EP2318149B1 - Device for separating paint overspray - Google Patents

Description

1. a) mindestens einer Abscheidefläche, an welcher die Kabinenabluft entlang führbar ist und welche elektrisch leitend sowie mit einem Pol einer Hochspannungsquelle verbunden ist;
2. b) einer im Luftstrom angeordneten Elektrodeneinrichtung, welche der Abscheidefläche zugeordnet und mit dem anderen Pol der Hochspannungsquelle verbunden ist;
3. c) Mitteln, mit welchen der abgeschiedene Lack-Overspray von der Abscheidefläche abtransportiert wird,
   wobei
4. d) der Abscheidefläche eine elektrisch leitfähige Abscheideflüssigkeit zuführbar ist, welche die Abscheidefläche überströmt, so dass ein Großteil zumindest der Feststoffe aus der vorbeiströmenden Kabinenabluft in die Abscheideflüssigkeit übergeht und von dieser abtransportiert wird;
5. e) mehrere Abscheideeinheiten vorgesehen sind, welche zwei in verschiedene Richtungen weisende plane Abscheideflächen umfassen;
6. f) die Abscheideflächen derart angeordnet sind, dass sich zwei Abscheideinheiten mit jeweils einer Abscheidefläche gegenüberliegen, und zwischen sich gegenüberliegenden Abscheideflächen zweier Abscheideeinheiten jeweils eine Elektrodeneinrichtung angeordnet ist.

The invention relates to a device for separating paint overspray from the laden with overspray cabin exhaust air from painting

1. a) at least one separation surface, on which the cabin exhaust air can be guided along and which is electrically conductive and connected to a pole of a high voltage source;
2. b) an air-flow electrode device which is associated with the Abscheidefläche and connected to the other pole of the high voltage source;
3. c) means with which the deposited paint overspray is removed from the separation surface,
   in which
4. d) an electrically conductive separation liquid can be supplied to the separation surface, which flows over the separation surface, so that a large part of at least the solids from the passing exhaust air passes into the separation liquid and is transported away therefrom;
5. e) a plurality of separation units are provided, which comprise two pointing in different directions plane Abscheideflächen;
6. f) the Abscheideflächen are arranged such that two Abscheideinheiten each with a Abscheidefläche opposite, and between each opposite Abscheideflächen two Abscheideeinheiten each an electrode device is arranged.

In the case of manual or automatic application of lacquers to objects, a partial flow of the lacquer, which generally contains both solids and solvents and / or binders, is not applied to the article. This partial flow is called in the professional world "over-spray". The overspray is detected by the air flow in the spray booth and fed to a separation.

Especially in systems with greater paint consumption, for example in systems for painting vehicle bodies, preferably wet separation systems are used. In the case of wet separators known from the market, water flows together with the exhaust air from the cabin to an air flow accelerating nozzle. In this nozzle there is a turbulence of the flowing cabin exhaust air with the water. In this process, the overspray particles largely pass into the water, so that the air leaves the wet scrubber substantially cleaned and the paint overspray particles are in the water. From this they can then be recovered or disposed of.

In known wet scrubbers relatively much energy is required to circulate the required quite large amounts of water. 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 causes high energy consumption in the recirculation mode Air treatment results.

In the case of devices known from the market, which correspond to the aforementioned type without separation liquid, by contrast, it is deposited in a dry way by ionizing the overspray particles entrained by the passing cabin exhaust air through the electrode device and by virtue of the electric field established between the separation surface and the electrode device migrate to Abscheidefläche on which they are deposited. The adhering to the separation surface paint Overspraypartikel can then, for example, mechanically stripped and transported away from this.

The cleaning effect of such separators is very high. For continuous operation, however, it must always be ensured that a sufficiently strong electric field can form between the deposition surface and the electrode device, which is possible only up to a certain layer thickness of paint overspray on the deposition surface, since such a layer has an insulating effect , However, the required continuous removal of the paint overspray from the separation surface is associated with structurally quite complex measures and can be prone to failure.

Electrostatic precipitator and / or separator are for example from the US 5 698 012 A , of the DE 44 13 118 A1 , of the DE 39 00 139 A1 , of the US Pat. No. 3,890,103 , of the JP 2001 038 244 A , of the JP H06 319 937 A or the US Pat. No. 3,785,125 known.

In devices such as those in the US 5 698 012 A described, the removal of paint overspray from the separation surface is improved by the Abscheideflüssigkeit and simplified.

There, therefore, the advantage of a good separation of paint overspray from cabin exhaust air via an electric field is combined with the good transport of paint overspray in a liquid.

As a result of the deposition liquid flowing continuously along the separation surface, the paint overspray taken up by it is continuously transported away, so that adhesion of paint overspray to the deposition surface is reduced, which would lead to an insulation thereof.

It is an object of the invention to provide a device of the type mentioned, whose deposition efficiency is improved in contrast.

• g) Abscheideflüssigkeit aus einer Überlaufrinne auf die Abscheideflächen einer Abscheideeinheit strömt, wobei sich die Überlaufrinne in einem gekrümmten Abschnitt der Abscheideeinheit befindet, so dass die Abscheideflüssigkeit jeweils als zusammenhängende Schicht über neben der Überlaufrinne verlaufende gekrümmte Flanken des gekrümmten Abschnitts der Abscheideeinheit zu den Abscheideflächen gelangt und an den Abscheideflächen als weiterhin zusammenhängende Abscheideflüssigkeitsschicht herabfließt.

This object is achieved in a device of the type mentioned in that

• g) separating liquid flows from an overflow channel to the separation surfaces of a separation unit, wherein the overflow channel is located in a curved portion of the separation unit, so that the separation liquid in each case as a contiguous layer passes over adjacent to the overflow trough curved edges of the curved portion of the separation unit to the Abscheideflächen and flows down at the Abscheideflächen as further contiguous Abscheideflüssigkeitsschicht.

In each case, a single electrode device cooperates with two separation surfaces, which improves the effectiveness of the device.

It is favorable if the electrode device comprises a plate-shaped electrode and at least one wire electrode. A wire electrode acts as a spray electrode, through which the paint overspray particles entrained by the booth exhaust air are effectively ionized. By means of a plate-shaped electrode, in cooperation with the separation surface, a homogeneous field can be built up by which the ionized paint overspray particles are reliably supplied to the separation surface.

It is advantageous if the plate-shaped electrode is formed as a grid electrode. Turbulence occurs at the grid, which causes the paint overspray particles to distribute more evenly in the exhaust air flowing past the cabin, which in turn has a favorable effect on the separation of the latter at the separating surface.

When the electrode means comprises a plurality of wire electrodes which are parallel to each other, the efficiency of ionization of the overspray particles is increased.

If the separation surfaces of at least one deposition unit extend parallel to one another at least in one section, a plurality of separation units can be arranged in cascade fashion one behind the other, thereby making good use of the space available.

If the at least one separation surface comprises at least one curved section which extends along the at least one wire electrode, a reduction in the flow rate of the exhaust air of the cabin in the region of the wire electrode can be achieved. Accordingly, a volume of the booth exhaust lingers longer in the area of influence of the wire electrode, so that a larger proportion of paint overspray particles in this volume is ionized. In addition, turbulence and turbulence occur in the region of the curvature, which even out the distribution of paint overspray particles in the booth exhaust air.

In this case, it is favorable if the number of curved sections of the at least one separating surface coincides with the number of wire electrodes, so that the mentioned effects occur in the region of each wire electrode.

It could be achieved with a device in which the curvature of one or more curved sections in cross section extends on a circular arc whose center is concentric with the wire electrode particularly good deposition results.

It is generally advantageous for effective deposition if the at least one wire electrode is arranged to be reached in front of the plate-shaped electrode by the overspray-laden cabin exhaust air.

Figur 1

eine Lackierkabine einer Oberflächenbehandlungsanlage mit einem ersten Ausführungsbeispiel einer Overspray-Abscheidevorrichtung in einer Vorderansicht;

Figur 2

die Lackierkabine von. Figur 1 in einer perspektivischen Ansicht;

Figur 3

eine perspektivische Ansicht zweier Abscheideeinheiten sowie dreier Elektrodeneinrichtungen der Abscheidevorrichtung von Figur 1;

Figur 4

die beiden Abscheideeinheiten mit Elektrodeneinrichtungen von Figur 3 im vertikalen Schnitt;

Figur 5

eine perspektivische Ansicht zweier Abscheideeinheiten sowie dreier Elektrodeneinrichtungen jeweils gemäß einem zweiten Ausführungsbeispiel;

Figur 6

eine perspektivische Ansicht eines zweiten Ausführungsbeispiels einer Overspray-Abscheidevorrichtung, welche mehrere Abscheideeinheiten und Elektrodeneinrichtungen nach Figur 5 umfasst;

Figur 7

eine perspektivische Ansicht zweier Abscheideeinheiten gemäß einem dritten Ausführungsbeispiel sowie dreier Elektrodeneinrichtungen gemäß dem ersten Ausführungsbeispiel nach Figur 3.

Embodiments of the invention will be explained in more detail with reference to the drawing. In this show:

FIG. 1

a painting booth of a surface treatment plant with a first embodiment of an overspray separation device in a front view;

FIG. 2

the paint booth of. FIG. 1 in a perspective view;

FIG. 3

a perspective view of two separation units and three electrode devices of the separator of FIG. 1 ;

FIG. 4

the two separation units with electrode devices of FIG. 3 in vertical section;

FIG. 5

a perspective view of two deposition units and three electrode devices each according to a second embodiment;

FIG. 6

a perspective view of a second embodiment of an overspray separation device, which a plurality of deposition units and electrode devices according to FIG. 5 includes;

FIG. 7

a perspective view of two deposition units according to a third embodiment and three electrode devices according to the first embodiment according to FIG. 3 ,

First, on the FIGS. 1 and 2 Referenced. There is a total of 2 a spray booth a surface treatment system referred to, in which vehicle bodies 4 are painted after they were in the paint booth 2 upstream, not specifically shown pretreatment stations, for example, cleaned and degreased.

The spray booth 2 comprises an overhead painting tunnel 6, which is bounded by vertical side walls 8a, 8b and a horizontal cabin ceiling 10, but open at the ends and downwards in such a way that over-laden cabin exhaust air can flow down. The cabin ceiling 10 is formed in the usual way as a lower boundary of the air supply space (not shown) with filter cover.

At the level of the flanked by the lower edges of the side walls 8a, 8b lower opening 12 of the painting tunnel 6, a steel structure 14 is arranged, which carries a known per se conveyor system 16, which will not be discussed here. With this vehicle body 4 to be painted can be transported from the input side of the painting tunnel 6 to its output side. Inside the paint tunnel 6 are not specifically shown application devices, by means of which the vehicle bodies 4 can be applied in a manner known per se with paint.

Below the lower opening 12 of the painting tunnel 6 is an up to the painting tunnel 6 open towards the separation chamber 18, in which is formed during painting paint overspray.

The separation chamber 18 is characterized by an in FIG. 2 to be recognized bottom plate 20, two vertical side walls 22a, 22b and two vertical end walls bounded, the latter two in the FIGS. 1 and 2 are omitted.

In the separation chamber 18 is a separation device 24 having a plurality of in the longitudinal direction of the separation chamber 18 successively arranged deposition units 26, which will be discussed in more detail below.

In the region of the separation chamber 18 between the separation device 24 and the painting tunnel 6 there are two air baffles 28a, 28b, which initially converge downwards from the side walls 22a, 22b of the separation chamber 18 and in their end region facing the separation device 24 to the lateral boundaries of the Divide separator 24. The air baffles 28a, 28b and corresponding air baffles (not shown) at the end faces extend from the top to the separating device 24.

The separation units 26 rest on a support frame 30 which allows air to flow downwardly out of the separation device 24. Below the separation device 24 is a further air guide plate 32, which extends along the separation device 24 in the separation chamber 18. The air guide plate 32 has a vertical portion 32 a, which in the FIGS. 1 and 2 left side wall 22a of the separation chamber 18 faces, and an obliquely downward in the direction of the opposite side wall 22b of the separation chamber 18 extending portion 32b.

Between the vertical portion 32 a of the baffle 32 and in the FIGS. 1 and 2 left side wall 22a of the separation chamber 18 is a only in FIG. 1 schematically illustrated collecting channel 34 which extends parallel to the vertical portion 32a of the air baffle 32 and which is inclined in the longitudinal direction relative to a horizontal plane.

In the Figures 3 and 4 are two adjacent separation units 26 of the separator 24 is shown. As can be seen there, a separation unit 26 comprises two spaced-apart parallel rectangular side plates 36a, 36b, which are interconnected at their upper opposite end edges by a curved portion 38, the clear contour of which corresponds in cross-section to a semicircle and forms the top of the separation unit 26 ,

At the apex of the curved portion 38 of the separation units 26, this is formed into an overflow channel 40, which will be discussed in more detail below.

The respective outer surfaces of the side plates 36a, 36b form Abscheideflächen 42a and 42b, which will also be discussed again below.

At their lower edges, the side plates 36a, 36b each carry a gutter 44a, 44b, which runs parallel to the side plates 36a, 36b of the separation units 26 and in the direction of a first, in FIG. 3 the front end 46 of the separation unit 26 is inclined downwards The drainage channels 44a, 44b terminate at the end face with the side plates 36a, 36b of the separation unit 26 (cf. FIG. 3 ). The gutters 44a, 44b are at their end 48a and 48b at the first end face 46 (see. FIG. 3 ) of the separation unit 26 open.

As in the FIGS. 1 and 2 can be seen, each separation unit 26 comprises a first end wall 50a, which is arranged on the first end face 46. The opposite end face of the separation units 26, which is not specifically provided with a reference numeral, is covered by a second end wall 50b. The end walls 50a, 50b the Abscheideinheiten 26 close the end faces of the associated overflow channel 40. The two end walls 50a, 50b are made of plastic. The first end wall 50a of the separation unit 26 comprises two openings 52a, 52b, into each of which a drainage channel 44a, 44b opens with its ends 48a, 48b. On the gutters 44a, 44b opposite side of each end wall 50a dripping plates 54a, 54b are attached to the apertures 52a, 52b. These are designed as a profile whose cross section corresponds to that of the gutters 44a, 44b.

When the separation device 24 is arranged in the separation chamber 18 of the spray booth 2, the drip plates 54a, 54b of each separation unit 26 protrude beyond the collection channel 34.

In the separation device 24, two adjacent separation units 26 are arranged in each case while maintaining a distance from each other. Between two adjacent deposition units 26 as well as at the free side plates 36a and 36b of the two outermost separation units 26 within the separation device 24, an electrode device 56, each of which is connected to a high voltage source extending in FIG FIG. 4 not specifically shown. Alternatively, the electrode means 56 may be powered by a single high voltage source. The separation units 26 are connected to ground potential.

Each electrode device 56 comprises two straight, parallel to each other electrode strips 58a, 58b. In a field section 60 of the electrode device 56, these hold a grid electrode 62 whose edges 64a, 64b extending between the electrode strips 58a, 58b are perpendicular to them. In a corona section 66 of the electrode device 56, the corona wires 68 extend in a predetermined by the electrode strips 58a, 58b plane parallel to the edges 64a, 64b of the grid electrode 62 and are arranged at equal distances from each other.

As in the Figures 3 and 4 can be seen, the electrode means 56 have an overall extension which substantially corresponds to the extension of the side plates 36a, 36b of the separation units 26. The electrode means 56 are arranged so that the lower edge 64b of the grid electrode 62 is located approximately at the level of the lower end of the side plates 36a and 36b, respectively.

In operation of the separation device 24 flows at the respective Abscheidefläche 42a, 42b of the side plates 36a, 36b of the separation units 26 from top to bottom, a Abscheideflüssigkeit in the gutters 44a, 44b, which is suitable to receive solid particles from the paint overspray formed during painting.

For this purpose, this separating liquid is supplied to the overflow channel 40 in the curved section 38 of the separating units 26. From there, the separating liquid reaches the side plates 36a, 36b via the curved flanks 70a, 70b of the curved section 38 of the separating unit 26 extending next to the overflow channel 40 as a continuous layer and flows down at their separating surfaces 42a, 42b as a further continuous separating liquid layer.

The number of corona wires 68 of the electrode device 56 and their distance from one another may vary depending on the deposition behavior of the overspray particles. At the present embodiment, four corona wires 68 are provided, of which the topmost next to the curved portion. 38 of the deposition unit 26 is arranged, whereas the underlying corona wire 68 is still in the area adjacent to the respective side plate 36a and 36b of the separation unit 26.

In FIG. 5 are as a second embodiment, a modified Abscheideeinheit 126 and an augewandelte electrode device 156 and in FIG. 6 a comprehensive modified separation device 124 shown this. Components of the deposition unit 126, the electrode device 156 and the separation device 124, which correspond to those of the separation unit 26, the electrode device 56 and the separation device 24 according to FIGS FIGS. 1 to 4 are denoted by the same reference numerals plus 100.

The separation unit 126 differs from the separation unit 26, inter alia, in that the drainage channels 144a, 144b project beyond the end face 146 of the separation unit 126. The projecting portions 172a, 172b correspond to the above-discussed drip plates 54a, 54b, which can therefore be dispensed with in the separating device 124.

As in FIG. 6 1, the projecting portions 172a, 172b of the drainage channels 144a, 144b of the separating unit 126 extend through the respective openings 152a, 152b in each end wall 150a of the separating device 124.

In FIG. 5 There is shown a high voltage source 174 disposed between the side plates 136a, 136b of each deposition unit 126 and with the electrode means 156 is connected. In a corresponding manner, the high-voltage source 174 may also be present in each deposition unit 26 according to the first exemplary embodiment. In each case, a single separation unit 126 and a single electrode device 156 thus form a separation module 176. Correspondingly, in each case a single separation unit 26 and a single electrode device 56 form after the FIGS. 1 to 4 a separation module 76.

In FIG. 5 Struts 178a, 178b, 178c, which connect the inner surfaces of the two side plates 136a, 136b of the separating unit 126 at the bottom, in the middle and at the top, can also be seen.

In the case of the electrode device 156 according to the second exemplary embodiment, a protective bar 180 extends perpendicularly between the electrode bars 158a, 158b above the uppermost corona wire 168, thereby reducing the risk of contact with objects or particles falling off the painting tunnel 6 on the electrode device 156 with the corona wires 168 becomes.

Otherwise, what has been said above for the separation unit 26, the electrode device 56 and the separation device 24 applies correspondingly to the separation unit 126, the electrode device 156 and the separation device 124.

The basic principle of the devices explained above will now be described using the example of the separating device 24 according to FIGS FIGS. 1 to 4 explained. The use of the separating device 124 according to the Figures 5 and 6 in the paint booth 2 is analogous.

When painting the vehicle bodies in the painting tunnel 6, the cabin air located there is loaded with paint overspray particles. These may still be liquid and / or sticky but also more or less firm. The cabin exhaust air laden with paint overspray flows through the lower opening 12 of the painting tunnel 6 into the separation chamber 18. There, this air is directed by the air guide plates 28a, 28b in the direction of the separation device 24 and flows between adjacent deposition units 26 in the direction of the lower Air baffle 32.

Corona discharges occur at the corona wires 68 in a manner known per se, by means of which the overspray particles are effectively ionized in the exhaust air flowing past the booth.

The ionized overspray particles pass the ground potential side plates 36a, 36b of two adjacent deposition units 26 and the intervening grid electrode 62 in the first portion 60 of the electrode means 56. Due to the electric field formed between the grid electrode 62 and side plates 32a, 32b, the ionized overspray particles deposit Abscheideflächen 42a, 42b of the side plates 36a, 36b of the separation units 26 and are there taken up by the deposition liquid flowing therealong.

Some of the ionized overspray particles are already deposited in the second section 66 of the electrode device 56 in the region of the corona wires 68 on the separation units 26. However, the electric field present between the corona wires 68 and the respective side plate 36a, 36b of the deposition unit 26 is less homogeneous than the electric field in the region of the grid electrode 62, therefore more directional and effective deposition of the ionized ones Overspray particles take place at the corresponding separation unit 26.

The cleaned in the passage between the separation units 26 air is from the lower air guide plate 32 in the direction of the in the FIGS. 1 and 2 shown side wall 22b of the separation chamber 18 directed from where it, optionally after a certain conditioning, the paint tunnel 6 can be supplied again as fresh air. The conditioning may in particular be a readjustment of the temperature, the humidity and possibly the removal of solvents still in the air.

The deposition liquid flowing down the separation units 26 and now loaded with the overspray particles passes down into the gutters 44a, 44b of the separation units 26. The slope of the drainage channels 44a, 44b causes the laden separation liquid to flow in the direction of the openings 52a, 52b in the respective end walls 50a through the collecting trough 34, the precipitating liquid laden with overspray particles flows out of the painting booth 2 and can be cleaned and reprocessed, in which the separating liquid is freed from the overspray particles. or disposal.

In FIG. 7 two again modified separation units 226 are shown according to a third embodiment. Components of the separation unit 226, which those of the separation unit 26 after the FIGS. 1 to 4 are denoted by the same reference numerals plus 200. Additionally are in FIG. 7 three electrode devices 256 which detect the electrode devices 156 after the Figures 3 and 4 correspond. A deposition unit 226 and an electrode unit 256 each form a module 276.

In the deposition unit 226, the side plates 236a, 236b have corrugated portions 282a, 282b which abut the respective flanks 270a, 270b of the curved portion 238 of the separation unit 226. Between the gutters 244a, 244b and the corrugated portions 282a, 282b, the respective side plate 236a, 236b includes a planar portion 284a, 284b.

Each corrugated section 282a, 282b has in each case in relation to the center plane of the separating unit 226 running parallel to and parallel to the plane sections 284a, 284b inwardly curved sections 286a, 286b, 286c, 286d and outwardly curved sections 288, which extend along a respective corona wire 268 extend. The number of inwardly curved portions 286 of each corrugated portion 282a, 282b of the side plates 236a, 236b thus corresponds to the number of corona wires 268 of the electrode device 256.

Of the inwardly curved portions 286a, 286b, 286c and 286d and the outwardly curved portions 288 of the sake of clarity, only one is provided with a reference numeral.

The curvature of the two lower and upper inwardly curved portions 286a, 286b and 286d, when viewed in cross section, follows a circular arc. The inwardly curved portions 286a, 286b, and 286d are disposed opposite each adjacent corona wire 268 so as to be concentric in cross section with that through the path of the respective arched portion 286a, 286b or 286d predetermined arc lies. The uppermost inwardly curved portion 86d extends slightly shorter in the vertical direction than the lower two inwardly curved portions 286a and 286b.

In the inward arched portion 286c disposed below the uppermost domed portion 286d, the radius of curvature decreases from the bottom to the top, so that the inwardly curved portion 286c has a parabolic like cross section. Thereby, the distance between the outer ends of opposite flanks 270a, 270b of two adjacent Abscheideeihheiten 226 in a horizontal plane is shorter than the distance between the opposite planar portions 284a, 284b of the respective side plates 236a, 236b.

The distances between two adjacent deposition units 226 with electrode means 256 arranged therebetween are coordinated so that the corona wires 268, viewed in cross-section, are each concentric with the center of the approximately circular arc-shaped segments predetermined in cross-section by two opposite inwardly curved portions 286a, 286b or 286d.

Due to the inwardly curved sections 286 of the corrugated sections 282a, 282b of the separation units 226, the channel formed between the separation units 226, through which the cabin exhaust air laden with overspray flows, is locally expanded in each case. As a result, at the level of the inwardly curved regions 286 of the side plates 236a, 236b, the flow velocity is reduced in each case, as a result of which the cabin exhaust air flowing past the respective corona wire 268 remains in its region of influence for a longer time. This in turn will increase the amount of overspray in a given volume the cabin exhaust air is ionized by the respective corona wire 268. By in the flow direction of the cabin exhaust air arranged inwardly curved portions 286 of the side plates 236a, 236b of the separation units 226 thus a significantly larger proportion of overspray in the second electrode portion 266 is ionized with the corona wires 268, as this at the same flow rate of the cabin exhaust air at consistently planar side plates 236a, 236b would be the case. For this reason, it is possible to increase the overall throughput of car exhaust air, since the flow speed of the overspray laden cabin exhaust air can be increased so that the residence time of the same in the region of the corona wires 268 of the residence time at a lower flow rate and fully flat side plates 236a, 236b equivalent.

For example, an increase in the flow rate by a factor of 4 to 6 is possible. If e.g. in a separation device 24 with separation units 26 according to the first embodiment, a flow rate of 0.25 m / s laden with Overspraypartikeln cabin exhaust air of 0.25 m / s is still a satisfactory Abscheidungsleistung achievable, so when using the separation units 226 Strömungsgeschwindikeit the cabin exhaust air to 1 Increased m / s to 1.5 m / s and still achieve a satisfactory separation result. If the flow rate is to be increased, the height of the separation devices can be increased accordingly to achieve the same deposition effect.

In addition, turbulence and turbulence occur in the region of the corrugated sections 232a, 232b of the opposing side plates 236a, 236b of two adjacent separation units 226, as a result of which the paint overspray particles entrained by the booth exhaust air become uniform in the region The corona wires 268 can be distributed and thus be ionized more effectively.

In each case, a modification of the electrode means 56 or 156, not shown here, instead of the grid electrode 62 or 162, a plate electrode is provided. However, in the presence of the grid electrode 62 or 162, the deposition of ionized paint overspray particles from the spent air is more effective, since small turbulences of the booth exhaust air are produced on the grid or the grating bars and the ionized paint overspray particles are thereby produced in the area of the grid electrode 62 or 162 are distributed more homogeneously than is the case with a plate electrode with a closed electrode surface.

In order to reduce the possibility of adherence of deposited paint overspray particles received from the deposition liquid to the deposition surfaces 242a, 242b of the deposition units 226 at the deposition surfaces 242a, 242b, the deposition surfaces 242a, 242b of each deposition unit 226 may be provided with a non-stick coating. such as Teflon, be coated.

Instead of the overflow channel, from which separating liquid via its outer edges and over the curved flanks 70a, 70b, 170a, 170b and 270a, 270b of the curved portion 38, 138 and 238 of the separation units 26, 126 and 226 to the side plates 36a, 36b, 136a, 136b and 236a, 236b respectively, an alternative device can also be provided at the separation units 26, 126, 226, with which deposition liquid can be applied to the separation units 26, 126, 226. For example, in each case a sprinkler device, a slot nozzle or simply a tube with openings above the curved portion 38, 138 and 238, respectively.

In interaction with the electrode device 56, 156, 256 and the ground potential side plates 36a, 36b, 136a, 136b, 236a, 236b of the separation units 26, 126, 226, it is important that the separation liquid be electrically conductive. The deposition liquid may be based, for example, on water or on an oil and provided with additives that promote agglomeration and / or curing and / or detackification of paint overspray particles in the deposition liquid.

The conductivity of the deposition liquid is preferably in the range of 50 to 5000 μS / cm, in particular from 1000 to 3000 μS / cm, and can be adjusted via additives such as salts.

By the above-described combination of an electrical separation of paint overspray from loaded Kalinenabluft with the use of the Abscheideflüssigkeit for receiving and transporting the paint Overspraypartikel an effective and effective cleaning of the overspray laden cabin exhaust air can be achieved. The cleaned cabin exhaust air can then be recycled to the spray booth, as explained above.

Claims (9)

1. Device for separating paint overspray from the overspray-laden booth exhaust air of paint shops having:

   a) at least one separation surface (42a, 42b; 142a, 142b; 242a, 242b), along which the booth exhaust air is guidable and which is electrically conductive and is connected with one pole of a high voltage source (74; 174; 274);

   b) an electrode apparatus (56; 156; 256) arranged in the air stream which is associated with the separation surface (42a, 42b; 142a, 142b; 242a, 242b) and is connected with the other pole of the high voltage source (74; 174; 274);

   c) means with which the separated paint overspray is conveyed away from the separation surface (42a, 42b; 142a, 142b; 242a, 242b),
   wherein

   d) to the separation surface (42a, 42b; 142a, 142b; 242a, 242b) an electrically conductive separation liquid is deliverable, which overflows the separation surface (42a, 42b; 142a, 142b; 242a, 242b) such that a majority of at least the solids passes from the by-passed booth exhaust air into the separation liquid and is conveyed away thereby,
   wherein

   e) multiple separation units (26, 126, 226) are provided, which comprise two plain separation surfaces (42a, 42b; 142a, 142b; 242a, 242b) oriented in different directions;

   f) the separation units (26, 126, 226) are arranged such that two separation units (26, 126, 226) are opposite one another by one separation surface (42a, 42b; 142a, 142b; 242a, 242b) each, and an electrode apparatus (56; 156; 256) is each arranged between the opposite separation surfaces (42a, 42b; 142a, 142b; 242a, 242b) of two separation units (26, 126, 226),
   characterized in that

   g) separation liquid flows from an overflow channel (40; 140; 240) over the separation surface (42a, 42b; 142a, 142b; 242a, 242b) of one separation unit (26, 126, 226), wherein the overflow channel (40; 140; 240) is provided in a curved portion (38; 138; 238) of the separation unit (26, 126, 226), such that the separation liquid passes in each case as a continuous film to the separation surfaces (42a, 42b; 142a, 142b; 242a, 242b) through curved flanks (70a, 70b; 170a, 170b; 270a, 270b) of the curved portion (38; 138; 238) of the separation unit (26, 126, 226) adjacent to the overflow channel (40; 140; 240) and flows down over the separation surfaces (42a, 42b; 142a, 142b; 242a, 242b) still as a continuous film of separation liquid.
2. Device according to claim 1, characterized in that the electrode apparatus (56; 156; 256) comprises a plate-shaped electrode (62; 162; 262) and at least one wire electrode (68; 168; 268).
3. Device according to claim 2, characterized in that the plate-shaped electrode (62; 162; 262) is configured as a grid electrode (62; 162; 262).
4. Device according to claim 2 or 3, characterized in that the electrode apparatus (56; 156; 256) comprises multiple wire electrodes (68; 168; 268) which extend parallel to one another.
5. Device according to one of the claims 1 to 4, characterized in that the separation surfaces (42a, 42b; 142a, 142b; 242a, 242b) of at least one separation unit (26, 126, 226) extend parallel to one another in at least one portion.
6. Device according to one of the claims 2 to 5 with reference to claim 2, characterized in that the at least one separation surface (42a, 42b; 142a, 142b; 242a, 242b) comprises at least one curved portion (286a, 286b, 286c, 286d) which extends along the at least one wire electrode (268).
7. Device according to claim 6, characterized in that the number of curved portions (286a, 286b, 286c, 286d) of at least one separation surface (242a, 242b) matches the number of the wire electrodes (268).
8. Device according to claim 6 or 7, characterized in that the curvature of one or more curved portions (286a, 286b, 286c, 286d) extends in cross-section over a circular arc, the center point of which is concentric to the wire electrode (268).
9. Device according to one of the claims 2 to 8, characterized in that the at least one wire electrode (68; 168; 268) is arranged such that it is reached by the overspray-laden booth exhaust air before the plate-shaped electrode (62; 162; 262) is reached.

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