Inlet filter or outlet filter for switch cabinet housing and corresponding switch cabinet device

Abstract

The invention relates to an air inlet filter (1.1) or an air outlet filter (1.2) for a switch cabinet housing (100), the air inlet filter or the air outlet filter having a filter housing (2), a filter substrate (3) having a pleated filter (4) being arranged in the filter housing, the filter substrate completely covering an air flow cross section (d) of the filter housing (2), characterized in that the filter substrate (3) has an absorbent pad made of a nonwoven fabric (6) capable of absorbing liquids. A corresponding switch cabinet device is also described.

Description

Technical Field

[0001] The invention relates to an air inlet filter or an air outlet filter for a switch cabinet housing, the air inlet filter or the air outlet filter having a filter housing, in which a filter substrate having a pleated filter is arranged, the filter substrate completely covering the air flow cross section of the filter housing. Such an air inlet filter or an air outlet filter is known from EP 1 909 548 B1. DE 201 07 242 U1 also describes a similar filter fan. DE 10 2010 016 504 A1 discloses a filter unit for a switch cabinet and WO 2011 / 054784 discloses a textile containing a superabsorbent. Background Art

[0002] The air inlet or air outlet filters known from the prior art have the disadvantage that they represent a weakness with regard to the achievable IP protection class of the switch cabinet housing in which they are installed, since the air inlet or air outlet filters naturally also have a certain liquid permeability due to their air permeability when they are loaded with large liquid volume flows for a longer period of time. Summary of the invention

[0003] It is therefore an object of the present invention to provide an inlet or outlet filter of the type mentioned at the outset which has the lowest possible permeability for liquids.

[0004] This object is achieved by an air inlet filter or an air outlet filter according to claim 1. The parallel claim 15 relates to a corresponding switch cabinet arrangement. Advantageous embodiments of the invention are respectively the subject of the dependent claims.

[0005] Therefore, in an inlet filter or outlet filter of the type mentioned at the beginning, it is proposed that the filter substrate has an absorbent pad made of a nonwoven fabric. The nonwoven fabric can have absorption properties for liquids, preferably water, and / or superabsorbents, wherein the superabsorbents are contained in the nonwoven fabric or the nonwoven fabric can be coated with superabsorbents.

[0006] The pleated filter can have a nonwoven fabric, so that the pleated filter and the absorption pad can be constructed in one piece or as the same component. In addition to the pleated filter, a nonwoven fabric can also be provided and cover the air passage cross section of the filter housing.

[0007] The nonwoven fabric can be liquid-absorbent and / or hydrophilic. The nonwoven fabric is preferably made of thermally and / or mechanically bonded polyester fibers. The fibers of the nonwoven fabric can be hydrophilic, and the nonwoven fabric (non-woven) formed from the hydrophilic fibers can have absorbent properties.

[0008] At least when the nonwoven fabric is hydrophilic, the nonwoven fabric and / or pleated filter can have a water-absorbing material strip, preferably a hydrophilic nonwoven fabric strip, on the bottom side. Due to the above-mentioned properties of the nonwoven fabric, water passing through the nonwoven fabric in the vertical direction can be absorbed in the liquid-absorbing material strip.

[0009] The material strip that absorbs liquid can be arranged outside the air flow cross section of the filter housing. Therefore, the liquid volume absorbed by the material strip remains outside this cross section, thus providing additional protection to prevent liquid from accidentally entering the switch cabinet housing.

[0010] The nonwoven fabric of the absorbent pad can have a thickness of less than 250 g / m 2 , preferably less than 200g / m 2 ,, particularly preferably less than 180g / m 2 The weight per unit area of ​​the absorbent pad can thereby be reduced to a negligible level. The absorbent pad made of nonwoven fabric can be arranged downstream of the pleated filter in the inlet filter in the flow direction and can be arranged upstream of the pleated filter in the outlet filter in the flow direction. The absorbent pad made of nonwoven fabric can be arranged adjacent to the pleated filter or below the pleated filter at a distance therefrom.

[0011] When using superabsorbents, the superabsorbents have the property that when loaded with liquid, their volume increases (considerably), thereby reducing the permeability of the filter substrate to any fluid. Depending on the concentration of the superabsorbent contained in the filter substrate, it is even conceivable that the superabsorbent completely blocks the filter substrate in the swollen state (hydrogel), thus making the air inlet or air outlet filter practically airtight at normal pressure differences (e.g. of the filter fan).

[0012] The filter substrate can be permeated with superabsorbent or can be coated with superabsorbent. In the case of a nonwoven, the superabsorbent provided in the form of particles can be retained by the fibers of the nonwoven material. An adhesive can be provided to retain the superabsorbent on the nonwoven material. Preferably, the superabsorbent is not provided in or on the pleated filter. Instead, the filter substrate can have an additional nonwoven which is coated with superabsorbent or has superabsorbent contained therein. The nonwoven can be provided as a separate component of the filter substrate independently of the pleated filter or in combination with the pleated filter.

[0013] The pleated filter can have a nonwoven fabric of a liquid absorption pad or a nonwoven fabric of a liquid absorption pad can also be provided as a nonwoven fabric covering the air flow cross section of the filter housing in addition to the pleated filter. Superabsorbents can be accommodated in the nonwoven fabric. Alternatively, the nonwoven fabric can be coated with superabsorbents. It is also conceivable that the nonwoven fabric is penetrated by superabsorbents and is coated with superabsorbents. Independently of whether the nonwoven fabric has superabsorbents, the pleated filter can also be composed of a nonwoven fabric and can therefore be a commercially available pleated filter used, for example, in an air inlet filter or an air outlet filter of a filter ventilator.

[0014] The nonwoven fabric can be coated and / or impregnated with the superabsorbent in the form of particles, wherein the particles of the binder are held on the fibers of the nonwoven fabric or on the fibers.

[0015] In order to prevent the filter substrate from being completely blocked due to the expanded superabsorbent when the inlet filter or outlet filter is loaded with liquid and the fresh air required for cooling the components accommodated in the switch cabinet housing can no longer be transported into the interior of the switch cabinet, in particular, in a special embodiment of the invention, it is provided that the nonwoven fabric has superabsorbent only in a part of the air flow cross section of the filter housing, wherein the part is preferably less than 50% of the air flow cross section. The part with superabsorbent can be provided in particular in the lower area of ​​the nonwoven fabric. Here, for example, rainwater passing by the laminated grid covering the filter substrate can be collected. Therefore, the inlet filter or outlet filter can easily allow liquid to enter the interior of the switch cabinet at this location, which is carried by the air flow, for example, which is generated by the ventilator of the inlet filter, and therefore by the filter ventilator.

[0016] Therefore, the superabsorbent can only be arranged in the region of the nonwoven fabric that is located at the bottom in the installation position of the inlet filter or outlet filter on the switch cabinet housing. In particular, the upper region of the nonwoven fabric relative to this lower region can be free of superabsorbent.

[0017] The superabsorbent can be provided in the crystalline state in or on the nonwoven, wherein the superabsorbent in the swollen state as a hydrogel has a volume that is at least 40 times, preferably at least 70 times, particularly preferably at least 100 times greater than in the crystalline state.

[0018] The nonwoven fabric can have a sandwich structure with a first outer filter nonwoven and a second outer filter nonwoven, between which an absorption layer with superabsorbent is arranged. In this embodiment, in particular, the two outer filter nonwovens can be free of superabsorbent. The absorption layer can be another filter nonwoven with superabsorbent that is independent of the filter substrate.

[0019] Preferably, the filter substrate has a pleated filter and an absorbent pad as separate components, which can be placed in the housing of an air inlet filter or an air outlet filter, for example, one above the other. The filter substrate is also particularly suitable for an air inlet filter with a horizontal or vertical lamination grid configured as a filter ventilator. Here, the pleated filter is used for filtering, and compared with a conventional nonwoven filter, it has a larger surface area, which helps to increase the volume flow of the filter ventilator. Up to now, the IP55 protection level can only be achieved by a cumbersome mechanical labyrinth seal or by two fine mesh nonwoven filters arranged in sequence. The absorbent pad is used as a water separator and ensures that, especially in a filter ventilator, no water reaches the switch cabinet when the ventilator engine is running / suctioning.

[0020] If the filter substrate has a pleated filter and an absorbent pad as separate components, the pleated filter and the absorbent pad can be arranged at a distance from each other. This reduces the transfer of liquid through the pleated filter to the absorbent pad and thus does not overload it. This advantageous effect can also be enhanced by arranging the pleated filter and the absorbent pad non-parallel, i.e. at an acute angle to each other. Preferably, the pleated filter is oriented parallel to the air flow cross section and the absorbent pad is at an angle to it, for example 5 to 15°.

[0021] According to another aspect, a switch cabinet arrangement is described, which has a switch cabinet housing and at least one inlet filter or outlet filter of the above-described type. In the case of the at least one inlet filter or outlet filter, the filter housing can be mounted in a vertical housing wall of the switch cabinet housing and has a laminated grid on the outer side of the switch cabinet housing.

[0022] The laminated grid can have a plurality of vertically extending laminated plates or can be composed of a plurality of laminated plates extending vertically and parallel to one another.

[0023] The filter housing can have a filter housing cover which comprises a laminated grid and can be swung relative to or removed from a filter housing lower part fixed in the housing wall. A filter substrate can be accommodated between the filter housing lower part and the filter housing cover. In order to replace the filter substrate more easily, the filter substrate can be held in a receptacle of the filter housing cover. In one embodiment, the pleated filter of the filter substrate is held in the filter housing cover, while the nonwoven fabric with the superabsorbent held therein or applied thereto is held in the filter housing lower part.

[0024] In the case of a multi-part filter substrate consisting of a pleated filter and a separate nonwoven with superabsorbent, in order to prevent the filter substrate from becoming clogged with particles filtered out of the ambient air during regular replacement of the filter substrate, only the pleated filter is replaced, since the nonwoven is subject to no or only significantly less wear than the pleated filter. The multi-part filter substrate is therefore particularly resource-saving.

[0025] The filter housing can have a filter cover which comprises a laminated grid and can be pivoted relative to the filter housing bottom part or can be removed therefrom, in which the pleated filter with the nonwoven and the superabsorbent accommodated therein is held.

[0026] The pleated filter can be arranged facing the laminated grid in the interior of the filter housing, wherein the laminated plates extend parallel to the pleated parts of the pleated filter, so that vertical channels that are open to the laminated grid are formed between adjacent pleated parts of the pleated filter, and the channels conduct away liquid that acts on the inlet filter or the outlet filter.

[0027] In one embodiment, the switch cabinet arrangement has an inlet air filter and an outlet air filter of the aforementioned type, wherein the inlet air filter is designed as a filter-ventilator. The basic design of a filter-ventilator is described in DE 10 2010 016 504 A1.

[0028] A method for operating a switch cabinet arrangement of the type described above comprises: ambient air is sucked into the switch cabinet housing via an air inlet filter, the ambient air is guided through the switch cabinet housing and the ambient air is blown out via an air outlet filter. The method also comprises charging the air inlet filter and / or the air outlet filter with liquid, preferably rainwater or splash water.

[0029] If liquid enters the inlet filter and / or the outlet filter and comes into contact with the superabsorbent there, the superabsorbent swells and turns into a hydrogel, which then reduces the air flow cross section of the filter housing of the relevant inlet filter and / or outlet filter or completely blocks the air flow cross section of the filter housing. If the absorbent pad does not have superabsorbent, the liquid is stored in the absorbent pad and / or is conducted away, for example, discharged, through the absorbent pad at the lower horizontal edge. Alternatively, the liquid can be stored in a liquid-absorbing nonwoven band on the underside of the pleated filter. In one embodiment, the liquid-absorbing nonwoven band can have a superabsorbent.

[0030] The absorbent pad can also have water-absorbing properties even without the use of absorbent additives, such as superabsorbents. For this purpose, the material of the nonwoven fabric, in particular the fibers, for example polyester fibers, can be designed to be highly hydrophilic and / or to have absorbent properties. When the inlet filter and / or outlet filter is loaded with liquid, the liquid can hit the preferably vertically inserted pleated filter. Due to this arrangement, the area between the pleats can form a vertical guide channel for drainage from the filter-ventilator.

[0031] If the jet now strikes the pleated filter with sufficiently high energy, the droplets can pass through the pleated filter and reach the inside of the switch cabinet. The optional hydrophobic effect of the absorbent pad comes into play. The droplets roll off the surface and flow downwards, where they flow outwards under the pleated filter. The underside of the pleated filter has a nonwoven band that absorbs the liquid. Individual areas of the pleated filter can be soaked with water, so that the droplets are sucked towards the inside of the switch cabinet by the suction effect of the optional fan of the inlet filter and / or outlet filter.

[0032] At this time, the absorption effect of the absorption pad can be brought into play. The droplets can be bound in the fibers of the absorption pad and cannot reach the switch cabinet even when the fan is running. Due to the absorption, the volume flow is temporarily reduced by closing individual partial areas of the active filter surface and thus additionally contributes to the existence of the IP protection grade requirements. In the absence of absorption materials, such as superabsorbents, the absorption pad can be simply removed and can be used again immediately. Alternatively, the absorption pad can be reused after the water absorbed in the air inlet filter and / or the air outlet filter evaporates. The evaporative cooling generated here can compensate for the air volume flow that is sometimes temporarily reduced due to liquid absorption. Compared with the solutions known in the prior art, this embodiment is therefore also reversible.

[0033] The filter substrates known from the prior art with at least two layers of nonwoven filters have the disadvantage that high pressure differences are generated, which significantly reduces the main function of cooling the inlet filter and / or outlet filter with ambient air. After the introduction of water, the nonwoven filter is saturated with liquid, so that liquid can enter the cabinet. The filter substrate must therefore be replaced. In addition, due to the mesh-like fibers, the filter assembly becomes clogged with dust more quickly, which necessitates short maintenance intervals.

[0034] The pleated filter is preferably inserted vertically into the filter housing. Tongues can be arranged on the sides, which on the one hand facilitate insertion into the filter housing and on the other hand serve the purpose of lateral sealing. The pleated filter can have a nonwoven band at the upper or lower longitudinal edge. The nonwoven band has a sealing effect with respect to the filter housing on the one hand and allows liquid to flow away in the lower area of ​​the filter housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further details of the present invention are described with reference to the following drawings. Here, it is shown:

[0036] Figure 1 An exemplary embodiment of an air inlet filter or an air outlet filter according to the prior art is shown;

[0037] Figure 2 A detailed view of a filter housing in a flipped open state according to one embodiment of the present invention is shown;

[0038] Figure 3 shows a schematic top view of a filter substrate according to one embodiment of the present invention;

[0039] Figure 4 shows a cross-sectional view of a nonwoven fabric according to one embodiment of the present invention;

[0040] Figure 5 A detailed view showing a switch cabinet device according to an embodiment of the present invention; and

[0041] Figure 6 Two embodiments of a multi-part filter substrate are shown. DETAILED DESCRIPTION

[0042] Figure 1 An exemplary air intake filter 1.1 according to the prior art is shown. The air intake filter 1.1 is inserted into a wall element, which is designed as a vertical housing wall 101. The vertical housing wall 101 can be, for example, a side wall, a rear wall or a front door of a switch cabinet housing 100. The housing wall 101 has a square notch 14, to which a spiral receptacle 15 is assigned in a corner area. The air intake filter 1.1 can be inserted into the notch 14. The air intake filter 1.1 has a filter housing 2, which surrounds an air guide area with a housing wall 21 of a filter housing bottom 11 and determines an air passage cross section d of the filter housing 2. A fan 25 is flange-connected to the bottom of the filter housing bottom 11. The fan 25 has an electric motor and a fan, which is configured to suck in ambient air and blow the ambient air into the switch cabinet interior 1, which is achieved by Figure 1 The arrows in the figure are shown symbolically. A circumferential flange 22 is molded on the housing wall 21 away from the ventilator 25. The insertion movement of the filter housing 2 in the recess 14 can be limited by means of the flange 22. Here, the flange 22 is placed on the housing wall 101 around the recess 14 at the front side. The flange 22 has a screw receptacle 15 in its corner area. The fastening screw 16 can pass through the screw receptacle and be screwed into the screw receptacle 15 of the housing wall 101. In this way, the filter housing 2 is fixedly connected to the housing wall 101.

[0043] As from Figure 1 It can be seen further that the filter housing 2 has, in addition to the filter housing bottom 11, a filter housing cover 12 which is substantially designed as an air passage grid. The air passage grid is coupled to the lower horizontal edge of the filter housing bottom 11 via two hinges 23 at its lower horizontal edge. The hinges 23 form a horizontal hinge axis about which the air passage grid or the filter housing cover 12 can be moved in a vertical installation position and in a horizontal position. Figure 1 The flip open shown in FIG. 1 is for moving between maintenance positions.

[0044] The filter housing cover 12 has three walls that merge into one another and form a filter support 26 for the filter substrate 3. The filter substrate 3 can be inserted into the filter support 26. The filter substrate 3 is supported with its front side on the laminations of the through-grid. The laminations 10 form air inlets through which ambient air can be conveyed through the filter substrate 3 into the filter housing 2 and into the switch cabinet housing 100 via the fan 25.

[0045] In the prior art air intake filter and the corresponding air outlet filter (not shown), the filter substrate is usually configured as a filter mat formed of a nonwoven fabric or a pleated filter formed of a nonwoven fabric.

[0046] The known inlet filter 1.1 and the corresponding outlet filter (not shown) therefore have the disadvantage that when the laminated grid 9 of the filter housing cover 12 is loaded with liquid, the filter mat 3 is soaked with liquid and, if necessary, at least in the case of the inlet filter 1.1, the liquid is sucked into the interior of the switch cabinet due to the negative pressure provided by the fan 25, whereby the ingress of liquid is undesirable due to the moisture-sensitive electrical components that are sometimes contained in the interior of the switch cabinet. The inlet filter and the corresponding outlet filter are therefore the main weak point in achieving a high IP protection class in the switchgear design.

[0047] In the inlet filter according to the invention, it is therefore provided that the filter base plate 3 accommodated in the filter housing has, in addition to the pleated filter, an absorption mat made of nonwoven fabric.

[0048] Figure 2 An exemplary embodiment of such a filter housing 2 is shown, wherein the filter base plate 3 is constructed in multiple parts and has a pleated filter 4 and an additional nonwoven fabric 6, which is similar to the one according to Figure 1The prior art embodiment of the invention is accommodated in the filter housing cover 12, the additional nonwoven fabric is formed as an absorption pad, which is accommodated in the filter housing bottom 11 and can optionally have a superabsorbent. In the folded state, i.e. when the filter housing cover 12 is against the filter housing bottom 11 and the illustrated snap-in connection is fixed to the filter housing bottom 11, the pleated filter 4 and the nonwoven fabric 6 extend essentially parallel to each other, wherein the pleated filter 4 and the nonwoven fabric 6 can be configured to be directly stacked one above the other and adjacent to each other. Alternatively, they can also be spaced apart from each other to prevent liquid from transferring from the pleated filter to the nonwoven fabric 6 of the absorption pad and thereby reduce the load of the absorption pad with liquid, so that it remains permeable to air for a longer time and the air inlet filter or air outlet filter can thus continue to maintain its original function.

[0049] Thus, when the laminated grid (not shown) of the filter housing cover 12 is loaded with liquid, the liquid passes through the pleated filter 4 (the pleated filter already has better liquid conduction compared to conventional filter mats due to its pleated geometry) and hits the nonwoven fabric 6 of the absorption pad. If the absorption pad has a superabsorbent, the superabsorbent can also absorb liquid and clog the nonwoven fabric 6 due to its increased volume, so that additional liquid that could no longer be absorbed by the absorption pad can no longer pass through the nonwoven fabric 6 into the interior of the switch cabinet.

[0050] The nonwoven fabric 6 can be coated with an optional superabsorbent or soaked with a superabsorbent. The superabsorbent can be provided as particles having a particle size coordinated with the nonwoven fabric 6, and the fibers can hold the superabsorbent without additional adhesives or adhesion promoters. However, the superabsorbent can also be coated with an adhesion promoter on the nonwoven fabric 6 or anchored in the nonwoven fabric 6.

[0051] Figure 3 An embodiment of a filter substrate 3 is shown, in which the pleated filter 4 has a superabsorbent 5 only in the lower region in the vertical direction, while the region located above it is free of superabsorbent 5. In particular, superabsorbent 5 can be provided only in the lower third or lower quarter of the filter substrate 3. Figure 2 Embodiments of can provide the superabsorbent 5 in the form of an additional nonwoven 6. Alternatively, the superabsorbent can also be applied directly to the pleated filter 4, for example coated thereon or impregnated therewith.

[0052] The laminations 10 of the lamination grid (not shown) of the filter housing cover are also shown. As can be seen, in contrast to the inlet and outlet filters known from the prior art, the laminations 10 are oriented vertically and parallel to the pleats of the pleated filter 4. In this way, the parallel pleats of the pleated filter form vertical channels 13, which can be used to drain away liquid. This is particularly useful when the pleated filter 4 is at least partially blocked due to the fact that the loading with liquid has already been completed and liquid that has accumulated directly on the pleated filter must be cleared, because the liquid can no longer pass through the pleated filter.

[0053] Figure 4 A further embodiment of a multi-layer nonwoven fabric 6 is shown, which consists of two outer filter nonwovens without superabsorbent and an absorbent layer arranged therebetween, which absorbent layer has superabsorbent 5 .

[0054] Figure 5 A switch cabinet housing 100 is shown, in which an inlet filter 1.1 and an outlet filter 1.2 are arranged vertically one above the other in a side wall 101. When the switch cabinet door is closed, the air volume contained in the interior of the switch cabinet is fluidically connected to the surroundings of the switch cabinet housing 100 essentially only via the two inlet filters 1.1 and the outlet filter 1.2. Thus, ambient air can be sucked into the switch cabinet housing 100 via the inlet filter 1.1, which is designed as a filter ventilator, through the inlet filter 1.1. The sucked-in ambient air can be guided through the switch cabinet housing 100 and blown out through the outlet filter 1.2 back into the surroundings of the switch cabinet housing 100. When the inlet filter 1.1 and the outlet filter 1.2 are acted upon by liquid, for example by rain or splashing water, the liquid can enter the inlet filter 1.1 and / or the outlet filter 1.2 and come into contact with the superabsorbent of the filter substrate, which then swells and transforms into a hydrogel. The superabsorbent can then reduce or completely block the air flow cross section of the filter housing of the associated inlet and / or outlet filter, thereby preventing or at least significantly reducing the ingress of liquid into the switch cabinet housing.

[0055] Figure 6 Two embodiments of a multi-part filter substrate 3 are shown, with a pleated filter 4 and a separate absorbent pad in the form of a nonwoven fabric 6. In the first embodiment (left), the absorbent pad is placed directly on the pleated filter 4. Preferably, the absorbent pad is arranged behind the pleated filter 4 in the direction of air flow through the filter substrate 3.

[0056] In contrast, in the second embodiment (right side), the absorbent pad is arranged below the pleated filter 4 with a spacing x therebetween. Similar to the first embodiment, the absorbent pad is arranged behind the pleated filter 4 in the direction of air flow through the filter substrate 3. This spacing has the advantage that liquid is difficult to transfer from the pleated filter 4 to the absorbent pad, thereby reducing the liquid load of the nonwoven fabric 6. Therefore, the service life of the absorbent pad can be increased.

[0057] Preferably, the absorption pad is arranged in parallel and spaced apart from the pleated filter 4. However, in one embodiment, the absorption pad can also be arranged at an angle, preferably an acute angle, relative to the pleated filter 4. The pleated filter 4 is preferably oriented vertically and the absorption pad is tilted from the vertical direction for this purpose, for example by 5° to 15°. The tilting of the absorption pad has the advantage that the absorption pad can be installed in the filter housing with a larger surface, thereby reducing the flow rate through the absorption pad, so that it is difficult for liquid to enter the interior of the switch cabinet when the absorption pad is saturated. In particular, in the case of hydrophobic absorption pads, for example made of hydrophobic polyester fibers, the liquid stored in the absorption pad can be better discharged vertically in the angled absorption pad.

[0058] The features of the invention disclosed in the preceding description, in the drawings and in the claims can be essential for the implementation of the invention both individually and in any combination.

[0059] Reference numerals list

[0060] 1.1 Inlet filter

[0061] 1.2 Exhaust filter

[0062] 2 Filter housing

[0063] 3 Filter substrate

[0064] 4 pleat filter

[0065] 5. Super Absorbent

[0066] 6 Nonwoven fabrics

[0067] 7 External filter non-woven fabric

[0068] 8 Absorption layer

[0069] 9 Laminated grille

[0070] 10 Lamination

[0071] 11 Filter housing lower part

[0072] 12 Filter housing cover

[0073] 13 channels

[0074] 14 Gap

[0075] 15 Spiral receiving part

[0076] 16 Fastening screw

[0077] 21 Shell wall

[0078] 22 Surrounding flange

[0079] 23 Hinge

[0080] 24 Bracket

[0081] 25 Ventilator

[0082] 26 Filter holder

[0083] 100 Switchgear housing

[0084] 101 Shell wall

[0085] d Cross-section of air flow

[0086] x Spacing

Claims

1. An air inlet filter (1.1) or an air outlet filter (1.2) for a switch cabinet housing (100), the air inlet filter or the air outlet filter having a filter housing (2), a filter substrate (3) having a pleated filter (4) being arranged in the filter housing, the filter substrate completely covering an air flow cross section (d) of the filter housing (2), wherein: The filter substrate (3) has a liquid-absorbing pad made of a non-woven fabric (6), which is liquid-absorbing, and wherein the non-woven fabric (6) and / or the pleated filter (4) have a liquid-absorbing material strip on the bottom side, characterized in that the liquid-absorbing material strip is arranged outside the air passage cross section (d) of the filter housing (2).

2. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 1, wherein: The nonwoven fabric (6) comprises a superabsorbent (5), wherein the superabsorbent (5) is contained in the nonwoven fabric (6) or the nonwoven fabric (6) is coated with the superabsorbent (5).

3. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 2, wherein: The pleated filter (4) has a nonwoven (6) or, in addition to the pleated filter (4), the nonwoven (6) also provides a covering of the air passage cross section (d) of the filter housing (2).

4. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 3, wherein: The nonwoven fabric (6) is coated and / or impregnated with a superabsorbent (5) in the form of particles, wherein the particles are held on fibers of the nonwoven fabric (6) or on a binder of the fibers.

5. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 4, wherein: The nonwoven fabric (6) comprises the superabsorbent (5) only in a portion of the air flow cross section (d) of the filter housing (2).

6. The air inlet filter (1.1) or the air outlet filter (1.2) according to any one of claims 2 to 5, wherein: The superabsorbent (5) is arranged only in a lower region of the nonwoven fabric (6) in the installation position of the inlet filter (1.1) or the outlet filter (1.2) on the switch cabinet housing (100), while an upper region of the nonwoven fabric (6) relative to the lower region is free of superabsorbent (5).

7. The air inlet filter (1.1) or the air outlet filter (1.2) according to any one of claims 2 to 5, wherein: The superabsorbent (5) is provided in or on the nonwoven fabric (6) in a crystalline state and has a volume in a swollen state as a hydrogel which is at least 40 times greater than its volume in the crystalline state.

8. The air inlet filter (1.1) or the air outlet filter (1.2) according to any one of claims 2 to 5, wherein: The nonwoven fabric (6) has a sandwich structure, comprising a first outer filter nonwoven fabric and a second outer filter nonwoven fabric (7), between which an absorption layer (8) having a superabsorbent (5) is arranged.

9. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 8, wherein: The absorption layer (8) is another filter nonwoven fabric having superabsorbent (5) which is independent of the filter substrate (3).

10. The air inlet filter (1.1) or the air outlet filter (1.2) according to any one of claims 2 to 5, wherein: The nonwoven fabric (6) has a thickness of less than 250 g / m 2 Weight per unit area.

11. The air inlet filter (1.1) or the air outlet filter (1.2) according to any one of claims 2 to 5, wherein: An absorption pad consisting of a nonwoven fabric (6) can be arranged downstream of the pleated filter (4) in the inlet filter (1.1) in the flow direction and can be arranged upstream of the pleated filter (4) in the outlet filter in the flow direction, wherein the absorption pad consisting of the nonwoven fabric (6) is arranged adjacent to the pleated filter (4) or arranged at a distance from the pleated filter (4).

12. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 1, wherein: The nonwoven fabric is made of thermally and / or mechanically bonded polyester fibers.

13. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 1, wherein: The material belt is a hydrophilic non-woven fabric belt.

14. The air inlet filter (1.1) or the air outlet filter (1.2) according to claim 5, wherein: The portion is less than 50% of the air passage cross section (d).

15. A switch cabinet arrangement having a switch cabinet housing (100) and at least one inlet air filter (1.1) or outlet air filter (1.2) according to any one of the preceding claims, wherein: The filter housing (2) is installed in a vertical housing wall (101) of the switch cabinet housing (100) and has a laminated grid (9) on the outer side (102) of the switch cabinet housing (100).

16. The switch cabinet device according to claim 15, wherein: The laminated grid (9) has a plurality of vertically extending laminated lamellae (10) or is composed of a plurality of vertically extending laminated lamellae (10) parallel to one another.

17. The switch cabinet device according to claim 16, wherein: The filter housing (2) has a filter housing cover (12) comprising a laminated grid (9) and being pivotable relative to or removable from a filter housing bottom (11) fixed in the housing wall (101), the pleated filter (4) being held in the filter cover, and an absorbent pad made of a nonwoven fabric (6) being held in the filter housing bottom (11).

18. The switch cabinet device according to any one of claims 15 to 17, wherein: The filter housing (2) has a filter housing cover (12) which comprises the laminated grid (9) and is pivotable relative to a filter housing bottom (11) or removable therefrom, and in which the pleated filter (4) and the absorbent pad made of nonwoven (6) are held.

19. The switch cabinet device according to any one of claims 15 to 17, wherein: The pleated filter (4) is arranged in the interior of the filter housing (2) facing the laminated grid (9), wherein the laminated lamellae extend parallel to the pleats of the pleated filter (4), so that vertical channels (13) are formed between adjacent pleats of the pleated filter (4) and are open toward the laminated grid (9).

20. The switch cabinet device according to any one of claims 15 to 17, wherein: An inlet air filter (1.1) according to any one of claims 1 to 8 or an outlet air filter (1.2) according to any one of claims 1 to 8 is provided, wherein the inlet air filter (1.1) is designed as a filter fan.

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