion chamber,
Many of the relatively heavy particles contained in the airflow entering from ducts 54 and 55 will fall out of the air and flow through outlet 73 into the tank.

Above each deflection plate 76 is a baffle (baffle plate) 7.
8 are arranged. This baffle acts as a final stage filter to prevent the liquid/gas in the solid particles from escaping from the duct arrangements 15 and 16 into the atmosphere.

The upper ends of the vertical ducts 58 and 59 are provided with manually adjustable vanes 80 which can control the amount of air drawn through the ducts 58 and 59. Adjust the blade 80 by hand to remove the duct 58.
By controlling the amount of air flowing in from ducts 58 and 59, it is possible to balance the amount of air flowing in from both ducts 58 and 59. Thereby, the air circulation within the passages 48 located on opposite sides of the inlet/outlet section 12 becomes uniform.

In operation, paint is supplied to the nozzle 35 of the rotating arm 36 through a pumping device (not shown) at relatively high pressure. The paint is sprayed from spray nozzles 35 onto the product as it is transported through the cabinet. Excess paint is collected from the bottom of the booth by siphon 38 and collected into a paint storage source (not shown). At the same time, fans 17 and 18 are activated to blow air into the outer end opening 4.
7 into the passage 48 from outside. conduit 5
Vanes 80 at 8 and 59 operate to maintain a uniform and balanced air flow in passageway 48. Applicants believe that the minimum airflow within each aisle is approximately 800 feet per minute;
We have found that the optimal speed is on the order of a few thousand feet per minute. By balancing the air flows in both passages 48, the amount of air becomes uniform over the entire cross-sectional area of the opening 47. This uniform airflow effectively acts as an obstacle to the escape of the spray through the inlets and outlets of the port sections 12 and 13. Since this air obstruction exists over the entire vertical plane of the inlet/outlet section, particles contained in the air are prevented from escaping into the atmosphere.

The cabinet 11 is sealed to prevent outside air from entering. Doorways 12 and 13 and passage 4
The structure of No. 8 is such that most of the air that is drawn into the inlet/outlet portion and forms an obstruction is outside air.
As a result, very little air flows from the cabinet to the inlet/outlet section. Paint particles in the air enter the inlet from the air curtain 108 and are drawn into the passageway 48 by the air flow. The airborne particles are then removed from the air stream by scrubbers 71 in ducts 54 and 55. The liquid exits the duct system at outlet 73
The liquid flows into the tank through. The exhausted air flows upwardly through the duct system and out through the fans 17 and 18.

The minimal air flow outwardly from the cabinet 11 through the exhaust system allows very fine control of the atmosphere within the cabinet. The atmosphere within the cabinet is maintained very close to solvent saturation, thereby avoiding build-up of paint on the interior walls of the cabinet.

The embodiment described above is suitable for applications in which wet paint or spray material is applied to passing product.
However, this device is equally applicable when using powdered dry paints. The device shown in FIG. 6 can be used equally well with dry or wet paint. This device is similar to the device shown in FIGS. 1-5, except that it does not include a liquefaction purifier for extracting airborne particles from the exhaust system. In other words, liquid spray nozzles are removed from devices such as drain pipe 73. Instead, a recovery filter 90 is installed in the exhaust port.
is provided to collect the sprayed material. These materials, if not collected, will be sucked into the exhaust system. In other respects, this apparatus is exactly the same in construction and operation as the apparatus shown in FIGS. 1 to 5.

A third embodiment is shown in FIGS. 7 and 8. This device is intended for applying liquid paint to products. In this device, the first
Components corresponding to the apparatus shown in Figures 5 through 5 are designated with corresponding numbers.

In the embodiment shown in FIGS. 7 and 8, the cabinet 11, the doorways 12 and 13,
The equipment for supplying and removing paint from the booth is then similar to the corresponding elements of the first embodiment. Duct devices 54, 55 and expansion chambers 74, 75
Air trapped in particles blown through /
The devices that prevent the solvent from escaping into the air are similar. Above the baffle 78, however, two vertical ducts 58 are connected to one exhaust fan 100 on one side of the cabinet 11, and two vertical ducts 59 are connected to one exhaust fan 101 on the other side. The points are different. However, as in the embodiment shown in FIGS. 1 to 5, the air discharged from the air recovery passageway 48 is balanced and distributed over the entire area of the outer openings 47 of the inlet/outlet portions 12 and 13. It is important to form the curtains. The vertical duct 58 of the duct system has a valve or damper 1 for regulating the air flow.
03 and 104, and the duct 59 also has a similar device (not shown). These valves 103 and 104 are manually operated and balance the flow from each inlet and outlet, albeit controlled by different fans 100,101.

The difference in this exhaust system is that whereas in the embodiment shown in FIGS. 1 to 5 one fan was connected to ducts 58 and 59 on each side of the cabinet, here the ducts on the same side of the booth The two devices are similar except that one fan is connected to the two devices. Each duct has valves 103 and 104 for airflow balance.
, the operation of the devices after balancing is similar to each other.

A major advantage of the three embodiments described herein is that a highly effective barrier is created and maintained at the exit of the sprayed material from the booth to the product inlet or outlet. In particular, the air entering through the inlet/outlet opening 47 ensures that neither the spray material nor the solvent emitted therefrom escapes from the sprayer into the atmosphere. Instead, material that would otherwise leak into the atmosphere is captured within the exhaust system where it is removed before the air is exhausted to the atmosphere.

It should be noted that the present invention should not be construed as being limited to the three embodiments described above, and it goes without saying that those skilled in the art can make various changes and improvements without departing from the basic idea thereof. For example, although the coating material includes and does not contain a solvent here, the type of coating material is not limited to these. Solvent-based paints also include water-based paints and sprays, where water acts as a solvent.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention;
Fig. 2 is an end view of the above embodiment, Fig. 3 is a schematic plan view of the above embodiment, Fig. 4 is a side view of the above embodiment, and Fig. 5 is a cutaway view of the entrance/exit portion of the above embodiment. FIG. FIG. 6 is a plan view showing a second embodiment of the invention. FIG. 7 shows the third embodiment of the present invention.
FIG. 8 is a side view showing the embodiment, and FIG. 8 is a plan view of the embodiment. [Explanation of symbols of main parts], 11... Booth (cabinet), 12, 13... Entrance/exit section, 1
5, 16...Duct device, 25...Hook, 29
...Strip, 30, 31... Doorway, 35...
... Nozzle, 47 ... Outer opening, 48 ... Passage (slot), 71 ... Scrubber, 78 ... Buzzful,
108...Air curtain.

Claims (1)

[Scope of Claims] 1. A coating chamber comprising a side wall, an end wall, a bottom wall and a ceiling wall and adapted to accommodate the object to be transported; an inlet and an outlet for access through the coating chamber; means for forming an area within the coating chamber for applying spray material to the object as it passes therethrough; a flow control opening extending outwardly from the end and having an opening longitudinally aligned with, but spaced from, the spraying material contained in the air; at least one air collection slot located on opposite sides of each front doorway, the means for preventing air from escaping from the application chamber through the air flow control doorways;
exhaust fan means and duct means connecting each of said air collection slots to said fan means, wherein air flows by said exhaust fan means from said opening to each of said inlets and from said inlets to said air collection slots and ducting means for causing the exhaust to be evacuated through the duct; and prevention means comprising: a. 2. A spray applicator as claimed in claim 1, including means for balancing the flow of air through air collection slots on opposite sides of each said inlet/outlet section. 3. A spray applicator as claimed in claim 1, wherein the duct means includes a scrubber section for allowing exhausted air to pass through a liquid scrubber in a passageway through the duct means. 4. The coating machine according to claim 1, wherein the duct means includes a baffle plate located between the liquid scrubber and the exhaust fan means. 5. A coating machine as claimed in claim 1, including means within each of said entrances and exits for forming an air curtain directed inwardly toward said coating chamber. 6. The coating machine according to claim 5, wherein the air curtain forming means forms an air curtain between the air collection slot and the coating chamber opening. 7. A coating chamber consisting of side walls, end walls, a bottom wall and a ceiling wall, adapted to accommodate objects to be transported, and an entrance formed in said end wall through which objects can be taken in and taken out. and an outlet; means for forming an area in the application chamber for applying spray material to the object as it passes; a flow control inlet/outlet section extending from the application chamber, the flow control inlet/outlet section having an opening longitudinally aligned with the inlet/outlet but spaced apart from the inlet/outlet; means for preventing escape into and from the opening to the atmosphere, the means creating an inwardly directed air pattern passing from the outside of the opening over the entire cross-sectional area of the opening; A coating machine comprising: a prevention means having an exhaust fan that discharges the air from the inlet/outlet portion to the atmosphere; and a removal means that removes the sprayed material from the air before it is exhausted to the atmosphere. 8. The coating machine according to claim 7, wherein the air flow forming means includes means for simultaneously exhausting air from both sides of each of the inlet and outlet sections. 9. The sprayer of claim 7, wherein said exhaust means includes air collection slots located on opposite sides of said inlet and outlet sections. 10. The coating machine according to claim 7, wherein each entrance/exit portion includes means for forming an air curtain extending inward toward each coating chamber. 11. A coating chamber consisting of a side wall, an end wall, a bottom wall and a ceiling wall, adapted to accommodate the objects to be transported, and an inlet formed in said end wall through which the objects can be taken in and taken out. and an outlet; means for forming an area in the coating chamber for applying spray material to the object as it passes; and an inlet and an outlet adjacent to the inlet and outlet of the coating chamber and extending outwardly from an end thereof. a flow control inlet/outlet section having an opening longitudinally aligned with the inlet/outlet but spaced apart from the inlet/outlet; air flow means for producing an inwardly directed air flow of uniform velocity over an area, the means for exhausting said inwardly directed air from said inlet/outlet portion without passing said inwardly directed air through said coating chamber; and means for preventing spraying material contained in the air from exiting the coating chamber through the control opening. 12. The coating machine according to claim 11, wherein the air flow forming means is arranged on opposite sides of each of the inlet and outlet sections, and is connected to a suction fan for sucking air from the inlet and outlet sections. . 13. Each of said air collection means is connected to a suction fan by a duct arrangement, said duct arrangement comprising means for removing blasting material from said air before said air is exhausted therefrom to the atmosphere. 11
Painting machine described in section. 14. The coating machine according to claim 13, wherein the sprayed material removing means includes a buttful portion. 15. The atomizer according to claim 13, wherein the sprayed material removal means includes a liquid scrubber. 16. The air flow forming means includes air collection means located on opposite sides of each of the inlet/outlet sections and connected to the absorption fan through a duct arrangement, and means within the duct arrangement for adjusting the air flow through the air collection means. A coating machine according to claim 11, comprising: 17. The air flow forming means balances the air flow through air collection means located on opposite sides of each of the inlet/outlet sections through which air is drawn, and air collection means located on both opposite sides of each of the inlet/outlet sections. 12. The coating machine according to claim 11, further comprising means for causing the painting to occur. 18. A coating machine as claimed in claim 11, including means disposed within each said doorway for forming an air curtain in said doorway directed inwardly toward said coating chamber. 19. A coating chamber consisting of side walls, end walls, a bottom wall and a ceiling wall, adapted to accommodate objects to be transported, and an inlet formed in said end wall, through which objects can be taken in and taken out. and an outlet; means for forming an area in the coating chamber for applying spray material to the object as it passes; extending outwardly from one end wall of the coating chamber adjacent to the one outlet or inlet; at least one air flow control port longitudinally aligned with, but spaced apart from, the air flow control port; and at least one air flow control port for spraying material contained in the air to escape from the coating chamber through the air flow control port. means for preventing the inlet/outlet portion from causing an inwardly directed air flow of uniform velocity across the entire cross-sectional area of the opening through the opening; and a means for preventing absorption of water. 20. The coating machine according to claim 19, wherein the air flow forming means includes air collecting means located on opposite sides of the inlet/outlet section and sucking air from the inlet/outlet section. Patent No. 21, wherein said air collecting means is connected to a suction fan by a duct arrangement, said duct arrangement including means for removing blasting material from said air before said air is exhausted from said duct arrangement into the atmosphere. A coating machine according to claim 19. 22 The air flow forming means includes air collecting means located on opposite sides of the inlet/outlet portion and connected to the suction fan by a duct device, and regulating the air flow passing through each of the inlet/outlet portions within the duct device. Claim 1 comprising means for performing
The coating machine described in item 9. 23. The air flow forming means includes air collecting means located on opposite sides of each of the inlet/outlet sections, through which air is absorbed from each of the inlet/outlet sections, and means for balancing the air flow passing through the collecting means. A coating machine according to claim 19, comprising: 24. A coating machine as claimed in claim 19, including means located on opposite sides of each said entrance and exit section for forming an air curtain therein directed inwardly toward said coating chamber. 25 A method of preventing materials contained in the air from escaping from a coating chamber where sprayed materials are continuously applied to transported products, excluding the entrance and exit of the coating chamber where products are taken in and out. sealing the coating chamber to an air inlet and outlet; sealing the inlet and outlet to the coating chamber around the outlet and inlet of the coating chamber; and an exhaust system for absorbing air from the inlet and outlet. and a step of absorbing air into the entrance/exit exhaust device from the outside without suctioning any air from the inside of the application chamber, so that the air-blown material is removed from the application chamber. forming a relatively high velocity airflow obstruction that prevents escape. 26. The method of claim 25, including the step of forming an air curtain within each of the entrances and exits directed inwardly toward the coating chamber. 27. A coating chamber consisting of side walls, end walls, a bottom wall and a ceiling wall, adapted to accommodate objects to be transported, and an inlet formed in said end wall, through which objects can be taken in and taken out. and an outlet; means for forming an area in the coating chamber for applying spray material to the object as it passes; and an inlet and an outlet adjacent the outlet and inlet of the coating chamber and extending outwardly from an end thereof. at least one control port having an opening longitudinally aligned with but remote from the port; means for exhausting air from the port; and means for exhausting air from the application chamber. means for absorbing air from outside the doorway into the interior through its outer opening without absorbing airflow, thereby creating an airflow obstruction for preventing the escape of airborne blasting material from the application chamber; A painting machine comprising: