EP3456420A1 - Method for the treatment of overspray and device for the separation of overspray - Google Patents

Abstract

The invention relates to a method for the treatment of overspray of a coating installation, comprising the steps of supplying overspray-laden cabin air to a filter module, separating overspray by means of a filter element located in the filter module, collecting deposited overspray, adding an additive containing a Curing or curing the overspray, wherein the additive is encased in a wrapper such that it can not function, and wherein the wrapper is dissolvable by the overspray, dissolving the wrapper and releasing the additive, and effecting or facilitating the curing process of the overspray Overspray by means of the additive.

Furthermore, the invention relates to a device for separating overspray from overspray-laden cabin air of surface treatment plants, with at least one separation unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

The invention relates to a method for the treatment of overspray of a coating system and to a device for separating overspray from overspray-laden cabin air of surface treatment plants.

2. Description of the Related Art

In the manual or automatic application of paints on objects, a partial flow of the paint, which generally contains both solid and / or binder and solvent, does not reach the object. This partial flow is referred to as overspray. In the following, the terms overspray or overspray particles are understood to mean a disperse system, such as an emulsion, suspension or a combination thereof. The overspray is detected by the air flow in the paint booth and fed to a separation, so that the air can optionally be returned to the coating booth after a suitable conditioning.

In systems with greater paint consumption, for example in systems for painting vehicle bodies, preference is given in a known manner to wet scrubbing systems on the one hand or electrostatic dry scrubbers on the other hand. As an alternative, systems with exchangeable disposable separation units are used, which are exchanged and discharged or optionally recycled after reaching a limit load with overspray against unloaded separation units. The treatment or / and disposal of such separation units can be energetically and also with regard to the required resources more compatible than with corresponding wet or dry separators.

Overspray may have adhesive properties and liquid components. In the case of disposable separation units, in particular, the liquid components of the overspray may collect, which may make handling them during disposal or further utilization more difficult. In particular, when transporting the disposable separation units, care must be taken that the liquid components collected do not leak during tilting. In general, the transport of liquids is expensive. If the paint and thus also the overspray have a solvent, corresponding amounts of solvent may be present in the collected overspray, which may undesirably present a potential hazard during handling, storage and transport.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a method and a device of the type mentioned, which reduce the disadvantages mentioned and in particular allow a simpler and / or safe transport of a separation unit after accumulation of overspray.

This object is achieved by a method according to independent claim 1. The method according to the invention for overspray treatment of a coating installation comprises the steps of supplying overspray-laden cabin air to a filter module, separating overspray by means of a filter element located in the filter module, collecting deposited overspray, adding an additive which causes the overspray to harden or wherein the additive is encased in a wrapper such that it does not exhibit its effect, and wherein the wrapper is dissolvable by the overspray, dissolving the wrapper and releasing the additive, effecting or supporting the curing process of the overspray by means of the additive.

The steps of the method need not necessarily be performed in the order named. In particular, the steps of collecting deposited overspray and adding an additive may also be performed in reverse order. For example, the coated or encapsulated additive may already be on the collection site of the overspray or on the way there before in the sense of the above-mentioned admitting be appropriate. For example, the filter element may be provided with a corresponding coating of additive and cladding so that the overspray on its way to its collection point or at the collection site itself can act on the enclosure such that the enclosure at least partially dissolves or weakens such that a Release of the additive can take place.

Alternatively or additionally, the step of releasing the additive may begin immediately or with a certain time delay.

The term "curing" is to be understood here and below as a transfer of the located in a liquid phase with a certain viscosity overspray in a state of higher viscosity. After curing, the overspray is pasty or solid, for example. Furthermore, alternatively or additionally, the term "curing" should be understood to mean the effect of at least partial outgassing of solvents present in the overspray. The targeted release of solvents may be advantageous because usually in the vicinity of the coating system suction devices are present, which are in principle suitable for a controlled discharge of such solvents and have the required Absaugluftvolumenströme. This is usually not the case in subsequent handling steps and the associated environment (storage location, transport vehicle).

The collection of separated overspray can take place within the filter element, within the filter module or even outside the filter module. For example, the overspray can be collected in a sump below the filter element.

The additive may be added before the collection process in the filter element, the filter module or a suitable container in the region of the filter module. Alternatively or additionally, the additive may be added during or after the collection process.

The adding of the additive may include actively mixing the additive with the collected overspray. For example, an additive can be added to the filter module or individual filter elements of the filter module and the filter module / filter element can be subjected to a vibrating, circular or jarring movement. The individual filter element can be removed for this purpose the filter module. Alternatively or additionally, an active mixing of the added additive with the overspray, for example by means of a stirring device, can take place in the filter element or the filter module.

The dissolution of the envelope can already be initiated during the collection process of the overspray. Additionally or alternatively, the dissolution process can only begin after the actual collection process.

The enclosing effect of the coating over the additive may be permanent or temporary. Thus, the coating of the additive may permanently prevent the additive from acting until the final dissolution of the coating. Alternatively, the wrapper may only delay release of the additive.

The dissolution of the wrapper can be initiated by the action of the overspray on the wrapper. In this case, only a single action of the overspray on the wrapper can suffice. Alternatively it can be provided that the overspray must act continuously on the envelope in order to effect a complete dissolution of the envelope. The exposure may be, for example, a direct contact between the overspray and the enclosure. Alternatively, it may suffice that only certain components of the overspray, such as solvents, act on the wrap to effect dissolution of the wrapper.

According to the invention it is thus possible to store the additive outside of the filter element / the filter module or outside of the collection process of overspray in an enclosed form. Since it can not unfold its effect in the wrapped form, it also represents no or less danger to the operator. It can thus be easily transported, stored or / and added. At the same time, the wrapper releases the effect of the additive as soon as the overspray dissolves the wrapper Has. Thus, curing of the overspray may be effected after or during the collection of overspray, thus significantly reducing the potential risk during shipping or generally during handling of containers with overspray.

Here and below, the term filter material is understood to mean a component that flows through overspray-containing air and / or flows around it and receives the overspray directly or / and separates it. This may be, for example, a depth filter or an inertial filter. In the present case, a filter element is understood to be an element which has a filter material and a receiving housing for this purpose. A filter module has one or more filter elements, a filter unit one or more filter modules. The filter material, the filter element and the filter module can be designed as disposable elements. The filter element and the filter module can also be designed as reusable elements.

In a preferred embodiment it is provided that the additive is present in the envelope in tablet form. The dosage form of the additive in a tablet-shaped enclosure allows easy positioning, storage and addition of the additive to the collected overspray. Accordingly, the step of adding an additive then comprises adding the additive in tablet form. The term "tablet" should not be defined in the present case a specific size or shape. Rather, "tablets" can be a dosage form or packaging form of the additive active ingredient, which can range from a few millimeters in diameter to many centimeters. Also, the geometric outer shape should not be specified. Rather, depending on the active ingredient, a suitable shape can be selected which allows inclusion in an envelope and offers easy handling, storage and transport. For convenient storage and handling, the tablets may be packaged, for example, in blisters or individually sealed in sheets. In a very small format execution as dispersible product with small grain sizes (for example in rice grain size or comparable to hail sugar, so that a coarse-grained powder results) are also other storage options such as cans or bags possible.

In one embodiment, it can be provided that, when the additive is released and the additive comes into contact with the overspray, a bubbling effect is produced. The effervescent effect can cause a greater effective range of the individual additive unit.

In a particularly preferred embodiment it is provided that a plurality of tablets is to be added for complete curing of the overspray. The distribution of the necessary for a complete curing of overspray amount of additive to a plurality of tablets is particularly advantageous. The total amount divided can also be distributed only after addition in the area of the overspray to be cured. This can be done, for example, a shaking of the filter element or the filter module, the use of an external mixing device or, for example, the addition of compressed air. In addition to the amount of additive per tablet, the single tablet has a performance space that depends on the reaction characteristics and kinetics between additive and overspray. It may be that the curing process due to the then cured overspray still includes remaining reactive additive and can be effectively ineffective through this shield. By dividing the total amount of additive required on a plurality of tablets, an optimization of the spatial and temporal reaction behavior between additive and overspray can be achieved.

An advantageous further development of the inventive concept provides that the additive and the associated casing are attached to parts of the filter element with which the overspray comes into contact during the collecting process. This further development has the advantage that the step of adding the additive is already carried out during the production of the filter element and thus does not require a separate addition of the additive after or during the collection of the overspray. Rather, the curing of the overspray may begin or be assisted just as it touches the parts provided with the additive and the wrapper and the wrapper is at least partially dissolved.

In an advantageous embodiment it can be provided that the additive and the envelope are arranged in a reservoir above the collected overspray. Such an arrangement can be advantageously used in two ways. On the one hand, the overspray flowing past from above at the reservoir can already - with a suitable spatial configuration - dissolve the casing when the reservoir passes, releasing the additive and assisting or causing the hardening. On the other hand, the collection of the reservoir can be configured such that an increasing liquid level of the overspray reaches the region of the reservoir where it dissolves the coating and can cause a release of the additive. This arrangement has the advantage that intervention from the outside is not required to achieve the release of the additive. Rather, this is caused by the overflow or the rising liquid level of the overspray.

The object is also achieved by a device for separating overspray from overspray-laden cabin air from surface treatment plants. The device according to the invention comprises a separation unit through which cabin air laden with overspray can be conducted and in which overspray separates, wherein the separation unit has a filter element and the filter element or the separation unit is at least partially provided with an additive which is in direct contact with the overspray Curing the overspray causes or suppressed, the additive is coated with a sheath, wherein the envelope is configured so that the envelope includes the additive so that it can not unfold its effect and the envelope dissolves in contact with the overspray and the Additive releases.

This results in the advantages already described in detail above. In the device, the additive can be applied, for example, as a planar coating on parts of the filter element, with which the overspray comes into contact during or after the filtration process. Alternatively or additionally, the additive may be incorporated in its coated state in the filter element, for example as a small additive capsules or as a cover of individual fibers or other constituents of the filter element filter material.

In a further development of the invention, it can be provided that the stratification of additive and coating is present twice or more than once. This allows a staggering of the activity of the additive into several phases. If, after a dissolution of the first coating, the first layer of the additive is consumed, in the case of a further attack of overspray, for example, a further layer of the additive can be released by dissolution of the second coating layer and thus activated. This makes it possible to supply an additive to larger amounts of overspray even with a smaller effective radius of the additive.

A particularly advantageous embodiment of the invention provides that the additive and the sheath are arranged on a grid-like structure in the filter element or below the filter element. For example, the additive and the cladding may be fixedly attached to the grid-like structure, for example applied as a coating. If the overspray flows past the lattice-like structure, the coating can be dissolved or dissolved and the additive released.

Alternatively or additionally, the additive can be applied in tablet form with encasing to the grid-like structure. When the liquid level reaches the lattice-like structure, the overspray can dissolve the envelope protecting the additive and release the additive. Alternatively or additionally, the additive may be stored in coated tablet form in the region of the grid-like structure. When the time comes for solidification of the overspray, the coated additive may be released from the lattice-like structure by, for example, shaking or mechanically enlarging the openings in the lattice-like structure and contacting the overspray accumulated thereunder.

In another embodiment, a container may be provided for the deposited overspray, wherein the additive and the enclosure are disposed on a surface having an extent perpendicular to the surface level of an overspray accumulated in the enclosure. The surface does not have to be arranged exclusively perpendicular to the surface mirror. It is sufficient if the surface has a sufficiently strong component in this direction. For example, on the ground a container may be provided with an elevation for individual encapsulated additive capsules. Alternatively or additionally, the elevation can be provided directly with an additive and a corresponding envelope.

The invention makes it possible to reduce or eliminate various dangers which occur when handling additives or filter aids for, for example, dry separators in paint booths or in the case of waste paint treatment. It is a basic idea to provide an enclosure or an encapsulation, which releases an additive only when this enclosure or encapsulation comes into contact with, for example, paint.

Depending on the paint system, the filter medium may under certain circumstances accumulate over time with liquid paint. It is advantageous to convert this liquid paint into a solid form, and for example to reduce the cost of disposal or to make the handling of the full filter medium easier. For this purpose, additives can be used.

There are basically two ways to use the additives. They can be used in-situ in the filter medium or they can be brought ex situ in contact with the liquid paint / medium later.

The additives can be added to the filter element, for example, as tabs with a size of, for example, a few centimeters of side length. This can happen before, during or after the filter element is subjected to overspray. An additional mixing of the tabs with the liquefied overspray can be an advantage, since the tabs are usually a very high additive concentrate due to their compact form. After opening or loosening the protective covering, mixing or distribution makes sense. This can be done for example by external mixing elements or by a movement of the filter element such as shaking.

In a further development, the tabs can be performed significantly smaller than one centimeter side length, thus causing a reduction in the additive room concentration. As a result, the tabs or pellets can be introduced into the filter element, for example during the deposition process, or can be introduced beforehand onto surfaces of the filter element Filter material or the filter element are applied. For example, this can be done in the manufacture or / and assembly of the filter material or the filter elements by sprinkling the surfaces with the tabs / pellets. As an adhesive material, for example, adhesive or the like may be previously applied to the components. This results in coated surfaces that come in contact with overspray material and thus dissolve the envelope and can release additives. The reduction of the tabs can go up to a size of a few millimeters side length or diameter. Similarly, the additive and wrapper may also be applied separately to the filter materials or filter elements. In this case, the surface is first coated with an additive as a separate production step, and then an envelope is applied in the sense of a surface covering. This is particularly suitable for structurally fissured filter materials.

To obtain temporally different behavior with respect to the dissolution of the coating and / or the reactivity of the additive, layered structures are also possible. For example, a first layer package of casing and a first additive may be consumed with a first amount of overspray to expose a second layer package including a second amount of additive for a second amount of overspray. In addition, a different structure can take place in the direction of flow of the overspray. Both options can be further improved by choosing different material compositions of the coverings and / or additives as well as different layer thicknesses.

With the encapsulation of the additives go from the applied and possibly also health-endangering additives significantly less dangers. The encapsulation provides protection against skin and lung burns and provides protection against aerosol development. The handling of additives - for example in the field of air treatment in painting technology - is significantly simplified. This allows untrained operators to handle additives, while at the same time significantly reducing the necessary protective and precautionary measures such as respiratory protection or skin protection. A temporal dosage of the additives is possible depending on geometry, wall thickness or positioning in the filter medium.

BRIEF DESCRIPTION OF THE DRAWINGS

Figur 1

in einem schematischen Ablaufdiagramm eine Ausführungsform eines erfindungsgemäßen Verfahrens;

Figur 2

in schematischen Perspektivansichten verschiedene Ein-und Abströmkonfigurationen für Filterelemente;

Figur 3

in einer schematischen Schnittansicht ein Filterelement in einem Zustand vor der Zugabe eines Additivs;

Figur 4

in einer schematischen Schnittansicht das Filterelement der Figur 3 nach der Zugabe eines Additivs in verkapselter Form;

Figur 5

in einer schematischen Schnittansicht eine Ausführungsform eines Filterelements, bei der das Additiv direkt auf die Innenseite eines Sammelbehälters als Schicht aufgebracht ist:

Figur 6

in einer schematischen Schnittansicht eine weitere Ausführungsform eines Filterelements, bei der das Additiv auf einer gitterartigen Zwischenlage angebracht ist;

Figur 7

in einer schematischen Schnittansicht eine Ausführungsform eines Filterelements als Kombination der Ausführungsformen der Figuren 5 und 6;

Figur 8

in einer schematischen Schnittansicht eine weitere Ausführungsform eines Filterelements, bei der das Additiv auf Aufständerungen in einem Sammelbehälter angebracht ist;

Figur 9

in einer schematischen Schnittansicht eine weitere Ausführungsform eines Filterelements, bei der das Additiv in ein Filtermaterial eingearbeitet ist;

Figur 10

in einer schematischen Schnittansicht eine beispielhafte Umhüllung eines Additivs in Kapselform;

Figur 11

in einer schematischen Ansicht eine beispielhafte Umhüllung eines Additivs mit mehreren Umhüllungslagen

Figur 12

in einer schematischen Schnittansicht eine Ausführungsform eines Filterelements, bei der das Additiv in Kapselform auf einem betätigbaren Rost oberhalb eines Sammelbehältnis gelagert ist und

Figur 13

in einer schematischen Schnittansicht die Ausführungsform eines Filterelements der Figur 10, bei der das Additiv dem gesammelten Overspray zugegeben ist.

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

FIG. 1

in a schematic flow diagram, an embodiment of a method according to the invention;

FIG. 2

in schematic perspective views different inlet and Abströmkonfigurationen for filter elements;

FIG. 3

in a schematic sectional view of a filter element in a state before the addition of an additive;

FIG. 4

in a schematic sectional view of the filter element of FIG. 3 after the addition of an additive in encapsulated form;

FIG. 5

in a schematic sectional view of an embodiment of a filter element, wherein the additive is applied directly to the inside of a collection container as a layer:

FIG. 6

in a schematic sectional view of another embodiment of a filter element, wherein the additive is mounted on a grid-like intermediate layer;

FIG. 7

in a schematic sectional view of an embodiment of a filter element as a combination of the embodiments of FIGS. 5 and 6 ;

FIG. 8

in a schematic sectional view of another embodiment of a filter element, wherein the additive is mounted on elevations in a collecting container;

FIG. 9

in a schematic sectional view of another embodiment of a filter element, in which the additive is incorporated in a filter material;

FIG. 10

in a schematic sectional view of an exemplary enclosure of an additive in capsule form;

FIG. 11

in a schematic view of an exemplary enclosure of an additive having a plurality of wrapping layers

FIG. 12

in a schematic sectional view of an embodiment of a filter element, in which the additive is mounted in capsule form on an actuatable grate above a collecting container and

FIG. 13

in a schematic sectional view of the embodiment of a filter element of FIG. 10 in which the additive is added to the collected overspray.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows in a schematic flow diagram an embodiment of a method according to the invention. The method comprises the following steps: A filter module is supplied with cabin air laden with overspray (S1). In the filter module is a filter element suitable for separating overspray (S2). The separated overspray is collected (S3). The collection of the overspray may, for example, take place in the filter element itself, in the filter module, in the deposition unit or below. A coated or encapsulated additive is added (S4). The additive is encapsulated by means of a wrapper that dissolves upon contact with the overspray and releases the additive (S5). The release of the additive triggers curing of the overspray (S6). In this case, the additive can be added to before the overspray is collected, for example during the production of the filter element or filter module.

FIG. 2 shows in several schematic perspective views different inlet and Abströmkonfigurationen for filter elements.

The filter element 1 has an inflow opening 2, which is opposite to an outflow opening 3. In the lower part of the filter element 1 is a collecting area 11th The flow takes place along a main flow direction A, which lies horizontally in the filter element 1 and along a longitudinal axis of the filter element 1. The longitudinal axis is also aligned parallel to the extension of the collecting area 11.

The filter element 4 is also traversed along a main flow axis B along a longitudinal axis of the filter element 4 from an inflow opening to an outflow opening along the horizontal - again parallel to the collecting area 11 - but in contrast to the filter element 1 along a shorter extension direction of the filter element 4. Overall For example, the filter element can have both a cubic and a cuboid basic shape.

The inflow of the filter element 5 takes place at the inflow opening 2 along a first flow direction A, the outflow at the outflow opening 3 takes place along a second flow direction B which extends from the first flow direction differs and in the present embodiment with the first flow direction forms an angle of about 90 °.

The filter element 6 of FIG. 2 has a flow configuration which is very similar to that of the filter element 5. While all the inflow and outflow directions A and B of the filter element 5 are in a horizontal plane takes place in the filter element 6, the inflow at the inflow opening 2 along a vertically disposed flow direction C, the outflow from the outflow opening 3, however, along a horizontally arranged flow axis B. ,

The filter element 7 of FIG. 2 is configured so that the inflow opening 2 and the outflow opening 3 are located on one side of the filter element 7. Accordingly, the inflow X and the outflow Y are parallel to each other. In the configuration of the filter element 7, the inflow port 2 is above the outflow port 3. #

Another situation lies with the filter element 8 of FIG. 2 in front. Again, the inflow opening 2 and the outflow opening 3 are on one side of the filter element 8. In contrast to the filter element 7, however, the openings are not on top of each other, but lie next to each other. Accordingly, the inflow X and the outflow Y are also parallel to each other, but just offset in the horizontal to each other.

A situation comparable to the filter elements 5 and 6 lies with the filter element 9 of FIG FIG. 2 in front. While inflow into the filter element 9 takes place at the inflow opening 2 along the horizontal inflow axis A, the outflow takes place at the outflow opening 3 along the outflow axis C in the vertical. The discharge opening 3 is located next to the collection area 11 in this configuration.

The filter element 10 provides a flow-through of the filter element 10 from an inflow port 2 to an outflow port 3 along a main flow direction C, which is vertically aligned. Again, the discharge opening 3 is arranged adjacent to the collecting area 11.

For the in FIG. 2 shown embodiments, of course, that also a configuration with a reverse flow direction can be provided, may be reversed in the inflow and outflow.

FIG. 3 shows a schematic sectional view of a filter element 100 in a sectional partial view. The filter element 100 has an inflow opening 102 and an outflow opening 103. As already in FIG. 2 As shown, there are a variety of possible configurations for the arrangement of the inflow port 102 and the outflow port 103. The configurations shown in this and the following embodiments are all substantially equivalent to those in FIG FIG. 2 executable arrangements shown.

Downstream of the inflow opening 102, a filter material 104 is arranged, which is flowed through along a main flow direction A. By way of the inflow opening 102, the cabin air 108 taken, for example, from a paint booth and loaded with overspray 106 is fed to the filter material 104. The filter material 104 is held on a filter element wall 110, which is indicated only schematically in the present embodiment and is to be adapted according to the requirements in form, strength and material necessary in the respective application.

Below the actual filter material 104, an overspray collection tray 112 is formed within the filter element 100. The collecting trough 112 can be integrated directly into the filter element 100 as in the present example, but alternatively it can also be designed, for example, as a push-in element or as a separate component arranged below the filter element 100. In the latter case of a separate component, a corresponding outlet for collected overspray would be provided on the underside of the filter element 100.

While the cabin air 108 laden with overspray 106 flows through the filter material 104, the overspray component of the cabin air is separated off. The overspray which forms as a liquid follows gravity and reaches the collecting trough 112. A liquid level 114 forms. After passing through the filter material 104, the cabin air leaves the filter element via the outflow opening 103 as air 109 freed from overspray 106 Overspray fluid located on filter element 100 poses a potential hazard to operators during handling of filter element 100.

FIG. 4 shows in a schematic sectional view of the filter element 100 of FIG. 3 with a plurality of added additive capsules 120. The additive capsules 120 have a construction described with reference to FIGS FIG. 10 will be explained in more detail below.

FIG. 10 shows in a highly schematic sectional view of the structure of an additive capsule 120. The additive capsule 120 has in its interior an additive 122 which is adapted to effect overspray 106 or at least one of its constituents, a solidification such as curing or gelation or at least to support or accelerate this process. Depending on the material used as overspray, it may be very different substances, mixtures or compounds. The accumulating overspray may, for example, be water-based or solvent-based. Accordingly, suitable examples of additives acting as solidifying material are: sulfonic acids, in particular p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenedisulfonic acid and dinonylnaphthalenesulfonic acid, and the salts and esters of sulfonic acids (sulfonates); Phosphoric acids, in particular: phosphoric (V) acid, phenylphosphoric acid, butylphosphoric acid and dibutylphosphoric acid and their salts and esters (phosphonates), dicarboxylic acids and their salts and esters, in particular maleic acid and monobutyl maleate; fumed silica; Amines, in particular triethylenediamine (TEDA); Organotin compounds, in particular Diocytlzinndilaurat, dibutyltin dilaurate; Bismuth carboxylates, especially bismuth trisoctate and bismuth trisneodecanoate; Bismuth-tin carboxylates; organic peroxides, especially benzoyl peroxide and 2-butanone peroxide; saturated water vapor. For a melamine resin paint, for example, good results can be obtained with a solidification material based on phosphoric acid and p-toluenesulfonic acid.

As mentioned above, the solidification material may also be a mixture of individual ones of said components and comprises one or more components selected from catalysts, polymerization reaction initiators, rheology additives, and / or crosslinker resins. Other solidification materials are in the patent application DE 10 2016 001 888 whose content is hereby incorporated by reference.

As can be seen from the above, the additive 122 and the health of an operator may be a hazardous substance / substance mixture. There may be a risk of inhalation, ingestion or even contact with the skin.

The additive 122 of the additive capsule 120 is enclosed by a sheath 124. The wrapper 124 is designed to be dissolved, at least partially dissolved, or at least weakened or mechanically pervious under the influence of overspray 106, such that the additive may at least partially exit or otherwise contact the overspray 106 in a manner that already described Effect of initiating or supporting the solidification process of the overspray can be effected.

As long as the additive 122 is within the enclosure 124, the additive 122 or the additive capsule 120 is less or no immediate danger to an operator.

The dissolution reaction of the enclosure 124 may be adapted to the expected overspray material system. As already mentioned, the overspray can be, for example, a water-based or solvent-based paint system. Accordingly, in a water-based overspray material system, the enclosure 124 may comprise, for example, a polyvinyl alcohol (PVOH) or similar material which, depending on the design, may have high solubility to water and thus contact upon overspray designed as a water-based material system dissolve and release the additive.

Alternatively, the overwrap 124 for a solvent-based overspray material system may comprise, for example, a polystyrene (PS) or similar material that may dissolve in contact with the solvent and release the additive 122.

The envelope 124 need not be made entirely of the dissolving material for an effect according to the invention. It may be sufficient if only portions of the enclosure 124 provide access to the interior of the additive capsule 120 after the dissolution process. For example, only certain separating strips can be made of the dissolving material, which cause the additive capsule 120 to break apart or fall after the dissolving process.

If the additive 122 has specific properties, such as a low pH, then the material of the enclosure 124 must, on the one hand, be soluble to the components of the overspray 106 and, at the same time, resistant to the additive 122 enclosed by the enclosure 124.

The shape and material thickness of the additive capsule 120 may be designed according to the application and promote release / containment of the additive 122.

FIG. 4 Now shows the state after an addition of a plurality of additive capsules 120 and a resolution of the respective enclosure 124 has already occurred. Accordingly, the amount of additive 122 present in the former envelope 124 in the collection trough 112 is now within the liquid quantity bounded by the liquid level 114 Overspray 106.

The amount of additive 122 released, depending on the mechanism of action, produces an effective radius 126 within which the additive 122 can cause solidification of the liquid overspray 106. Depending on the configuration of the influx of the overspray 106, it may happen that the additive 122 is trapped by the solidifying overspray and is prevented from further effect. It may therefore be important to match the amount of additive 122 and the number of additive capsules 120 introduced according to the mechanisms of action to achieve sufficient solidification of the liquefied and accumulated overspray 106.

FIG. 5 FIG. 13 illustrates, in a schematic cross-sectional view, another embodiment of a filter element 200. Features that are similar or equivalent to features of the previous embodiment are provided with reference numerals to which 100 has been added.

As with the filter element 100 described above, an inflow port 202 and an outflow port 203 are provided for supplying a cabin air 108 laden with overspray 106 and discharging the purified air 109.

In contrast to the embodiment of the FIGS. 3 and 4 For example, the filter element 200 has a coating 218 applied to the inside of the wall 210 of the collecting region 212. The coating 218 is constructed in two parts. A first layer 220 is located within the area of the inside of the wall 210 and has an additive 222. The additive 222 may be the same additive 122 as used for the additive capsule 120. However, it may also be that a modified or different composition of the additive 120 is necessary for the application of the coating 220.

The layer 220 is covered by a cladding layer 224, which according to the above to FIG. 10 Embodiments designed so that on the one hand, a dissolution of the cladding layer 224 is possible in contact with the accumulating in the sump 212 overspray 106. On the other hand, the additive 222 under the cladding layer 224 should be trapped by the cladding layer 224 and remain inactive until the dissolution of the cladding layer 224 begins, so that a safe handling of the filter element 200 during transport, storage and / or installation is possible.

The two layers 218, 224 are mounted in the lower region of the collection trough 212. The cladding layer 224 substantially completely covers the additive layer 218, so that a solidification reaction can only take place after an at least partial dissolution of the overlying cladding layer 224.

FIG. 6 illustrates in a schematic sectional view of another embodiment of a filter element 300. To avoid unnecessary repetition of features already described, the same or similar features in the FIG. 6 and all the following figures are denoted by reference numerals to which 100 has been added as compared with the previously described embodiment. These features will not be explained separately again.

Compared to the embodiment described above FIG. 5 sees the embodiment of the FIG. 6 a grid-like intermediate layer 326. In or on the intermediate layer, for example, additive capsules 120 may be applied, the envelope 124 of which dissolves on contact with an overspray 106 running on the intermediate layer 326 and releases the additive 122. The possibility of mechanical release of the additive 122 and a corresponding decrease of the additive below the liquid level 314 allows the effective radius 126 to be increased. Additionally or alternatively, the grid-like structure 326 itself may be coated with an additive and an associated coating.

FIG. 7 shows in a schematic sectional view of an embodiment of a filter element 400. This embodiment represents a combination of the embodiments of the in the FIGS. 5 and 6 Accordingly, a coating 418 and a grid-like structure 426 are provided accordingly.

FIG. 8 illustrates in a schematic sectional view of another embodiment of a filter element 500. The filter element 500 has in addition to those already described Features in the pool bucket 512 elevations 528. The elevations have surfaces 530 that extend at least partially perpendicular to the liquid level 514. On the one hand, this extension enables a spatial enlargement of the effective radius 526 of the individual additive capsules 520 or of a coating applied to the elevations. On the other hand, there is also an availability of the additive material 522 that is stretched in time with the filling of the collection trough 512-over the entire sump interior.

FIG. 9 FIG. 12 illustrates a schematic sectional view of another embodiment of a filter element 600. In the filter element 600, the approach for contacting overspray 106 and additive 622 is different. Additive 622 is incorporated into filter material 604 with a wrap 624. While in the previous embodiments the contact could be in the dormant state of the overspray 106, in the present embodiment it is necessary for the overspray 106, which accumulates as a liquid, to have sufficiently intense contact with the additive 622 as it forms in the filter material 604 initiate the solidification process or already sufficiently support it there.

It may be advantageous to provide a delay between contact and initiation of solidification, so that a drainage of the overspray 106 after contact with the additive 622 is still possible. This can be realized for example by a suitable reaction kinetics. In FIG. 9 already the state is shown in which the wrapper has dissolved and the additive 622 is exposed.

FIG. 11 illustrates in a highly simplified representation of an alternative structure of a coating 718. In contrast to the coating 218, as in the embodiment of the filter element 200 of the FIG. 5 has been shown, the coating 718 of FIG. 11 a multi-layered construction. Specifically, first of all a first layer 734 of an additive is applied to the carrier material 732-this may be, for example, a filter material 604, an inner wall of a collection trough or the surface of a lattice-like structure or an elevation. This first layer 734 is covered by a first layer 736 of a wrapping material. Above it is another layer 738 of an additive. The second additive layer 738 may comprise the same additive as the first additive layer. Alternatively, the second additive layer 738 may comprise an additive having, for example, a different reaction kinetics or other other properties. This second additive layer 738 is covered and passivated by a further outermost cladding layer 740. In this sense, it is also possible to build up coatings 718 with a larger number of, in particular, additive layers-not just two as present.

In this way, a staged delivery of one or more different additives can be achieved. Accordingly, the overall reaction between overspray and additive (s) can be better controlled by choosing different material compositions of the cladding layers and / or the additives as well as by choosing different layer thicknesses.

The application of the various components of the individual layers can take place, for example, by rolling, spraying or / and by dipping.

The FIGS. 12 and 13 show a further embodiment of a filter element 800. The filter element 800 has a grate 840 in which additives 822 are present in a coated form, for example as additive capsules. The grate allows liquid overspray 106 to flow past without contact between overwrapped additive 822 and overspray 106. The grate 840 has an actuating element 842, which can be designed, for example, manually or by motor actuation. By means of the actuating element 842, openings 844 can be opened and closed in the grate. FIG. 13 FIG. 11 shows the state of opened openings 844. Accordingly, additives 822 fall through openings 844 into the underlying amount of liquid overspray 106, where they initiate or assist solidification.

Alternatively or additionally, removal may take place for a filter element or filter module without grate 840. Before or after removal of the filter element or filter module, an additive is added. The filter element or filter module is coupled with a vibrator or mixing device so that the additive is mixed with the overspray.

Claims (9)

Process for the treatment of overspray of a coating plant, with the steps a) supplying overspray-laden cabin air to a filter module (s1); b) separating overspray by means of a filter element (S2) located in the filter module; c) collecting deposited overspray (S3); d) adding an additive which causes or assists curing of the overspray, wherein the additive is enclosed in an enclosure so that it can not exert its effect and wherein the enclosure is dissolvable by the overspray (S4); e) dissolving the coating and releasing the additive (S5); f) effecting or supporting the curing operation of the overspray by means of the additive (S6). The method of claim 1, wherein the additive is in the enclosure in tablet form. The method of claim 2, wherein a plurality of tablets is to be added for complete curing. Method according to one of the preceding claims, wherein the additive and the associated envelope are attached to parts of the filter element, with which the overspray comes into contact during the collection process. The method of any one of claims 1 to 3, wherein the additive and the enclosure are disposed in a reservoir above the collected overspray. Device (100) for separating overspray (106) from overspray-laden cabin air of surface treatment plants, comprising at least one separation unit through which overspray-laden cabin air can be conducted and in which overspray separates, wherein a) the separation unit has a filter element (100) and b) the filter element (100) or the separation unit is at least partially provided with an additive (122) which causes or assists curing of the overspray in direct contact with the overspray, c) the additive is coated with a sheath (124), wherein the sheath is designed so that - The wrapping encloses the additive in such a way that it can not unfold its effect and - The coating dissolves on contact with the overspray and releases the additive. Apparatus according to claim 6, wherein the layer of additive and coating is present twice or more times. Apparatus according to any one of claims 6 to 7, wherein the additive and the enclosure are attached to a grid-like structure (326) in the filter element (300) or below the filter element. The apparatus of any of claims 6 to 8, including a deposited overspray container (512), wherein the additive and wrapper are disposed on a surface (530) that extends perpendicular to the surface mirror (514) of an overspray accumulated in the container having.

Images