AIR INLET OR AIR OUTLET FILTER FOR A CONTROL CABINET ENCLOSURE AND A CORRESPONDING CABINET ARRANGEMENT

Description

[0001] The invention is based on an air inlet or air outlet filter for a control cabinet housing, comprising a filter housing in which a filter substrate with a pleated filter is arranged, which completely covers an air passage cross-section of the filter housing. Such an air inlet or air outlet filter is known from EP 1 909 548 B1. A similar filter fan is also described in DE 201 07 242 U1. A filter unit for a control cabinet is known from DE 10 2010 016 504 A1, and textiles containing superabsorbents are known from WO 2011 / 054784 A1. An air inlet or air outlet filter according to the preamble of claim 1 is known from JP 2019013903 A. A similar device is also described in US Pat. No. 6,197,709 B1.

[0002] The air inlet or air outlet filters known from the state of the art have the disadvantage that they represent a weak point with regard to the achievable IP protection class of a control cabinet housing in which they are installed, since the air inlet or air outlet filters, due to their air permeability, naturally also have a certain permeability for liquid if the air inlet or air outlet filter is exposed to a considerable liquid volume flow over a longer period of time.

[0003] It is therefore the object of the invention to propose an air inlet or air outlet filter of the type described above which has the lowest possible permeability for liquids.

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

[0005] The nonwoven fabric may inherently have absorbent properties with respect to liquid, preferably water, and / or a superabsorbent, wherein the superabsorbent may be incorporated into the nonwoven fabric or the nonwoven fabric may be coated with the superabsorbent.

[0006] The pleated filter can comprise the nonwoven fabric, meaning the pleated filter and absorber mat can be formed as a single piece or be the same component. The nonwoven fabric can also be provided in addition to the pleated filter and cover the air passage cross-section of the filter housing.

[0007] The nonwoven fabric is liquid-absorbent. The nonwoven fabric is preferably made of thermally and / or mechanically bonded polyester fibers. The fibers of the nonwoven fabric can be hydrophobic, while the nonwoven fabric formed from the hydrophobic fibers can have water-absorbing properties.

[0008] The nonwoven fabric and / or the pleated filter has a liquid-absorbing material strip, preferably a hydrophilic nonwoven strip, on its underside. Due to the properties of the nonwoven fabric, water can run off the nonwoven fabric vertically and be absorbed into the liquid-absorbing material strip.

[0009] The liquid-absorbing material strip is positioned outside the air passage cross-section of the filter housing. The volume of liquid absorbed by the material strip is thus kept outside the cross-section, providing additional protection against accidental liquid penetration into the control cabinet housing.

[0010] The nonwoven fabric of the absorber mat can have a basis weight of less than 250 g / m 2 , preferably less than 200 g / m 2 , and particularly preferably less than 180 g / m 2 . This allows the pressure loss of the absorber mat to be reduced to an insignificant level. The nonwoven absorber mat can be arranged downstream of the pleated filter in the flow direction for an air inlet filter and upstream of the pleated filter in the flow direction for an air outlet filter. The nonwoven absorber mat can be arranged adjacent to the pleated filter or at a distance from the pleated filter.

[0011] When used with a superabsorbent, it has the property of (significantly) increasing its volume when exposed to liquid, 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, in its swollen state (hydrogel), completely blocks the filter substrate, thus making the air inlet or outlet filter virtually impermeable to air at typical pressure differences (e.g., those of a filter fan).

[0012] The filter substrate can be permeated with the superabsorbent or coated with it. If the filter substrate is a nonwoven, a granular superabsorbent can be held by the fibers of the nonwoven material. A binder can be provided to hold the superabsorbent to the nonwoven material. Preferably, the superabsorbent is not provided in or on the pleated filter. Instead, the filter substrate can have an additional nonwoven fabric coated with the superabsorbent or in which the superabsorbent is incorporated. The nonwoven fabric can be provided as a separate component of the filter substrate, independent of the pleated filter, or in combination with the pleated filter.

[0013] The pleated filter can comprise the nonwoven fabric of the liquid-absorbing mat, or the nonwoven fabric of the liquid-absorbing mat can be provided in addition to the pleated filter as a nonwoven fabric covering the air passage cross-section of the filter housing. The superabsorbent can be incorporated into the nonwoven fabric. Alternatively, the nonwoven fabric can be coated with the superabsorbent. It is also conceivable for the nonwoven fabric to be both permeated with the superabsorbent and coated with the superabsorbent. Independently of the nonwoven fabric containing the superabsorbent, the pleated filter can also be made of a nonwoven fabric, thus being a commercially available pleated filter for use in air inlet or air outlet filters, such as a filter fan.

[0014] The nonwoven fabric can be coated and / or interspersed with the superabsorbent as granules, wherein the granules are held by fibers of the nonwoven fabric or by a binder on the fibers.

[0015] To prevent the filter substrate from becoming completely blocked due to the swelling of the superabsorbent when the air inlet or outlet filter is exposed to a liquid, and thus in particular the fresh air required for cooling the components accommodated in the control cabinet housing can no longer be transported into the interior of the control cabinet, a particular embodiment of the invention provides that the nonwoven fabric contains the superabsorbent only within a portion of the air passage cross-section of the filter housing, wherein the portion is preferably less than 50% of the air passage cross-section. The portion containing the superabsorbent can be provided in particular in a lower region of the nonwoven fabric. There, rainwater running off a louvre grille covering the filter substrate can collect, for example.This means that the air inlet or air outlet filter at this point is particularly susceptible to the ingress of liquid into the interior of the control cabinet, which is carried along, for example, by an air flow generated by a fan of an air inlet filter, i.e. by a filter fan.

[0016] The superabsorbent can thus be arranged exclusively in a lower region of the nonwoven fabric, depending on the installation position of the air inlet or outlet filter on a control cabinet housing. In particular, an upper region of the nonwoven fabric relative to the lower region can be free of the superabsorbent.

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

[0018] The nonwoven fabric can have a sandwich structure with a first and a second outer filter fleece, between which an absorber layer containing the superabsorbent is arranged. In this embodiment, in particular, the two outer filter fleeces can be free of superabsorbent. The absorber layer can be a further filter fleece, independent of the filter substrate, which contains the superabsorbent.

[0019] The filter substrate preferably comprises the pleated filter and the absorber mat as separate components, which can, for example, be inserted one on top of the other into the housing of the air inlet or air outlet filter. This filter substrate is particularly suitable for air inlet filters designed as filter fans with horizontal or vertical louvre grilles. The pleated filter serves for filtration and, with its larger surface area compared to conventional fleece filters, can contribute to increasing the volume flow of the filter fan. Until now, protection classes of IP55 could only be achieved with a complex, mechanical labyrinth seal or with two closely spaced fleece filters. The absorber mat, on the other hand, serves as a water separator and ensures that, particularly in the case of filter fans, no water enters the control cabinet when the fan motor is running / suctioning.

[0020] If the filter substrate comprises the pleated filter and the absorber mat as separate components, they can be arranged at a distance from each other. This reduces the transfer of liquid passing through the pleated filter to the absorber mat, thus reducing the strain on the mat. This positive effect can be further enhanced by arranging the pleated filter and the absorber mat not parallel, i.e., at an acute angle to each other. Preferably, the pleated filter is aligned parallel to the air passage cross-section, and the absorber mat is angled to it, for example, by 5 to 15°.

[0021] According to another aspect, a control cabinet assembly comprising a control cabinet housing and at least one air inlet or air outlet filter of the type described above is described. In the case of the at least one air inlet or air outlet filter, the filter housing can be mounted in a vertical housing wall of the control cabinet housing and can have a louvre grille on an outer side of the control cabinet housing.

[0022] The louvre grille may have a plurality of vertically extending louvres or may consist of a plurality of vertically extending louvres parallel to one another.

[0023] The filter housing can have a filter housing cover that includes the louvre grid and is pivotable relative to or removable from a filter housing lower part fixed in the housing wall. The filter substrate can be accommodated between the filter housing lower part and the filter housing cover. To facilitate changing the filter substrate, the filter substrate can be held in a receptacle in the filter housing cover. In one embodiment, the pleated filter of the filter substrate is held in the filter housing cover, while a nonwoven fabric with the superabsorbent accommodated therein or coated thereon is held in the filter housing lower part.

[0024] With a multi-part filter substrate consisting of a pleated filter and a separate nonwoven fabric containing the superabsorbent, only the pleated filter can be replaced during regular replacement of the filter substrate to prevent it from becoming blocked by particles filtered out of the ambient air, as the nonwoven fabric is subject to no or significantly less wear than the pleated filter. Multi-part filter substrates are therefore particularly resource-efficient.

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

[0026] The pleated filter can be arranged inside the filter housing facing the louvre grille, wherein the louvres extend parallel to the folds of the pleated filter, so that between adjacent folds of the pleated filter a vertically extending channel is formed which is open towards the louvre grille and promotes the drainage of liquid which is applied to the air inlet or air outlet filter.

[0027] In one embodiment, the control cabinet assembly can have an air inlet filter and an air outlet filter of the type described above, wherein the air inlet filter is designed as a filter fan. The basic structure of a filter fan is described in DE 10 2010 016 504 A1.

[0028] A method for operating a switch cabinet assembly of the type described above may include drawing ambient air through the air inlet filter into the switch cabinet housing, passing the ambient air through the switch cabinet housing, and expelling the ambient air through the air outlet filter. The method further includes applying liquid, preferably rain or splash water, to the air inlet and / or air outlet filter.

[0029] When the liquid penetrates the air inlet and / or air outlet filter and comes into contact with a superabsorbent, the superabsorbent swells and transforms into a hydrogel, whereupon the superabsorbent reduces the air passage cross-section of the filter housing of the respective air inlet and / or air outlet filter or completely blocks the air passage cross-section of the filter housing. If the absorber mat does not contain a superabsorbent, the liquid can be stored in the absorber mat and / or drained from it at a lower horizontal edge, for example, by dripping. Alternatively, the liquid can be stored in a liquid-absorbing nonwoven strip on the underside of the pleated filter. In one embodiment, the liquid-absorbing nonwoven strip can contain a superabsorbent.

[0030] The absorber mat can exhibit water-absorbing properties even without the use of absorbent additives such as superabsorbents. For this purpose, the material of the nonwoven fabric, particularly the fibers, such as polyester fibers, can be highly hydrophobic and / or have absorbent properties. When the air inlet and / or outlet filter is exposed to liquid, the liquid can impinge on the preferably vertically installed pleated filter. This arrangement allows the areas between the pleats to form a vertical guide channel to an outlet from the filter fan.

[0031] If a jet of sufficiently high energy hits the pleated filter, droplets can pass through the pleated filter and onto the inside of the control cabinet. This is where the optional hydrophobic effect of the absorber mat comes into play. The droplets bead up and run downwards, where they can drain beneath the pleated filter to the outside. The underside of the pleated filter features a liquid-absorbing fleece strip. It can happen that individual areas of the pleated filter become so saturated with water that droplets are drawn toward the inside of the cabinet by the suction effect of an optional fan on the air inlet and / or air outlet filter.

[0032] Now the absorbing effect of the absorber mat can take effect. The droplets can be bound in the fibers of the absorber mat and cannot enter the control cabinet, even when the fan is running. Absorption temporarily reduces the volume flow by closing off individual sections of the active filter surface, thus contributing positively to meeting IP protection requirements. In the absence of absorber materials such as superabsorbents, the absorber mat can simply be tapped out and immediately reused. Alternatively, the absorber mat can be reused after the absorbed water in the air inlet and / or outlet filter has evaporated. The resulting evaporative cooling can compensate for the sometimes temporarily reduced air flow due to liquid absorption. This makes this design reversible, even compared to prior art solutions.

[0033] State-of-the-art filter substrates with at least two layers of fleece filters have the disadvantage of generating a high differential pressure, which significantly reduces the primary function of the air inlet and / or outlet filter—cooling with ambient air. After water ingress, the fleece filters become so saturated with liquid that this liquid can enter the cabinet. The filter substrates therefore require replacement. In addition, due to the close-meshed fibers, these filter combinations become clogged with dust more quickly, necessitating short maintenance intervals.

[0034] The pleated filter is preferably inserted vertically into the filter housing. Tabs can be arranged on the sides, which facilitate insertion into the filter housing and also act as a lateral seal. The pleated filter can have a fleece strip on either an upper or lower longitudinal edge. This strip seals the filter housing and allows fluid to drain away from the lower part of the filter housing.

[0035] Further details of the invention are explained with reference to the following figures. Figure 1 shows an exemplary embodiment of an air inlet or air outlet filter according to the prior art; Figure 2 shows a detailed view of a filter housing in the unfolded state according to an embodiment of the invention; Figure 3 shows a schematic plan view of a filter substrate according to an embodiment of the invention; Figure 4 shows a cross-sectional view of a nonwoven fabric according to an embodiment of the invention; Figure 5 shows a detailed view of a switch cabinet arrangement according to an embodiment of the invention; and Figure 6 shows two embodiments of a multi-part filter substrate.

[0036] The Figure 1shows an exemplary air inlet filter 1.1 according to the prior art. The air inlet filter 1.1 is inserted into a wall element, which in this case 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 the control cabinet housing 100. The housing wall 101 has a square opening 14, to which screw receptacles 15 are assigned in the corner regions. The air inlet filter 1.1 can be inserted into the opening 14. In this case, the air inlet filter 1.1 has a filter housing 2, which, together with a housing wall 21 of the filter housing lower part 11, encloses an air guidance area and defines the air passage cross-section d of the filter housing 2. A fan 25 is flanged to the bottom of the filter housing lower part 11.The fan 25 has an electric motor and a fan which is designed to suck in ambient air and blow it into the switch cabinet interior 1, as indicated by the arrow in . Figure 1 is symbolized. A circumferential collar 22 is formed on the housing wall 21, facing away from the fan 25. By means of the collar 22, the insertion movement of the filter housing 2 into the opening 14 can be limited. The collar 22 then rests on the front side around the opening 14 on the housing wall 101. The collar 22 has screw receptacles 15 in its corner areas. Fastening screws 16 can be passed through these and screwed into the screw receptacles 15 of the housing wall 101. In this way, the filter housing 2 is firmly connected to the housing wall 101.

[0037] How Figure 1As can be further seen, the filter housing 2 has, in addition to the filter housing lower part 11, a filter housing cover 12, which is essentially designed as an air passage grille. The air passage grille is coupled via two hinges 23 at its lower horizontal edge to the lower horizontal edge of the filter housing lower part 11. The hinges 23 form a horizontal hinge axis around which the air passage grille or the filter housing cover 12 can be rotated between a vertical mounting position and a Figure 1 shown, folded down maintenance position, is adjustable.

[0038] The filter housing cover 12 has three converging walls that form a filter holder 26 for the filter substrate 3. The filter substrate 3 can be inserted into the filter holder 26. The front side of the filter substrate 3 rests on slats 10 of the passage grille. The slats 10 form air inlet openings through which ambient air can be conveyed through the filter substrate 3 into the filter housing 2 and the fan 25 into the control cabinet housing 100.

[0039] In the air inlet filters and corresponding air outlet filters known from the prior art (not shown), the filter substrates are often designed as filter mats made of a nonwoven material or as pleated filters made of nonwoven material.

[0040] The known air inlet filters 1.1 and corresponding air outlet filters (not shown) accordingly have the disadvantage that when liquid is applied to the louvre grille 9 of the filter housing cover 12, the filter mat 3 becomes saturated with liquid. The liquid may be sucked into the switchgear cabinet interior due to the negative pressure created by the fan 25, at least in the case of an air inlet filter 1.1. The ingress of liquid is undesirable due to the moisture-sensitive electrical components sometimes contained within the switchgear cabinet interior. Accordingly, air inlet filters and corresponding air outlet filters are the main weak point in achieving high IP protection classes in switchgear construction.

[0041] Accordingly, in an air inlet filter according to the invention, it is provided that the filter substrate 3 accommodated in the filter housing has, in addition to a folding filter, an absorber mat made of a nonwoven fabric.

[0042] The Figure 2 shows an exemplary embodiment of such a filter housing 2, wherein the filter substrate 3 is formed in several parts, with a pleated filter 4, which is analogous to the embodiment from the prior art according to Figure 1is accommodated in the filter housing cover 12, and an additional nonwoven fabric 6, which forms the absorber mat, which is accommodated in the filter housing lower part 11 and can optionally comprise a superabsorbent. In the folded state, ie when the filter housing cover 12 rests against the filter housing lower part 11 and the indicated snap-in connection is fixed to the filter housing lower part 11, the pleated filter 4 and the nonwoven fabric 6 extend substantially parallel to one another, wherein the pleated filter 4 and the nonwoven fabric 6 can be designed to lie directly on one another and to be adjacent to one another.Alternatively, they can also be spaced apart from each other in order to prevent the transfer of liquid from the pleated filter to the nonwoven fabric 6 of the absorber mat and thus reduce the load of the absorber mat with liquid, so that it remains permeable to air for longer and thus the air inlet or air outlet filter can continue to maintain its original function.

[0043] Accordingly, when liquid is applied to the louvre grid (not shown) of the filter housing cover 12, if liquid passes through the pleated filter 4 (which, due to its pleat geometry, already offers better liquid drainage than conventional filter mats), the liquid strikes the nonwoven fabric 6 of the absorber mat. If the absorber mat contains a superabsorbent, this can also absorb the liquid and, due to its increased volume, block the nonwoven fabric 6, so that additional liquid, which may no longer be absorbed by the absorber mat, can no longer pass through the nonwoven fabric 6 into the interior of the control cabinet.

[0044] The nonwoven fabric 6 can be coated with the optional superabsorbent or impregnated with the superabsorbent. The superabsorbent can be provided as granules having a grain size tailored to the nonwoven fabric 6 such that the fibers can hold the superabsorbent without the need for an additional binder or adhesion promoter. However, the superabsorbent can also be coated onto the nonwoven fabric 6 with an adhesion promoter or anchored in the nonwoven fabric 6.

[0045] The Figure 3 shows an embodiment of a filter substrate 3 in which the pleated filter 4 has the superabsorbent 5 only in a vertically lower region, while an area above it is free of the superabsorbent 5. In particular, the superabsorbent 5 can be provided only in a lower third or in a lower quarter of the filter substrate 3. Analogous to the embodiment according to Figure 2 The superabsorbent 5 can be provided in the form of an additional nonwoven fabric 6. Alternatively, the superabsorbent 5 can also be applied directly to the pleated filter 4, for example, coated thereon or impregnated by it.

[0046] Also indicated are the louvres 10 of the filter housing cover's louvre grille (not shown). As can be seen, the louvres 10, unlike the air inlet and outlet filters known from the prior art, are also vertically aligned and parallel to the pleats of the pleated filter 4. In this way, the parallel pleats of the pleated filter form vertical channels 13 that can be used to drain liquid. This is particularly important when the pleated filter 4 is at least partially blocked due to liquid already being applied, and liquid accumulating directly at the pleated filter must be channeled because it can no longer pass through the pleated filter.

[0047] The Figure 4shows a further embodiment of a multi-layer nonwoven fabric 6 consisting of two outer filter nonwovens 6 which are free of superabsorbent and an absorber layer arranged between them which comprises the superabsorbent 5.

[0048] The Figure 5shows a control cabinet housing 100 in which an air inlet filter 1.1 and an air outlet filter 1.2 are arranged vertically one above the other in a side wall 101. When the control cabinet door is closed, the air volume absorbed inside the control cabinet is fluidically connected to the environment of the control cabinet housing 100 essentially exclusively via the two air inlet and air outlet filters 1.1, 1.2. Accordingly, ambient air can be sucked into the control cabinet housing 100 through the air inlet filter 1.1 via the air inlet filter 1.1, which is designed as a filter fan. The sucked-in ambient air can be passed through the control cabinet housing 100 and blown out back into the environment of the control cabinet housing 100 through the air outlet filter 1.2. If the air inlet and / or air outlet filter 1.1, 1.2 is exposed to liquid, for example rain or splash water, the liquid can enter the air inlet filter 1.1 and / or the air outlet filter 1.2 and come into contact with the superabsorbent of the filter substrate, whereupon the superabsorbent 5 swells and transforms into a hydrogel. The superabsorbent can then reduce or completely block the air passage cross-section of the filter housing of the respective air inlet and / or air outlet filter, thus preventing or at least significantly reducing the ingress of liquid into the control cabinet housing.

[0049] The Figure 6 shows two embodiments of a multi-part filter substrate 3 with a pleated filter 4 and a separate absorber mat in the form of a nonwoven fabric 6. In the first embodiment (left), the absorber mat rests directly on the pleated filter 4. Preferably, the absorber mat is arranged behind the pleated filter 4 in the direction of air flow through the filter substrate 3.

[0050] In comparison, in the second embodiment (right), the absorber mat is arranged at a distance x from the pleated filter 4. Analogous to the first embodiment, the absorber mat is arranged behind the pleated filter 4 in the direction of air flow through the filter substrate 3. This arrangement has the advantage of making it more difficult for liquid to transfer from the pleated filter 4 to the absorber mat, thereby reducing the liquid load on the nonwoven fabric 6. This can increase the service life of the absorber mat.

[0051] Preferably, the absorber mat is arranged parallel and spaced apart from the pleated filter 4, as shown. In one embodiment, however, the absorber mat can also be arranged at an angle, preferably an acute angle, to the pleated filter 4. In this case, the pleated filter 4 is preferably aligned vertically and the absorber mat is tilted from the vertical for this purpose, for example by 5° to 15°. This tilting of the absorber mat has the advantage that the absorber mat can be installed with a larger surface area in the filter housing and thus the flow velocity through the absorber mat is reduced, which makes it more difficult for liquid to enter the interior of the control cabinet when the absorber mat is saturated. In particular with hydrophobic absorber mats, for example made of hydrophobic polyester fibers, the liquid stored in the absorber mat can drip off vertically more effectively with an angled absorber mat.

[0052] The features of the invention disclosed in the above description, in the drawings and in the claims may be essential for the realization of the invention both individually and in any combination. List of reference symbols

[0053] 1.1 Air inlet filter 1.2 Air outlet filter 2 Filter housing 3 Filter substrate 4 Pleated filter 5 Superabsorbent 6 Nonwoven fabric 7 Outer filter fleece 8 Absorber layer 9 Louvered grille 10 Louver 11 Filter housing base 12 Filter housing cover 13 Channel 14 Opening 15 Screw receptacle 16 Fastening screw 21 Housing wall 22 Circumferential collar 23 Hinge 24 Holder 25 Fan 26 Filter holder 100 Switch cabinet housing 101 Housing wall d Air passage cross-section x Distance

Claims

1. Air inlet or air outlet filter (1.1, 1.2) for a switchgear cabinet housing (100), with a filter housing (2), in which a filter substrate (3) with a pleated filter (4) is arranged, which completely covers an air passage cross-section (d) of the filter housing (2), wherein the filter substrate (3) has a liquid-absorbing absorber mat made of nonwoven fabric (6), which is liquid-absorbing and preferably consists of thermally and / or mechanically bonded polyester fibers, and wherein the nonwoven fabric (6) and / or the pleated filter (4) has a liquid-absorbing material strip, preferably a hydrophilic nonwoven fabric, on an underside, characterized in that the liquid-absorbing material strip is arranged outside the air passage cross-section (d) of the filter housing (2).

2. Air inlet or air outlet filter (1.1, 1.2) according to claim 1, in which the nonwoven fabric (6) has a superabsorber (5), wherein the superabsorber (5) is accommodated in the nonwoven fabric (6) or the nonwoven fabric (6) is coated with the superabsorber (5).

3. Air inlet or air outlet filter (1.1, 1.2) according to claim 1 or 2, in which the pleated filter (4) has the nonwoven fabric (6) or the nonwoven fabric (6) is provided in addition to the pleated filter (4) covering the air passage cross-section (d) of the filter housing (2).

4. Air inlet or air outlet filter (1.1, 1.2) according to claim 2 or 3, in which the nonwoven fabric (6) is coated and / or interspersed with the superabsorber (5) as granules, wherein the granules are held on the fibers by fibers of the nonwoven fabric (6) or by a binder.

5. Air inlet or air outlet filter (1.1, 1.2) according to one of claims 2 to 4, in which the nonwoven fabric (6) has the superabsorber (5) only within a proportion of the air passage cross-section (d) of the filter housing (2), wherein the proportion is preferably less than 50% of the air passage cross-section (d).

6. Air inlet or air outlet filter (1.1, 1.2) according to claim 2 to 5, in which the superabsorber (5) is arranged exclusively in a lower region of the nonwoven fabric (6) in the installed position of the air inlet or air outlet filter (1.1, 1.2) on a switchgear cabinet housing (100), while an upper region of the nonwoven fabric (6) in relation to the lower region is free of the superabsorber (5).

7. Air inlet or air outlet filter (1.1, 1.2) according to one of claims 2 to 5, in which the superabsorber (5) is provided in a crystalline state in or on the nonwoven fabric (6) and has a volume in a swollen state as hydrogel which is at least 40 times, preferably at least 70 times and particularly preferably at least 100 times greater than in the crystalline state.

8. Air inlet or air outlet filter (1.1, 1.2) according to one of claims 2 to 6, in which the nonwoven fabric (6) has a sandwich structure, with a first and a second outer filter nonwoven fabric (7), between which an absorber layer (8) having the superabsorber (5) is arranged.

9. Air inlet or air outlet filter (1.1, 1.2) according to claim 8, in which the absorber layer (8) is a further filter nonwoven fabric which is independent of the filter substrate (3) and which has the superabsorber (5).

10. Air inlet or air outlet filter (1.1, 1.2) according to one of the preceding claims, in which the nonwoven fabric (6) has a basis weight of less than 250 g / m2, preferably of less than 200 g / m2 and particularly preferably of less than 180 g / m2.

11. Air inlet or air outlet filter (1.1, 1.2) according to one of the preceding claims, in which the absorber mat of nonwoven fabric (6) is arranged downstream of the pleated filter (4) in the flow direction in an air inlet filter (1.1) and upstream of the pleated filter (4) in the flow direction in an air outlet filter, wherein the absorber mat of nonwoven fabric (6) is arranged adjacent to the pleated filter (4) or at a distance from the pleated filter (4).

12. Switchgear cabinet assembly with a switchgear cabinet housing (100) and at least one air inlet or air outlet filter (1.1, 1.2) according to one of the preceding claims, in which the filter housing (2) is mounted in a vertical housing wall (101) of the switchgear cabinet housing (100) and has a lamella grid (9) on an outer side (102) of the switchgear cabinet housing (100).

13. Switchgear cabinet assembly according to claim 12, in which the lamella grid (9) has a plurality of vertically extending lamellas (10) or consists of a plurality of lamellas (10) extending vertically and parallel to one another.

14. Switchgear cabinet assembly according to claim 12 or 13, in which the filter housing (2) has a filter housing cover (12) which has the lamella grid (9) and can be pivoted with respect to a filter housing lower part (11) fixed in the housing wall (101) or can be removed therefrom, in which filter housing cover the pleated filter (4) is held, wherein an absorber mat of nonwoven fabric (6) is held in the filter housing lower part (11).

15. Switchgear cabinet assembly according to one of claims 12 to 14, in which the filter housing (2) has a filter housing cover (12) which has the lamella grid (9) and can be pivoted with respect to a filter housing lower part (11) or can be removed therefrom, in which filter housing cover the pleated filter (4) and an absorber mat of nonwoven fabric (6) are held.

16. Switchgear cabinet assembly according to one of claims 12 to 15, in which the pleated filter (4) is arranged in the interior of the filter housing (2) facing the lamella grid (9), wherein the lamellas extend parallel to the pleats of the pleated filter (4), so that a vertically extending channel (13) open towards the lamella grid (9) is formed in each case between adjacent pleats of the pleated filter (4).

17. Switchgear cabinet assembly according to one of claims 12 to 16, which has an air inlet filter (1.1) according to one of claims 1 to 8 and an air outlet filter (1.2) according to one of claims 1 to 8, wherein the air inlet filter (1.1) is designed as a filter fan.