DE10361266A1 - Air filtration system for a liquid-paint spraying booth e.g. for automobile finishing, has at least partial recycling of exhaust air - Google Patents

Abstract

The The invention relates to a device (1) for the removal of air pollutants in a wet painting plant. The device (1) comprises a cleanable filtering separator (3) containing air pollutants Air flow from a painting space (2) is supplied, wherein at least one Part of the cleaned in the cleanable filtering separator (3) Air flow as return air flow is introduced into the painting room (2).

Description

The The invention relates to a device for the removal of air pollutants in a wet painting plant.

Nasslackieranlagen This type are used for example in the automotive industry for painting Body or body parts of motor vehicles used. The painting of these units takes place in closed painting rooms. A essential condition for Achieving the required paint quality in the painted units is a sufficiently high purity of the ambient air in the painting room, since airborne contaminants otherwise contained in the air, in particular Dust or paint particles while of the painting process in the paint layer to be applied to deposit.

to fulfillment These requirements are in known wet painting a from running the paint shop Air flow, which forms a stream of exhaust air, by means of a storage filter filtered. Alternatively you can be provided for filtering washout systems. Furthermore, a air flow to be introduced into the paint shop, which is a supply air flow forms, filtered by means of another memory filter. To achieve the required surface quality are supply air filter qualities of typically F6 to F9 according to the standard Required according to DIN EN 779.

adversely in such wet painting is that the operating costs too their operation undesirable are high. A substantial portion of the operating costs is due Energy costs, maintenance costs, disposal costs and material costs Filtration causes the exhaust air or supply air. It is in particular disadvantageous that memory filter only a limited absorption capacity for from the respective airflow filtered particles and therefore at regular intervals be replaced. Apart from the material required for this purpose arise through the necessary for this Maintenance work additional Standstill times of the wet-paint systems, which reduce their productivity in undesirable Minimize way.

at Systems which work with leaching systems are particularly disadvantageous, that paint particles (overspray) are bound in the water. To a concentration To avoid paint particles, these paint particles from the Water with great effort, for example through the use of Entklebungschemikalien or discharge machines, such as separators discharged.

Of the Invention is the object of a device of the initially To provide said type, by means of which at high quality, the economy the operation of a wet painting plant is improved.

to solution This object, the features of claim 1 are provided. advantageous embodiments and appropriate training The invention are described in the subclaims.

The inventive device serves to remove airborne contaminants in a wet paint shop. This device has a cleanable filtering separator on which an air stream containing air contaminants fed to a paint shop is. In this case, at least part of the filterable in the cleanable Separator cleaned air flow as return air flow in the paint room initiated.

With the device according to the invention At low operating costs, a high supply air filter quality is achieved at the same time, to achieve the required surface qualities in the paint shop conducted Painting processes is necessary.

A Significant reduction in the operating costs of the wet coating plant results through the use of the cleanable filtering separator for eliminating particles, in particular paint particles and dust particles, from the airflow that runs out of the paint shop.

There preferably the cleanable filtering separator during operation while predetermined time intervals, is a frequent replacement of filter materials, such as the use of memory filters the case is avoided. This will be a significant reduction the maintenance effort and the use of the filter materials achieved.

In the case, that in the purified in the separating filtering separator Airflow no unwanted Substances are more, the entire purified air flow than Return air stream fed back to the paint shop become.

In the case, that undesirable substances are still present in the purified air stream, is the purified air flow in an advantageous embodiment by means of a branching unit in a return air flow, which in the Lackienaum is recycled, and split into an exhaust air stream.

About the branch unit is a defi nierter, preferably adjustable, proportion of purified in the cleanable filtering separator air flow introduced as return air flow back into the painting. In the event that the required exhaust air limits are complied with, the exhaust air flow can be dissipated without further exhaust aftertreatment. Otherwise, the remaining part of the purified air stream is supplied as exhaust air stream of an exhaust air aftertreatment unit, in which preferably in the exhaust air stream contained gaseous air contaminants such as hydrocarbons in particular are eliminated.

The Distribution of the amounts of return air flow and the exhaust air stream is usually before Commissioning of the wet painting plant and remains during the subsequent Constant operation. If necessary, the distribution of the quantities of Return air stream and the exhaust air flow even while the operation still changed become. With the division of the filter from the cleanable Separators guided purified air stream in a return air and exhaust air flow is a uniform air volume flow achieved. A further advantage is that by the return of a Part of the air flow at the outlet of the cleanable filtering separator as return air flow a closed air cycle is obtained, in which a concentration the gaseous Air pollution is obtained, which increases the efficiency of the eventuality increased exhaust aftertreatment unit increases. Another significant advantage the branching of the air flow in the branching unit exists in that the capacity of Exhaust aftertreatment unit to the distribution of air flow in the branching unit can be adjusted, whereby at appropriate Choice of the quantity distribution of the return air flow and the exhaust air flow, the capacity of the exhaust aftertreatment unit can be optimized and minimized. This can reduce the operating costs of the Wet painting can be further lowered.

Around a certain temperature and substance concentration in the painting room not to exceed this is next to the return air flow also fed a fresh air stream. According to one first variant, the fresh air after cleaning in another Filter be introduced directly into the paint room. Advantageous here is that while the amount of running from the paint room airflow not increased must be, so that, consequently, the capacity of the cleanable filtering separator not increased must become. According to a second Variant, a fresh air stream can also be supplied to the air stream, the from the painting room in the cleanable filtering separator guided becomes. While doing so it must filter the capacity of the cleanable Increased accordingly separator become. The advantage here, however, is that the fresh air flow be supplied without prior cleaning the air flow from the paint room can.

Of the Cleanable filtering separator preferably consists of a Filter which is cleaned with a compressed air cleaning unit. The filter is advantageous as a rigid body filter consisting of a Arrangement of PE (polyethylene) tubes formed, on which filter membranes, consisting of PTFE (polytetrafluoroethylene), laminated.

In an advantageous embodiment is assigned to the cleanable filtering separator a metering unit, via which Filtrationshilfsstoffe in the cleanable filtering separator supplied to be cleaned airflow become.

The Filtration aids settle with the air pollutants on the filter and protect so the filter surface. In addition, the filtration aids are used, on the one hand the To increase the degree of separation of air contaminants on the filter and to on the other hand, the replacement the separated air contaminants from the filter surface of the filter to improve.

to Further improvement of the filtering effect, the device can have the pre-separating stage upstream of the cleanable filtering separator, for example, a washout system or various filter systems is formed. Alternatively or additionally, the cleanable Filtering separator to be followed by another filter stage, which is formed in particular by a memory filter. As the memory filter the purified from the cleanable filtering separator air flow supplied is guaranteed that the memory filter during the operation of the wet painting or not after a long time with Saturated particles is, eliminating unwanted downtime be avoided by replacing the memory filter.

The The invention will be explained below with reference to the drawings. It demonstrate:

1 : First embodiment of a device for the removal of air pollution in a wet painting.

2 : Second exemplary embodiment of a device for removing air contaminants in a wet painting plant.

1 schematically shows the structure of a first embodiment of a device 1 to remove airborne contaminants in a wet paint shop. The wet painting plant comprises a closed paint shop 2 in the form of a cabin, in which parts, in particular body parts of motor vehicles, are painted. To ensure a high paint quality, the ambient air in the paint shop 2 be as free as possible from air pollution. In such wet paint systems are as air pollution in paint shops 2 in particular particles such as dust and paint particles as well as gaseous substances, such as hydrocarbons.

To eliminate such air pollutants is an air flow from the Lackierraum 2 the device 1 fed. The device 1 has in the present case a cleanable filtering separator 3 , a cleanable filtering separator 3 assigned dosing unit 4 and an optional exhaust aftertreatment unit 5 on.

The airflow is via a first pipeline 6 the cleanable filtering separator 3 fed. The cleanable filtering separator 3 is in a container 7 integrated and has a filter 8th and a Druckluftabreini supply unit 9 on. The filter 8th is formed in the present case of a rigid body filter, which consists of an array of PE (polyethylene) tubes. The PE tubes are each coated with a filter membrane made of PTFE (polytetrafluoroethylene). The filter thus formed 8th thus combines the advantages of rigid body filtration with membrane filtration. With the filter thus formed 8th In particular, dust and paint particles contained in the air stream are filtered out.

About the cleanable filtering separator 3 assigned dosing unit 4 become the filter 8th guided air flow filtration aids supplied. As filtration aids clay or lime dust are preferably used. The filtration aids are stored on the filter with the air contaminants to be filtered out 8th and thus protect the filter 8th , At the same time, the filtration efficiency of the filter is improved by the use of filtration aids 8th improved.

To the functionality of the filter 8th To maintain even over long periods, this is with the Druckluftabreinigungseinheit 9 preferably cleaned during predetermined time intervals at predetermined time intervals.

The compressed air cleaning unit 9 includes blower tubes fed with compressed air, by means of which they are connected to the filter 8th deposited air contaminants and filtration aids are removed. Furthermore, the Druckluftabreinigungseinheit 9 a control unit, by means of which at predetermined times the blowpipes to carry out the cleaning of the filter 8th be subjected to the compressed air. The at a cleaning of the filter 8th Filtrationshilfsstoffe contained clean air contaminants are in a container 10 at the bottom of the container 7 is placed, collected. Conveniently, in the collection container 10 also not contaminated filtration aids are introduced. By stirring up the Filtrati onshilfsstoffe in the collection container 10 These can be returned to the air flow and thus back to the filter 8th be deposited. This will be another dosing unit 4 obtained, in addition or as an alternative to the external dosing unit 4 can be used.

The one in the filter 8th cleaned airflow is via a fan 11 in the container 7 from the cleanable filtering separator 3 executed and in another pipeline 12 fed.

The pipeline 12 leads to a branching unit 13 , The branching unit 13 has a branch from which two pipes 14 . 15 branch. A pipeline 14 leads back to the paint shop 2 , the other pipeline 15 leads to the exhaust aftertreatment unit 5 , Furthermore, the branching unit 13 Control means such as controllable valves, by means of which a predetermined proportion of the in the pipeline 12 guided purified air stream as return air flow in the paint room 2 passed and the remaining part of the purified air stream as exhaust air flow in the exhaust aftertreatment unit 5 is directed.

The adjustment of the amounts of the return air flow and the exhaust air stream is carried out before the commissioning of the wet painting and the device 1 and remains constant during operation of the wet painting plant. Alternatively, the quantity setting can also be changed during the operation of the wet painting. According to the in the branching unit 13 adjusted air volume distribution become the capacities of the cleanable filtering separator 3 and the exhaust aftertreatment unit 5 designed.

In the event that with the cleanable filtering separator 3 the required exhaust air limits can be met, on the exhaust aftertreatment unit 5 be waived. In the event that after filtering in the cleanable filtering separator 3 no unwanted substances are left in the air stream, this can completely in the paint shop 2 be recycled so that in addition to the exhaust aftertreatment unit in addition to the branching unit 13 can be waived.

In the exhaust aftertreatment unit 5 , to which the return air flow is supplied, an oxidation of the air contaminants still contained in the return air flow takes place. In particular, hydrocarbons can be removed from the exhaust air stream as air pollutants in the combustion process become. For example, the exhaust aftertreatment unit 5 designed as a thermal afterburning unit. Alternatively, other exhaust aftertreatment methods can be used. To increase the efficiency can in the exhaust aftertreatment unit 5 the air contaminants in the exhaust air stream are suitably concentrated.

The in this way in the exhaust aftertreatment unit 5 final cleaned exhaust air flow is via another pipeline 16 and a heat exchanger 17 executed from the wet painting plant. As a result, the exhaust air stream is cooled before it runs out of the wet-paint system. The heat obtained is expediently used via a heat cycle, not shown.

The device according to the invention 1 thus forms a closed air circuit, in which the air flow from the painting 2 the cleanable filtering separator 3 is fed and a part of the cleaned there air flow as return air flow to the painting 2 is fed again. An approximately constant part of the purified air stream is decoupled from the closed air circuit as a stream of exhaust air and in the exhaust aftertreatment unit 5 'departure. In this way, an approximately uniform air flow in the device 1 achieved. It is particularly advantageous that the cleanable filtering separator 3 remains functional for long periods of time due to continuous cleaning and does not need to be replaced. This is a continuous operation of the device 1 guaranteed without frequent interruptions due to maintenance intervals.

If a certain substance concentration, for example of volatile organic compounds for reasons of explosion protection, must not be exceeded, only a part of the filter that filters in the cleanable filter will be used 3 cleaned air stream as return air flow back to the paint shop 2 fed. To compensate, the painting room 2 fed back filtered fresh air.

In the present embodiment, a fresh air flow via a further pipeline 18 the airflow coming out of the paint shop 2 is executed, supplied. The pipeline 18 flows into this from the painting room 2 outgoing pipeline 6 one. An essential advantage of this arrangement is that the fresh air flow with the air flow from the painting 2 the cleanable filtering separator 3 is fed and cleaned there. Thus, no separate filter stage for cleaning the fresh air flow must be provided. If required, a temperature control (heating or cooling) of the air flows takes place.

In an advantageous embodiment of the embodiment according to 1 are in the bottom area of the paint shop 2 arranged dust-binding devices not shown. For this purpose, oiled filter mats, other sticky or dust-binding devices or water may be provided.

2 shows a further embodiment of a device 1 to remove airborne contaminants in a wet paint shop. The construction of the device 1 according to 2 essentially corresponds to the embodiment according to 1 , In particular, corresponding to the components of the device 1 according to 2 as well as their arrangement of the embodiment according to 1 , Thus, in turn, the from the paint shop 2 executed, the air pollution containing air flow to the cleanable filtering separator 3 fed to which the dosing unit 4 assigned. The structure of the cleanable filtering separator 3 corresponds to the cleanable filtering separator 3 according to 1 , The in the cleanable filtering separator 3 cleaned airflow is again in the branching unit 13 in a return air flow, which on the painting 2 is returned, and in an exhaust air stream, which the exhaust aftertreatment unit 5 for final cleaning, divided.

In the present case, in contrast to the embodiment according to 1 the fresh air flow via a supply line 19 directly into the paint shop 2 introduced. There is an additional filter unit 20 provided by means of which the fresh air is purified, before this in the paint shop 2 is introduced. The filter unit 20 may be formed by a memory filter or the like. The advantage of this arrangement over the embodiment according to 1 is that by the direct supply of fresh air, a fresh air supply in the from the paint shop 2 for cleanable filtering separator 3 leading pipeline 6 eliminated. As the cleanable filtering separator 3 thus a small amount of air is supplied, this can be dimensioned correspondingly smaller, resulting in a corresponding cost savings.

Another difference of the device 1 according to 2 compared to the embodiment according to FIG 1 is that between the painting room 2 and the cleanable filtering separator 3 a pre-separation stage 21 is arranged. In the pre-separation stage 21 In a first purification stage, particles are already being removed from the pipeline 6 guided airflow away. The pre-cleaned air stream is then the cleanable filtering separator 3 fed. This pre-separation can meet the requirements for the cleanable filtering separator 3 be reduced. The preliminary stage 21 consists, for example, of a washout system or various filter system men.

Finally, there is a difference of the device 1 according to 2 compared to the embodiment according to FIG 1 in that the cleanable filtering separator 3 another filter stage 22 is downstream, which is preferably formed by a memory filter.

With the further filter stage 22 are in the from the cleanable filtering separator 3 executed purified air stream still contained air pollution, especially dust and paint particles, further filtered out, causing the quality of the filter in the Lackierraum 2 recirculated return air flow is further increased. Because the filter stage 22 the branching unit 13 upstream, also points to the exhaust aftertreatment unit 5 guided exhaust air flow on a reduced particle concentration.

An essential aspect here is that of the further filter stage 22 forming memory filter the cleanable filtering separator 3 is subordinate. As in the cleanable filtering separator 3 already a large part of the air flow from the paint shop 2 contains filtered particles contained in the purified air stream supplied to the storage filter only a small particle concentration. Accordingly low during the operation of the device 1 accumulated in the accumulator filter amount of particles. This saturates the memory filter during operation of the device 1 largely avoided, so that the storage filter during operation of the device 1 is not exchanged or only in correspondingly large time intervals. Thus, also for the device 1 according to 2 a low-maintenance operation guaranteed.

The embodiment according to 2 represents an expansion stage of the embodiment according to 1 because, in the device 1 according to 2 in addition to the cleanable filtering separator 3 an upstream pre-separation stage 21 and a downstream of this further filter stage 22 are provided. In general, modifications of the embodiment according to 2 so possible that the cleanable filtering separator 3 either only one pre-separation stage 21 or just another filter stage 22 assigned.

1

contraption

2

dyeing room

3

Abreinigbarerer filtering separator

4

dosing

5

Exhaust after-treatment unit

6

pipeline

7

container

8th

filter

9

Druckluftabreinigungseinheit

10

receptacle

11

fan

12

pipeline

13

branching unit

14

pipeline

15

pipeline

16

pipeline

17

heat exchangers

18

pipeline

19

supply

20

filter unit

21

Pre-separation stage

22

filter stage

Claims (22)

Apparatus for removing airborne contaminants in a wet painting plant, comprising a cleaner-filtering filtering separator ( 3 ), which contains an air stream containing air contaminants from a painting room ( 2 ), wherein at least a part of the filter to be cleaned in the more cleanable ( 3 ) purified air stream as return air flow into the paint room ( 2 ) is initiated. Device according to claim 1, characterized in that it comprises a branching unit ( 13 ), by means of which in the cleanable filtering separator ( 3 ) purified air stream is split into a return air stream and a recirculating air stream. Apparatus according to claim 2, characterized in that the exhaust air flow of an exhaust air aftertreatment unit ( 5 ) is supplied, in which a final cleaned exhaust air flow is generated. Device according to one of claims 1-3, characterized in that the cleanable filtering separator ( 3 ) a filter ( 8th ), which by means of a Druckluftabreinigungseinheit ( 9 ) is cleanable. Device according to claim 4, characterized in that the filter ( 8th ) is designed as a rigid body filter. Device according to claim 5, characterized in that that the rigid body filter is formed of an array of PE (polyethylene) tubes. Device according to claim 6, characterized in that that on the PE tubes respectively a filter membrane is laminated. Device according to claim 7, characterized in that the filter membranes are made of PTFE (polytetrafluoroethylene). Device according to one of claims 2-8, characterized in that the cleaning of the filter ( 8th ) takes place at predetermined time intervals. Device according to one of claims 1-9, characterized in that the cleanable filtering separator ( 3 ) a dosing unit ( 4 ) is assigned, by means of which the filtration to be cleaned air flow filtration aids can be fed. Device according to claim 10, characterized in that that the filtration aids of clay dust or limestone flour are formed. Device according to one of claims 1-11, characterized in that the cleanable filtering separator ( 3 ) in a container ( 7 ), at the output of which a pipeline ( 12 ), via which the purified air stream of the branching unit ( 13 ) is supplied. Apparatus according to claim 12, characterized in that the branching unit ( 13 ) two of the pipeline ( 12 ) branching off further pipelines ( 14 . 15 ) and control means, by means of which the division of the purified air flow into the return air flow and the exhaust air flow takes place. Device according to one of claims 1-13, characterized in that in the exhaust aftertreatment unit ( 5 ) eliminates further air pollution contained in the exhaust air stream. Device according to one of claims 1-14, characterized in that this means for supplying purified fresh air into the painting room ( 2 ) having. Device according to one of claims 1-15, characterized in that this means for supplying unpurified fresh air in the cleanable filtering separator ( 3 ) has supplied air flow. Device according to one of claims 1-16, characterized in that the cleanable filtering separator ( 3 ) a pre-separation stage ( 21 ) is arranged upstream. Apparatus according to claim 17, characterized in that the pre-separation stage ( 21 ) is formed by a washout system. Device according to one of claims 1-18, characterized in that the filterable filtering separator ( 3 ) another filter stage ( 22 ) is subordinate. Apparatus according to claim 19, characterized in that the filter stage ( 22 ) is formed by a memory filter. Device according to one of claims 1-20, characterized in that in the bottom region of the painting room ( 2 ) Dust-binding devices are arranged. Device according to one of claims 1-21, characterized in that from this the exhaust air flow via a heat exchanger ( 17 ) is carried out, wherein in the heat exchanger ( 17 ) recovered heat the exhaust aftertreatment unit ( 5 ) is supplied.