FILTER MODULE FOR SEPARATION OF OVERSPRAY

Description

[0001] The invention relates to a filter module with a plurality of filter elements for separating overspray from the air. State of the art

[0002] When coating and painting objects such as vehicle bodies or vehicle components in a coating booth, the coating material is atomized and conveyed onto the object by an air stream. Only a portion of the coating material stream intended for the object to be coated reaches the object. Another portion remains in the air stream as overspray and must be removed from the air stream. In a broader sense, the terms overspray, overspray particles, and overspray solids are understood here and below to refer to a dispersive system such as an emulsion, a suspension, or a combination thereof. The overspray is captured by the air stream and fed into a separator so that the air can be returned to the coating booth after suitable conditioning, if necessary. A coating system of this type is described, for example, in DE 10 2013 004 082 A1.

[0003] The aforementioned publication describes replaceable disposable filter modules as a possible separation technology. Overspray-laden coating booth air flows through the disposable filter modules during operation, gradually becoming further loaded with overspray. Once a maximum permissible loading limit is reached, the loaded filter modules are replaced with unloaded filter modules.

[0004] Disposing of such filter modules generates large amounts of waste, which must be temporarily stored in coating plants. Due to the filter modules' typically approximately 2m³ volume, disposal is complex and expensive. Another disadvantage is the high resource consumption required to manufacture new filter modules.

[0005] DE 20 2014 103 177 U1 describes a filter system for a paint shop. The filter system has several filter modules into which fresh filter elements can be inserted and removed when they become contaminated. While the filter module can be designed, for example, as a reusable cart, the filter elements can be disposable. Task

[0006] The object of the present invention is to provide a filter module for absorbing overspray, which has good filtration performance as well as good and resource-efficient handling, even during disposal, and at least partially eliminates the disadvantages of the prior art. Technical solution

[0007] This task is solved by a filter module as described and claimed below.

[0008] According to the invention, it was recognized as advantageous to combine a frame in a reusable and cleanable design with components for absorbing overspray in a disposable design for the filter module.

[0009] The filter module according to the invention has a plurality of filter elements for separating overspray from the air and is suitable for use in a coating system, e.g., a paint booth or paint line. The filter module has a reusable and cleanable frame as a supporting structure, which serves to accommodate components for absorbing overspray. The frame can be made, in particular, of metal, e.g., aluminum, or plastic. Likewise, the filter module has a plurality of components for absorbing overspray, which are inserted into the frame and can be pushed in and out, or inserted and removed, and are designed as disposable products.

[0010] This design advantageously allows, when the maximum permissible overspray load of the filter module is reached, only the components wetted with overspray are disposed of and replaced with new ones. The frame itself is reusable. Preferably, the components for absorbing overspray are manufactured predominantly using recycled or renewable raw materials. Furthermore, it is preferred if the components for absorbing overspray are suitable for thermal recycling. The frame can be cleaned and reused multiple times. This reduces the amount of waste and conserves resources.

[0011] According to the invention, the components for absorbing overspray are at least filter elements and frame linings. The filter elements can be specifically optimized for absorbing overspray. Several shelf-like support shelves can be provided as part of the frame for inserting the filter elements. The filter elements form at least a first filter stage.

[0012] All surfaces of the frame exposed to the airflow or areas of the frame upstream of the first filter stage are provided with linings in such a way that these areas of the frame are protected from overspray. In other words, the linings advantageously prevent the overspray-laden airflow from coming into contact with these surfaces and potentially contaminating them. Instead, the linings are contaminated. This can minimize the effort required to clean the frame before reuse. The areas of the frame exposed to the airflow and fitted with linings can, in particular, be the upper inlet area of ​​the frame and an area at the bottom of the frame.

[0013] After the first filter stage, the air flow has already undergone an initial cleaning by the filter elements, so that it is not necessary to provide the areas of the frame located after the first filter stage with corresponding linings.

[0014] The lined surfaces of the rack are defined here as surfaces with a flat extension. Narrow surfaces with relatively small widths and a length-to-width ratio greater than 20:1, such as the front edges of shelves, are not considered such surfaces. These narrow surfaces can be covered with adhesive tape, for example, to protect them from overspray.

[0015] It appears particularly advantageous if the linings are made of cardboard, e.g. corrugated cardboard, carton, or paper. The linings can be specially cut to size and, if necessary, folded. If the linings are also folded, they have a three-dimensional design. In an alternative and equally advantageous embodiment, the linings can be made of plastic sheets or films. Recycled plastic can be used, in particular, for the plastic sheets and films. The films can also be so-called spray films, which can be applied particularly easily using the spray-on film technique, also known as peel-and-stick coating. Such spray films can be removed from the surfaces particularly easily.

[0016] In a particularly advantageous refinement, the linings are provided with small flow obstructions on the surface facing the airflow for optimized overspray separation. In contrast to a flat lining design, overspray can be separated more effectively this way. If the linings are made of cardboard, paper, or plastic sheets, they can be slotted, i.e., have a plurality of slots, with each slot forming a flow obstruction.

[0017] It appears particularly advantageous if the filter elements of the filter module are made of cardboard, paper, or paper, e.g., corrugated cardboard, slotted and / or wound cardboard, or cardboard with honeycomb structures. One possible design for such a filter element comprises several layers of slotted cardboard through which the air to be cleaned flows. The layers are housed in and connected to an outer cardboard box.

[0018] The filter elements of the filter module can additionally or alternatively contain filter mats made of a synthetic nonwoven fabric. The filter mat can be housed in a frame. It is particularly advantageous if the filter mat is folded several times, especially pleated, to achieve a larger effective filtration area.

[0019] In an advantageous development of the filter module according to the invention, a plurality of filter elements of a first type are arranged parallel to one another and form a first filter stage, and a plurality of filter elements of a second type are arranged parallel to one another and form a second filter stage. The first and second filter stages are directly adjacent to one another, i.e. the filter elements of the first and second type are arranged in series with one another without any space between them. In other words: filter elements of the first type and filter elements of the second type are in contact with one another, so that when the air flows from the respective filter element of the first type to the subsequent filter element of the second type, the frame cannot become dirty. The filter elements can have a zone without a filter medium, which forms a space for homogenizing the flow of the air flowing through.

[0020] In a further development of the filter module, the frame features support surfaces for the filter elements, e.g., the shelves mentioned above, and these support surfaces have a low surface energy, namely less than 50 mJ / m 2 . This results in poor wettability and adhesion of the support surfaces, and overspray can adhere poorly or, at best, not at all to the support surfaces.

[0021] In a further development of the filter module, components for absorbing overspray are a wall on the frame. This wall then forms the separating layer between the interior and exterior of the filter module. Grooves can be provided as part of the frame for inserting and guiding the walls. The components can be made of cardboard, paper, or paper, e.g., pre-folded and / or punched cardboard sheets. Such cardboard sheets can be easily inserted into the frame or attached to it.

[0022] The frame of the filter module may have an air inlet and an air outlet, and the frame and the overspray absorption components form an air duct from the air inlet to the air outlet, with the air to be cleaned being guided through the filter elements.

[0023] In a further development of the filter module according to the invention, the air guide has an air duct which - viewed in the flow direction - is positioned between the air inlet and the filter elements, in particular between the air inlet and the filter elements of a first filter stage. The air duct is funnel-shaped in such a way that the air duct tapers, i.e. its horizontal cross-sectional area can decrease from an air inlet located in the upper region of the filter module to the bottom of the frame. This allows a low-loss inflow of air up to the filter elements to be achieved, which manifests itself in the form of lower pressure losses, meaning that only a low fan power is required to move the air flow through the filter module.In addition, the funnel-shaped design leads to a more even loading of the parallel filter elements of the first filter stage, since successive portions of the air flow with overspray are discharged into the filter elements of the first filter stage. In a possible advantageous embodiment, the air duct can have a trapezoidal shape in its vertical cross-section in the flow direction, e.g., a right-angled trapezoid with an interior angle of approximately 93 to 97°.

[0024] In an advantageous design of the filter module, the frame is constructed of aluminum profiles, and the aluminum profiles are covered with aluminum sheet. Such a frame is stable, relatively lightweight, resistant to overspray, and easy to clean.

[0025] In an advantageous embodiment, a breaking device can be provided in the filter module to break up adhesions from overspray and facilitate the replacement of the filter elements. The breaking device can be formed, for example, by foldable shelves on which the filter elements sit. The breaking device can be formed, for example, by shelves with at least one groove-shaped recess for guiding a saw blade operated by a machine operator.

[0026] The crushing device can, for example, be formed by a holder for filter elements of the second filter stage that can be moved axially in the direction of flow.

[0027] In an advantageous development of the filter module, a collecting tray is provided on the top of the frame base for collecting liquid, e.g., liquid paint. This tray can also be equipped with an opening flap for inserting filter elements, with the filter elements located directly above the collecting tray in their operating position. This allows for the optimal use of the available space in the filter module for accommodating filter elements.

[0028] In a particularly practical development of the filter module, a device with two recesses is provided on the underside of the frame floor for inserting the tines, i.e., the forks, of an industrial truck, especially a pallet truck. This ensures that the filter module can be easily moved and replaced by a machine operator. The device can, in particular, be designed as a Euro pallet, which can be integrated into the frame. Such a device is inexpensive and widely available.

[0029] The described invention and the described advantageous developments of the invention also represent advantageous developments of the invention in combination with one another - insofar as this is technically reasonable.

[0030] With regard to further advantages and advantageous embodiments of the invention in terms of construction and functionality, reference is made to the dependent claims and the description of embodiments with reference to the accompanying figures. Example

[0031] The invention will be explained in more detail with reference to the accompanying figures. Corresponding elements and components are provided with the same reference numerals in the figures. For the sake of clarity, the figures have not been drawn to scale.

[0032] They show in schematic representation Fig. 1 a spatial view of a filter module according to the invention Fig. 2 the filter module from Fig. 1 in a partial section Fig. 3 the assembly of the filter module from Fig. 1 Fig. 4the reusable frame of the filter module made of Fig. 1

[0033] Fig. 1 shows a spatial view of a filter module 100 according to the invention. The filter module 100 can be arranged below a painting chamber or painting line 1 (not shown) and serves to separate overspray from the air, such as that which occurs during the painting of sheet metal parts. The filter module 100 has a reusable and cleanable frame 10, in which various components for absorbing overspray 20 can be inserted and are accommodated. In the illustration of Fig. 1 20 cardboard sheets can be seen on the components for absorbing overspray, which serve both as a wall 23 on the frame 10 and as a lining 24 in the frame 10. The lining 24 covers an area 25 of the frame 10 in front of the first filter stage formed by first filter elements 21 (not visible here). The wall 23 is formed by a U-shaped folded cardboard and is fixed to the frame 10 by means of a securing plate 18. The components for absorbing overspray 20 are basically disposable products in a single-use design.

[0034] A Euro pallet 14 is arranged on the underside of the floor 11 of the frame 10. This serves as a device with two recesses into which the forks of a pallet truck or other industrial truck can be inserted. This allows the filter module 100 to be easily moved across a hall floor. This makes it easy to replace a used filter module 100 with a new or re-equipped one.

[0035] Fig. 2 shows the filter module 100 from Fig. 1 in a partial section revealing the interior of the filter module 100. Filter elements 21 of a first type and filter elements 22 of a second type are arranged inside the filter module 100 as further components for absorbing overspray 20. The filter elements of the first type 21 are each arranged parallel to one another. The filter elements of the second type 22 are also arranged parallel to one another. The filter elements of the second type 22 are arranged in series with the filter elements of the first type 21, so that an air flow L to be cleaned first flows through the filter elements of the first type 21 and then through the filter elements of the second type 22, and the air flow L is cleaned in the process. The filter elements of the first type 21 form a first filter stage, and the filter elements 22 form a second filter stage, with the first and second filter stages adjoining one another seamlessly and without any gaps. That is,, between the filter elements of the first type 21 and the filter elements of the second type 22 there are no gaps in which overspray could accumulate and thus contaminate the frame 10.

[0036] The filter module 100 has an air inlet 16 and an air outlet 17 in its frame 10. An air flow L to be cleaned is guided from the air inlet 16 through the filter elements 21 and 22 to the air outlet 17 and is thereby cleaned by the filter elements 21 and 22. The filter elements 21 and 22 are arranged in the filter module 100 such that an air duct 16.1 is formed between the air inlet 16 and the first-type filter elements 21. The air duct 16.1 has a funnel-shaped design and tapers from the air inlet 16 toward the base 11 of the frame 10. This ensures a low-loss inflow of the air flow L to be filtered into the filter module 100 up to the first-type filter elements 21. In order to collect liquid and dripping particles of overspray from the air stream L, a collecting tray 12 is arranged on the top side of the base 11 of the frame 10.

[0037] To prevent electrical charging of the filter module 100, the frame 10 is equipped with a grounding connection 19. This prevents unwanted impairment of the filtration performance caused by a charge on the air stream L to be cleaned, and thus the risk of ignition. This also enables operation in so-called ATEX zones, i.e., potentially explosive atmospheres (ATmospheres EXplosible).

[0038] After reaching a maximum permissible limit load of the filter elements 21, 22 with overspray particles filtered out of the air stream L, the components 20 for absorbing overspray can be removed from the frame 10 and disposed of. Before fresh components 20 for absorbing overspray are inserted into the frame 10, the frame 10 can be cleaned.

[0039] The insertion and insertion of the components for receiving overspray 20 into the frame 10 is in Fig. 3 shown.

[0040] Fig. 3 shows the assembly of the filter module 100 from Fig. 1 , namely the assembly with components for absorbing overspray 20. As indicated by the dashed arrows, the components for absorbing overspray 20 are introduced into the frame 10 and attached to the frame 10. First, filter elements of the second type 22 are inserted into the receiving bases 15 of the frame 10. Subsequently, filter elements of the first type 21 are also inserted into the receiving bases 15. After all filter elements 21, 22 are positioned in the frame 10, the wall 23 is attached to the frame 10 and the lining 24 is inserted. The wall 23 then forms the separating layer between the interior and exterior of the filter module 100. In Fig. 3 Shown is an assembly state in which a second type filter element 22 has already been inserted into the lowest receiving base 15 and the lining 24 has been inserted. The additional components for absorbing overspray 20 still have to be inserted into the frame 10 and attached to the frame 10.

[0041] Fig. 4 shows the reusable frame of the filter module 100 from Fig. 1 without components for collecting overspray 20, so that the elements of the frame 10 can be better recognized. The frame 10 has three receiving shelves 15, into each of which filter elements 21, 22 can be inserted and placed. To enable the insertion of filter elements 21, 22 also on the lowest receiving shelf 15, the collecting tray 12 is provided with an opening flap 13 in one of its side walls. When the opening flap 13 is open, as is also the case in Fig. 3 As shown, the lowest filter elements 21, 22 can be easily inserted. A surface 25 at the bottom of the frame 10 can be provided with a lining 24, which is inserted into the collecting tray 12.

[0042] The frame 10 is constructed from aluminum profiles 10.1 and aluminum sheet 10.2, as shown in the sectional view of Fig. 2 can be seen. The aluminum sheet 10.2 covers the frame made of aluminum profiles 10.1, creating flat, easy-to-clean surfaces.

Claims

1. Filter module (100) having a plurality of filter elements (21, 22) for separating overspray out of an air stream (L), wherein the filter module (100) has a reusable and cleanable rack (10) as supporting structure for accommodating components for absorbing overspray (20), and a plurality of components (10) for absorbing overspray (20), which are inserted into the rack, characterized in that the components for absorbing overspray (20) involve at least filter elements (21, 22) and liners (24) in the rack (10) that are designed for single use as disposable products, in that the filter elements (21) form at least a first filter stage, and in that all those surfaces (25) of the rack (10) before the first filter stage which are impinged on by the air stream (L) are provided with the liners (24) such that said surfaces (25) of the rack (10) are protected from overspray.

2. Filter module according to Claim 1, characterized in that the surfaces (25) of the rack (10) with the liners (24) that are impinged on by the air stream (L) are an upper inflow region of the rack (10) and a region at the base of the rack (10).

3. Filter module according to one of the preceding claims, characterized in that the filter elements (21, 22) are formed from paperboard, cardboard or paper, and / or in that the liners (24) are formed from paperboard, cardboard or paper, plastic sheets or films.

4. Filter module according to one of the preceding claims, characterized in that the linings (24) are provided with flow obstacles on the surface for optimized separation of overspray.

5. Filter module according to one of the preceding claims, characterized in that the filter elements (21, 22) have filter mats composed of a synthetic non-woven material.

6. Filter module according to one of the preceding claims, characterized in that multiple filter elements (21) of a first type are arranged parallel to one another and form a first filter stage, and in that multiple filter elements (22) of a second type are arranged parallel to one another and form a second filter stage, and in that the first and second filter stages directly adjoin one another.

7. Filter module according to one of the preceding claims, characterized in that the rack (10) has supporting surfaces for the filter elements (21, 22), and the supporting surfaces have a low surface energy.

8. Filter module according to one of the preceding claims, characterized in that the components (20) for absorbing overspray involve a wall (23) on the rack, in particular composed of paperboard, cardboard or paper.

9. Filter module according to one of the preceding claims, characterized in that the rack (10) has an air inlet (16) and an air outlet (17), and in that an air guide from the air inlet (16) to the air outlet (17) is formed by the rack (10) and the components for absorbing overspray (20).

10. Filter module according to Claim 9, characterized in that the air guide has an air channel (16.1) which - as seen in the throughflow direction - is positioned between the air inlet (16) and the filter elements (21), wherein the air channel (16.1) is of funnel-shaped form.

11. Filter module according to one of the preceding claims, characterized in that the rack (10) is constructed from aluminium profiles (10.1), and the aluminium profiles (10.1) are lined with aluminium sheet (10.2).

12. Filter module according to one of the preceding claims, characterized in that a breaking device is provided for the purpose of breaking up adhesions of overspray on the filter module and the filter elements (21, 22) being able to be exchanged more easily.

13. Filter module according to one of the preceding claims, characterized in that a collecting trough (12) is provided on a top side of the base (11) of the rack (10) for the purpose of collecting liquid, said collecting trough having in particular an opening flap (13) for pushing-in of filter elements (21, 22).

14. Filter module according to one of the preceding claims, characterized in that an apparatus with two cutouts is provided on the bottom side of the base (11) of the rack (10) for moving-in of the forks of an industrial truck, in particular a lifting truck, and in that the apparatus is designed in particular as a Euro pallet (14).