EP2170519A2

EP2170519A2 - Device for separating paint overspray

Info

Publication number: EP2170519A2
Application number: EP08773946A
Authority: EP
Inventors: Werner Swoboda; Erwin Hihn; Jürgen Hanf; Kersten Link; Apostolos Katefidis
Original assignee: Eisenmann Anlagenbau GmbH and Co KG
Current assignee: Eisenmann SE
Priority date: 2007-07-25
Filing date: 2008-07-10
Publication date: 2010-04-07
Also published as: WO2009012892A3; JP2010534123A; EP2324928A1; BRPI0813544A2; EP2343130A1; RU2010106242A; JP3180566U; BRPI0813544A8; WO2009012892A2; CN101861210A; US20100291848A1; DE102007036553A1

Abstract

A device (1) for separating paint overspray from the air of painting cubicles that is laden with overspray has in a housing (2) at least one separating element (4), the surface of which is electrically conductive and is connected to one terminal of a high-voltage source (14). The separating element (4) is assigned an electrode arrangement (12), which is connected to the other terminal of the high-voltage source (14). The air of the cubicle is made to flow past the separating element (4) and the electrode arrangement (12) in such a way that the overspray particles are colonized and deposited on the surface of the separating element (4). The separating element (4) is moved continuously or intermittently, wherein a wiping device (10) wipes off the overspray that is on the surface of the separating element (4). This can then be carried away by a suitable transporting device (3) for disposal or re-use.

Description

Device for separating paint overspray

The invention relates to a device for separating paint overspray from the overspray-laden cabin air of paint booths with

a) a housing;

b) at least one separator element arranged in the housing, on the surface of which the cabin air can be guided, as a result of which overspray particles remain on the surface while wholly or partially purified air continues to flow;

c) a device with which the deposited overspray is removed from the surface of the separation element.

For efficient collection and separation of Wasserlackbzw. Solvent lacquer overspray are used in the automotive sector almost exclusively wet scrubbers, also called wet scrubbers, as described, for example, in EP 0 740 576 B1 or DE 44 01 741.

In general, such wet scrubbers have below the rust-like cabin floor two sheets inclined to the middle of the cabin, which are overflowed with water from the edge of the cabin. The water flows together with the coming of the top cabin air through an opening between the inner edges of the two sheets and from there into an air flow accelerating nozzle. In this nozzle, a swirling of the air flowing through takes place with the water. During this process, the overspray particles largely pass into the water, so that the air leaves the water separator substantially purified and the overspray particles in the water

Water are located. From this they can then be recovered or disposed of.

The main effect of these wet scrubbers, as mentioned above, is based on the turbulence of air and water; Although the water flowing over the bottom floor plates absorbs overspray particles to some extent from the air passed by; the sheets can therefore be referred to as "separating elements" in the above sense. This effect is low compared to the main effect.

The known wet scrubbers have the advantage of a good cleaning performance in unproblematic operation. However, this also faces several disadvantages: For example, they require a great deal of energy to circulate relatively large quantities of water, as well as the pressure loss at the flow points, in particular the accelerating nozzle. The treatment of the rinse water is costly due to the high use of paint-binding and detackifying chemicals and the Lackschlammentsorgung. Furthermore, the air absorbs a lot of moisture due to the intensive contact with the rinse water, which in turn results in a high energy consumption for the air treatment in the recirculation mode.

Object of the present invention is to provide a device of the type mentioned, in which in particular the energy consumption is reduced.

This object is achieved in that d) the surface of the separating elements is electrically conductive and connected to a pole of a high voltage source;

e) the separating element is associated with an arranged in the air flow electrode device which is connected to the other pole of the high voltage source;

f) a device is provided, with which the

Abscheideelement continuously or intermittently can be set in motion;

g) the separating element is assigned a stripping device which strips off the overspray on the surface of the separating element by utilizing a relative movement between the separating element and the stripping device.

The present invention thus leaves the basic idea, with large amounts of water, which are swirled with the air flow, to remove the overspray particles from the air, but causes the deposition in a "dry" way. This eliminates all the disadvantages mentioned above in detail and associated with the use of water. The dry separation takes place on electrically conductive surfaces of separation elements. The efficiency of this deposition is enhanced by ionization of the overspray particles, which causes the overspray particles to be electrostatically attracted to the conductive surfaces of the precipitators. In order to ensure continuous operation of the device, the separating elements and optionally the wiping device are movable, so that a relatively clean surface area of the air can always be presented while other surfaces Chen areas are freed by the wiper of deposited overspray.

The separation device may comprise at least one endless circulating belt. Such tapes can provide large separation surfaces in a cost effective manner. A certain disadvantage is that the space, which is surrounded by the band, as a "dead space" contributes to the Abscheidwirkung no contribution.

It is particularly advantageous if several contiguous endless belts are provided next to each other. In this way, even larger surfaces can be provided for separating the overspray and manage even larger air flows.

The strands of endlessly circulating bands may be oriented substantially vertically. The reason for this is that then the time, which are the air and the entrained with this overspray particles in the region of the Abscheidelemente is relatively long and in this way the probability is increased that the overspray particles by the electrostatic force actually on the surface of a tape are deposited. In addition, the pressure loss of the air flow at such arranged bands is relatively low.

Alternatively, however, the two strands of endlessly circulating belts can also be aligned substantially horizontally. As a result, although the throttle effect is slightly increased; However, the surfaces of the strands are then substantially perpendicular to the flow direction of the air, so they serve as baffles, which enhances the purely mechanical deposition by adhesion. A compromise between advantages and disadvantages can be achieved in that the two strands of the endlessly circulating belts are aligned at an angle that is neither 0 ° nor 90 ° with respect to the horizontal.

Particularly advantageous in view of the separation effect, it is when the endlessly circulating belts are arranged in several superimposed layers.

This is increasingly true when the parallel strands of the bands in superimposed layers are inclined in an opposite sense to the horizontal.

At least one separating element can also be a rotatable roller. Rollers are relatively inexpensive parts. Disadvantage is again that the inner volume of the roller makes no contribution to the separation effect.

It is preferred if a plurality of rolls with parallel axes are arranged side by side and / or one above the other.

This measure also serves to increase the Abscheideooberflächen and increasing the Abscheidekapazität.

The axis of each roller can be approximately horizontal. This has the consequence that the substantially vertical cabin air flow impinges on the lateral surface of the rollers, which obtains in this way an impact flap effect, which is advantageous in view of the deposition efficiency.

Alternatively, the axis of each roller may be approximately vertical. Although this means that the "baffles" that provide the rolls with airflow are reduced. However, the dwell time of the overspray particles in the electric field between increases again Electrode device and roller.

A compromise can again be achieved in that the axis of each roller runs at an oblique angle that is neither 0 ° nor 90 ° to the horizontal. The smaller this oblique angle, the more pronounced the "impact effect" of the roll shell surface in the foreground, and the closer the angle is at 90 °, the longer is the residence time of the overspray particles in the electric field.

Another possibility of the embodiment of the separation element is that as a rotatable disc. Such a disk is even more cost effective than belts or rollers and has the additional advantage that the "dead volume" is particularly small.

To increase the Abscheideooberfläche preferably several discs may be arranged parallel to each other on a common axis.

The axis of each disc can be approximately vertical. Then the full main surfaces of the discs act as impact elements in the above sense.

Alternatively, the axis of each disc can also run approximately horizontally, which, as already explained above for the rollers, is accompanied by an extension of the residence time of the overspray particles in the electric field.

Again, a compromise between the two desired but excluding effects can be achieved by having the axis of each disc at an oblique angle that is neither 0 ° nor 90 ° to the horizontal. An interesting embodiment of the invention is that at least one deposition element has the form of a rotatable coil. With this embodiment, a Föderwirkung of the separation element can be achieved in the axial direction.

It is expedient if a squeegee device is provided which comprises two squeegees which rest on opposite surfaces of the helix.

If such a squeegee device is displaceably guided on a guide rail, it is passively taken along during the rotation of the helix, so that in the extreme case a single squeegee device suffices for the entire helix.

In general, a plurality of electrically parallel connected electrode means should be provided, which engage in the spaces between the separation elements and / or the spaces between the separation elements and the walls of the housing. The number and density of the electrode devices is chosen so that as complete as possible ionization of the overspray particles is achieved.

The electrode means may be in the form of a straight wire or rod. This simple form guarantees a low price.

The electrode device may also have the shape of a wire or rod, which may be bent back and forth several times in one plane. It thus obtains a kind of "flat" character, which increases the interaction between electrode means and passing air. The electrode means may also comprise a plurality of divergent electrode tips. As is well known, peaks produce particularly high electric fields, which are particularly conducive to ionization. In addition, such electrode devices are also easier to clean after a certain period of operation than those which consist of thin wires or rods.

Such an electrode device can be arranged in front of the separation elements in the cabin air flow, where it is easily accessible, in particular for maintenance purposes.

In a particularly preferred embodiment, an air supply device is provided, with which at least one electrode device, independently of the cabin air, a separate air flow for ionization can be supplied. The ionization of the cabin air and the entrained by this overspray particles happens at least partially indirectly, by first the separately supplied air flow is ionized and then jumps from this the ionization of the cabin air and the overspray particles.

It is particularly advantageous if the separate air stream is moistened, since such a humidified air stream can be ionized more easily than dry air.

At least one stripping device may be a squeegee which scrapes off the overspray from the surface of at least one deposition element. This mechanical way of removing the overspray from the surfaces is particularly reliable and unproblematic.

Finally, in an advantageous embodiment the invention, at least one device be provided, with which the surface of a separating element, a wetting liquid can be supplied. This wetting liquid is used in contrast to the water in the wet separators mentioned above only in small quantities; it should moisten only the surfaces of the separation elements. As wetting liquid, for example, an adsorber in question, which only has the function to promote the deposition of the overspray particles on the surfaces. In order to prevent the overspray deposited on the surface of the precipitation elements from becoming too solid and therefore no longer being able to be removed, it is also possible to use solvent or possibly fresh enamel as the wetting liquid.

For the ionization of the overspray particles, it may be beneficial if the high voltage source is capable of generating a pulsed high voltage.

Embodiments of the invention will be explained in more detail with reference to the drawing. Show it

FIG. 1 shows a first exemplary embodiment of an overspray

Separator in vertical section;

FIG. 2 shows the separation device of FIG. 1 in perspective with the front wall removed;

FIG. 3 shows a section, similar to FIG. 1, through a second exemplary embodiment of an overspray separation device;

Figure 4 is a perspective view, similar to the figure

2, the separator of Figure 3; FIG. 5 shows a section, similar to FIGS. 1 and 3, through a third exemplary embodiment of an overspray separation device;

Figure 6 is a perspective view, similar to Figures 2 and 4, of the separator of Figure 5;

Figure 7 is a section similar to Figures 1, 3 and

5, by a fourth embodiment of an overspray separation device;

Figure 8 is a perspective view, similar to Figures 2, 4 and 6, of the separator of Figure 7;

9 shows a section, similar to FIGS. 1, 3, 5 and 7, through a fifth exemplary embodiment of an overspray separation device;

Figure 10 is an enlarged scale sectional view of a detail of Figure 9;

Figure 11 is a section along line XI-XI of Figure 10;

FIG. 12 shows in perspective, again on a larger scale, a detail from FIGS. 10 and 11;

FIG. 13 shows a section similar to FIGS. 1, 3, 5,

7 and 9, by a sixth embodiment of an overspray separation device;

FIG. 14 is a perspective view, similar to FIGS. 2, 4, 6 and 8, of the deposition apparatus of FIG. 13; FIG. 15 shows a section similar to FIGS. 1, 3, 5,

7, 9 and 13, by a seventh embodiment of an overspray separation device;

FIG. 16 is a perspective view, similar to FIGS. 2, 4, 6, 8 and 14, of the deposition apparatus of FIG. 15.

First, reference is made to Figures 1 and 2. The overspray separator shown here and designated overall by the reference numeral 1 comprises a housing 2 which has in its upper region rectangular cross section and only vertical side walls, while in the lower region by two obliquely downwardly converging side walls 2b, 2c and two vertically extending End walls 2d (only one shown in Figures 1 and 2) is limited. In this way, the lower portion of the housing 2 is formed in the manner of a funnel.

Below the limited by the lower edges of the housing walls 2b, 2c and 2d outlet opening 2e of the "funnel" a conveyor 3 is arranged. The conveyor 3 comprises an endless conveyor belt 3a, which is guided over two guide rollers 3b. In Figures 1 and 2, only one of these guide rollers 3b is shown; one of the two guide rollers 3b is driven in a known manner.

In the upper, cuboid region 2a of the housing 2, a plurality of endless steel strips 4 are arranged side by side. All steel strips 4 are guided over two vertically stacked guide rollers 5 and 6 such that their parallel runs run vertically. The upper guide rollers 5 are each by a motor 7, which is indicated schematically as a rectangle in a box 8 attached to the right-hand side wall of the housing 2. The drive connection between the motor 7 and the pulleys 5 is indicated schematically by a dash 9. These

Drive connection 9 can take place in any desired manner, for example via belts, chains, drive shafts, gears or the like.

At the bottom of each right run of the steel bands 4 is located on the outside of a tilted blade 10. A similar squeegee may also be attached to the inside of the steel bands 4 (not shown).

The lower ends of the steel strips 4 and the deflecting rollers 6 located there each dive into a trough-shaped, downwardly closed and upwardly open trough 11. The tub 11 can optionally, depending on the processed paint, a liquid adsorbent, solvent, detergent or fresh paint are supplied.

In each case, an electrode device 12 extends parallel to the vertical strands of adjacent steel strips 4 and, in the exemplary embodiment shown, consists of a wire bent several times through 180 ° and extends essentially over the entire height and depth of the respective vertical run of the steel strip 4. This can be seen in particular from FIG.

All electrode devices 12 are via a line

13 connected to a high voltage source 14, which is also housed in the box 8 on the outside of the housing 2.

Below the steel bands 4 are two after 1 between the upper edges of the two inclined lower housing walls 2b and 2c and between the lower edges of the overlying vertical housing walls of the upper housing portion 2a is in each case an air outlet slot 17, 18th ,

The top of the housing 2 is partially formed by walk-on and sideways movable gratings 19.

The above-described overspray separation apparatus 1 operates as follows:

The interior of the housing 2 19 cabin air is supplied from above in the direction of the arrows 20 through the gratings, which is loaded with overspray particles. These can still be liquid / sticky but also more or less firm. This air also gets into the areas between the vertically extending strands of neighboring

Steel bands 4 or at the two outermost steel strips 4 between the respective outer strand and the adjacent wall of the housing 2. With the help of the high voltage source 14 is applied to all electrode devices 12 such a high voltage, which is sufficient, the overspray particles in the passing To ionize air.

The steel bands 4, however, are at ground potential; they are set in motion by means of the motor 7. They dive in the area of the guide roller 6 in the

Wetting liquid, which is located in the trough-shaped trays 11. The overspray particles separate on passage of the steel strips 4 on their outer surfaces, where appropriate, the wetting liquid ensures that too rapid solidification of the Overspray on the steel strips 4 is omitted, which would prevent removal of the overspray of the steel strips 4. Therefore, it is easily possible with the help of the squeegee 10 from the moving steel strips 4 to strip the overspray deposited there. This then falls down and is passed from the housing walls 2b, 2c to the conveyor 3 and transported away from there, be it now for rejection or for reprocessing.

The air cleaned by overspray during passage between the steel belts 4 is partially upwardly directed by the air baffles 15 and 16 in the direction of the arrows 21 and then by a gap 23 between the upper edges of the baffles 15 and 16 and the adjacent vertical walls of the baffles Housing 2 again led down. This part of the air flow then exits via the air outlet slots 17, 18.

Another part of the air stream, which has passed through the various steel belts 4, moves under the lower edges of the air baffles 15, 16 in the direction of the arrows 22 and then also exits through the air outlet slots 17, 18. The cleaned air can then - optionally after a certain conditioning - be returned to the spray booth. The conditioning may in particular be a readjustment of the temperature, the humidity and, if necessary, the removal of solvents.

The exemplary embodiment of an overspray separation device illustrated in FIGS. 3 and 4 and identified overall by reference numeral 101 is similar to that described above with reference to FIGS. 1 and 2. Corresponding parts are therefore with the same Reference number 100 is marked.

Identical coincident in both embodiments, the configuration of the lower, downwardly converging housing walls 2b, 2c; 102b, 102d, the upper gratings 19; 119 and the air outlet slot 18; 118th

The main difference between the two embodiments is in the nature of the moving separation elements. Instead of the endless steel belts 4 of the embodiment of Figures 1 and 2, the embodiment of Figures 3 and 4, a plurality of superimposed and adjacent rollers 104 with steel lateral surfaces whose axes are horizontal and in the illustrated embodiment in four superimposed horizontal planes lie. In each of these levels several rollers 104 are provided at the same height. The arrangement is such that the rollers 104 are laterally offset from each other in adjacent planes such that in the lower plane the rollers 104 are each mounted below a gap between two rollers 104 of the overlying plane.

All the rollers 104 are driven by a toothed belt drive 109 from the motor 107, which is also housed in this embodiment, as well as the high voltage source 107 in a box 108 on the right in the drawing side wall of the housing 102.

Each roller 104 is associated with a doctor blade 110, which extends over the entire length of the roller 104 in the horizontal direction.

Between the rolling planes extend electrode means 112 either as well as in the embodiment each consist of a plurality of individual wires which extend parallel to the axes of the rollers 104. The electrode devices 112 are electrically connected to the high voltage source 107.

The left in the drawing air outlet slot 17 of Figures 1 and 2 is omitted in Figures 3 and 4. Instead, a portion of the air leaves the lower portion of the housing 102 via the lower exit opening 102e and is then guided upwardly into an air passage 163 along the outside of the housing wall 102b. As in the first exemplary embodiment, another part of the air passes through the air outlet slot 118 and enters a second air channel 164 there. Both air channels 163 and 164 merge in their further course and lead into the open air or into an air treatment plant.

The conveyor system 103 comprises a catch plate 160 mounted directly below the outlet opening 102e and a channel 162 arranged next to it, in which, for example, a scraper conveyor moves (not shown). A pneumatically actuated slide device 161 serves to push the overspray collecting on the catch plate 160 into the adjacent groove 162 from time to time.

The operation of the overspray separation device 101 is as follows:

The laden with overspray particles air enters in the direction of the arrows 120 through the gratings 119 in the interior of the housing 102 a. A large part of this air strikes the lateral surfaces of the rotating rollers 104 in the top row, which serve as "baffles" in this way. Already hereby the cladding is divided Chen the rollers 104 a large part of the overspray. The air then flows along the lateral surface of the rollers 104 in the slot located between adjacent rollers 104 of the uppermost roller level and unites there with the portion of the air flowing from above, which is not directly impacted on the roller jacket surface.

The air that has passed through the uppermost roll level now encounters the second uppermost level of rolls 104. Since the arrangement of the rolls 104 in the two planes is offset in the above-described sense, these air streams hit the outer surfaces of the rolls 104 in the second uppermost Level. Substantially the same operations are then repeated as the air streams pass through the second upper roll level and the lowest level of rolls 104.

The efficiency of the deposition of the overspray particles on the rollers 104 is again electrostatically enhanced because the overspray particles are ionized upon passage of the electrode assemblies 112 and attracted by the lying on ground potential, metallic lateral surfaces of the rollers 104.

The overspray collecting on the roll surfaces is scraped off with the aid of the doctor 110, falls downwards as in the exemplary embodiment of FIGS. 1 and 2, is fed to the conveyor system 103 with the aid of the lower housing walls 102b, 102c and falls onto the catch plate 160. From there he pushed at intervals with the aid of the slider 161 in the groove 162 and removed there with the scraper conveyor or otherwise.

The cleaned air enters the air duct 163 and the air outlet slot 118 via the outlet opening 102e the air duct 164.

The third exemplary embodiment of an overspray separation device 201, which is illustrated in FIGS. 5 and 6, largely corresponds to the two exemplary embodiments described above. Corresponding parts are therefore provided with reference numerals, which are increased by 200 compared to the first embodiment.

Completely identical to the previously described embodiments are the housing 202 with the lower, downwardly converging housing walls 202b, 202c, the upper gratings 219, the air outlet slots 217, 218 and the conveyor system 203rd

While in the second embodiment of Figures 3 and 4, a plurality of rollers 104 was provided with horizontally extending axes, can be found in the embodiment of Figures 5 and 6, a plurality of matrix-like rollers 204, whose axes are aligned vertically. All rollers 204 are driven by a toothed belt transmission 209 from the motor 207. On a vertical generatrix of each roller 204 is again a squeegee 210 at.

In the spaces between the rollers 204, a plurality of electrode means 212 is provided, which in this embodiment have the form of straight wires or bars. All electrode devices 212 are electrically connected to the high voltage device 207.

The operation of this third embodiment of an overspray separation device 201 is close to that of the previously described embodiments identical, one looks from the detailed flow of air in view of the different geometry of the moving Abscheideelemente. Thus, in the exemplary embodiment of FIGS. 5 and 6, the air flows in via the gratings 219 in the direction of the arrows 220 into the air

Inner of the housing 202 passes, in the vertical direction through the spaces between the vertical rollers 204. The overspray particles are ionized by the electrode means 212 and pulled toward the grounded, metallic, in particular steel lateral surfaces of the rollers 204. The overspray which separates there is scraped off with the aid of the doctor blade 210, falls into the lower region of the housing 202 and finally onto the conveyor belt of the conveyor 203.

The cleaned air exits the overspray separator via the air exit slots 217, 218 as in the embodiments described above.

The fourth exemplary embodiment of an overspray separator 301, which is illustrated in FIGS. 7 and 8, again differs from the exemplary embodiments described above only by the type of moving separator elements. Parts of the embodiment according to FIGS. 7 and 8, which correspond to those of the first exemplary embodiment, are provided with the same reference number plus 300.

Instead of endless steel belts or horizontally or vertically arranged rollers, the embodiment 301 comprises a multiplicity of circular disks 304, whose opposing main surfaces in the present case serve as separation surfaces. All disks 304 are seated on a common shaft 330, which is rotated by a motor 307 can be offset. The connection between the motor 307 and the shaft 330 is not shown in detail in the drawing.

Between the individual disks 304, electrode devices 312 are provided parallel to these, which in this case have the shape of a plurality of U-shaped bent wires.

Each disk 304 is associated with two squeegees 310 which abut opposite major surfaces of the respective disk 304.

The operation of the overspray separation device 301 of FIGS. 7 and 8 is again substantially the same:

The air passing through the gratings 319 in the direction of the arrows 320 enters the space between the rotating disks 304. Due to the oblique position of these disks 304 relative to a vertical one

Alignment does not simply bypass most of the air past the major surfaces of the discs 304, but encounters and redirects these major surfaces so that the discs 304 simultaneously act as baffles. Similar to the embodiment with the horizontally extending rollers 104, this impingement of the air flow has the consequence that a part of the overspray deposits on the main surface of the disks 304 that has been flown on. The separation effect is further improved by the fact that the electrode arrangements 312 ionize the overspray particles, which are then attracted by the disks 304 lying at ground potential.

The overspray collecting on the main surfaces of the disks 304 is stripped off with the aid of the squeegee 310 and falls down so that it can eventually be removed from the conveyor system 303.

The cleaned air leaves the housing 302 of the overspray separation device 301 via the air outlet slots 317, 318.

The embodiment of an overspray separation device 401 shown in FIGS. 9 to 12 differs from that according to FIGS. 3 and 4 only in the orientation of the rollers 104; 404 and in the electrode device 112; 412. This means in particular that both embodiments with regard to the configuration of the housing 102; 402, the gratings 119; 419, the air exit slots 117, 118; 417, 418, of the transport system

103; 403 and the squeegee 110; 410 completely agree.

The axes of the rollers 404 in FIG. 9 extend perpendicular to the axes of the rollers 104 in FIG. 3. In addition, in FIG. 9 there are five planes in which the roller axes are arranged. Of these five levels, however, only three are shown. For clarity, the intermediate two levels are omitted in the drawing.

However, instead of straight or curved wires extending between the rollers 404, in the embodiment of FIG. 9, an ionizer 450 is used, which is located above the topmost level of rollers 404. This ionizer 450 comprises a plurality of tubes 440 extending parallel in a horizontal plane and provided at regular axial intervals with downwardly facing outlet ports 441. The interior spaces of the tubes 440 can be supplied with air via a line 442 by means of a blower 443. This may be cabin air or conditioned, in particular humidified, air.

Within the tubes 440, in the central region and parallel to their axes, a support strut 444, to which a plurality of electrode means 412 is attached, extends in each case. The support struts 444 are held by isolators 445 on the tubes 440 (see Figure 11). Each electrode device 412 comprises a vertically extending support tube 412a, which is connected at its upper region to the support strut 444, for example by a threaded connection.

In the interior of each support tube 412a, a high voltage source 414 is housed, which is shown schematically in Figures 10 and 11 as a rectangle. All high-voltage sources 414 are supplied via lines, not shown, which run through the various support struts 444 and support tubes 412 a, a relatively low voltage. The high voltage sources 414 generate a high voltage from these supply voltages. The output of the high voltage sources 414 is connected to star-shaped, downwardly divergent electrode tips 412b which are attached to the lower end of the support tube 412a.

The lower region of the lateral surface of the support tubes 412a carries in each case a plurality of air guide vanes 446, as can be seen in particular in FIG.

To explain the mode of operation of the embodiment of an over-spray separation device 401 shown in FIGS. 9 to 12, it is sufficient to address the different types of ionization of the air and the overspray particles that are conducted through. This happens as follows :

The oversprayed particles passing through the gratings 419 into the interior of the housing 402 pass between the tubes 440 of the ionizer 412 and then mix with the optionally conditioned air exiting the outlet ports 441 of the tubes 440. In particular, this conditioned air is ionized at the electrode tips 412b, an ionization which is then transferred to the latter when the air flowing out of the outlet nozzles 441 is mixed with the air flowing through between the pipes 440. In the passage of the underlying rollers 404 then takes place a deposition of the charged overspray particles in the same manner as in the embodiment of Figures 3 and 4 instead.

Advantage of the ionization device 450 of the last-described embodiment 404 with respect to the electrode devices 12; 112; 212 and 312 of the other embodiments is the better way of cleaning.

The embodiment of a separating device illustrated in FIGS. 13 and 14 is identical to the exemplary embodiment of FIGS. 1 and 2 with regard to all structural components, with the exception of the separating element, the stripping device and the electrode device. Corresponding parts are identified in FIGS. 13 and 14 with the same reference numerals as in FIGS. 1 and 2 plus 500.

The separating element of the separating device 501 of FIGS. 13 and 14 is formed by a helix 504 bent around a shaft 530. The coil 504 is preferably made of sheet steel, includes several gears and is of the motor 507 driven. A squeegee device 510 comprises two squeegees 510a, 510b which abut opposite surfaces of the helix 504. It is displaceable on a horizontal guide rail 570. The electrode device 512 comprises a multiplicity of straight wires or rods which run parallel to the shaft 530 of the helix 504 and lie on a cylinder jacket surface whose axis coincides with the axis of the helix 504.

If, during operation, the coil 504 overspray deposits on the two opposite surfaces, it can be scraped off by twisting the coil 504 by the two doctor blades 510a, 510b. The doctor device 510 is passively taken along and moves on the guide rail 510. The rotation of the helix 504 can again take place continuously or intermittently.

The last embodiment illustrated in FIGS. 15 and 16 is similar in terms of the design of the separating elements to the exemplary embodiment of FIGS. 1 and 2 with regard to the construction of the housing and the transport system, the embodiment of FIGS. 3 and 4. Corresponding parts are denoted in Figures 15 and 16 with the same reference numerals as in Figures 1 and 2 plus 600.

The separation elements in FIGS. 15 and 16 are again continuous endless steel belts 604. They are arranged here in two superimposed "layers" 604a and 604b. The lower layer steel straps 604a are laterally offset from the upper layer steel straps 604b so that the upper deflection rollers 605a of the lower steel straps 604a are "gap" between and below the lower deflection rollers 606b of the upper steel straps 604b. The parallel strands of the upper steel bands 604b and the lower steel bands 606a are inclined in the opposite direction to the vertical, so that in the side view of Figure 15 results in a kind of herringbone pattern. This arrangement ensures that the airflow laden with overspray can not simply flow past the runners of the steel belts 604a, 604b, but hits them and is deflected to them.

In all embodiments, the nature of the conveyor system, the air duct and the electrode device can be changed as desired, provided that only the desired function is achieved. Instead of a downwardly open housing hopper, under which a conveyor system is angordnet, also a closed tray may be provided, in which a scraper removes the collected overspray.

Instead of a constant direct current, a pulsed direct current can also be applied to the electrode devices.

In all the embodiments described above, the air flows vertically from top to bottom. However, it is also conceivable separation devices in which the air flow direction is horizontal. In this case, the described separating devices can be used twisted by 90 °, so that from the direction indication "vertical" becomes "horizontal" and from the direction indication "horizontal" becomes "vertical". Also twists around angles other than 90 ° are conceivable.

Claims

claims

1. Apparatus for separating paint overspray from the cabin air laden with overspray of spray booths

a) a housing,

b) at least one deposition element arranged in the housing, on the surface of which the cabin air can be guided, as a result of which overspray particles remain on the surface while wholly or partially purified air continues to flow;

c) a device with which the deposited overspray is removed from the surface of the separation element;

characterized in that

d) the surface of the separation element (4; 104; 204; 304; 404; 504; 604) is electrically conductive and with a

Pol is connected to a high voltage source (14; 114; 214; 314; 414; 514; 614);

e) the deposition element (4; 104; 204; 304; 404; 504; 604) is an air-flow electrode device

(12; 112; 212; 312; 412; 512; 612) connected to the other pole of the high voltage source (14; 114; 214; 314; 414; 514; 614);

f) a device (7; 107; 207; 307; 407; 507; 607) is provided, with which the separation element (4; 104; 204; 304; 404; 504; 604) can be set in motion continuously or intermittently;

g) the separating element (4; 104; 204; 304; 404; 504; 604) is assigned a stripping device (10; 110; 210; 310; 410; 510; 610) which, by utilizing a relative movement between separating element (4; 204; 304; 404; 504; 604) and stripping means (10; 110; 210; 310; 410; 510; 610) located on the surface of the separation member (4; 104; 204; 304; 404; 504; 604) Overspray strips off.

2. Device according to claim 1, characterized in that at least one separating element is an endlessly circulating belt (4).

3. Apparatus according to claim 2, characterized in that a plurality of adjacent endless circulating belts (4) are provided.

4. Apparatus according to claim 2 or 3, characterized in that the two strands of endlessly circulating

Ribbons (4) are oriented substantially vertically.

5. Apparatus according to claim 2 or 3, characterized in that the two strands of endlessly circulating

Bands are essentially level.

6. Apparatus according to claim 2 or 3, characterized in that the two strands of endlessly circulating belts (604) at an angle which is neither 0 ° nor 90 °, are aligned relative to the horizontal.

7. Device according to one of claims 2 to 6, characterized characterized in that the endlessly circulating belts (604a, 604b) are arranged in a plurality of superimposed layers.

8. The device according to claim 8, characterized in that the parallel runs of the bands (604a, 604b) are inclined in superimposed layers in the opposite direction to the horizontal.

9. Device according to claim 1, characterized in that at least one separating element is a rotatable roller (104; 204; 404).

10. Apparatus according to claim 9, characterized in that a plurality of rollers (104; 204; 404) with parallel

Axes are arranged side by side and / or one above the other.

11. Device according to claim 9 or 10, characterized in that the axis of each roller (104; 404) runs approximately horizontally.

12. The device according to claim 9 or 10, characterized in that the axis of each roller (204) extends approximately vertically.

13. The device according to claim 9 or 10, characterized in that the axis of each roller at an oblique angle, which is neither 0 ° nor 90 °, to the horizontal runs.

14. The device according to claim 1, characterized in that at least one separating element is a rotatable

Disk (304) is.

15. The apparatus according to claim 14, characterized in that a plurality of discs (304) are arranged parallel to each other on a common axis (330).

16. The apparatus of claim 14 or 15, characterized in that the axis of each disc extends approximately vertically.

17. The apparatus of claim 14 or 15, characterized in that the axis of each disc extends approximately horizontally.

18. The apparatus of claim 14 or 15, characterized in that the axis (330) of each disc (304) at an oblique angle, which is neither 0 ° nor 90 °, to the horizontal.

19. The device according to claim 1, characterized in that at least one separating element (604) has the form of a rotatable coil.

Device according to claim 19, characterized in that it comprises a squeegee device (510) comprising two squeegees (510a, 510b) abutting opposite faces of the helix (504).

21. The apparatus according to claim 20, characterized in that the doctor device (510) on a guide rail (570) is guided displaceably.

22. Device according to one of the preceding claims, characterized in that a plurality of electrically parallel connected electrode means (12; 112; 212; 312) are provided, which in the intermediate spaces between the separation elements (4; 104; 204; 304) and / or the interspaces between the separation elements (4; 104; 204; 304) and the walls of the housing (2; 102; 202; 302) engage.

23. Device according to one of the preceding claims, characterized in that at least one electrode means (112; 212) has the shape of a straight wire or rod.

24. Device according to one of the preceding claims, characterized in that at least one electrode device (12; 312) has the shape of a possibly in a plane repeatedly bent back and forth wire or rod.

25. Device according to one of the preceding claims, characterized in that at least one electrode means (412) comprises a plurality of divergent electrode tips (412b).

26. Device according to claim 25, characterized in that the electrode device (412) is arranged upstream of the separation element (404) in the cabin air flow.

27. Device according to one of the preceding claims, characterized in that an Luftzuführeinrich- device (440, 441, 442, 443) is provided, with which at least one electrode means (412) is fed independently of the cabin air, a separate air flow to the ionization.

28. The device according to claim 27, characterized in that the separate air stream is moistened.

29. Device according to one of the preceding claims, characterized in that at least one stripping device is a squeegee (10; 110; 210, 310; 410) which controls overspray from the surface of at least one deposition element (4; 104; 204; 304) 404) strikes off.

30. Device according to one of the preceding claims, characterized in that at least one device (11) is provided, with which the surface of a separating element (4) is a wetting liquid can be fed.

31. Device according to one of the preceding claims, characterized in that the high voltage source (14; 114; 214; 314; 414; 514; 614) is capable of generating a pulsed high voltage.