JPH0256945B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to improvements in powder coating booths.

Powder coating has excellent coating film, anti-pollution measures,
It has extremely advantageous characteristics from the standpoint of saving quality and resources, and its importance is increasingly being recognized in recent years. However, it is extremely difficult to change colors in booths, guns, collection equipment, etc., and in particular, changing colors in powder coating booths and collection equipment is extremely difficult and takes a long time, which reduces the operating efficiency of powder coating lines. This has led to a significant increase in the cost of powder coating. As a countermeasure for this, there are two methods: preparing multiple booths, replacing the booths themselves when changing colors, cleaning the removed booths outside the line for the next color change, and cleaning the inside of the booths. Booths that are constructed from materials that are easy to clean, such as stainless steel plates, and have rounded corners that are difficult to clean so that they can be cleaned in a short time. A method using . Among these methods for changing the color of the booth itself, the method of preparing a replacement booth for color change requires that the floor space required to install rails and other equipment for changing the booth is It gets bigger, especially if the booth is large.
The time required for replacement work and internal cleaning work is long, and internal cleaning work is likely to be undesirable work for health management, and it takes a considerable amount of time. It must be said that it is an applicable method.
On the other hand, making the interior of the booth easier to clean due to its material and shape is an effective method as it allows the interior to be cleaned in a fairly short period of time. The paint must be cleaned, which is not good for health management.

In addition, the booth itself has drawbacks such as the fact that it is made of expensive materials such as stainless steel and has a rounded shape to make cleaning easier, making the booth itself more expensive.

Regarding changing the color of the powder coating booth, in addition to changing the color of the booth body described above, there are two other problems: changing the color of the powder coating recovery device and the duct that connects the booth body and the recovery device.

As a measure to change the color of the collection equipment, the exhaust gas inside the booth is treated with a dust collector with a simple structure such as a cyclone that is easy to clean, and the collected powder is reused. The powder paint that escapes due to the low efficiency of the primary recovery machine is processed by a secondary recovery machine such as a back filter, and is finally recovered, and the recovered paint from this secondary recovery machine is normally not used. There is a way to dispose of it.
In this case, the primary recovery machine may be one in which cyclones are prepared as many times as the number of colors of powder paint to be used as needed to speed up the color change work without cleaning, or one in which the cyclones are structured so that they can be easily disassembled and reassembled. Two methods are usually used: cleaning the inside of the cyclone that has been removed for color change and preparing it for the next color change. However, this method has a cyclone recovery efficiency of 5% because it is not possible to obtain a very high value for ordinary powder coatings.
Up to 10% of paint is often disposed of without being recovered, which is a major cause of increased paint costs, and is often unsatisfactory as a color change countermeasure in recovery equipment.

Another method for dealing with color changes in collection equipment is to prepare cartridge-based filtration and dust collection equipment with a small footprint for each color, and instead of changing the color of the collection equipment, replace the filtration equipment to change the color. is proposed. This method is much better than the previous methods in terms of powder recovery efficiency, but since it is usually difficult to clean the inside of the filtration equipment, only as many filtration units as the number of colors used in the painting line are used. Therefore, a set of dust collection equipment is required even for a small amount of color paint that is only used occasionally, which tends to increase equipment costs, and
Compared to cyclone dust collectors, etc., filtration dust collectors are larger in size, and the unused color change filtration equipment occupies a larger site area, which imposes many restrictions on installation conditions, and overall fixed costs are lower. It has the disadvantage that it tends to be expensive.

As a countermeasure for color change related to the duct connecting the booth and recovery equipment, in a normal powder coating booth, the main part of the exhaust gas is normally sucked in from the bottom of the booth. In order to prevent hoppers from accumulating at the bottom of the booth, it is necessary to increase the slope of the bottom of the hoppers.
This tends to increase the height of the booth and increase equipment costs for installing conveyors, etc.
On the other hand, cleaning a hopper with a steep slope increases the time it takes to clean the inside of the booth for color change, and also makes the structure complicated, which is not desirable. However, since there is usually no suitable method for cleaning the inside of the piping that connects the booth and the recovery device, it is necessary to use flexible gutters and the like to clean the ducts as many times as there are colors of powder paint used in the painting line. The usual method is to prepare and replace the duct every time you change the color. However, for this purpose, it is usually necessary to reduce the number of booth hoppers in order to reduce the number of replacement ducts, which increases the height of the booth hopper and complicates the structure of the bottom of the booth. Become. On the other hand, in the color change booth system in which replaceable cartridge-type filtration devices are prepared for each color, a method has been proposed in which the bottom of the booth is directly connected to the bottom of the filtration device. Although this is an excellent method in that it saves work, unless the bottom slope is quite large, the amount of powder paint deposited on the bottom of the booth will increase.
Since the dimensions of the filter and dust collector cannot be made that small, the filter and dust collector must be installed over a significant portion of the booth length, and it is usually difficult to perform painting operations from both sides of the booth. Another major drawback is that the entire booth becomes taller.

This invention solves the various problems of the powder coating booth system described above, and allows easy color change work in an extremely short time, the booth system occupies an extremely small area, and the equipment is simple. Nevertheless, the present invention provides a powder coating booth system with high paint recovery efficiency, low overall equipment cost, and easy color change.

The basic idea and detailed embodiments of the invention will become clear from the following description.

The most important basic concept of this invention is to completely abandon the idea common to conventional color change booths of cleaning the inside of the booth for color change, and to avoid cleaning the inside of the booth for color change. In order to achieve this, the members that make up the inner surface of the booth body are made of curtains, and this is attached to the frame.When changing colors, only the frame of the booth body is left as is, and the curtain is, in principle, painted. The curtains that make up the inner surface of the booth are prepared for each color to be used on the line, and when changing colors, the curtains that make up the inside of the booth are retracted or folded, removed from the frame, and placed in dedicated curtains for the next color to be applied. By replacing the curtains, in principle, the inner surface of the booth body is not cleaned, and instead of the cleaning work for changing the color, only the work of re-covering this curtain is performed, which makes it possible to change the color of the booth body. This succeeded in significantly shortening the working time.

FIG. 1 is a cross-sectional view of one embodiment of the color change booth system for powder coating according to the present invention, viewed from the direction of the conveyor, and mainly centered on the curtain.
FIG. 2 is a plan view seen from the direction of arrow AA in FIG. 1, and a part of it shows a broken surface so that the inside of the booth can be seen. Note that FIG. 1 shows a sectional view taken along the arrow BB in FIG. 2. In addition, in FIGS. 1 and 2, in order to simplify the explanation, only the minimum necessary parts of the frame are shown, and the rest are omitted, and details regarding the frame can be found in Chapter 7. 8 and 8. 3 and 4 show one method of configuring the bottom of the color changing booth according to the invention shown in FIGS. 1 and 2, and FIG. 3 is a plan view of the bottom, respectively. 4 is a side view of the bottom.
FIG. 7 shows only the frame of the color changing booth main body according to the present invention viewed from the same direction as FIG. 1, and FIG. 8 shows the same direction as FIG. 2 of the color changing booth system main body according to the present invention. It shows only the frame as seen from above. 6 is a sectional view of a storage box for storing curtains constituting the color change booth main body according to the present invention, viewed from the same direction as FIG. 1, and FIG. 5 is a sectional view of the storage box shown in FIG. 6. A top view of the box,
The main part of this storage box viewed from the same direction as Figure 2, a part of the booth frame to which it is connected, and a part of the stored curtain body are shown in detail in a cutaway view. be.

Below are figures 1, 2, 3, 4, and 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the color changing booth according to the present invention shown in FIGS.

In FIGS. 1 and 2, the workpiece 4 is suspended by a hanger 3 and inserted into the booth through a working opening 19 while being passed through the booth by the conveyor 1. The powder coating is electrostatically applied by the electrostatic powder coating gun 5, and the powder coating process is completed by a baking device (not shown). Note that 1' in FIG. 2 is a simplified representation of the conveyor 1 in FIG. 1 along the center line. In FIGS. 1 and 2, the ceiling and side walls of the booth during operation are basically made of flexible thin members such as a piece of cloth or a curtain, and each has a ceiling 21 with the conveyor 1 in between.
-C and side wall 21-S and ceiling 22-C and side wall 2
It is composed of 2 digits, and these pair of curtains 2
1 and 22 extend through metal fittings 29 and 30 by curtain rails 23 and 24 fixed to a frame 32, and constitute the booth ceiling and side walls. In Figure 2, the curtain that makes up the left half of the booth is attached to the mounting bracket 2 by curtain rails 25 and 26 fixed to the frame 33.
7 and 28 to form a ceiling part 22-C and a side wall part 22-S, respectively, thereby forming the ceiling and side walls of the booth. The inlet and outlet of the booth are arranged to form an inlet and outlet opening 18 according to the shape of the object to be coated so that air is not sucked through unnecessary spaces, as shown in FIGS. 1 and 2. , an exit curtain body 31 is installed as part of the side wall of the booth.

As shown in FIGS. 1, 3, and 4, the bottom of the booth has a spring 1 mounted on a bottom fixing frame 55.
A bottom curtain 14, which is elastically coupled via 5, 37, etc., is attached so as to be able to vibrate as a whole by a vibration exciter 17. As shown in detail in FIGS. 3 and 4, this bottom curtain 14 is usually made of relatively lightweight cloth, canvas, sheet, etc., and has an edge 35 as necessary, and is fixed at one point. It is configured to have a bottom portion 36 that slopes towards the side, and this is configured to have a bottom portion 36 that is inclined toward the frame body 55, and the springs 15, 37
etc., the whole is held in an elastically tensioned state, and this is held in an elastically tensioned state by the vibration exciter 17 as indicated by the arrow 3.
The vibration is applied as shown in 8. In this way, the bottom curtain as a whole vibrates in conjunction with the vibration exciter, and due to this vibration, the powder deposited on the bottom part 36 is easily moved downward as shown by the arrow 39. can be collected and collected. Due to the action of this excitation force, the slope of the bottom surface is approximately 10 to 30 degrees, which is sufficient to quickly collect the powder, which allows it to be coated on the object to be coated inside the booth. A considerable portion of the powder that has not been removed settles on the bottom screen 14 and is easily recovered as shown by arrow 13'.

As described above in detail, the inner surface of the booth according to the present invention is formed of curtains that are all extended during operation, as shown by the curtains 21, 22 and the bottom curtain 14, so that the interior of the booth is A painting space is formed in the area. As shown in FIGS. 1 and 2, the air inside the booth is supplied through an intake pipe 7 located away from the electrostatic powder coating gun 5.
The powder paint contained in the exhaust gas is collected by a cyclone 11 as a primary dust collector, as shown by arrow 13, and is sucked from the side wall of the booth through 8 and 9 as shown by arrow 10. It can be easily taken out of the system, and the cleaned exhaust gas is discharged out of the system as shown by arrow 12, and guided to a secondary dust collector as required. As is clear from the figure, the intake pipes 7, 8, 9, etc. from inside the booth are simply inserted into the side wall of the booth, and these are usually extremely short, and the primary dust collector and short It has a structure in which the air collection pipes are directly connected. As shown in the figure, the primary dust collector, for example, the cyclone, is attached with appropriate moving devices such as wheels, and these devices allow the primary dust collector 11 and the booth body to be extremely easily attached and detached. .

The color changing booth according to the present invention, which has been explained in detail with reference to FIGS. The powder paint discharged from the gun 5 to perform the powder coating work is mainly applied to the object 4 to be coated, but a considerable portion of the overspray powder paint that is not applied is transferred to the booth. It settles toward the bottom as shown by arrow 13, and this means that the larger amount of general air from the bottom is separated and recovered by a method that does not use this, and this is the main exhaust air normally found in conventional booths. This is a feature of the method according to the invention that is significantly different from methods in which the portion is extracted from the bottom with powder.

Therefore, the powder paint contained in the exhaust gas sucked by the primary dust collector 11 is reduced to about half of the overspray paint, so the powder paint contained in the exhaust gas sucked by the primary dust collector 11 is reduced to about half of the overspray paint. Even if a simple and small dust collector with high recovery efficiency is applied, a fairly high paint recovery rate of about 95 to 99% can be obtained. Therefore, from the viewpoint of paint recovery rate, it is easy to use a small and inexpensive ordinary cyclone as the primary dust collector 11;
Even if you prepare as many primary dust collectors as there are colors, there is no problem in terms of installation space, color change work, equipment costs, etc. In this case, the exhaust gas from the primary dust collector is normally led to a secondary dust collector such as a back filter or a liquid washing type filter for complete dust collection for the purpose of environmental protection. In this embodiment, the primary dust collector 11 is not necessarily limited to a cyclone; instead, a compact filtration and dust collection device such as a cartridge filter may be applied. In this case, in many cases, the load on the primary dust collector 11 is reduced by discharging the exhaust air from the booth in a well-balanced manner through multiple short suction pipes from the side of the booth, as shown in FIGS. 1 and 2. In order to take advantage of this feature, it is often better not to apply the conventional exhaust method, which exhausts a large amount of air from the lower part of the booth, as a method for collecting powder from the lower part of the booth. By doing this, as is clear from Figure 1, it is possible to reliably exhaust air even from the relatively upper part of the booth, thereby reliably preventing the conveyor and hanger from becoming contaminated. can. This exhaust system is extremely effective especially when the height of the booth is relatively high. The heated air inside the booth is discharged from the slit at the top of the booth along with fine particles, and problems such as accidents that contaminate the space around the booth, hangers, conveyors, etc. can be reliably prevented.

Regarding the primary dust collector 11, in the case of a multicolor painting line, a cartridge filter with high recovery efficiency is applied for the main colors, and a cyclone filter is applied for paints of colors that are used in relatively small quantities to reduce equipment costs. , it is also easy to construct an economical plant. In addition, when applying a cartridge filter, the exhaust part that does not contain recovered paint should be used as common equipment, and a well-known filtration-type dust collector should be applied, in which only the filter part is replaced as necessary. You can also do that.

Figures 5 and 6 show curtains 21-C, 21-S, 22- that make up the booth body when changing colors.
C, 22-S, device for retracting exit curtain 31, etc.;
and its progress is explained. In FIGS. 5 and 6, 48 is a storage box for storing the curtain body when it is not in use. It is a box body with curtain rails 23, 24, 25, 2 fixed to the booth body shown in Figs. 1, 7, and 8.
Storage rails 24', 23', 25', and 26' are attached to the storage rails 24', 23', 25', and 26', which are fixed so as to be smoothly connected to the housings 6 and 6. As is clear from FIG. 6, this storage box is constructed so that it can be easily moved and adjusted by using appropriate methods such as wheels, and from the bottom plate 44, as shown at 49 and 51, An exhaust pipe is attached. When changing the color, first the empty storage box 48 is opened as shown in FIG.
The storage curtain rails 23', 34', 25',
A storage box 48 is connected to the frame of the booth from one side of the booth so that the curtain rails 26' are smoothly connected to the curtain rails 23, 24, 25, 26 fixed to the frame of the booth. Next, while performing strong exhaust air from the ducts 51 and 49 as shown by arrows 50 and 52, the curtains 22-C and 22- were extended by the rails fixed to the frame.
S, 21-C, 21-S, 31, etc. are stored in the storage rail of the storage box as shown in 21-C in FIG. 5. Note that 22-C in FIG. 5 shows the curtain body extended to the frame body immediately before being retracted. This work is performed on the support 2 for the curtain rail of the curtain body.
7, 28, 29, 30, etc. can be easily stored in the storage box from outside the booth without entering the inside of the booth using strings, etc. not shown in the diagram. In this case, as a general rule, the curtain body is not cleaned when changing colors. At this time, the powder paint adhering to the inside of the curtain when retracting the curtain can be removed by tapping the curtain from the outside, or if the curtain is made of air-permeable cloth. It is also possible to perform the shrinking operation after brushing off the powder paint adhering to the inside of the curtain onto the bottom cloth 14 by blowing air or the like from the outside through the cloth. However, even if this is done, the paint powder adhering to the inside of the curtain during the shrinking work will stray out of the booth if left unattended, so to prevent this, ducts 49, 51, etc. Therefore, by performing forced exhaust as shown by arrows 50, 52, etc., air is sucked into the booth at a much faster speed in the same direction as the direction in which the booth is being retracted. It is possible to completely suppress the straying of powder generated during work, and to effectively prevent contamination of the surrounding environment. After the work of storing the curtains forming the side walls and ceiling is completed, the curtain 14 forming the bottom surface is removed, thereby completing the work of retracting the curtains forming the booth. Next, the storage box 48 in which the curtain body is retracted is removed. Incidentally, reference numerals 45 and 46 are guide plates for effectively carrying out the evacuation work of the storage box, and are used as doors of the storage box when the storage box is removed from the booth frame. After the curtain body that has been used until now is removed while being stored in the storage box 48 through the process described above, the bottom cloth of the curtain body that corresponds to the powder paint of the color to be used next is Another storage box houses the side and ceiling curtains newly installed on the frame and corresponding to the color of the powder coating to be used next.
It is newly connected to the frame in the state shown in Figure 5, and extended to the frame by retracing the procedure described above, thereby allowing a new color of powder paint to be applied. All preparations for the booth itself have been completed.

As described in detail above, when changing the color of a powder coating booth according to the present invention, there is no need to enter the booth to clean the inside of the booth, and the work is extremely simple, simply by shrinking the old booth and expanding the new booth. The replacement of the booth was completed through extensive work, and the length of the retracted booth in the direction of the conveyor is usually 1/5 to 1/5 of the length of the extended booth.
The booth itself, which has been reduced to about 1/20 and moreover, can usually be moved and stored at any location, so even if you prepare as many booth curtains as you need, there will be times when the booth is not in use. The floor space required for storage of curtains is extremely small, and the system is highly applicable to facility planning. It only takes a few minutes to retract the curtain, and there is no need to clean the inside of the booth, which was required in almost all cases of color change work in conventional color change booths. Summer is an extremely important feature of this invention. Furthermore, by providing sufficient exhaust air during the color change operation through the storage box, which can essentially be considered as the inside of the booth, it is practically possible to effectively prevent powder adhering to the inside of the booth from escaping, which tends to scatter during the color change operation. can be prevented and can have a significant effect on improving the working environment. Figures 5 and 6
The space inside the storage box shown in the figure, that is, the exhaust operation during storage work from the storage space, is not necessarily performed only from the bottom of the storage box. In such a case, the dust generated during storage can be more completely prevented from escaping by simultaneously exhausting from the upper point of the storage box. There is no need to clean the inside of the booth during color change work, and this method of performing color change work while powerfully exhausting air from the storage space through the inside of the booth is particularly effective when handling tall objects. This is extremely effective in large painting booths, and when combined with the method shown in Figure 1, in which the short intake pipe is used to exhaust air from multiple points in the height direction, this method has a significant effect on improving the environment around the booth. It is large, so this only allows for a more complete color change operation that prevents color mixing. Furthermore, in the color change booth according to the present invention, the time required to shrink the old booth, extend the new booth, and replace the temporary dust collector is extremely short, and usually one or two workers can complete the booth and collection. The time required to change the color of the dust device is about 10 to 15 minutes. As shown in Figures 5 and 6, the most suitable method for performing a complete color change is to cover the curtain storage box to form a closed chamber, and to perform forced exhaust air from the inside. However, if the booth is small or the colors to be changed are similar without much difference, a box-shaped storage box like the one shown in the figure is not necessarily necessary and a movable storage box can be used instead. In some cases, only a rail or a frame with fixed laces is required. The storage rail can be moved not only by supporting it from the floor but also by hanging it from the ceiling.

An example of the structure of the frame body for fixing the curtain body of the color change booth according to the present invention is shown in FIGS. 7 and 8.
As shown in detail in the figure, in order to fix the curtain rails 23, 24, 25, 26 for fixing the ceiling and side walls, a support shown at 55 and a beam 6 connecting these are used as shown in FIG. A frame body is constructed as shown in Fig. 8, and a curtain rail 23 for fixing the curtain of the frame body is constructed.
24, 25, and 26 are fixed thereto, and a frame body 56 is provided to fix the curtain forming the bottom surface, and a fixing device 16 of a vibrator 17 for applying vibration to the curtain on the bottom surface is further set to this. There is. In this example, the conveyor 1 is fixed to a frame 6 that constitutes a booth. However, the frame for fixing the curtain body is not limited to the form shown in Figures 7 and 8, and may be constructed using the building itself or a part of the floor as necessary. Sometimes it's okay.

Figure 3 shows how to configure the bottom of the booth.
As explained in detail with reference to FIG. 4, in addition to the method of constructing only a curtain that is tilted in a predetermined direction and supported elastically, an inclined curtain that is elastically supported In some cases, this is used in combination with another powder transport device, and examples of this are shown in FIGS. 9, 10, and 11. FIG. 9 is a plan view of this method, and FIG. 10 is an arrow D in FIG.
-D, and FIG. 11 is a side sectional view of FIG. 9. In these figures,
There is a trough 54 whose bottom is formed by an elongated perforated plate 58, and this perforated plate is installed inclined in the longitudinal direction.
is installed, and an air supply pipe 52 is installed in the pressurized chamber.
Pressurized air is introduced through the perforated plate 58 as shown by the arrow 53, and the powder that comes to the surface of the perforated plate 58 quickly collects toward one end of the perforated plate as shown by the arrow 39'. It constitutes a so-called air slide. Elastically supported by a spring 15 toward this air slide,
In addition, a curtain 14 is combined with the air slide and extended in an inclined direction, and this curtain is moved by a vibration exciter 17 fixed to the frame 16 as necessary, as shown by an arrow 38. It is formed to vibrate as a whole. In addition, 36 is spring 1
This is a frame for fixing 5.

When the powder descends and is appropriately deposited on the curtain body 14 stretched by the spring in this way, the vibrator 1
7, these powders move along the slope of the curtain 14 as shown by the arrow 39, eventually reaching the top of the perforated plate 58 of the air slide 54, and forming the perforated plate 58 as shown by the arrow 39'. They gather at one end of the downstream side of the board. The elastic retaining curtain vibrating type powder collection device combined with the air slide of the type explained in Figures 9, 10, and 11 is mainly suitable for wide booths, and is explained in Figures 3 and 4. The powder aggregation device has an aggregation point on the vibrating elastic retaining curtain itself.
It is mainly effective when applied to the bottom curtain of a small booth. This is because the systems shown in Figures 9, 10, and 11 can easily form a wide booth bottom by providing vibrating curtains on both sides of the air slide, and The action of the air slide allows the powder to be finally collected toward a relatively small number of points, so that the number of powder transport devices for transporting the powder to the collection device can be reduced. Incidentally, the powder collecting device of the type shown in FIGS. 9, 10, and 11 may be provided with an edge as shown at 35 in FIGS. 3 and 4 around the powder collecting device, if necessary.

As explained in detail above, a powder collecting device of the type that vibrates an elastically supported curtain as shown in FIGS. 3, 4 and 9, 10, and 11 is used in a powder coating booth. However, the application of this device is not limited to this only; for example, by applying it to the bottom of a dust collector, the height of the dust collector can be significantly reduced. This has a significant effect on reducing construction costs and improving the adaptability of the equipment.
Of course, this is effective when applied to the bottom of an independent back filter or electrostatic precipitator, but
As shown in Figs. 15 and 16, which will be described later, when a method of coupling the booth and recovery device is adopted in which the bottom of the booth and the bottom of the recovery device are directly connected and an air slide is sandwiched between them. This is extremely effective for simplifying the color change of the device, reducing equipment costs, etc.

The method of configuring the bottom of a powder coating booth according to the present invention is not limited to the above-described method of vibrating an elastically supported ramp,
A system in which the entire bottom section is made up of a belt conveyor is extremely suitable. Figures 12, 13, and 14 show examples to which this method is applied. Figure 12 is a plan view of the example during operation, and Figure 13 is a side view. , FIG. 14 shows a front view taken along the arrow CC in FIG. 13. In the embodiments shown in FIGS. 12, 13, and 14, the ceiling and part of the side walls of the booth made up of curtains are omitted, and only the lower part of the side wall 21-S is shown.
In the embodiment shown in FIGS. 12, 13, and 14,
The painting space is composed of a conveyor belt 60 forming the bottom of the booth, side walls 20-S, 31, 31', and a curtain forming the ceiling 21 (not shown). The coating of the objects to be coated and the structure of the upper part of the booth are the same as those shown in FIGS. 1 and 2, so their description will be omitted. In Figures 12, 13 and 14, the belt conveyor has pulleys 60 and 61.
The curtains 21-S, 31, 31' forming the side walls of the booth are in contact with the upper surface of the belt conveyor 62, and the main part of the overspray powder is driven by the belt conveyor 62 in the direction of the arrow 64.
comes down on top of. At the exit of the belt conveyor 62 on the dry pulley 61 side, there is a side wall 31 of the booth.
A small gap forms a conveyor exit 67 between the conveyor exit frame 68 that forms the lower end of the conveyor 62 and the conveyor 62. The sprayed powder is sucked and collected by the cleaning duct 65 via the suction slit 65. At this time, if the overspray paint powder is strongly charged, the suction slit 65
Static electricity is removed by a static eliminator 69 provided immediately before the belt conveyor, and care is taken to ensure that the belt conveyor is sufficiently cleaned by the suction slit 65. It should be noted that the belt conveyor is preferably constructed with an electrostatic conductor system, which is grounded by a conductor 63. In addition, the side wall 31 on the side of the idle pulley 60 is fixed to the frame 55 so that the curtain forming the side wall of the booth does not shift due to the rotation of the conveyor, and the side wall 31' on the side of the drive pulley 61 is fixed to a frame 55 such as a conveyor exit frame. Depending on the frame body 55
It is becoming fixed. The exhaust from the coating space constructed inside the booth, the insertion of the gun, the construction of the object conveyor, etc. are generally the same as those in the embodiment shown in FIGS. 1 and 2, and therefore will not be described here.

In the embodiment in which the bottom of the booth is configured with this belt conveyor, the amount of dust-collecting air sucked from the cleaning slit 65 is extremely small, so the collection device used to collect the paint may be extremely small. , this makes it easy to prepare dedicated collection equipment for each color, where the majority of the paint is collected. The paint collected through the intake pipe, not shown in the diagram, therefore constitutes a much smaller proportion of the discharged paint, so the primary dust collector for the paint collected there is less expensive. The first thing is that there is often no need to prepare something efficient.
This embodiment is similar to the embodiment shown in FIG. 2, and the handling of the curtains forming the side walls and ceiling of the booth and the primary dust collector during color change work is almost the same as the embodiment shown in FIGS. 1 and 2. In other words, if the booth has been operated for a long time, a considerable amount of powder may adhere to the inner surface of the curtains that make up the side walls, so in such a case, the conveyor belt 62 should not be operated. At the same time, the curtain is lightly tapped from the outside or high-speed air is blown from the outside to drop the adhered powder onto the belt, which is immediately collected by the suction device 65. When carrying out color change work,
The curtain storage box is applied from the side wall 31 side. A suction duct is installed on the side wall 31 to prevent floating powder from escaping by brushing off powder adhering to the side walls of the booth during color change.
The storage box is inserted into the painting space from the lower part thereof, or forced exhaust is performed through the side plate of the storage box through an opening provided in the side wall 31 through which the object to be painted passes. In this example,
An extremely significant feature is that the powder adhering to the inside of the booth is automatically collected by the collection device 66 when changing colors. In this embodiment as well, as in the embodiments shown in Figures 1 and 2, the installation of the curtains that make up the side walls and ceiling of the booth can be completed in a very short time, so as soon as this is completed, Immediately remove the storage box containing the curtain and replace it with the storage box containing the curtain coated with the powder paint of the next color to be used, reversing the procedure described above. However, the curtain was stretched out and fixed, and the color change of the booth was completed. When changing the color using the method shown in this embodiment, the conveyor and collection device 66 are operated until the removal of the old booth for the color change work is completed, and the conveyor is stopped when the work is completed. Conveyor cleaning device 6
5, 66 and later paint recovery systems need only be replaced with those prepared for the new color.
As soon as the above work is completed, the primary dust collector and intake ducts 7 and 8 prepared for the new color will be replaced, and the color change related to the booth will be completed. The time required for color change in this example is usually 10 minutes with two people.
It is extremely easy to carry out in about 30 minutes, and it is no exaggeration to say that it has almost completely solved the color change problem in powder coating. Regarding cleaning of the belt conveyor, if the material of the belt conveyor and the design and operating conditions of the cleaning devices 65 and 66 are appropriate, cleaning alone is usually sufficient when changing colors, but in the case of changing the paint. If you want to ensure complete cleaning as in the case of Apply well-known methods as necessary.

In the embodiments described in FIGS. 1, 2, and 12, 13, and 14, the method for extending the curtains that make up the side walls and ceiling is to use curtain rails installed parallel to the traveling direction of the conveyor. However, this is not limited to this, and it is possible to install a curtain rail as necessary in a direction perpendicular to the direction of conveyor movement, and to install a corresponding storage curtain rail and curtain storage box. can. In this case, the curtain can be divided into two parts by a conveyor and stored.
In addition, in the case of powder coating booths that are used to coat very long objects, the side walls of the curtain may be extremely high and difficult to handle. You can also use two tiers of curtain rails.

FIGS. 15 and 16 show a method of forming the ceiling and side walls of a painting booth using curtains, and shows an embodiment using a method different from the method using curtain rails. FIG. 15 is a cross-sectional view of the booth of this embodiment during operation, viewed from a direction perpendicular to the traveling direction of the conveyor. The relationship between the conveyor for the objects to be coated and the booth is the same as that shown in FIGS. 1 and 2, and is therefore omitted.

The condition of the booth during operation is the same as that shown in FIGS. 1 and 2, but in this embodiment, the partition curtains 22-C and 22-S that make up the ceiling and side walls are placed at right angles to the plane of the paper. A rod 7 having a length in the direction
This rod 7 is tensioned by fixing it to 0.71.
0,71 is suspended from a fixed hook 74 fixed to the frame 33 by a hanging ring 73, thereby constructing a booth. Although the above explanation has been made for the left half of the booth, the method of configuring the right half of the booth during operation is similar to the left half. Note that, similarly to FIG. 1, 31 is a side wall for forming an entrance and an exit of the booth perpendicular to the traveling direction of the object conveyor. In FIG. 15, the overspray powder that has not been applied to the object to be coated descends toward the curtain 14 forming the bottom of the booth as shown by the arrow 13, but this curtain is located at the 9th, 10th, 11th It is composed of a curtain that is elastically supported in combination with the air slide 54 shown in the figure and is connected to a vibration exciter. The arrow 85 gathers and reaches the bottom end of this air slide.
As shown in FIG. 3, the overspray is recovered and reused by the overspray recovery device 86. In addition, in FIG. 15, the elastic support device and vibration device of the curtain 14 constituting the bottom surface are omitted. Further, the functions of each part of the air slide are given the same numbers as in FIG. 11. The overspray that has not reached the bottom surface 14 of the booth is sucked together with air into a back filter 80 that communicates with the lower side of the booth as shown by arrow 88 and passes through filter cloth 75 as shown by arrow 78. Filtering and dust collection is performed. The paint deposited on the surface of the filter cloth 75 is blown off by blowing backwashing air indicated by the arrow 76 into the filter bag from the nozzle 77 at an appropriate time, and the powder paint that is blown off is sent to the dust collector 80. As shown by the arrow 87, it is gently sent to the air slide 54 by the action of the elastic support vibrating screen 14' that constitutes the bottom of the dust collector, and the dust falls onto the bottom of the booth. The paint is eventually collected by the paint recovery device 86 and reused in the same manner as the paint recovered from the paint.

FIG. 16 is a simplified diagram showing the intermediate stages of color change in the color change booth system shown in FIG. 15. When changing the color of this embodiment, as soon as the painting work is finished, first tap the side walls and ceiling of the booth, or, if the curtain is made of cloth, blow high-velocity air through it. Brush off the powder adhering to the inside surface of the booth by spraying. At this time, the dust collection chamber 80 is of course kept in an operating state. After this dusting work is completed, the hanging rings 73 and 74 for hanging the curtains forming the ceiling and side walls are removed. At this time, the other curtain fixing rod 72, which is perpendicular to the plane of the paper and has approximately the same length as the side wall, remained fixed, so the hanging rings 73 and 74 were removed as shown on the left side of Figure 16. In this state, the curtains 22-C and 22-S constituting the ceiling and side walls are folded so that the surfaces constituting the inner surface of the booth are on the inside. In this state, fix the folded curtain to the frame 3
3', and is rolled up into a separately prepared curtain winding device 81 as shown by an imaginary double-dashed line 83, thereby storing the ceiling and side wall membranes. The side wall of the right half of the booth is stored in the winding device 82 in exactly the same manner as shown by the imaginary two-dot broken line 84. As soon as this work is completed, the intake of air through the back filter storage chamber 80 of the dust collector is stopped, and the curtain 1 that forms the bottom of the dust collector chamber 80 is closed.
4' is rolled up and closed as shown in the figure, it is cut off from the intake chamber 79, and at the same time the curtain 14 that makes up the bottom of the booth is also removed, and then the final collection device 86 prepared for each color is also removed. Once removed, the surface of the air slide is cleaned with a vacuum cleaner, etc., and preparations for color change are completed. In this case, the intake chamber 79 is
Since only air that has been purified through the filter cloth 75 comes into contact with it, the interior will not be contaminated with paint, so it can be used as a common facility. After the above preparations for color change work have been completed, a winding device containing curtains to form a booth prepared for the paint of the next color to be used is set, and from this point on, the above-mentioned The curtains that make up the booth are hung in the reverse order, and then the dust collection chamber 80 corresponding to that color is set, completing the color change operation.

Changing the color of the painting booth according to the present invention as shown in FIGS. 15 and 16 described above in detail does not require cleaning the inside surface of the booth and only requires cleaning the air slide, so the color changing operation is extremely easy. It is simple and typically requires about two workers to complete a color change involving the booth and paint recovery device in 15 to 30 minutes. In the embodiments shown in FIGS. 15 and 16, FIGS.
As explained in the figure, by combining the air slide and the vibrating elastic support curtain type powder collection device, the bottom of the booth and dust collector can be configured with a gentle slope, and the collected paint powder can be collected. By collecting the powder on a common air slide and collecting it at a small number of powder collecting points, the overall system is extremely simple and the height of the device is low, which makes color changing work easier. At the same time, it is extremely effective, and at the same time brings various advantages, such as reducing the equipment cost of the equipment itself, allowing the height of the conveyor to be lowered, and by extension, the height of the building. can.

17 and 18 show still another embodiment of the method of constructing the bottom surface of the booth according to the present invention, in which FIG. 17 is a plan view and FIG.
The figure is a side sectional view. When the booth is small, as shown in the above explanation, there is no need to use an elastically supported vibrating curtain or belt conveyor to form the bottom of the booth, and instead a booth hopper 90 as shown in FIGS. 17 and 18 is used. It is also possible to construct the bottom surface of the booth by covering the booth with a curtain as shown in 91 above, and to replace this curtain and exhaust pipe 93 when changing the color. If colors are frequently changed and the amount of paint that accumulates at the bottom of the booth is not that large for each color, the bottom cloth 91 may be formed into a bag shape without making holes in the bottom so that it can be applied evenly when changing colors. In some cases, it may be practical to collect the powder directly, but as shown in FIG. In some cases, it is preferable to exhaust the exhaust pipe 93 when changing the color.
It is necessary to replace it. In addition, if the booth is small, it is also possible to change the color of the bottom without using a bottom cloth and by using a vacuum cleaner to vacuum up and collect accumulated paint.

The embodiments of the powder coating booth according to the present invention described above will be summarized below. In the booth according to the present invention, the side walls and the ceiling are constructed by using a first mold that is movably connected to the curtain rail, and the ceiling curtain and the side wall curtain being rolled up and stored. There is a second type configured as follows. Also, as a method of configuring the bottom of the booth,
The first type is a powder aggregation device that vibrates an elastically supported inclined curtain, the powder aggregation device is a powder aggregation device that vibrates an elastically supported inclined curtain, and other powder aggregation devices such as an air slide are used. There are three types: a second type that forms the bottom of the booth in combination with a device, and a third type that forms the bottom of the booth with a belt conveyor.
In the above explanation, examples of suitable combinations of these types necessary for explanation have been explained, but these combinations are not limited to the above examples only, and appropriate combinations can be made as necessary. Of course, it is possible to apply.

The main part of the curtain used in this invention is preferably non-flammable or flame-retardant in principle. or,
It is often better to use something that has been treated to have some conductivity to prevent the buildup of charges coming from the gun.

Examples of noncombustible curtains include glass fiber cloth and sheets, and examples of flame retardant curtains include cotton cloth treated with flame retardant treatment and sheets, but are limited to these. It is not something that will be done.

Methods of making the curtain conductive include weaving conductive fibers into the cloth, applying conductive treatment to the fibers themselves - for example, applying graphite treatment to glass fibers - and A method of attaching conductive members at appropriate intervals - for example, a method of attaching thin conductive rods in parallel to a cloth at regular intervals, which also serves as a reinforcing means to make the cloth expand and contract regularly. Various methods can be applied. In the powder coating booth according to the present invention, the belt conveyor is made of a conductive material and is grounded as described above, so that the potential is stable. Therefore, it is possible to efficiently and sufficiently remove static electricity.

Further, since the suction slit is provided downstream of the static eliminator, overspray paint on the conveyor belt is easily separated from the belt conveyor before reaching the suction slit. Therefore, since all of the paint is sucked through the suction slit, the paint recovery rate is improved and there is no need to frequently clean the top surface of the belt conveyor.

[Brief explanation of the drawing]

The accompanying drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a plan view taken along line A--A in FIG. 1, and FIG. 3 is a partial plan view of FIG. Figure 4 is a side view of the part shown in Figure 3, Figure 5 is a plan view of the part shown in Figure 2 and the storage device connected thereto, Figure 6 is a front view of the part shown in Figure 5, and Figure 7. 1 is a front view of the other parts shown in FIG. 1, FIG. 8 is a plan view of the part shown in FIG. 7, FIG. 9 is a plan view of another embodiment of the part shown in FIG. 3, and FIG. 9 is a sectional view taken along the line D-D in FIG. 9, FIG. 11 is a sectional view of the portion shown in FIG. 9, FIG. 12 is a plan view of still another embodiment of the portion shown in FIG. 3, and FIG. 14 is a sectional view taken along line CC in FIG. 13, FIG. 15 is a longitudinal sectional view of another embodiment of the present invention different from the embodiment shown in FIG. 1, and FIG.
The figure is a longitudinal sectional view of the embodiment shown in Fig. 15 in another state, Fig. 17 is a plan view of yet another embodiment corresponding to the part shown in Fig. 3, and Fig. 18 is the part shown in Fig. 17. FIG. 7, 8, 9... Exhaust duct, 14... Bottom curtain, 1
5... Spring, 17... Vibrator, 21, 22... Shikiri curtain, 21-C, 22-C... Ceiling curtain, 21-S,
22-S...Side wall curtain, 23, 24, 25, 26...
Extension curtain rail, 23', 24', 25',
26'... Curtain rail for storage, 32, 33... Frame for forming a painting room, 62... Belt conveyor, 81...
Ingestion device.

Claims (1)

[Claims] 1. The bottom of the booth is made of conductive material, and
The paint powder recovery device is composed of a grounded belt conveyor, and the device for collecting paint powder from above the belt conveyor is a static eliminator and a suction slit provided downstream of the static eliminator. A powder coating booth characterized by being equipped with.