DE4215397A1 - Vehicle paint spray water recirculation assembly - has system tank with suction pump to extract floating paint particles without using chemicals - Google Patents

Abstract

The assembly, to remove paint particles from the recirculating water for a vehicle paint spray cabin, has a system tank (26) with a separation zone (34) following the inlet (24), where the paint particles form a floating layer (36). The entry (42) of a suction unit (40) is at the opposite end of the tank (26) to the inlet (24), for suction extraction of the floating matter (36, 38). The entry (42) into the suction unit (40) is arranged in the system tank (26) so that it is aligned with the floating matter (36, 38) at all levels within the tank, with a floating pump (40) to keep the entry at the water surface (30). A unit (22) to separate foreign matter is in front of the entry (24) into the tank (26), to remove light and heavy coarse particles from the water, with a trough to catch precipitated matter. Floating matter is retained within the trough by a barrier with openings for the water to pass through, also acting as the entry (24) to the tank (26) to deliver water flow streams (28) parallel to the water surface (30) in the tank (26), directed by a guide plate across the water flow direction (28). The level in the separation trough is held at a constant level at or slightly over the level (30) in the system tank (26). USE/ADVANTAGE - The assembly is for the recirculation of water in a vehicle paint spraying station. The appts. gives an effective sepn. and removal of the paint particles, from the recirculating water, without the use and cost of coagulation chemicals.

Description

The invention relates to a device for discharging Paint particles from circulating water from paint spray booths holding a system tank, which from the paint spray The circulating water coming into the cabin can be supplied via an inlet is.

In the previously known devices of this type added a variety of chemicals to the circulating water, to coagulate the paint particles on the one hand and others to avoid foam formation in the system tank.

The disadvantage of these devices is that the addition of chemicals to coagulate the paint par on the one hand, considerable financial expense mean, partially increase the coagulum volume, weight and eventually problems with recovery prepare the lacquer coagulate.

The invention is therefore based on the object direction of the generic type to improve such that effective use with the least use of chemicals it is possible to carry the paint particles from the circulating water.  

This object is achieved in that in a separation after the system tank following the inlet zone is provided in which the paint particles in a float near the surface, and that on a side of the separation zone opposite the inlet an inlet of a suction for the near-surface Floating phase in the system tank is arranged.

The advantage of the solution according to the invention is there too see that on the one hand the system tank for separation and Concentration of the paint particles is used, wherein the paint particles in a layer close to the surface swim and that on the other hand via the inlet both the concentrated paint particles near the surface Layer as well as on the circulation water surface forming foam are suctioned off, so that on the one hand The addition of defoamers is eliminated, and secondly the small, finely distributed and preferably re-opened Processable paint particles from coarse particles in circulation water are separated in the course of the separations zone to the bottom of the system tank, for example Such coarser particles are lumps of lacquer or Paint patties or other particles on the bottom of the System tanks occur and can also be removed from the bottom are.

Another advantage of the solution according to the invention is to see that this device is universal for everyone Lacquer types can be used, since the addition of Chemicals, for example flocculants, ent depending on the type of paint is possible.  

In addition, an advantage of the solution according to the invention is also to see that there is a separation in the separation zone the paint particles into reworkable paint particles takes place, which float into the near-surface layer and others, with dirt and other contaminants seen paint particles, such as lumps of paint, etc., that sink to the bottom of the system tank and in the Usually not reprocessable, but only disposed of are cash.

So that the inlet always the floating phase in the system tank is either to ensure that a revolution water surface in the system tank always at a constant height stands so that the inlet can be arranged fixed can. Since this is a complex regulation of the amount of Circulating water in the system tank is required particularly advantageous if the inlet is so in the system tank is arranged that with this a suction of floating phase regardless of the state of the environment water surface occurs in the system tank, d. that is, the Inlet of the level of the circulating water surface in the system tank follows.

It is preferably realized in that in the system tank arranged a floating pump having the inlet is that swims in the circulating water and so one is ordered inlet that this each the swim phase.  

In order for the solution according to the invention to be flawless Separation of the paint particles in the separation zone achieve that, in particular, not through foreign dirt is disturbed, is preferably a stranger before the enema dirt separator provided.

This foreign dirt separator is conveniently so out it forms sinking and floating coarse particles separates from the circulating water before it enters the system tank entry.

This can be realized particularly simply by the fact that the foreign dirt separator has a trough to hold sinking coarse dirt.

Furthermore, this can also be achieved by that in the foreign dirt separator one over a liquid coarse particles floating Element is arranged.

This element is preferably designed so that it Has openings for the circulating water, which are smaller are as the coarse particles to be retained.

The element is expediently designed such that it forms the inlet into the system tank so that the circulation water from the foreign dirt separator directly into the System tank overflows.

For optimal separation of the paint particles in the Sepa ration zone, the inlet is designed so that he had an approximately parallel to the  Circulating water surface in the system tank directed inlet generated flow that is particularly free of eddies. As a result, the circulating water flows in as evenly as possible the separation zone, is distributed in the separations zone, so that on the one hand the fine and refurbished floatable paint particles or paint coagulate particles, while coarse and especially dirty lacquer coagulate lumps or patties in the course of the separation zone in Lower towards the bottom of the system tank.

In terms of construction, such an inlet can be cheaper Realize wise that this one with the one running flow generating baffle is provided.

Another improvement in the effect of the separation zone can also be achieved in that the inlet is not focused on a small area in the system tank follows, but that the inlet is in a transverse direction to the direction of flow approximately parallel to the circulating water surface over a significant portion of the extent of the Separation zone or the system tank in this Rich tion extends.

So that at least partially in the area of the inlet directed towards the surface of the circulating water Inlet flow arises, it is also advantageous if the liquid level in the foreign dirt separator same height of the circulating water surface in the system tank or is kept slightly higher.  

This can either be achieved in that the circulation water surface in the system tank is kept constant or in that the entire foreign dirt separator is height-adjustable is arranged in the system tank and according to the The level of the circulating water surface is adjustable.

In connection with the previous description of the inventions device according to the invention was not discussed in more detail thereon like the floating one sucked through the inlet Phase is further processed in the system tank. Here are usual processing methods for further Aufkon centering of the paint particles conceivable. As special before It has been shown to be partial if through the entrance extracted floating phase in a flotation unit can be introduced, which has a flotation area, in which the paint particles float as flotate. The Advantage of using such a flotation unit is a further concentration of the paint particles.

It has proven to be favorable if in the Flo tationseinheit a clearing device for the flotate is seen where that concentrate by clearing the flotate lacquer particles or concentrated lacquer coagulate is available for further processing.

Such a clearing device can for example be built up that it constantly clears the flotate. Still However, it is more advantageous if the flotation unit comprises a control which the clearing device so  controls that it removes the flotate at intervals. The There is the advantage of clearing the flotate at intervals in that a much greater concentration of Paint particles or paint coagulate in the flotate is possible as with constant clearing of the flotate, so that this is resulting flotate a very high paint particle concentration and has a low liquid concentration.

It is particularly advantageous if on the control the intervals are variably adjustable.

To further verify the liquid content of the flotate wrestle, it is advantageously provided that the Flo tationseinheit has a drainage zone and that the The flotate is cleared into the drainage zone transferred. A then takes place in this drainage zone Reduction of the liquid content in the flotate.

Such a drainage zone is advantageous an upward rising wall surface on which the Flotat is held by the clearing device and lengthways which the liquid from the flotate into the flotation unit flows back.

When dewatering the flotate in the drainage zone it would be conceivable in the simplest case that the clearing direction of the flotate at the same speed the drainage zone moves, with which also the clearing clears the flotate from the flotation area. However, it is even more advantageous if the control of the Clearing device is adjustable so that the flotate in the drainage zone during an adjustable Ent watering time remains.  

The drainage time is, for example, one adjustable that the clearing the flotate with a adjustable speed through the drainage zone emotional. However, it is even more advantageous if the Control is adjustable that the flotate in the Ent irrigation zone during a drainage period that is also variably adjustable via the control.

It is structurally particularly advantageous if the Ent watering zone by an adjoining the flotate area closing ascending ramp is formed.

The further treatment of the flotate was carried out within the framework of the long-described embodiments of the fiction measured device not explained in detail. Preferably provided that the flotate leads to post-drainage is cash.

Such post-drainage is preferably up builds the flotate from the drainage zone into one Sludge buffer can be transferred.

A conveniently takes place in this sludge buffer Homogenization of the flotate.

In addition, it is advantageously provided that in the Flotate contained in sludge buffer in a post-drainage is transferable.  

This drainage can be done in many different ways be constructed. One type of post-drainage sees one centrifugal post-drainage before, preferably a Decanter is used.

In one embodiment of the invention nothing was said in the direction of whether there were others Chemicals added to the individual processing steps will.

So see preferred embodiments of the Invention appropriate solution before that individual process steps dosing devices and feeders for flocculation aids agents or flocculants are assigned.

Preferably, in a circulating water cycle between the spray booth and the system tank Direction assigned for flocculants.

Also preferred is the supply of the floating phase of the system tank in the flotation unit direction and a feed device for flocculation aids assigned to medium.

In addition, the sludge buffer is advantageous a metering device and a feed device for Flocculant assigned and preferably also Feeding the flotate from the sludge buffer into the post-drainage tion a metering device and a feed device for Flocculant assigned.  

This can also be advantageously carried out in the aftermath dewatering device separated liquid existing dene flocculants useful in the Reuse device according to the invention by the one separated in the post-drainage facility Liquid of the flotation unit, preferably that Flotation area of the same, feeds again.

In addition, this can also be done in the flotations contained flocculation aid reuse appropriately by clear phase in the system tank or the circulation circuit between Paint spray booth and system tank can be introduced.

Other features and advantages are the subject of the following description and the graphic representation development of some embodiments. The drawing shows:

Fig. 1 is a schematic representation of an exemplary embodiment of the device according to the invention;

Fig. 2 is a perspective view of an exemplary embodiment of a foreign dirt separator of the device according to the invention;

Fig. 3 is a schematic side view of a swimming pump of the device according to the invention;

FIG. 4 shows a top view of the floating pump according to FIG. 3;

Fig. 5 is a perspective view of an upper side of a flotation unit of the device according to the invention with floating flotate, and

Fig. 6 is a schematic representation of the top similar to Fig. 5 during the clearing of the flotate.

A device according to the invention shown schematically in FIG. 1 comprises a spray booth designated as a whole as 10 , in which vehicle bodies 12 are painted by spraying devices 14 . The excess paint mist passes through a grid floor 16 in a ge of circulating water of a circulating water circuit washed out wash 18 , is collected there in a collecting space 20 and fed to a whole designated 22 foreign separator. From this foreign dirt separator, the paint residues from the spray booth 10 with the circulating water leading via an inlet 24 into a system tank designated as a whole as 26 , on one side of the same, with the circulating water entering the system tank 26 having a flow direction 28 , which runs approximately parallel to a circulating water surface 30 .

Following the inlet 24 , a separation zone 34 is provided in the system tank 26 comprising a bath 32 of the circulating water, in the course of which a separation of the lacquer residues occurs in the circulating water in that fine lacquer particles float into a layer 36 near the surface and also together with themselves on the circulating water surface 30 forming foam form a floating layer 38 , while coarse paint residues, in particular special paint coagulate, sink to the bottom of the system tank and be removed with a floor scraper tape 33 .

The floating layer 38 and the near-surface layer 36 are suctioned off following the separation zone 24 by a floating pump 40 arranged on the side of the separation zone 34 opposite the foreign matter separator 22 with an inlet 42 , the inlet 42 as the floating phase of the system tank 26, the floating layer 38 ge detected together with the near-surface layer 36 during suction.

The floating phase is suctioned off in such a way that a solid concentration of approximately 0.1% to approximately 1%, more preferably approximately 0.2% to approximately 0.5%, is maintained in the system tank 26 .

From the swimming pump 40 , the phase floating in the system tank 26 is fed via a line 44 to a flotation unit designated as a whole by 46 . This flotation unit 46 comprises a flotation tank 48 , in which a flotation area 50 and a clear phase area 52 are arranged, both of which are separated from one another by a partition wall 54 immersed in the flotation tank 48 , one between a lower end of the partition wall 54 and the flotation tank 48 Provided under flow opening 57 , through which clear phase 50 can pass into the clear phase region 52 from the floating region 50 .

The line 44 opens into the flotation area 50 , in which a separation of the phase swollen in the system tank 26 takes place in that paint particles, which are also partially coagulated, and foam float on as a flotate 56 and form a layer on a surface 58 of a liquid phase 60 floats, a clear phase being formed in this liquid phase 60 and entering the clear phase region 52 via the underflow opening 57 .

In the clear phase area 52 , an overflow wall 62 is provided, through the upper edge 64 of which the surface 58 of the liquid phase and the clear phase are defined. The clear phase in the clear phase area 52 flows over the upper edge 64 of the overflow wall 62 into an outlet 66 and is passed by this via a clear phase line 68 back into the system tank 26 for diluting the circulating water.

The floating layer 56 of the flotate in the flotation area 50 on the surface 58 is cleared by a clearing device 70 , moved into a dewatering zone 72 and from there discharged into a buffer container 74 , in which the flotate 56 is preferably stirred with a stirring device 76 , to keep the flotate 56 flowable. The flotate 56 can be fed from the buffer tank 74 by means of a pump 78 via a line 80 to a post-dewatering unit 82 , which is designed, for example, as a decanter and finally produces a reworkable concentrate 84 that can be removed from the post-dewatering unit 82 . Furthermore, liquid is still separated in the post-dewatering unit 82 , which can be introduced via a line 86 into the liquid phase 60 in the flotation container 48 .

Depending on the type of lacquer, flocculation aids are already added in line 44 via a metering device 88 and a feed device 90 in order to achieve the formation of lacquer coagulate and a floating thereof in the flotation unit 46 .

In the same way, a flocculant, for example melamine resin or layer silicate, can be fed to the buffer container 74 via a metering device 92 and finally flocculants can also be fed via a metering device 94 and a feed device 96 into the line 82 . Depending on the type of paint, flocculants and flocculants are added.

As flocculants, synthetic, water soluble polyelectrolyte use. For example it would also be conceivable to use these flocculants in omit one case or another and flocculate, for example, in the case of water-based paints only via the to achieve natural water hardness.

A preferred embodiment of a Fremdschmutzab separator 22 , shown in Fig. 2, comprises a collecting trough 100 , which is closed in the lower region up to a liquid level mirror 102 of the circulating water in the foreign dirt separator 22 , with the fixing of this liquid level 102 above the same on a side wall arranged and designed as a perforated plate with openings 106 retaining element 104 leads. The liquid level 102 is defined by the lowermost openings 106 of the retaining element.

The retaining element 104 is arranged in such a way that an inflow of circulating water from the collecting pan 100 into the system tank 26 takes place through the openings 106 and, in fact, divides ver via a transverse direction 108 running parallel to the circulating water surface 30 , which extends transversely to the flow direction 28 .

In order to keep the flow direction 28 substantially parallel to the circulating water surface 30 , a baffle 110 is provided below the openings 106 of the retaining element 104 forming the inlet 24 with a guiding surface 112 aligned essentially parallel to the circulating water surface 30 , which is also located below the transverse direction 108 below of the openings 106 extends and thus gives the circulating water flowing into the system tank 26 via the inlet 24 the flow direction 28 which runs approximately parallel to the circulating water surface 30 .

The circulating water coming from the spray booth 10 is fed via an inlet connection 111 to the collecting trough 100 , is distributed in the collecting trough, with non-floating coarse particles such as screws etc. settling down in the collecting trough 100 and then flows out of the collecting trough 100 through the openings 106 of the perforated plate 104 in the system tank 26 , wherein the perforated plate 104 on the liquid level 102 in the collecting basin floating coarse dirt, for example cardboard cups or similar floatable parts.

In order to always ensure that the inlet 24, supported by the guide surface 102 of the guide plate 110, generates a flow 28 directed essentially parallel to the circulating water surface 30 in the system tank, the entire foreign matter separator 22 is held and adjustable in height in the system tank 26 by means of a lifting device 114 always adjusted so that the guide surface 112 is slightly below the circulating water surface 30 in the system tank 26 and thus the liquid level 102 is approximately at the same level as the circulating water surface 30 or is slightly higher than this.

As shown in FIGS. 3 and 4, the floating pump, designated as a whole by 40 , comprises the inlet 42 , which is arranged facing the separation zone 34 and also the foreign dirt separator 22 and tapers conically up to a pump inlet 120 of a pump unit 122 , the pump unit 122 is driven by a motor 124 . The pump unit 122 and the motor 124 are held in a floating manner in the system tank 26 by floating bodies 126 arranged on both sides of the same, in such a way that the inlet 42 detects the phase floating in the separation zone 34 , namely the near-surface layer 36 and the floating layer 38 , and the pump inlet 120 to leads. The floating phase is then discharged from the pump unit 122 via an outlet port 128 .

As shown in FIGS. 5 and 6, a preferred embodiment comprises the flotation unit 46 to Flota tion tank 48 to the dewatering zone 72, which is formed by a starting angle from the surface 58 upwardly until rising to a discharge edge 130 wall portion 132 of the flotation tank 48.

The clearing device comprised by the flotation unit 46 has two parallel running rails 134 on which a clearing carriage 136 with rollers 138 is guided and can be moved parallel to the running rails 134 in a clearing direction 140 from the partition wall 54 in the direction of the wall area 132 and vice versa. The clearing carriage 136 carries a clearing blade 142 which can be raised and lowered by means of a lifting device 144 arranged on the clearing carriage 136 , the clearing blade with a lower edge 146 being immersed in the liquid phase 60 in the lowered state, while the lower edge was in the raised state 146 is movable over the layer of flotate 56 floating on surface 58 .

The movement of the clearing carriage 136 in the clearing direction 140 and opposite to this takes place via rails 134 arranged near the running tracks 147 , which can be driven via a train drive 148 .

Both the traction drive 148 and the lifting device 144 can be controlled by a controller 150 such that the clearing plate 142 is moved in the raised state up to the partition 54 opposite to the clearing direction 140 in the variable state, then in the lowered state in clearing direction 140 the layer of the flotate 56 clears away from the surface 58 and moves in the direction of the drainage area 72 and thereby pushes the flotate layer onto the inclined wall area 132 in the drainage area 72 .

The dewatering zone 72 is either passed at low speed so that there is sufficient time for dewatering the flotate 56 or the clearing blade 142 is stopped in its movement in the clearing direction 140 at one point in the dewatering zone 72 , so that over the wall area 132 liquid can flow back from the cleared flotate 56 into the liquid phase 60 in the flotation tank 48 .

After the dewatering of the flotate 56 in the dewatering zone 72 , the clearing blade 142 moves this further to the throwing edge 130 , from which the flotate 56 falls into the buffer container 74 , in which a uniform mixing and intermediate storage in front of the post-dewatering unit 82 via the stirring unit 76 he follows.

Claims (23)

1. Device for discharging paint particles from circulating water from paint spray booths, comprising a system tank to which the circulating water coming from the paint spray booth can be fed via an inlet, characterized in that a separation zone () in the system tank ( 26 ) following the inlet ( 24 ) 34 ) is provided in which the paint particles float into a layer ( 36 ) close to the surface, and an inlet ( 42 ) of a suction device ( 40 ) for a layer close to the surface on a side of the separation zone ( 34 ) opposite the inlet ( 24 ) ( 36 ) comprehensive floating phase ( 36 , 38 ) is arranged in the system tank ( 26 ). 2. Device according to claim 1, characterized in that the inlet ( 42 ) in the system tank ( 26 ) is arranged that with this a suction of the floating phase ( 36 , 38 ) regardless of the level of the circulating water surface ( 30 ) in the system tank ( 26 ) it follows. 3. Apparatus according to claim 2, characterized in that in the system tank ( 26 ) has an inlet ( 42 ) pointing to the floating pump ( 40 ). 4. Device according to one of the preceding claims, characterized in that an external dirt separator ( 22 ) is connected upstream of the inlet ( 24 ). 5. The device according to claim 4, characterized in that the foreign dirt separator ( 22 ) sinking and floating coarse particles from the circulating water separates. 6. The device according to claim 5, characterized in that the foreign dirt separator ( 22 ) has a trough ( 100 ) for receiving sinking coarse dirt. 7. Apparatus according to claim 5 or 6, characterized in that an element ( 104 ) is arranged to hold up coarse particles floating above a liquid level ( 102 ). 8. The device according to claim 7, characterized in that the element ( 104 ) has openings ( 106 ) for the circulation water. 9. Apparatus according to claim 7 or 8, characterized in that the element ( 104 ) forms the inlet ( 24 ) in the system tank ( 26 ). 10. Device according to one of the preceding claims, characterized in that the inlet ( 24 ) is formed from that it generates an approximately parallel to To circulating water surface ( 30 ) in the system tank ( 26 ) directional inlet flow ( 28 ). 11. Device according to one of the preceding claims, characterized in that the inlet ( 24 ) is provided with a baffle plate ( 110 ) generating the inlet flow ( 28 ). 12. The apparatus of claim 10 or 11, characterized in that the inlet ( 24 ) extends in a transverse direction ( 108 ) to the flow direction ( 28 ) approximately parallel to the circulating water surface ( 30 ). 13. Device according to one of claims 4 to 12, characterized in that in the foreign dirt separator ( 22 ) a liquid level ( 102 ) of the circulating water is at a predetermined level. 14. The apparatus according to claim 13, characterized in that the liquid level ( 102 ) in Fremdschmutzab separator ( 22 ) at the same height as the circulating water surface ( 30 ) in the system tank ( 26 ) or slightly higher. 15. Device according to one of the preceding claims, characterized in that the phase sucked through the inlet ( 24 ) can be conducted into a flotation unit ( 46 ) which has a flotation area ( 50 ) in which the paint particles form the flotate ( 56 ) swim up. 16. The apparatus according to claim 15, characterized in that in the flotation unit ( 46 ) a Räumeinrich device ( 70 ) for the flotate ( 56 ) is provided. 17. The apparatus according to claim 16, characterized in that the flotation unit ( 46 ) comprises a controller ( 150 ) which controls the clearing device ( 70 ) so that it clears the flotate ( 56 ) at predeterminable intervals. 18. Device according to one of claims 15 to 17, characterized in that the flotation unit ( 46 ) has a drainage zone ( 72 ) and that the clearing device ( 70 ) transfers the flotate ( 56 ) into the drainage zone ( 72 ). 19. The apparatus according to claim 18, characterized in that the flotate ( 56 ) remains in the dewatering zone ( 72 ) during an adjustable dewatering period. 20. The apparatus according to claim 19, characterized in that the flotate ( 56 ) in the dewatering zone ( 72 ) rests during a dewatering period. 21. Device according to one of claims 18 to 20, characterized in that the dewatering zone ( 72 ) is formed by an ascending ramp ( 182 ) which adjoins the flotation area. 22. Device according to one of claims 15 to 21, characterized in that the flotate ( 56 ) from the flotation unit ( 46 ) can be transferred into a sludge buffer ( 74 ). 23. The apparatus according to claim 22, characterized in that the flotate ( 56 ) contained in the sludge buffer ( 74 ) can be transferred into a post-drainage ( 82 ).