DE29521972U1 - Powder coating booth - Google Patents

Abstract

The invention concerns a powder coating booth (1) comprising at least one spraying unit (4) connected to at least one powder-preparation and feed unit (6). This booth has a small base surface and is in the form of a column whose height depends on the workpiece to be coated. A closable slot (3) is provided in at least one of the booth walls and is designed for the passage of at least one powder-spraying unit (4) . In cross-section, the booth can be circular or square or combined, for example oval, rectangular or the like. When the slot(s) (3) is (are) closed, a cleaning unit (20) is introduced and automatically cleans the booth interior. In addition, at least one double flap arrangement (32) can be provided on a booth wall area such that the booth can be switched universally to automatic and/or manual operation. If a lock device is provided on the inlet and/or outlet side, it can be transformed to form a pre-coating space or after-coating space. Furthermore, preferably at least the booth wall area opposite the powder-spraying unit (4) is non-conductive. To this end, this wall area can be made totally or partially from a non-conductive material. If necessary, a non-conductive coating can be applied to the corresponding necessary areas or to entire wall surfaces.

Description

Powder coating booth
Description

The invention relates to powder coating booths which are particularly, but not exclusively, intended for continuous operation and which are also suitable for manual coating operations, for example. Such a powder coating booth has at least one powder spraying device which is connected to at least one powder preparation and supply device.

Powder coating booths of the usual design include, for example, several powder spraying devices, which must be movable over the entire height of the booth and which can be arranged next to each other on opposite wall areas of the booth. There are also systems which have one or more powder spraying devices arranged on just one side of the wall, both for manual coating and for automatic operation. In all cases, a powder coating booth requires a lot of space and, depending on the number of powder spraying devices, has a considerable length of, for example, more than 6 m. When integrating such a powder coating booth into a coating line, difficulties arise with regard to a suitable hall design due to the large space required, especially in terms of floor space. In view of the large internal volume of such a powder coating booth, a large air requirement is also required, which means that powerful extraction devices have to be used, which has an uneconomical effect on the operation of the powder coating booth.

Furthermore, cleaning the interior walls of such a powder coating booth is difficult due to its size, which is necessary, for example, when changing colors, since suitable automatic cleaning devices have to be arranged so that they can move in the longitudinal direction, which requires a great deal of construction effort. Therefore, in most cases, cleaning is carried out by hand when changing colors, which is time-consuming and labor-intensive. In addition, color changes are required much more frequently these days, since different colors are often desired and users are usually offered a free choice of color, even in the prefabricated parts sector. This makes it increasingly important to realize the aspect of simple and reliable cleaning.

Furthermore, there are now powder spraying devices that include several fingers, which, by exploiting the tribology effect, create a very uniform and increased veil effect in the cabin interior and can achieve greater spray heights and distances.

The invention aims to overcome the difficulties described above and to provide a powder coating booth of the generic type which has a reduced space requirement, can be used universally for automatic operation and manual operation, and also enables simplified cleaning of the interior of the booth according to a preferred design.

According to the invention, a powder coating booth is provided with at least one powder spraying device, which is connected to at least one powder preparation and supply device, which is characterized in that the booth has a small base area and is designed in the shape of a column, and that in at least one wall of the booth there is a closable slot for carrying out the automatic powder spraying device.

device is provided. Powder spraying devices with several spray fingers can preferably be used here, which use the tribology effect during the powder spraying process. Even with a reduced number of powder spraying devices, a greater spray height and width as well as increased veil formation are achieved.

The design of the powder coating booth according to the invention has a significantly reduced space requirement, especially in terms of floor space, since it is relatively short in the longitudinal direction. This means that the available space for such a powder coating booth can be reduced considerably and it can be integrated into a powder coating line without difficulty. Despite the relatively small longitudinal extension of the booth, a sufficiently uniform and dense veil for powder coating the goods can be produced over a relatively short distance with the help of the powder spray devices arranged vertically one above the other, which are preferably arranged on opposite walls of the booth, without requiring larger height dimensions. As a result, the invention provides a compact powder coating booth which also has a smaller internal volume than conventional powder coating booths, so that more favorable conditions are achieved with regard to the air balance and the equipment for this can be operated and procured more cost-effectively, since a reduced supply capacity is required compared to the powder coating booths known per se and a significant energy saving is achieved.

Depending on the goods to be coated or the space available, the cabin can have a circular or square cross-section. With a circular cross-section, the cabin forms a structure similar to a standing cylinder, while with a square cross-section, a tower-like design is obtained. The corners of a square cross-section are at least in the interior of the

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Powder coating booth preferably rounded or bevelled.

Preferably, the slots arranged in the opposite wall areas of the powder coating booth can be closed by means of at least one flap that opens to the outside, whereby the flap directly delimits the respective slot. Such a design enables the slots to be tightly closed when cleaning, so that according to a preferred embodiment, when the slots are closed, the booth forms a closed container, the inner walls of which can be cleaned, preferably automatically, by means of a cleaning device that can be moved in a vertical direction, for example, thereby preventing powder dust from escaping during cleaning in order to minimize workplace pollution.

Alternatively, a fixed slot could be provided, for example in an openable door, which can be closed in a suitable manner to carry out the cleaning work.

The design of the powder coating booth created according to the invention with a small footprint and column-shaped construction also makes cleaning, in particular automatic cleaning, significantly easier and can be carried out more efficiently, since no guide carriage-like constructions of the cleaning devices that can be moved in the longitudinal direction are required, but rather a cleaning device can be used which only needs to be moved in the vertical direction if necessary and thus guides itself in a self-centering manner on the booth walls.

In a powder coating booth that is designed for automatic continuous operation and has a passage on the ceiling surface for a conveyor frame that hangs on a conveyor device, such as a chain conveyor, a

Such a slot-shaped passage in the ceiling surface is preferably automatically and tightly closed by the cleaning device when used as intended, so that even in a booth designed for continuous operation, cleaning can be carried out in a closed container formed by the booth.

The conveyor device can have an articulated arm or swivel arm construction, whereby a double-articulated arm construction, an auxiliary conveyor or the like can be provided for the arrangement of a cleaning device. The cleaning device could even be connected directly to the conveyor

According to a preferred embodiment, the cleaning device comprises a telescopic arrangement by means of which the cleaning device can be moved in a vertical direction in the interior space formed by the cabin.

According to an alternative embodiment, the cleaning device can be adapted to the cross-sectional shape and height of the booth in terms of design. Such a cleaning device can be arranged or used in a fixed position for cleaning. It can then, for example, perform a rotary movement around its longitudinal axis and/or preferably a slight oscillating movement around the longitudinal axis and/or in a lateral direction. The cleaning device can expediently have a basket-shaped support structure. With such a cleaning device, it can, for example, be moved into the booth from the side, and the cleaning of the inner wall or walls of the booth can be carried out quickly and completely with a large area coverage by the cleaning device.

With the design of the powder coating booth according to the invention, the most varied design forms of cleaning

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Use equipment that can be operated with compressed air and/or suction air and/or wet. When changing color from one color to another, only ionized air can be used for cleaning and the remaining fine dust can remain.

Since after closing the slots for the powder spraying devices and passing through the ceiling surface in an automatic continuous operation, a tightly closed container is obtained, the powder coating booth according to the invention also makes it easy for the cleaning device to be operated wet in order to ensure more efficient and reliable cleaning, particularly when changing the color of the booth. Of course, combined designs of the cleaning device, such as compressed air operation and wet operation, are also possible.

According to a preferred embodiment, the cleaning device sweeps over the inner walls of the closed container, and in particular sponge parts, nozzles or the like can be provided on the same.

According to a further advantageous embodiment of the powder coating booth, the floor area of the booth is funnel-shaped and there is a powder outlet and, if necessary, a closable opening for liquid drainage during wet cleaning. With this design, during cleaning with the help of the automatic cleaning device, the powder that has been scraped off or blown off the walls of the booth can be transported to the powder outlet, sucked off and, if necessary, recovered. In the case of a downstream wet cleaning device, the liquid can also be drained off the floor area of the booth through the funnel-shaped design, so that the cleaning work can be carried out fully automatically with the recovery of the powder.

Preferably, in the powder coating booth, a lock is arranged in the direction of flow of the goods to be coated on the inlet side and outlet side of the booth, which can be converted into a post-coating station or a pre-coating station. These locks are of course designed in such a way that they can be tightly closed when the interior of the booth is cleaned. The essential feature of this preferred design is the fact that these locks have a dual function and can also be converted into a post-coating station or a pre-coating station, where, depending on the configuration of the parts to be coated, manual pre-coating or post-coating can be carried out, if necessary, either from the right or left, even when the system is running. This means that the powder coating booth according to the invention can be universally adapted in a simple manner to the specific characteristics of the goods. The lock floor is preferably designed to be fixed.

Another preferred design of the powder coating booth according to the invention enables a simple conversion from manual coating operation to automatic coating operation and vice versa. In this preferred design, adjacent flaps of different sizes for manual operation and/or automatic operation are provided in the opposite wall areas of the booth assigned to the powder spraying devices in a mirror-image arrangement. The adjacent flaps can all be opened outwards. For automatic operation, opening the smaller flap is sufficient to expose the corresponding slot for the powder spraying device to pass through. When the powder coating booth is used in manual operation, the larger flap is also opened and the interior of the booth is accessible for the manually operated powder spraying device(s), whereby thanks to the mirror-image arrangement of the flaps, the flaps on the opposite wall surfaces

The hand-operated powder spray device(s) to be used can be offset from one another in the longitudinal direction to act on the material. This avoids mutual obstruction when the hand-operated spray devices work on the opposite surfaces. The powder spray devices can be arranged directly opposite one another and, for example, can be moved synchronously in the vertical direction if necessary. This can cause a type of "pusher effect" due to the electrostatics. In certain applications, it may even be sufficient to arrange the spray device(s) on a wall surface of the booth.

According to a further embodiment of the powder coating booth according to the invention, the booth wall areas adjacent to the locks can be folded outwards in such a way that an opening is formed that is large enough for the cleaning device to be introduced and retracted into the booth from the side. Of course, the powder coating booth according to the invention can also be designed in such a way that the cleaning device is retracted from above.

If the powder coating booth is designed in such a way that the cleaning device is moved into the booth interior from above, the booth is preferably open at the top. In such a design, the side of the booth that is open at the top can be assigned a blow ring or nozzles that can be fed by exhaust air, for example from the after-filter. If necessary, blow nozzles can also be provided in the area of the locks. This air supply can effectively prevent the powder/air mixture from escaping from the booth in the most energy-efficient way possible. If necessary, blow nozzles can also be provided in the area of the locks in the direction of the booth height.

If the cleaning device in the powder coating booth according to the invention, which is arranged vertically from above

works downwards, is to be introduced from the top of the cabin, the top of the cabin is preferably closable by means of a lid, which is preferably made in one piece and attached to the cleaning device. The top of the cabin is thus automatically closed when the cleaning device is used as intended in order to have a tightly closed container interior for carrying out the cleaning work.

According to a further preferred embodiment, a part of the booth wall forms a rear wall of the central powder preparation and supply device, and there is a connecting opening to the interior of the booth, which can be closed by means of a flap that opens to the interior of the booth. Such a design allows the excess powder that has accumulated in the central powder preparation and supply device to reach the interior by opening the connecting opening in the event of a color change, to be sucked out and then recovered via the powder circuit. This increases the effective use of the powder for powder coating. Of course, this connecting opening is then closed using the flap when the necessary cleaning work is to be carried out fully automatically using the cleaning device according to the invention.

Furthermore, the flaps provided in the cabin according to the invention are designed in such a way that they have seals on their sealing edges, so that the interior of the cabin is reliably sealed and also pressure-tight when the flaps are closed, which is particularly advantageous for carrying out wet cleaning work using the cleaning device according to the invention.

In summary, according to the invention, the powder coating booth is designed in such a way that it has a considerably reduced

floor space and that it also encloses a smaller internal volume than conventional coating booths. The booth therefore has a reduced air output volume and operation is significantly more energy efficient. Furthermore, such a design of a powder coating booth also enables effective and automatic cleaning of the internal walls in a structurally simple manner by using a self-centering cleaning device, which allows time-saving automatic cleaning.

Further preferred embodiments of the powder coating booth according to the invention are reproduced with regard to further design details in particular in claims 2 to 25, which, through this express reference, are fully part of the disclosure content of the present application.

In particular, the design forms of cleaning devices are also specified, which are adapted to the cross-sectional shape and height of the powder coating booth in terms of their outline and which do not need to move vertically. For cleaning, these can be used in a fixed position or rotating around their longitudinal axis, and/or such a cleaning device can also perform an oscillating movement around the longitudinal axis and/or in a lateral direction.

It has also been shown that the wall or wall areas opposite the spraying devices should preferably be non-conductive in order to prevent charging. To this end, the corresponding walls or wall areas could be made of non-conductive material or a non-conductive coating could be provided on the entire surface or only on parts of it. The booth can therefore discharge itself and charging can be suppressed, ensuring safe operation.

The invention is explained in more detail below using preferred embodiments with reference to the accompanying drawing. In the drawing, identical or similar parts are provided with the same reference numerals. The figures of the drawing show the following:

Fig. 1 is a schematic, perspective overall view of a powder coating booth according to the invention,

Fig. 2 a side view of the powder coating booth to illustrate automatic and continuous operation with the lock open,

Fig. 2a an enlarged detail view of the upper and/or lower end area of the powder coating booth,

Fig. 3 is a schematic longitudinal sectional view of the cabin shown in Fig. 2 with several different designs of an automatically operable cleaning device,

Fig. 4 a cross-sectional view of another embodiment of a cabin with several flaps of different sizes on the opposite wall areas for the use of the powder spraying devices,

Fig. 5 a schematic example of a connection of flaps which, when closed, allow a tight seal of the interior of a powder coating booth,

Fig. 6 is a schematic plan view of another preferred design of a powder coating booth, which allows the cleaning device to be moved in from the

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side or in the direction of passage of the cabin during automatic operation,

Fig. 7 shows a further embodiment of a powder coating booth with an associated cleaning device that can be retracted from the side and which has a square cross-section,

Fig. 8 is a schematic longitudinal sectional view of an alternative embodiment of a cleaning device,

Fig. 9 is a schematic side view of a suitable embodiment of a powder spraying device with an integrated cover for the feed-through slot in the booth wall, and

Fig. 10 a perspective detail view of a floor area of a powder coating booth with a flat floor and an associated floor cleaning device.

With reference to Figures 1 and 2, a preferred embodiment of a powder coating booth, designated overall by 1, is shown, which has a circular or possibly oval cross-section and is designed in the form of a standing cylinder. The powder coating booth 1 has a small base area 2 and is designed in the shape of a column. As shown by an arrow in Figure 1, the material to be coated is moved in the direction of passage A through the interior formed by the powder coating booth 1 in an automatic operation. On a wall or on opposite walls of the powder coating booth 1, at least one slot 3 can be seen, through which at least one powder spray device 4 passes, which has, for example, finger-shaped spray parts, which are arranged in the interior of the booth, for example, in a vertical direction one above the other. This

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Powder spraying devices 4 are known per se and they allow powder coating even when the powder spraying devices 4 are arranged directly opposite one another in a line. Each slot 3 is assigned a flap 5 which is open towards the outside during coating operation. Although not shown, instead of the arrangement comprising the slot 3 and the flap 5, a design can also be chosen such that, for example, a fixed slot is provided in an openable door for the passage of the powder spraying device(s) 4. This or these fixed slots can then be closed to carry out the cleaning described below. The powder spraying device(s) 4 are connected to a central powder preparation and supply device 6, a so-called "powder center", which in the embodiment shown is arranged in such a way that part of the booth wall forms the rear wall of this central powder preparation and supply device 6. As is shown in general form in broken lines in Figure 6, for example, in the area of the central powder preparation and supply device 6 there is a connecting opening 7 to the interior of the booth 1, which can be opened and closed by means of a flap 8.

According to Figure 1, the ceiling surface 9 of the powder coating booth 1 has a slot-shaped passage 10 which extends in the direction of flow A. As can be seen from Figure 2, in continuous operation, a conveyor frame 11 extends through this slot-shaped passage 10, on which goods to be coated (not shown in detail) are arranged. This conveyor frame 11 with the goods to be coated attached to it is guided through the interior of the powder coating booth 1 in continuous operation in the direction of flow A and past the powder spraying devices 4 via a conveyor device, for example a chain conveyor 12 or the like indicated in Figure 2.

As shown in broken lines in Figure 2, the ceiling surface 9 can alternatively be omitted in the powder coating booth 1, for example, so that it is open at the top. An annular air blowing device 40 can then be arranged at a certain distance above the booth 1 and/or blowing nozzles 41 can also be arranged in the middle area. The annular air blowing device 40 has an annular base body and several nozzle openings (not shown in detail) which are designed and aligned in such a way that they blow air towards the interior of the powder coating booth 1. The annular air blowing device 40 and/or the blowing nozzles 41 can be fed with exhaust air from the post-filter, i.e. with ultra-pure air. This air prevents the air/powder mixture from escaping upwards at the open top of the powder coating booth 1 during coating operation. With such a construction of the powder coating booth, not only is a structure simplified, since a ceiling area 9 is missing, but corners and difficult-to-clean areas can also be avoided in order to make the cleaning process, which is explained in more detail below, more efficient.

As is also indicated in Figure 2, an outwardly projecting edge 42 can be formed at the upper and/or lower end of the longitudinal wall surface of the powder coating booth 1, which forms a type of pocket 43. This detail is shown in an enlarged view in Figure 2a. If, as is shown for example in Figure 3 of the drawing, the cleaning device 20 has a scraper 25 or a scraper lip (not shown), this scraper 25 can be pushed into the pocket-shaped expanded space 43 at the end of the cleaning work, and the pocket-shaped space 43 can then be sealed with a sealing part 45 which is provided on the cleaning device 20 (see Figure 2a). A

Cleaning medium, such as compressed air or the like (see description below), can be introduced, whereby suction can be used to assist if necessary. The exhaust air flow containing the discharged powder can then be fed to a cyclone or the like via an outlet 48, for example to enable recovery. The nozzles 47 can be arranged opposite one another or offset from one another and, of course, several such nozzles 47 and possibly also several outlets 48 are provided over the circumference of the pocket-shaped space 43 formed. With the help of this design, the scraper 25 itself can be cleaned at the end of the cleaning process, which ensures that the scraper 25 does not cause contamination of the powder during a further color change.

Furthermore, in the embodiment shown, the powder coating booth 1 has a lock 13 on the inlet side and outlet side as seen in the flow direction A. The lock 13 comprises a preferably fixed floor 14 and door-shaped flaps 15, which are rotatably arranged on the base body of the powder coating booth 1.

As can also be seen from Figure 1, for example, blowing nozzles 46 can be arranged in the area of the longitudinal edges and/or the transverse edges of the lock 13. These blowing nozzles 46 direct an air flow in the direction of the interior of the powder coating booth and thus prevent the powder/air mixture from escaping from the interior of the powder coating booth 1 when the lock 13 is open, similar to the embodiment described above, in which the powder coating booth 1 is open at the top.

In the powder coating booth 1 shown in Figure 1, for example, the door-shaped flaps 15 of the lock 13 are shown in such a state that the lock 13 forms a pre-coating station, at which a

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Pre-coating can be carried out on the goods to be coated. The design of the lock 13 on the outlet side can be carried out in the same or similar way, so that a post-coating station can then also be provided through the lock 13 if necessary. The post-coating station or pre-coating station thus formed can be accessed either from the right or left depending on the requirements, for which the door-shaped flaps 15 are opened or closed accordingly. In the case of a pre-coating and/or post-coating station, access is thus possible either from the right or left, while a wall surface is provided opposite as a counter wall, which is formed by a door-shaped flap 15 that opens outwards by approximately 90°.

As is schematically indicated in Figures 2 and 3, the floor area 16 of the powder coating booth 1 is preferably funnel-shaped and a connection can be made to a powder outlet 17 or, if necessary, to a liquid outlet line 18. Of course, the floor can be flat or slightly inclined. With the help of swivel slides or sliding devices or the like (not shown in detail), the powder accruing during cleaning can be conveyed, for example, to the powder outlet 17.

If, according to Figure 10, the powder coating booth (not shown in detail) has a flat floor 57, the powder can be cleared during operation by means of a floor cleaning device 58 in the direction of a suction channel 59, which is connected, for example, to a downstream cyclone (not shown in detail). In the example shown, the floor cleaning device 58 comprises a curved, preferably spiral-shaped clearing arm 60, on which stripping devices, such as brushes or the like and/or blowing devices can be provided. As shown by an arrow in Figure 10, this clearing arm 60 is rotated around an approximately vertical axis 61 in the interior of the powder coating booth.

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cabin is moved so that the flat floor 57 is completely covered during one complete rotation of the clearing arm 60 around the axis of rotation 61. This design also allows a flat floor 57 of a powder coating booth to be cleaned automatically.

As can be seen from the illustrations discussed above, the powder coating booth 1 according to the invention has a compact design and in particular a relatively small footprint. This results in a reduced volume enclosed by the powder coating booth 1, so that the powder coating booth 1 can be operated with a reduced air balance of only 25% of the previous or less. This reduction in the output volume results in considerable energy savings when operating the powder coating booth 1. In particular, the more favorable air balance of the powder coating booth 1 that can be achieved with the invention is also due to the fact that there are significantly smaller opening areas, the length of the slots 3, 3' is greatly reduced, and the number of slots 3, 3' is also significantly lower than in conventional powder coating booths. On the other hand, the pre- and post-coating stations are completely eliminated.

In the illustration according to Figure 3 and Figure 8, which will be explained later, preferred embodiments of a cleaning device, designated overall by 20, are shown, which allows automatic cleaning of the inner walls of the powder coating booth 1. If, for example, a powder change is to be carried out, the flaps 5 for the powder spray devices 4 and the door-shaped flaps 15 of the locks 13 are closed. The connection opening 7 from the central powder preparation and supply device 6 to the interior of the powder coating booth 1 can be exposed by opening the flap 8, and the excess powder accumulated in the central powder preparation and supply device 6 can enter the interior of the powder coating booth.

sucked in and discharged via the powder outlet 17 to the powder circuit for recovery. In the example shown in Figure 3, the cleaning device, designated overall by 20, is then retracted, whereby the slot-shaped passage 10 in the ceiling surface 9 of the powder coating booth 1 can be automatically closed by means of a plug-shaped seal 21, which can be attached to the cleaning device 20. The cleaning device 20 is then moved in the interior of the powder coating booth 1 in a vertical direction from top to bottom and possibly back, whereby in the preferred embodiment according to Figure 3 a telescopic arrangement 22 is provided for this purpose. Nozzles 23 for wet cleaning of the inner walls of the powder coating booth 1, brushes 24, sponges or the like and/or scrapers 25 can be provided on the cleaning device 20. The detailed design of this cleaning device 20 depends on the geometric conditions and the application purposes, but in particular the interior of the powder coating booth 1 can be cleaned in a vertical direction in a dry manner, for example using compressed air and/or suction air, ionized air and/or wet, for example using water and additives. During wet cleaning, hot air and/or room air can possibly be used in addition to accelerate the cleaning process, for example using propulsion nozzles. Since all openings on the powder coating booth 1 that are required for the intended operation of the powder coating booth 1 for powder coating are closed with associated devices, the powder coating booth 1 forms a closed container that can be cleaned dry and wet in an effective and automatic manner. During wet cleaning, the liquid outlet line 18 is provided in the floor area 16, which can be opened using a flap 26 if the liquid has previously been cleaned dry. stripped powder from the inner wall of the powder coating booth 1 and, if applicable, from the central powder preparation and supply device 6 has been transported to the powder outlet 17. Thus, the

cleaning liquid introduced into the wet cleaning device 20 can be reliably drained off via the liquid outlet line 18 on the bottom side of the powder coating booth 1. In the case of wet cleaning, this can be accelerated using hot air and/or room air and/or blow-off nozzles.

This self-centering cleaning device 20, which is also essential according to the invention, in conjunction with the column-shaped design of the powder coating booth 1, allows automatic and efficient cleaning of the booth 1 in the vertical direction, in a structurally simple manner, since rail guides and the like are not required for movement of the cleaning device 20 in the longitudinal direction or in the direction of passage A of the booth 1.

Figure 4 shows a schematic cross-sectional view of another preferred embodiment of a powder coating booth, designated overall by 1'. In contrast to the preferred embodiment explained above, this powder coating booth 1' has a double flap arrangement on the opposite wall areas for introducing the powder spraying devices 4' in a mirror-image arrangement, which comprises at least two flaps of different sizes. The flap 5' provided in the above illustration is small and serves to open and close the associated slot 3' for passing through the powder spraying devices 4'. This is followed by a larger flap 30 on each side, which is also open to the outside, as shown in broken lines in Figure 4. This mirror-image arrangement of two flaps 5' and 30 on both opposite wall areas of the powder coating booth 1' enables the powder coating booth 1' to be easily converted for manual operation and automatic operation. In automatic mode, which is shown in Figure 4 with solid lines, only the small flaps 5' are opened and the associated powder spraying devices 4'

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retracted, which, as shown there, lie in a line and face each other. If, instead of the small flap 5, the larger flap 30 or both are opened outwards, as shown in broken lines in Figure 4, an access opening is exposed for the use of powder spraying devices (not shown in detail) for manual coating. The mirror-image arrangement of the double flaps 5', 30 then exposes openings on the opposite wall areas of the powder coating booth 1' for manual operation, which are offset from each other in the longitudinal direction. This makes it possible to powder coat both sides using manual powder spraying devices (not shown in detail) without any mutual obstruction. According to this flap design, which is shown as an example in Figure 4, the powder coating booth 1' can be converted from automatic operation to manual operation and vice versa without great difficulty.

This means that the design is of course also such that, as explained above, automatic cleaning of the interior of the powder coating booth 1' is possible with the help of an associated cleaning device 20, for example by carrying out a vertical movement. To do this, the two flaps 5' and 30 on each side are then closed. Of course, there can also be just one arrangement of flaps 5', 30 of different sizes.

The powder spray device(s) can be arranged horizontally or vertically next to or above each other.

As also indicated in Figure 4, thanks to the design of the lock 13 explained above, it is also possible to use the powder coating booth 1' with a pre-coating station and/or a post-coating station from the left or right.

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Figure 5 schematically shows a connection of two flaps 5 ¹ and 30, for example from Figure 4, in the closed position. On the respective sides assigned to the joint of the flap 5', 30, corresponding seals 31 are provided, which ensure a reliable tight closure of the interior of the powder coating booth ^{1 1} when the flaps 5', 30 are in the closed position. Of course, seals different from those shown can also be used, and of course the same or similar and corresponding seals are also provided on the sealing edges of the other flaps of the powder coating booth structure 1, 1' that may be provided, in order to have a tightly closed container for the cleaning process and use of the cleaning device 20, which is formed by the powder coating booth 1, 1'.

Figure 6 shows a further variant of a powder coating booth, designated as a whole with 1". The details that correspond to the previous embodiments are not explained again, only the essential differences. These identical or similar parts are therefore provided with the same reference numerals in Figure 6.

In the powder coating booth 1", the booth wall areas adjacent to at least one lock 13 can be folded outwards, as shown with the flap arrangement designated as a whole with 32, so that the cleaning device 20 explained above and shown schematically in Figure 6 can be inserted and retracted into the powder coating booth 1" in the direction of passage A or from the side. As shown in broken lines, the flap arrangement 32, which can optionally be linked to the arrangements described above, for example according to Figure 4, allows such a large opening area to be exposed on the powder coating booth 1" that the cleaning device 20 can be inserted from the side into the interior of the powder coating booth 1"

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is moved in. When the cleaning device 20 is then located in the interior of the powder coating booth 1", the flap arrangement 32 is closed again and brought into the position shown with a solid line, the door-shaped flaps 15 of the locks 13 are closed and the flap 8 for the connection opening 7 to the powder preparation and supply device 6 can be opened. When carrying out a dry cleaning process of the interior of the powder coating booth 1", the excess powder from the central powder preparation and supply device 6 can then reach the interior of the powder coating booth 1" and be returned to the powder circuit via the powder outlet 17 explained above.

Figure 7 shows a further embodiment of a powder coating booth 1"' in a similar sectional view to Figure 6. What is different from the preferred embodiments explained above is that the powder coating booth 1"' is square in cross section. The inner edge areas are rounded or beveled as shown for effective cleaning. Here too, for example, similar to Figure 6, a corresponding flap arrangement 32' is provided in the area of at least one lock 13, which allows the cleaning device 20' to be introduced from the side when the flap arrangement 32' is open. As with the previous embodiments, a double flap arrangement with a smaller flap 5' and a larger flap 30 is also provided on the opposite wall areas of the powder coating booth 1"', which is arranged in mirror image on the opposite wall areas of the powder coating booth 1"'. Apart from the cross-sectional shape differing from the previous embodiments, identical or similar parts in Figure 7 are provided with the same reference numerals.

Figure 8 serves to illustrate a further embodiment of a cleaning device, designated overall as 20". This cleaning device 20" is adapted in terms of height and cross-sectional shape to the corresponding design of the powder coating booth designated there as 1"". In the example shown, the cleaning device 20" has a support structure 50, for example in the shape of a basket, on which brush inserts 51 are optionally provided that can rotate about their own axes. For cleaning, this cleaning device 20" is arranged essentially stationary in the interior of the powder coating booth 1"". This cleaning device 20" sweeps over all the inner wall surfaces of the powder coating booth 1"". For effective cleaning, the cleaning device 20" can perform a rotary movement about its longitudinal axis. To assist, it can preferably perform a slight oscillating movement about the longitudinal axis and/or a slight movement in the lateral direction. This cleaning device 20" is designed similarly to a brush arrangement, for example, which is used in vehicle washing systems, for example. Otherwise, the further details shown in Figure 8 have already been explained above in connection with other embodiments of a powder coating booth.

Figure 9 shows a schematic side view of a preferred embodiment of a powder spray device 4", which comprises, for example, finger-shaped spray parts. In contrast to the embodiment described above, the powder spray device 4" shown in Figure 9, for example, has cover parts 56 arranged loosely on a shaft 55, which are preferably designed in such a way that they overlap in a scale-like manner. With the help of these cover parts 56, the slot or feed-through slot 3, 3' formed in the powder coating booth can also be reliably covered during the powder coating operation, although the powder spray devices 4", for example in Figure 1, are in

vertically or, if necessary, horizontally in a suitably controlled manner. With such a design, the overall air balance of the powder coating booth 1, I ¹ , 1", 1"', 1"" can be improved even further, since practically no air escape is possible in the area of the feedthrough on the wall surface.

From this it can be seen that, regardless of the cross-sectional shape of the powder coating booth 1, 1', ¹ ", 1 ", 1"", the versatile use of the same for manual or automatic operation is given and that a cleaning device 20, 20', 20" which can be moved in the vertical direction can be used.

Of course, the invention is not limited to the details of the preferred embodiments described above, but numerous changes and modifications are possible, which the person skilled in the art will make if necessary. Combined cross-sectional shapes other than round and square, such as oval or the like, are also possible. Furthermore, the flap arrangements can also be partially omitted or designed differently depending on the application, provided that a closed container is formed for cleaning with the help of the cleaning device 20, 20', 20" of the powder coating booth 1, 1', 1", 1"', 1"", which allows automatic cleaning without complex slide guides and at the same time enables cleaning of the flaps by closing them.

To improve operational safety, at least the wall area(s) opposite the powder spray device(s) 4, 4', 4" can be made of non-conductive material, for example an insulator. In an equivalent manner, instead of manufacturing from a non-conductive material, a coating of non-conductive material can be applied to a conductive base material, which can make manufacturing significantly cheaper. This can result in a much

- 25 -

A smaller distance between the part to be coated and the edge of the booth can be chosen, as the disruptive effect of the outer wall (powder is attracted to the outer wall by the earthing) is avoided. This allows the dimensions of the booth to be reduced even further.

List of reference symbols

1 powder coating booth in total according to Figures 1 to 3

1' Powder coating booth in total in Figure 4

1" powder coating booth in total in Figure 6

l" ¹ powder coating booth in total in Figure 7

1"" powder coating booth in total in figure

2 Floor area

3, 3' slot

4, 4, 4" powder spraying equipment

5, 5 ¹ Flap for powder spraying equipment 4

6 Central powder preparation and supply facility

7 Connection opening

8 flap

9 Ceiling area

10 Slot-shaped passage for continuous operation

11 Conveyor frame

12 chain conveyors

13 Lock

14 Fixed floor

15 door-shaped flaps

16 Floor area

17 Powder outlet

18 Liquid outlet line

20, 20' )

20" ) Cleaning equipment in total

21 Plug-shaped seal

22 Telescopic arrangement

23 nozzles

24 brushes

25 scrapers

26 Flap for liquid outlet line 18

30 Larger flap

31 Seals

32, 32' Flap arrangement in Figures 6 and 7

40 ring-shaped air blowing device 41 Blow nozzles 42 outward-projecting edge 43 Bag 45 Sealing part 46 Blow nozzles 47 Nozzles in Figure 2a 48 Outlet in Figure 2a 50 basket-shaped support structure 51 Brush inserts 55 shaft 56 Panel parts 57 Flat bottom 58 Floor cleaning device 59 Suction channel 60 Clearing arm 61 vertical axis of rotation

Direction of flow

Claims (25)

Powder coating booth requirements 1. Powder coating booth, in particular for continuous operation, with at least one powder spraying device (4, 4 ¹ , 4") which is connected to at least one powder preparation and supply device (6), characterized in that the booth (1, 1', 1", 1'", 1"") has a small base area and is column-shaped, and that a closable slot (3, 3') for the powder spraying device (4, 4 ¹ , 4") to pass through is provided in at least one wall of the booth (1, 1', 1", 1"',1""). 2. Powder coating booth according to claim 1, characterized in that the booth (1, 1', 1", 1"') is circular or oval in cross-section. 3. Powder coating booth according to claim 1, characterized in that the booth (I" ' ) is square or rectangular in cross section. 4. Powder coating booth according to one of claims 1 to 3, characterized in that in at least two opposite walls of the booth (1, 1', 1", 1"', 1"") at least one closable slot (3, 3') is provided for the passage of powder spraying devices (4, 4", 4"). 5. Powder coating booth according to one of claims 1 to 4, characterized in that the slot(s) (3, 3') are closed by means of at least one flap opening to the outside (5, 5') can be closed and the flap (5, 5') limits the respective slot (3, 3'). 6. Powder coating booth according to one of the preceding claims, characterized in that the booth (1, 1 ¹ , 1 ", 1"', 1"") forms a closed container with the slots (3, 3 ¹ ) closed, the inner walls of which can be cleaned by means of a cleaning device (20, 20', 20"). 7. Powder coating booth according to claim 6, characterized in that in a booth (1, 1', 1", ¹ ", 1"") with a passage (10) for a conveyor frame (11) in the ceiling area (9) in automatic continuous operation, this passage (10) can be automatically and tightly closed by the cleaning device (20, 20', 20") when it is working. 8. Powder coating booth according to claim 6 or 7, characterized in that the cleaning device (20, 20', 20") can be operated with compressed air and/or suction air and/or wet. 9. Powder coating booth according to one of claims 6 to 8, characterized in that the cleaning device (20, 20', 20") sweeps over the inner walls of the closed container and is preferably equipped with sponge parts, nozzles (23) or the like. 10. Powder coating booth according to one of claims 6 to 9, characterized in that the cleaning device (20, 20') is movable in the vertical direction in the interior of the booth (1, 1', 1", 1 ¹ "). 11. Powder coating booth according to claim 10, characterized in that the cleaning device (20, 20') is movable in the vertical direction by means of a telescopic device (22). 12. Powder coating booth according to one of claims 6 to 9, characterized in that the cleaning device (20") is designed to be adapted to the cross-sectional shape and the height of the booth (1, 1', 1", 1" ¹ , 1""). 13. Powder coating booth according to claim 12, characterized in that for cleaning the cleaning device (20") is arranged in a fixed position or preferably carries out a rotary movement about its longitudinal axis and/or preferably a slight oscillating movement about the longitudinal axis and/or in a lateral direction. 14. Powder coating booth according to claim 12 or 13, characterized in that the cleaning device (20") is designed in the shape of a basket as a support structure (50). 15. Powder coating booth according to one of the preceding claims, characterized in that the booth (1, 1', 1", 1"', 1"") is funnel-shaped at the bottom area (16) and has a powder outlet (17) and optionally a closable opening for liquid discharge (at 18) during wet cleaning. 16. Powder coating booth according to one of the preceding claims, characterized in that in the direction of flow (A) of the material to be coated, a lock (13) is arranged on the inlet side and/or outlet side of the booth (1, 1', 1", ¹ ", 1""), which can be converted into a post-coating station or a pre-coating station. 17. Powder coating booth according to claim 16, characterized in that the post-coating station or pre-coating station formed can be used optionally from one side or the other. 18. Powder coating booth according to one of the preceding claims, characterized in that in the opposite wall area of the booth (1, 1', 1", 1" ^f , 1"") assigned to the powder spraying devices (4, ⁴ 1 , 4") an arrangement of adjacent flaps (5, 5', 30) of different sizes for manual operation or automatic operation is provided. 19. Powder coating booth according to claim 18, characterized in that in the case of powder spraying devices (4, 4', 4") provided in opposite wall areas of the booth (1, 1', 1", 1"', 1""), the arrangements of adjacent flaps (5, 5', 30) of different sizes assigned to the opposite wall areas are provided in mirror image. 20. Powder coating booth according to one of claims 16 to 19, characterized in that the booth wall areas (32, 32') adjacent to at least one of the locks (13) can be folded in such a way that the cleaning device (20, 20', 20") can be introduced laterally into the booth (1, ^{1 1} , 1", 1"',1""). 21. Powder coating booth according to one of claims 6 to 20, characterized in that the upper side of the booth (1, 1', 1", 1"', 1"") can be closed by means of a cover which is preferably formed in one piece and is attached to the cleaning device (20, 20', 20"). 22. Powder coating booth according to one of the preceding claims, characterized in that a part of the booth wall forms a rear wall of the central powder preparation and supply device (6) and a connecting opening (7) to the interior of the booth (1, 1', 1", 1"', 1"") is present, which can be closed by means of a flap (8) opening to the interior of the booth. 23. Powder coating booth according to one of the preceding claims, characterized in that the flaps (5, 5', 8, 30, 32) have seals (31) for tightly closing the interior of the booth (1, 1', 1", 1", ¹ ", 1"") when the flaps are closed. 24. Powder coating booth according to one of the preceding claims, characterized in that at least the wall area(s) opposite the powder spray device(s) (4, 4', 4") consists or consists of non-conductive material or has or have a coating of non-conductive material. 25. Powder coating booth according to one of the preceding claims, characterized in that the respective powder spray device(s) (4, 4', 4") comprises cover parts (56) for covering the associated slot (3, ³¹ ), which preferably overlap in a scale-like manner and are preferably arranged loosely on the shaft (55) of the respective powder spray device(s) (4, 4', 4").