DE8705361U1 - Paint booth with recirculation ventilation and wet disposal - Google Patents

Description

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The invention relates to a painting booth which, on the one hand, contains a perforated air supply wall and, on the other hand, air discharge openings, to which a vortex washer is adjacent, each with a downstream exhaust air shaft with baffle plates arranged one after the other, a filter insert and a fan, the exhaust air pipe of which leads to an air shaft which is connected via parallel air guide channels to a partial area of the air supply wall on the inlet side, which is adjacent to the position of the respective downstream air discharge opening.

Such a paint booth and an arrangement of several booths is known from DE-PS 33 34 257, which ensures that overspray is practically avoided across the air flow direction and from zone to zone, especially with multi-color painting, and solvent accumulation in the air flow from zone to zone and booth to booth is progressively brought about up to the explosion limits without the risk of local overconcentration. The appropriate choice of the ratio of the supply and exhaust air volumes of the zone on the inlet side enables operation without an inlet lock, without solvent vapors escaping. This known paint booth has a vertical air flow, the disadvantage of which is that painting or conveying horizontally lying objects is relatively complex and/or the painted object is gripped or touched by the conveyor at critical points, which leads to paint damage there. In particular. With automatic barrel painting systems, paint damage can occur on the edges of barrels that are conveyed horizontally, which are particularly critical for sealing. In addition, an alignment device is required when transferring from a horizontal conveyor in the painting booth to the evaporation zone, which is advantageously not required with continuous, upright barrel conveying.

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For this reason, barrel painting booths with vertical barrel conveyors are known, which are also equipped with dry filters that are difficult to dispose of.

Furthermore, a painting booth with horizontal air flow is known from a brochure from the Klieverik B.V. machine factory, in which the items to be painted are transported vertically and in which a parallel air flow is forced by a water-sprinkled slatted wall on the air outlet side. This water-sprinkled slatted wall has the disadvantage that after a relatively short period of operation it becomes dirty due to deposits of paint in an uneven distribution, so that the air distribution changes and complex cleaning and maintenance is often required. In addition, progressive ventilation in several zones is not provided there, so that a defined accumulation of the solvent does not occur.

The object of the invention is to disclose a painting booth with parallel horizontal air flow, in which the paint particles from the overspray are removed largely maintenance-free by an easily disposable wet scrubber and which offers zone-by-zone separated ventilation, which enables a progressive increase in the solvent concentration in the air, so that it can be fed to an incineration plant with solvent at the maximum permissible saturation and a lock is not required on the inlet and outlet sides.

The solution of the invention consists in the fact that the air discharge openings are arranged parallel to the rear and are each closed off by a water-sprinkled inclined guide plate, the distance of which from the air supply wall increases from top to bottom and the lower end of which is in

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one of the vortex washers leads.

Further advantageous embodiments are specified in the subclaims.

In the case of painting booths for objects that have a very high vertical extension, more than two zones can be arranged one above the other, which means that they can be designed with a lower height extension. Several booths can be lined up in a row without partition walls in the transport direction of the objects to be painted, and a drying device is arranged after the last booth. In front of the first booth, into which the transport device introduces the objects to be painted, an entrance lock is also advantageously dispensable if a slightly smaller amount of air is fed into the first ventilated zone, preferably the lower one on the inlet side of the air distributor, via a first fan than is taken off by the associated extraction fan on the opposite side, and if the second extraction fan from the second zone removes an even larger amount of air than the first, so that there is always a slight negative pressure at the entrance to the booth at all heights, which prevents solvent vapors from escaping from the inlet opening. The required fan performance is determined by appropriate control and regulation circuits. The fan performance difference is preferably between 5 and 20% depending on the ratio of the inlet opening to the

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The sprayed rear walls are arranged with such a slope from top to bottom in the direction of the object that in the object and painting area there is a practically parallel air flow with a constant speed distribution from top to bottom*

The details are shown in Fig. 1 and 2.

Fig. 1 shows a vertical section through a lacquer kab-"ne ··' parallel to the air duct;

Fig. 2 shows schematically a complete system consisting of several

Painting booths in the transport direction of the items to be painted in perspective in an exploded view.

Fig. 1 shows a painting booth in vertical section. The booth is built on a base plate (10) and extends up to the ceiling (11). The booth is delimited on the one hand by a perforated air supply wall (LZ) in which an inlet air shaft (12) and an outlet air shaft (13) are introduced from above, and on the other hand by two guide surfaces (26, 36) inclined from top to bottom in the direction of air flow, which are sprinkled with rinsing water (WS) (*) and each have their lower end in a Vortex washer (25, 35) ends. A transport system (not shown), preferably a hanging conveyor, is guided through the booth, perpendicular to the image area, with which the objects to be painted, here a tank CF), are conveyed in cycles in front of the spray guns (P), which are arranged on the air inlet side on the air supply wall, as well as above and below the object. A rotating device (D) for the barrel (F) is set up below the barrel (F), with which it is rotated around its vertical axis for uniform painting on all sides.

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First air guide channels (14) are arranged in the air supply wall (LZ), which ensure a uniform distribution of a first inlet air flow (Lie) over the lower half of the spray area, the first zone (ZD), into a parallel air flow with the same speed distribution, and further partial air channels (15) are arranged, which distribute a further incoming circulating air flow (L2u) accordingly to the upper half of the spray area, the second zone (Z2). The air speed in the entire painting area is e.g. 0.5 m/s. The guide surfaces (26, 36) are arranged at such a distance and inclination from the object (F) that a practically horizontal, parallel flow of air through the spray area takes place and only behind this does a convergence of the outlet air (Lia, L2a) occur at the inlet gap of the water vortex washers (25, 35). Behind the vortex washers, the air streams are guided through shafts (22, 32) of a droplet separator with alternately arranged baffle plates (23, 33) and filters (24, 34) and are passed on by a fan (V2, V3) as a recirculating air stream (L2) to the recirculating air shaft (13) or as an exhaust air stream (L3). The inclination of the baffles is preferably about 30 degrees from the vertical. The average distance of the baffle surface from the object area corresponds approximately to its height.

The water (W) mixed with flocculant in a known manner is contained in a tank (17) below the scrubber and is circulated through a coke filter (KF) with a pump (WP) via a pipe (Wa) to a water inlet (We) in a channel (37), through which the water is distributed from above onto the guide surface (36), so that it runs over this into the vortex (35) and the collecting channel (27) . The water then flows accordingly over the lower guide surface (26) into the lower vortex (25) and is then taken up again in the tank (17). The tank and the coke filter (KF) are connected by

the cover (16) is accessible for disposal. The air flow (LD) is fed in by a supply air fan (V1) arranged in front of the supply air shaft (11). When several painting booths are connected in series, this is identical to the exhaust air fan (V3) of the previous booth.

The drives (LA1, LA2, LA3) are controlled or designed taking into account the resistances to be overcome in such a way that the extraction flow (L1a, L2a) of a zone (Z1, Z2) is slightly higher than its input flow (L1e, L2e), so that there is a slight negative pressure at the front of the booth and no air laden with solvent escapes there. Due to the relative weight of the solvent vapors, the first zone is placed at the bottom so that the fresh supply air at the entrance to the booth absorbs vapors on the floor.

The details of the air flow in an entire system are shown schematically in exploded form in Fig. 2. The cabins (K1, K2), the evaporation zone (AZ) and the combustion system (VA) are shown exploded along the conveyor (TR), which extends from the entrance (E) to the exit (A). The air flow (L1, L2, L3, L4, L5, Lo) is continuously, according to the designation, guided through the zones (Z1, Z2, Z3, ZA) of the individual booths and then from the first booth (KD in accordance with the direction of transport of the paint to the next booth (K2) and then through the evaporation zone (AZ) to the combustion plant (VA). The fan power of the fans (V4, V5, Vo) of the booth (K2) at the back in the direction of transport and the evaporation zone (AZ) correspond to the fan power of the exhaust fan (V3) of the first booth (KD, so that dye-laden air does not wander between the booths.

Claims (5)

lsi &igr;*· ·*· ■ie |i &igr; ca« Protection claims 1. Painting booth (K1, K2) which on the one hand contains a perforated air supply wall (LZ) and opposite air discharge openings, each of which is adjoined by a vortex washer (25, 35), each with a downstream exhaust air shaft (22) with baffle plates (23) arranged one after the other therein, a filter insert (24) and a fan (V2, V3), the exhaust air pipe (L2, L3) of which leads to an air shaft (12, 13) which is connected via parallel air guide channels (14, 15) to a partial area of the air supply wall (LZ) on the inlet side, which is adjacent to the position of the respective downstream air discharge openings, characterized in that the air discharge openings are arranged in parallel and are each closed at the rear by a water-sprinkled inclined guide plate (26, 27), the distance of which from the air supply wall (i, Z) increases from top to bottom and the lower end of which leads into one of the vortex washers (25, 35). 2. Painting booth according to claim 1, characterized in that the guide plates (26, 36) are arranged one above the other and their angle of inclination to the vertical is approximately 30 degrees. 3. Painting booth according to claim 2, characterized in that an upper distribution channel (37) with sprinkling water (WS) is arranged above the upper guide plate (36) and a collecting channel (27) is arranged below the upper vortex washer (35) as a distribution channel above the lower guide plate (26) and below the lower vortex washer (25) there is a tank (17) in which a filter, preferably a coke filter (KF), is arranged at the bottom, behind which a circulation pump (WP) is arranged on the suction side, which is connected to the upper distribution channel (37) on the pressure side. I·· ■·« «· t ■&igr; » t« agtt « 4. Painting booth according to claim 3, characterized in that the filter (KF) is detachably attached in the tank (17). 5. Painting booth arrangement of several painting booths according to one of the preceding claims, characterized in that several of the painting booths (K1, K2) are arranged next to one another and one of the exhaust air pipes (L3) from the first painting booth (K1) is connected to one of the air shafts (12) of the second booth (K2). «4 4444 44 4444 «»·« ·« 4 t * *#*· '* it 4* fl ·«*« «444 4