WO1997014508A1

WO1997014508A1 - Device for transporting finely distributed media produced during the surface treatment of articles

Info

Publication number: WO1997014508A1
Application number: PCT/AT1996/000201
Authority: WO
Inventors: Michael Eder
Original assignee: Michael Eder
Priority date: 1995-10-18
Filing date: 1996-10-18
Publication date: 1997-04-24
Also published as: AU7206096A

Abstract

A device is disclosed for transporting finely distributed media produced during the surface treatment of articles along at least one wall. Gas outlets (3) are distributed throughout the wall (1). The gas that comes out of these outlets (3) forms a gas cushion which keeps the medium away from the wall (1).

Description

Device for transporting finely divided, in the surface treatment of

Media

The invention relates to a device for the transport of finely distributed media occurring during the surface treatment of objects along at least one wall.

In particular with wet paint spray painting, there is the problem that the paint particles, which pass on the surface of the workpiece (overspray), are deposited on collecting surfaces and in the pipes of the suction devices and are therefore not available for further use on the one hand and on the other hand with increasing layer thickness of the paint deposit to disturb. It has therefore already been proposed to coat the walls which carry away the overspray with special materials, for example Teflon, in order to prevent the paint from adhering. However, it has been shown that, in areas with a lower flow rate, paint deposits cannot be avoided in such coatings. In addition, such coatings are very expensive and sensitive. Attempts have also been made to place a curtain of water behind the workpiece to catch the overspray. However, realizing such a water curtain is technically complex. In addition, the recovery of paint particles from the water sludge is practically impossible.

The object of the invention is therefore to provide a device for transporting finely divided media, with which the medium (in particular overspray) can be collected or transported without causing annoying deposits.

According to the invention this is achieved in that the wall has outlet openings distributed over it, through which gas emerges to form a gas cushion which keeps the medium away from the wall.

It is known to generate a gas flow by means of nozzles, which is then able to transport finely divided media (for example DE-OS 36 36 235). In this state of the art, liquid paint particles in particular - as they occur in wet paint spray painting - would accumulate on the respective nozzles. By the Material construction would narrow the pipes and prevent their function

In contrast, the invention provides for one in the area of the wall

To produce a gas cushion that keeps the transported particles of the finely divided medium as completely as possible from the wall. Basically, the gas cushion does not have to move in the main flow along the wall

Rather, it is possible to separate a device from the discharge openings

Use a gas flow that runs parallel to it at a distance from the wall and carries the medium to be transported with it. The mentioned separate

A device for generating a gas flow can be, for example, a large extraction system of an air-conditioned spray painting booth. But it is also possible that the separate device for generating a gas flow comprises nozzles, which in turn can be attached in or on the wall, but which are of the

Outlet openings for generating the gas cushion are different.

According to a further embodiment, it is also conceivable that the gas cushion moves in the main flow direction and thus also assumes a transport function in addition to the holding function from the wall. For this purpose, it can be provided that the gas flowing out of the outlet openings forms a gas flow with a flow component directed directly along the wall.

In this way, a closed gas curtain (moving gas cushion) can be achieved, which flows along the wall and entrains the finely divided media particles before they hit the wall.

It is possible to provide a heating device with which the escaping gas can be heated. This is particularly advantageous in the case of Nacklackspπtzlackierung because the heated gas dries the overspray particles faster and can be easily separated from the gas by means of a separator, for example a cyclone at the end of the transport route

Conversely, it is also possible to catch the moving particles with a wet separating device, for example a moving belt, which is circulated and constantly scraped off. Then it can be beneficial that the supplied Cooling and / or moistening the gas in order to prevent the paint particles or the like from drying before hitting the separating device

Further advantages and details of the invention are explained in more detail with reference to the following description of the figures

1 and 2 each show perspective exemplary embodiments of essentially cuboid wall sections of a device according to the invention, FIG. 3 shows a schematic perspective of a tubular wall section, FIGS. 4a to 8a show a partial plan view of exemplary embodiments of wall sections according to the invention, which show FIGS. 4b to 8b 9 shows a section along the line AA of FIG. 10 of an exemplary embodiment of a paint spray booth designed according to the invention, FIG. 10 shows a plan view of this paint spray booth, FIG. 11 shows a schematic sectional view of a separating device at the end of the Transport route, FIG. 12 shows a closed paint spray booth with a device according to the invention for removing the overspray, FIG. 13 shows a schematic section of part of an exemplary embodiment of an inventive device n Device for transporting finely distributed media, FIG. 13a shows part of the wall of FIG. 13 on an enlarged scale, FIGS. 14, 15, 16 and, 17 show further embodiments in a sectional view, FIGS. 14a, 15a, 16a being enlarged representations 18 shows a schematic plan view of a further exemplary embodiment of a device according to the invention, FIG. 19 shows a further exemplary embodiment in a vertical section, FIGS. 20 and 21 likewise show further exemplary embodiments in a horizontal section and a vertical section which FIG. 22 shows a further embodiment in a vertical section, while FIG. 22 shows the associated top view

The wall sections shown in FIGS. 1 and 2 have a cuboid shape and are essentially hollow on the inside. Gas which is under pressure can be introduced into the interior of the wall sections 1 via a supply line 2, for example air required via a pump standing gas now emerges from the many outlet openings 3 distributed over wall 1 a As will be explained in more detail, these outlet openings are arranged and aligned such that the outflowing gas results in a gas stream 4 which is directed essentially directly along the wall surface and which gives the finely divided medium

(especially overspray) carries along without it accumulating on the wall 1a

The exemplary embodiments shown in FIGS. 1 and 2 differ in that, in the exemplary embodiment according to FIG. 1, the rear side, which is not visible in the illustration, is completely closed with respect to side 1a, while in FIG. 2, exit openings are also provided on the rear side 1a ' result in a gas flow 4 in the opposite direction to the front

The exemplary embodiment shown in FIG. 3 is a tubular wall section which has a plurality of outlet openings 3 in the interior. The gas outlet from the outlet openings 3 can form an angle with the axis 5 of the tube, so that there is a helical gas movement in the interior of the tube

With the wall sections shown in FIGS. 1 to 3, which are preferably made of metal and / or plastic, the most varied spatial structures, in particular multi-sided closed paint spray booths, can be assembled in the manner of a modular construction, as will be explained with reference to FIGS. 9 and 10

In order to be able to achieve a gas flow directed directly along the wall surface, there are several possibilities, some of which are shown in FIGS. 4a to 8b

4a to 7b are scale structures, the outlet openings 3 being arranged in the region of the two ends 6a of the scale 6

As FIGS. 8a and 8b show, instead of the scales, lamellae 7 can also be provided, at the ends 7a of which slit-shaped outlet openings 3 are provided The scales 6 or the lamellae 7 are favorably formed in one piece with the rest of the wall surface. They can already be provided during the initial production or can be subsequently formed by impressing

9 and 10 show a spray painting booth with a device according to the invention for transporting the overspray

On the sieve bottom 9 there is a frame 8 for carrying the workpiece 10 to be painted. The painting can be carried out, for example, by hand with a spray gun 11. Those paint particles that do not hit the workpiece 10 (overspray) are removed cleanly and quickly by the device according to the invention. The spray painting booth is essentially made up of cuboid wall sections 1. Via the connecting piece 12, air under pressure is blown into the interior 1 b of the wall sections 1. This air is distributed along the dash-dotted line in FIG. 9, whereby it passes through wall openings 13 from wall section to wall section as an alternative it would of course be possible to supply air to each individual wall section separately under excess pressure

The air under pressure now flows out of the interior 1 b of the wall sections 1 via the numerous outlet openings 3 which form a closed air curtain (moving air cushion), which entrains the overspray and essentially without touching the wall, first into the vertical duct 14 and then dissipates in the horizontal channel 15

The air is brought outside to the necessary overpressure by a pump 15, from where it reaches the interior of the wall elements 1 via lines 16, 12 and 12 '

Before the air flow conducted via line 16 reaches the interior 1b of the wall sections 1 of the actual spray painting booth, the air is heated via a heating device 17 to a temperature of, for example, between 60 ° C. and 100 ° C. This ensures that the overspray is immediate dries and then loses its affinity for investing on the transport route. It is therefore essentially tubular shaped horizontal section 15 no longer necessary to use heated air

Air can be supplied unheated via the pipe 12 '

At the end of the transport route, a dry working separator 18 in the form of a cyclone is arranged, which can be configured, for example, as in FIG. 11 fail The air can reach the pump 15 via a filter 21 and the line 22. A fresh air supply 23 can also be arranged in the line 22. This makes it possible, on the one hand, to circulate the air and, on the other hand, in principle the particles in the container 20 again to recycle

The exemplary embodiment shown in FIG. 12 is an automatic paint spray booth as used, for example, in the automotive industry. Here, too, the excess paint particles can be removed below the grate 9 'through wall sections 1 designed according to the invention

The air flow in the tubular sections of a device according to the invention can either be caused only by the air flowing out of the outlet openings 3. However, there is the possibility of additionally superimposing a blown or extracted air flow, as will be described below

In addition to the rectangular and tubular wall sections shown, other shapes are of course also conceivable and possible, for example helical wall sections. Air is advantageously suitable as the gas, but other gases, for example nitrogen or other inert gases, can also be used for special applications

In the exemplary embodiment shown in FIG. 13, the wall 1 is designed in a stepped manner. In a region 1c that is horizontal in FIG. 13, the wall is designed as a perforated plate which has a scale structure, such as is shown in FIGS. 7a and 7b This design results in a leading directly along the wall area 1 c Gas flow, which, however, does not have the primary task here of transporting finely divided media in the main direction of movement 23, but rather that

The task is to form an air cushion that separates the finely divided media from the

Wall keeps the actual movement of the gas flow in the Hauptstromungsπchtung 23 take care of the nozzle slots 23 in the other, on the

Regions 1c are arranged substantially vertical regions 1d These nozzles

23 thus represent a separate device from the outlet openings 3, which can be designed differently and arranged differently to its main one

However, it is still possible for the outlet openings 3 and the nozzles 23 to be under pressure from the same

To spend room 24

In the exemplary embodiments shown in FIGS. 14 and 14a, exit ducts 24 are provided in the wall, which exit into the outlet openings 3. These exit ducts 24 run obliquely to the normal on the wall surface through the wall and thus lead to a slightly moving air cushion

In the exemplary embodiments shown in FIGS. 15, 15a and 16, 16a and 17, the air flows out of the outlet openings 3 without a preferred directional component in the direction of the main transport direction 25 Rather, the gas flowing out through the outlet openings 3 serves essentially only to form a gas cushion which keeps the medium from the wall 1 The separate nozzles 23 are provided for the transport function

In the embodiment shown in FIGS. 15 and 15a, the exit channels 24 are flared. The embodiment shown in FIGS. 16 and 16a are cylindrical exit channels 24 that are perpendicular to the wall surface. In the embodiment shown in FIG. 17, the wall partially exists made of air-permeable material, for example foam, sintered material, fleece, felt or fabric (tissue). The outlet openings are then the finely distributed pores of this material 26

In the exemplary embodiment shown in FIG. 18, a device for transporting finely divided media is provided with a device 27 (here a gun for wet paint Spray painting) combined to apply media to a surface, the

Device for transporting the overspray as it is distributed on the surface 29 collects and transported away as a finely divided medium. The collecting function is essentially achieved in that the sections of the wall in the entrance area converge towards one another in a funnel shape, i. H. that the cross-sectional area A is transverse to

Main transport direction 25 tapers in the transport channel 30 thus formed.

The exemplary embodiment shown in FIG. 18 furthermore has a separating device, generally designated 31, for separating the transported medium (overspray) from gas (air). In the exemplary embodiment shown in FIG. 18, this separating device essentially consists of a belt 33 endlessly guided by rollers 32 and a device 34a, 34b for removing the medium from this belt 33. In the exemplary embodiment shown, this device for removing is made in two parts. The strips 34a resting on the strip initially form a track which is narrower than the strip width and which is then removed from the strip by the actual removal strip 34b and can be collected, for example, in a collecting pot. Such a separation device can be constructed, for example, as described in international application WO 94/02254, the belt 33 being arranged such that it essentially forms part of the wall of the transport surface 30.

In order to be able to press the entrained medium particles better onto the surface of the belt 33, blowing nozzles 23 'are provided which blow air supplied via a blower 36 and a supply air duct 37 into the transport duct 30 transversely to the main flow direction there.

Otherwise, the wall 1 according to the invention is provided with numerous outlet openings 3 through which air is blown in to form an air cushion, the air cushion preventing the medium from adhering to the fixed wall 1 and thus at least a large part of the medium being able to be caught by the belt 33.

It is possible to pressurize the supplied air through a single blower 36. In the embodiment shown in FIG. 18, however, are for example Two blowers 36, 36 'are provided, which pass through the respective supply air channels 37, 37'

Supply air under pressure

In the exemplary embodiment shown in FIG. 18, a large-sized suction system 28 is provided for generating a gas flow in the main transport direction 25. Instead of such a suction system or in addition to this, of course, blow nozzles 23 can also be provided in the wall, such as, for example, in the exemplary embodiments in FIGS 17 are shown

The exhaust air from the exhaust air duct can be returned to the supply air blowers 36, 36 'via a return line (not shown), a filter in this return line being able to remove any remaining amounts of the medium

It is also possible to heat the supplied air, which is particularly advantageous when using a dry separator (for example a cyclone). Conversely, cooling and / or moistening of the air can be advantageous for wet-working separation devices, such as a circulating belt 33

The embodiment shown in FIG. 19 is a painting booth 40, in which the overspray is discharged downward, for example, through a grate 39. First, the air laden with the medium is brought together, the air cushion produced according to the invention preventing the walls from sticking to it Medium is then collected by a circulating belt 33 and removed from it via the device 34a, 34b

In the exemplary embodiment shown in FIG. 20, the medium is collected via a rotating roller 35 from the surface of which, by means of scrapers or the like (not shown), the absorbed medium can be removed again

While in the embodiment shown in FIG. 20 the medium is collected on the outside of the roller 35, in the embodiment shown in FIG. 21 this is done inside the rotating roller 35 'by centrifugal action In the painting booth shown in FIGS. 22 and 23, painting can be carried out automatically via a spraying system 42 or manually via a spray gun 27. The supply air is fed into the spray booth 40 from above via filter 41. The air loaded with the overspray is discharged downwards, the walls tapering towards one another in a funnel shape and supplying the medium (overspray) to the removal device 31.

Claims

claims

Device for transporting finely divided media occurring during the surface treatment of objects along at least one wall, characterized in that the wall (1) has outlet openings (3) distributed over it, through which gas, forming a medium from the wall (1 ) holding out the gas cushion

Device according to claim 1, characterized in that the outlet openings (3) are arranged and aligned in such a way that a gas flow with a flow component directed directly along the wall (1) is formed by the gas flowing out of the outlet openings (3)

Device according to claim 2, characterized in that the outlet channels penetrating the wall (1) and opening into the outlet openings (3)

(24) run obliquely to the normal on the wall surface (1a) through the wall (1)

Device according to claim 2 or claim 3, characterized in that the wall (1) facing the medium has a scale or lamella structure, the outlet openings (3) being arranged in the region of the free ends of the scale or lamella (7)

Device according to claim 4, characterized in that the scales (6) or lamellae (7) projecting from the wall (1) are integral with the rest

Wall (1) are formed

Device according to one of claims 1 to 5, characterized by at least one device (23, 28) separate from the discharge openings (3) for generating a gas flow which at least partially runs at a distance from the wall (1) essentially along the same and carries the medium to be transported Device according to claim 6, characterized in that the separate device for generating a gas flow comprises an extraction system (28)

Device according to claim 6 or 7, characterized in that the separate device for generating a gas flow one or more nozzles

(23)

Device according to claim 8, characterized in that the nozzles (23) are also formed or arranged in the wall (1), but are designed and / or oriented differently with respect to the outlet openings (3)

Device according to claim 8 or 9, characterized in that at least some of the nozzles (23) are slot-shaped

Device according to one of claims 8 to 10, characterized in that the wall (1) is step-shaped, the outlet openings (3) being formed or arranged on one step surface (1c), while the nozzles (3) are on the intermediate, are formed or arranged transversely to the other step surfaces (1d) lying on one step surface (1c)

Device according to one of claims 1 to 11, characterized in that the outlet openings (3) at the end of channels penetrating the wall (1)

(24) or slots are formed, the channels (24) preferably having a cylindrical or conically widening cross section

Device according to one of claims 1 to 11, characterized in that the outlet openings (3) from the pores of a gas-permeable material (26) forming the wall, preferably foam. Sintered material fleece, felt or fabric are formed

Device for transport according to one of claims 1 to 13, characterized by the combination with a device (27) for applying media to a surface (29), in particular for wet paint spray painting or powder painting. coat, the device for transporting away the overspray passing the surface (29) as a finely divided medium

15 device according to one of claims 1 to 14, characterized in that sections of the wall (1) are arranged relative to one another in such a way that a transport channel (30) delimited by the wall (1) is formed, which is at least on Begin tapering preferably in the cross-sectional area (A) lying transverse to the main transport direction (25)

16 Device according to one of claims 1 to 15, characterized by a separating device (11, 31, 35, 35 ') for separating the transported medium from the gas

17 Device according to claim 16, characterized in that a return line is provided, via which at least part of the freed from the medium

Gases can be fed back to the outlet openings (3)

18 device according to claim 16 or 17, characterized in that the separating device comprises a cyclone (11) or a filter

19 Device according to claim 16 or 17, characterized in that the separating device (31) comprises a circumferential belt (33) for collecting the medium and a device (34a, 34b) for removing the medium from this belt

20 Device according to claim 16 or 17, characterized in that the separating device comprises a rotating roller (35, 35 ') for collecting the medium

21 Device according to claim 20, characterized in that the gas loaded with the medium is passed through the interior of the roller (35 ')

22 Device according to claim 20, characterized in that the gas loaded with the medium is guided past the outer surface of the roller (35) Device according to one of claims 19 to 22, characterized in that a section of the belt (33) or a section of the roller (35, 35 ') form part of the wall of that transport channel (30) through which the medium is initially loaded Gas is discharged, the outlet openings (3) being missing in the part of the wall mentioned

Device according to one of claims 1 to 23, characterized by a heating device or a cow device for changing the temperature of the gas supplied through the outlet openings

Device according to one of claims 1 to 24, characterized by a device for moistening the supplied gas

Method for transporting finely divided media, characterized by the creation of a gas cushion which keeps the medium from a wall and by the generation of a gas flow essentially parallel to the wall