HOLDING DEVICE FOR FILTER ELEMENTS OF A FILTER MODULE

Abstract

A holding device for filter elements of a filter module for separating overspray from booth air of a coating installation, in particular painting installations, which booth air is laden with overspray, the filter module having a filter housing, which bounds a filter chamber, through which booth air laden with overspray can be conducted in a main flow direction, a plurality of filter elements made of a filter material permeable to the booth air being arranged in the filter chamber in such a way that a flow labyrinth is formed between the filter elements, the holding device being designed to hold one or more filter elements and to position said one or more filter elements within the filter module, the holding device extending along a longitudinal axis, which is arranged transversely to the main flow direction, the holding device having a grate structure that forms the outer contour, and the one or more filter elements being holdable by means of the grate-type outer contour and thus being positionable relative to the outer contour in a stationary manner.

Claims

1. A holding device for filter elements of a filter module for separating overspray from overspray-laden booth air of a coating system, wherein the filter module comprises a filter housing, which delimits a filter space through which overspray-laden booth air can be delivered in a primary flow direction, and wherein a multiplicity of filter elements made of a filter material which is permeable for the booth air are arranged in the filter space in such a way that a flow labyrinth is formed between the filter elements, the holding device comprising: a grid tube, wherein the holding device is configured in order to hold one or more filter elements and to position them inside the filter module and is configured to extend along a longitudinal axis which is arranged transversely to the primary flow direction, and further wherein the one or more filter elements can be held by means of the grid tube and can thus be positioned in a fixed location relative to the outer contour.

2. The holding device as claimed in claim 1, wherein the outer contour is configured to be cylindrical or prismatic.

3. The holding device as claimed in claim 2, wherein, in the case of a prismatic configuration of the outer contour, at least two side edges are of unequal length.

4. The holding device as claimed in claim 1, wherein the grid structure comprises a flow structure on the outside and/or a retaining structure on the inside and/or a connecting structure and/or a depot structure on the end side.

5. The holding device as claimed in claim 4, wherein the depot structure, in the case of a vertical orientation of the holding device, is arranged in a lower region of the holding device.

6. The holding device as claimed in claim 1, wherein the grid structure comprises one or more segments.

7. The holding device as claimed in claim 6, wherein the segments are connected to one another assemblably and/or separably and/or mutually articulatedly.

8. The holding device as claimed in claim 7, wherein articulations allow tilting of the segments along an axis which extends essentially parallel to the longitudinal axis of the holding device.

9. The holding device as claimed in claim 1, for a first and a second filter element, wherein the holding device is configured in such a way that the filter elements can be arranged successively and/or next to one another along the longitudinal axis inside the holding device.

10. The holding device as claimed in claim 9, wherein, in the case of arrangement of the filter elements next to one another, a first filter material is configured for fine filtering and a second filter material is configured for coarse filtering.

11. The holding device as claimed in claim 9, having a first and a second filter element, wherein the first filter element differs in terms of its filter effect from the second filter element.

12. The holding device as claimed in claim 11, wherein the first filter element comprises a different filter material, a different filter capacity and/or a different filter material density than the second filter element.

13. A coating system comprising a filter module having a holding device as claimed claim 1.

14. A method for coating vehicle bodies and/or vehicle parts with a coating system which comprises a filter module having a holding device as claimed in claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Exemplary embodiments of the invention will be explained in more detail below with the aid of the drawings, in which:

[0032] FIG. 1 shows, in a schematic cross-sectional view, a painting booth having a separating device for overspray, in which booth air is guided to filter modules by means of an air guiding instrument,

[0033] FIG. 2 shows, in a perspective partially cutaway view, an embodiment of a filter module not equipped with filter elements

[0034] FIG. 3 shows the filter module of FIG. 2, partially equipped with filter elements;

[0035] FIG. 4 shows a plan view of the filter module of FIG. 3;

[0036] FIG. 5 shows a side view of the filter module of FIGS. 3 and 4;

[0037] FIG. 6 shows a perspective view of a first segment of a first embodiment according to the invention of a holding device;

[0038] FIG. 7 shows a perspective view of a second segment of the first embodiment of a holding device;

[0039] FIG. 8 shows the first segment of FIG. 6 connected to the second segment of FIG. 7 to form the first embodiment of the holding device,

[0040] FIG. 9 shows a perspective view of a second embodiment according to the invention of a holding device in an opened position;

[0041] FIG. 10 shows the second embodiment of FIG. 9 in a closed position;

[0042] FIG. 11 shows the second embodiment of FIGS. 9 and 10 with an inlaid filter material in an opened position;

[0043] FIG. 12 shows the second embodiment of FIG. 11 in a closed position;

[0044] FIG. 13 shows a perspective view of a third embodiment according to the invention of a holding device in an opened position; and

[0045] FIG. 14 shows a side view of a plurality of holding devices of the third embodiment of FIG. 13.

DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS

[0046] FIG. 1 shows a coating booth 10 as well as a surface treatment system, denoted overall by the reference 12, in which objects 14 are painted. Vehicle bodies 16 are shown as an example of objects 14 to be coated. Before these enter such a coating booth 10, they are for example cleaned and degreased in pretreatment stations (not shown per se).

[0047] The coating booth 10 comprises a coating or painting tunnel 18 arranged above, which is bounded by vertical side walls 20 and a horizontal booth roof 22 but is open at the end sides. The painting tunnel 18 is furthermore open in such a way that overspray-laden booth air can flow downward. The booth ceiling 22 is conventionally a lower boundary of an air delivery space 24 and configured as a filter roof 26. The vehicle bodies 16 are transported by a conveyor system 28, which is fitted in the coating tunnel 18 and is known per se, from the entry side of the coating tunnel 18 to its exit side. Inside the coating tunnel 18, there are application instruments 30 in the form of multiaxial application robots 32, such as are likewise known per se. By means of the application robots 32, the vehicle bodies 16 can be coated with the corresponding material.

[0048] Towards the bottom, the coating tunnel 18 is open through a walkable grating 34 to a system region 36 arranged underneath, in which overspray particles entrained by the booth air are separated from the booth air.

[0049] To this end, during a coating process, air flows down from the air delivery space 24 through the coating tunnel 18 to the system region 36. In this case, the air takes up paint overspray present in the coating tunnel 18 and entrains it. This overspray-laden air is guided with the aid of an air guide instrument 38 to a separating device in the form of one or more single-use filter modules 40 (referred to below as filter modules).

[0050] For this purpose, in the present exemplary embodiment, the air guide instrument 38 comprises a guide channel 42, which is formed by metal guide plates 44 that extend inward and are inclined downward from the side walls 20. The guide channel 42 opens at the bottom into a plurality of connecting channels 46 which in turn end at the bottom in a connector 48.

[0051] During a coating operation, each filter module 40 is connected fluidically and releasably to the air guide device 38. In the filter module 40, the booth air flows through one or more filter elements, on which the paint overspray is separated. This will be discussed in detail below. Overall, each filter module 40 is configured as a replaceable component.

[0052] The booth air, substantially freed of overspray particles after the filtering by the filter module 40, flows out from the filter module 40 into an intermediate channel 50, through which it enters a collecting flow channel 52. The booth air is delivered through the collecting flow channel 52 to further processing and conditioning, and is subsequently passed in a circuit (not shown separately) back into the air delivery space 24, from which it again flows into the coating tunnel 18 from above.

[0053] If the booth air is in fact not yet sufficiently freed of overspray particles by the filter modules 40 present, the filter modules 40 may be followed by further filter stages to which the booth air is delivered and in which, for example, electrostatically operating separators, such as are known per se, are also used.

[0054] FIG. 2 shows the basic structure of a filter module 40. The filter module 40 comprises a filter module housing 60, which bounds a filter housing interior 62 that extends between a module inlet 64 and a module outlet 66 and through which the booth air flows. This gives rise to a flow profile, along which the booth air entering through the module inlet flows through the filter housing interior 62.

[0055] The module housing 60 comprises a bottom part 70, which in the present exemplary embodiment is configured in its geometry and its dimensions as a standardized carrying structure, for example according to the specification of an EUR-pallet. The arrangement of a plurality of filter modules 40 in the system region 36 of the coating booth 10 may correspondingly be carried out according to a grid which is based on the standardized bottom part 70 used.

[0056] A lower collecting region of the filter module 40 is configured fluid-tightly and in this way as a collecting trough 72 for coating material that is separated in the filter module 40 and flows away downward.

[0057] Arranged in the filter space 62, there is a retaining bracket 74 which comprises recesses 76 (not shown in FIG. 2) for retaining holding devices. The retaining bracket 74 spans a filter space 78, within which the actual filtering of the overspray-laden booth air flowing in takes place. During the filter process, the booth air flows along a primary flow direction 80 through the filter space 78, and in doing encounters the filter elements. This is represented in more detail in FIGS. 3-5 below.

[0058] FIG. 3 shows the filter module 40 of FIG. 2 with two fitted holding devices 82. FIGS. 4 and 5 show the same situation in a schematic plan view (FIG. 4) and a schematic side view (FIG. 5).

[0059] The holding devices 82 are configured as grid tubes and carry filter elements, which can thus be positioned in the filter space 78 along the primary flow direction 80 and which the booth air can flow onto and through.

[0060] When flowing through the filter space 78, a partial flow 87 passes through the holding device 82 to a filter element located therein and flows through the latter, so long as the filter element is not fully loaded. Another partial flow 88 is deviated by the filter elements located in the holding devices. By this deviation of the air flow, heavier particles, that is to say for example overspray particles, fall out of the air flow and thus reach the filter element. The two partial flows 87, 88 are not to be understood as fixed flow paths, but rather both partial flows may be formed at one and the same filter element depending on the local loading and the direction of flow of the respective filter element, and they may also be variable over time.

[0061] The holding devices 82 may, contrary to the arrangement which can be seen well particularly in FIG. 4, be arranged offset along the primary flow direction 80. The number of holding devices 82 perpendicular to the primary flow direction 80 may increase as seen in the direction of the primary flow direction 80. This gives rise to a combination of depth filter and inertial separation. For residual overspray parts still remaining in the air, a bag filter may for example be arranged downstream.

[0062] The specific structure of the filter elements will be discussed in more detail below with reference to FIGS. 11 and 12. In the embodiment of a filter module 40 as shown in FIGS. 2-5, the filter elements arranged in the holding devices 82 cannot be flowed onto from above since the holding devices 82 are covered by a cover plate 84 which provides moldings 86 for the holding devices 82. The moldings 86 correspond in their shape to the outer geometry of the holding devices 82, and thus allows accurate and simple positioning of the holding devices 82 in the flow along the primary flow direction 80.

[0063] In the embodiment shown, the moldings 86 are arranged only in the upper cover plate 84, since flow on the underside of the retentate out of the filter elements into the collecting trough 72 is intended to be possible. As an alternative, moldings may also be provided in a lower region, if for example the stability of the overall design so requires.

[0064] In the embodiment shown in FIGS. 2-5, the holding devices 82 are about 2000 mm long. This, however, only represents an exemplary embodiment. Longer or significantly shorter holding devices may, of course, also be used depending on the intended application.

[0065] FIGS. 6-8 show a first embodiment of an embodiment according to the invention of a holding device 82. A first segment 90 is shown in FIG. 6, and a second segment 92 is shown in FIG. 7. FIG. 8 shows the two segments 90, 92 assembled to form a holding device 82. In the embodiment represented in FIGS. 6-8, the two segments 90, 92 are identical. This significantly facilitates production, storage and assembly. It is, however, also possible to produce two differently shaped segments and assemble them to form a holding device 82.

[0066] The segments 90, 92 extend along a longitudinal axis A whichas shown in FIG. 5may be arranged transversely to the primary flow axis 80. The segments 90, 92 comprise a grid structure, forming the outer contour, with longitudinal struts 94 arranged parallel to the longitudinal axis and transverse struts 96 arranged transversely to the longitudinal axis. The grid structure is produced in terms of manufacturing technology by means of an injection-molding technique. As an alternative, as already explained above, such grid structures may also be produced by a pressing process, for example by using a round blank. If material containing cellulose is used as the material for the grid structures, advantages are for example obtained in the disposal of the holding devices together with the filter elements.

[0067] The outer geometry of the holding devices 82 may, for example, be configured to be hollow-cylindrical or hollow-prismatic. If the prismatic outer geometry is configured in such a way that it has no rotational symmetry with respect to the longitudinal axis A, the holding device 82 can only be fitted in one orientation with respect to the primary flow axis. This makes it possible to adapt the filter element filling of the holding device 82 to the flow direction to be expected, and in particular to optimize it in this respect. It is furthermore possible to configure the outer geometry of the holding devices 82 differently for different positions of the holding device 82 inside the filter space 78. Thus, on the one hand, a particularly simple assignment of the holding devices 82 with the filter elements may be achieved when constructing a filter module 40. On the other hand, the outer geometry of such a holding device 82 may take into account the different flow conditions inside the filter space 78.

[0068] Besides the pure outer geometry, structures which influence the flow, for example lugs or flow guiding structures, may also be provided, which may lead to an improvement of the flow onto the holding devices.

[0069] The grid structure may, for example, have variable material thicknesses of the longitudinal struts 94 or the transverse struts 96. For example, these may be adapted to the forces to be expected because of the intrinsic weight of the filter elements after full loading, and thus ensure a particularly good stability of the holding devices 82.

[0070] It is furthermore possible, besides the pure grid structure, to fit additional structures. The additional structures may, for example, be configured in order to permit fastening of a segment 90 to another segment 92. In this context, the segments 90, 92 comprise hook structures 98, which cooperate with eyelet structures 100. This is represented in FIG. 8: the hook structures 98 engage in the eyelet structures 100 and retain the two segments 90, 92 together.

[0071] Besides the aforementioned retaining structures 98, 100, it is also possible, as is represented in FIGS. 9 and 10 in a second alternative embodiment of a holding device 182, to provide solid hinges, for example the film hinge 102. This allows particularly simple mobility of the individual subsegments 192, 194 and particularly accurate fixing of the subsegments 192, 194 to one another.

[0072] FIGS. 11 and 12 show the embodiment of a holding device 182 of FIGS. 9 and 10 with inlaid filter elements 110, 112. The filter elements 110, 112 are configured as nonwoven filters and differ in their fabric structure, particularly in their filter effect and capacity. While the first filter element 110 of a first filter type has a higher filter material density, the second filter element 112 has a lower filter material density. In conjunction with a rotational asymmetry of the assembled holding device 182 with respect to the longitudinal axis A, a simply assemblable holding device 82 for filter elements 110, 112 is thus obtained, which is for example installable uniquely in a retaining bracket 74 in respect of its orientation with respect to the primary flow direction 80. With the inlaid filter elements 110, 112, the holding device 182 forms a filter element combination 114.

[0073] The filter element combination 114 offers the possibility of, for example, taking into account different flow conditions inside the filter space 78. Thus, a filter element combination 114 at a peripheral position 116 (see FIG. 4) is likely to experience a different incoming flow on its side lying toward the center of the flow than on its peripherally lying side. At the same time, for a filter element combination 114, the incoming flow at a central positionfor example at position 118is significantly more symmetrical. At the same time, the flow conditions and the loading of the air flow again differ significantly at a position lying downstreamfor instance position 120from a position lying upstreamfor instance position 116. These effects may be counteracted by the selection of different filter materials for different filter elements 110, 112 inside a filter element combination 114.

[0074] FIGS. 13 and 14 show a third embodiment of a holding device 282. Features which are the same or are comparable to features of the first or the second embodiment of the holding devices 82, 182 are provided with references to which 100 or 200 has respectively been added.

[0075] The two segments 292, 294 are, as in the second embodiment, connected tiltably to one another with a film hinge 202 parallel to a longitudinal axis A, and can be latched fixed in rotation by means of hook and eyelet structures 298, 300.

[0076] Conical pins 310pointing inward in a closed stateare fitted on the segments 292, 294. The pins 310 are configured in such a way that a filter element 110, 112 located in the holding device is penetrated at least partially by the pins 310 and is thus fixed in its position inside the holding device 282. This contributes, in particular, to an improved stability of the filter element combination during increasing loading of a filter element.

[0077] The holding device 282 comprises depot structures 312, 314 at one end. The depot structures may, for example, be filled with an active agent, for example a curing agent or a catalyst. The depot structures 312, 314 are arranged on the holding device 282 in such a way that, in the case of a vertical orientation of the holding device 282, the depot structures 312, 314 protrude into the collecting trough 72. In this way, in the event of contact of the retentate being collected in the collecting trough 72 with the active agent contained in the depot structures, a corresponding reaction, for example curing of the retentate, is initiated or accelerated.

[0078] FIG. 14 shows a side view of a plurality of holding devices 282 stacked on one another. In this case, the pins 310 fulfil a different function. The pins 310 engage at least partially in recesses which are located on the outer side of the pins 310. In this way, a high packing density is obtained for a multiplicity of holding device for transport and storage purposes, and the holding devices can be transported securely against slipping and without tilting.