Filter element for filtering gaseous fluids

Abstract

The invention relates to a filter element (100) for filtering, in particular, a gaseous fluid, in particular air, in particular for filtering air for a fuel cell system, comprising at least two filter medium bodies (10, 20), which can be passed successively in a flow direction (80) and which each have an inflow side (14, 34) and an outflow side (16, 36), at least one of the at least two filter medium bodies (10, 20) has an adsorbent filter medium (30) with a particulate adsorbent material. A safety filter (50) covers the outflow side (36) of the at least two filter media bodies (20) arranged on the outflow side, which safety filter prevents the outflow side of the particulate adsorbent material from exiting.

Description

[0001] This patent application claims priority to German patent application number DE102023128734.6, filed on October 19, 2023, with the German Patent and Trademark Office, the contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to a filter element for filtering, in particular gaseous fluids, especially air, and particularly for filtering air for use in fuel cell systems. Background Technology

[0003] The cathode air filter element used in fuel cell systems has the task of adsorbing certain gases from ambient air and separating dust particles. Adsorption and filtration are typically carried out using two different filter media. One filter media usually consists of a filter medium with an activated carbon layer, and the other filter media is made of cellulose or synthetic nonwoven fabric. In this case, the activated carbon corrugated element for gas adsorption is usually arranged on the clean side of the filtration system.

[0004] According to existing technology, two-stage filter elements provide pre-filtration by means of a non-woven filter media body that covers the upstream side and optionally the lateral side.

[0005] US 11,149,699B2 discloses a filter element for an air filter assembly for a motor, comprising a primary filter medium and a secondary filter medium. The primary filter medium includes a plurality of folds, including a first fold edge at an inlet face of the primary filter medium and a second fold edge at an outlet face of the primary filter medium. The first and second fold edges extend from a first lateral side to a second lateral side of the primary filter medium. The secondary filter medium is composed of a nonwoven fabric material and includes a first section disposed at the inlet face of the primary filter medium, a second section attached to the first lateral side of the primary filter medium, and a third section attached to a second lateral face of the primary filter medium.

[0006] US 2013 / 167490 A1 describes a filter assembly including a housing, a filter element, and a permeable material layer. The housing includes an inlet and an outlet. The filter element is disposed inside the housing and includes an upstream face, a downstream face, and a first end face facing the inlet and extending between the upstream and downstream faces. The permeable material layer is fastened to the filter element and covers the upstream side and a portion of the first end face exposed to the inlet. Summary of the Invention

[0007] The object of the present invention is to provide a filter element for filtering, in particular, gaseous fluids, especially air, and particularly for filtering air for use in fuel cell systems.

[0008] According to one aspect of the invention, the above objective is achieved by a filter element for filtering, in particular, gaseous fluids, especially air, particularly for filtering air for fuel cell systems. The filter element comprises at least two filter media bodies that can be sequentially passed through in a flow direction. Each filter media body includes an inflow surface and an outflow surface. At least one of the at least two filter media bodies comprises an adsorbent filter media having a particulate adsorbent material. A safety filter covers the outflow surface of the filter media body located on the outflow side of the at least two filter media bodies, preventing the outflow side of the particulate adsorbent material from being discharged.

[0009] Beneficial embodiments and advantages of the present invention are derived from further claims, the specification and drawings.

[0010] According to one aspect of the invention, a filter element is provided for filtering, particularly gaseous fluids, particularly air, and especially for filtering air for fuel cell systems. This element comprises at least two filter media bodies capable of being successively flowed through in a flow direction. Each filter media body includes an inflow surface and an outflow surface, wherein at least one of the at least two filter media bodies comprises an adsorbent filter media having a granular adsorbent material. In this case, a safety filter covers the outflow surface of the filter media body arranged on the outflow side of the at least two filter media bodies, preventing the outflow side of the granular adsorbent material from being discharged.

[0011] The proposed filter element includes at least two filter media bodies: an inflow-side filter media body for filtering particles, such as cellulose and / or nonwoven fabric, and an outflow-side filter media body, such as having activated carbon, for adsorbing and / or absorbing gases.

[0012] In an outflow-side filter media that may include, for example, granular activated carbon, carbon particles may become lodged between the folds of the carrier medium in the filter media due to the manufacturing process of the activated carbon corrugated element. These particles could reach the clean side of the filtration system and potentially damage the fuel cell. Therefore, to prevent this, a safety filter, such as a breathable nonwoven fabric, is incorporated and is circumferentially and tightly sealed to the activated carbon corrugated element. The safety filter prevents particles from falling out of the filter media.

[0013] Advantageously, this method prevents particles from the activated carbon corrugated elements from being discharged to the outflow side of the filter element. Therefore, it can advantageously prevent damage to downstream fuel cell systems.

[0014] According to an advantageous embodiment of the filter element, the outflow-side filter media body may include a circumferential lateral strip at its end face, which is arranged transversely to the outflow surface. In particular, in this case, the safety filter may be tightly and sealably connected, especially glued or fused, to the outflow-side edge of the lateral strip. The lateral strip seals the end face of the filter media body.

[0015] Therefore, this method can advantageously prevent particles from the activated carbon corrugated parts from being discharged to the outflow side of the filter element, since the safety filter is thus tightly and sealed to the outflow side filter media.

[0016] According to an advantageous embodiment of the filter element, the edge of the side strip may at least partially protrude beyond the outflow surface of the outflow side filter media. In this way, the safety filter can be directly connected to the edge of the side strip, either to the end face of the edge or to the inwardly oriented side of the edge.

[0017] According to an advantageous embodiment of the filter element, the safety filter can be glued or fused to the end face of the protruding edge of the side belt. In this way, the safety filter can be directly and tightly sealed to the side belt in a simple manufacturing process.

[0018] According to an advantageous embodiment of the filter element, the safety filter can be arranged inside the protruding edge of the side belt and glued or fused to the edge of the side belt. In this preferred embodiment, the safety filter can also advantageously be glued directly during the side belt gluing process.

[0019] According to an advantageous embodiment of the filter element, the safety filter can be incorporated into the junction of the filter media in the side belt and the outflow side filter media body, and in particular, can be glued together. In this way, the manufacturing process of the filter element can be carried out particularly cost-effectively.

[0020] According to an advantageous embodiment of the filter element, at least a portion of the side strip may protrude beyond the outlet surface of the filter media body at least at two opposite end faces on the outlet side, and may be folded over the safety filter in the flow direction on the outlet side. In particular, said at least a portion of the side strip may be tightly and sealably bonded to the safety filter.

[0021] Advantageously, in this way, the safety filter can be directly bonded to the side belt during the side belt bonding process. For this purpose, the side belt can protrude, for example, by approximately 1 to 2 mm, at the outlet surface of the filter media body on the outlet side, and an adhesive can also be provided in this area. In this way, the safety filter can be simultaneously bonded to the side belt during the side belt bonding process. The sealing effect of the safety filter at the opposing end faces of the corrugated part can be achieved, for example, in the form of an L-shaped angle, because a portion of the side belt at the end face folds over the safety filter on the outlet side and is bonded to the safety filter.

[0022] According to an advantageous embodiment of the filter element, two filter media bodies can be arranged to overlap each other in area, wherein the outflow surface of the inflow-side filter media body is arranged opposite to the inflow surface of the outflow-side filter media body, and can be connected to a common seal that radially surrounds the connection area of ​​the two filter media bodies. With this arrangement, the two filter media bodies can be mechanically connected in a simple manner. Simultaneously, when installed in the filter housing as intended, the circumferential seal reliably seals the filter element between the uncleaned side and the clean side. This seal can be formed from, for example, PUR (polyurethane) foam.

[0023] According to an advantageous embodiment of the filter element, the safety filter can cover the end face of the outflow-side filter media and can be tightly and sealingly connected to a seal, particularly embedded within the seal. In this alternative embodiment, the safety filter can be pulled to cover the end face and glued to the seal. In this way, the outflow surface of the outflow-side filter media can also be reliably fixed, preventing the discharge of activated carbon particles.

[0024] According to an advantageous embodiment of the filter element, the safety filter can be formed into a shape with an outflow side filter media body by deep drawing. In this way, the installation process of the safety filter can be achieved in a particularly advantageous manner, as it can be simply placed on top of the filter media body.

[0025] According to an advantageous embodiment of the filter element, the inflow-side filter media can be configured as a particulate filter, and the outflow-side filter media can be configured as an adsorption filter, particularly an activated carbon filter. In this way, dust particles can be reliably removed from the supply air of the fuel cell system. With the aid of the activated carbon filter, harmful gases that may impair the function of the fuel cell can be filtered out in a beneficial manner. Attached Figure Description

[0026] Further advantages will become apparent from the following description of the accompanying drawings. Embodiments of the invention are illustrated in the drawings. The drawings, description, and claims comprise a number of combinations of features. Those skilled in the art will also readily consider these features individually and combine them into convenient further combinations.

[0027] This is illustrated by example: Figure 1 This is a perspective view of a filter element according to an embodiment of the present invention, which is used to filter fluids, particularly gaseous fluids, particularly air, especially air for use in fuel cell systems. Figure 2 It is based on Figure 1 A plan view of the filter element; Figure 3 It is along according to Figure 2 A cross-sectional view of the filter element of BB. Figure 4 It is along according to Figure 2 A cross-sectional view of the filter element AA; Figure 5 This is a schematic cross-sectional view of a filter element according to another embodiment of the present invention; and Figure 6 This is a schematic cross-sectional view of a filter element according to another embodiment of the present invention. Detailed Implementation

[0028] In the accompanying drawings, parts of the same type or similar designation are identified by the same reference numerals. The drawings are merely examples and should not be construed as limiting.

[0029] To explain the present invention, Figure 1 An embodiment of a filter element is shown in a perspective view. This filter element is used to filter a particular gaseous fluid, especially air, and is particularly used to filter air for fuel cell systems.

[0030] exist Figure 2 The diagram shows the data based on... Figure 1 A plan view of the filter element, and Figure 3 The filter element is shown along the path according to Figure 2 The cross-sectional view of section BB, and Figure 4 The filter element is shown along the path according to Figure 2 The cross-sectional view of section AA.

[0031] The filter element 100 includes two filter media bodies 10 and 20, which can be flowed through sequentially along the flow direction 80. The filter media bodies 10 and 20 respectively include inflow surfaces 14 and 34 and outflow surfaces 16 and 36.

[0032] Two filter media bodies 10 and 20 are stacked on top of each other in area. The outflow surface 16 of the inflow-side filter media body 10 is positioned at the inflow surface 34 of the outflow-side filter media body 20. In the connection area 60 of the two filter media bodies 10 and 20, a common seal 62 extending radially outward is arranged, for example, made of PUR. This common seal mechanically connects the two filter media bodies 10 and 20 and provides a reliable seal when installed in the filter housing of the filtration system.

[0033] In this configuration, the inflow-side filter media 10 is specifically implemented as a particulate filter that filters dust particles from the fluid, particularly the air, as it flows through it. The outflow-side filter media 20 includes an adsorption filter media 30 having granular adsorption material, such as activated carbon.

[0034] The safety filter 50 covers the outflow surface 36 of the filter media body 20 arranged on the outflow side, and in this way prevents the outflow side of particulate adsorbent material from being discharged.

[0035] like Figure 4 As can be seen, the two filter media bodies 10 and 20 include folded filter media 12 and 30. Therefore, the filter media bodies 10 and 20 are sealed transversely to the flow direction 80 by the lateral bands 18 and 38, respectively.

[0036] Specifically, the outflow-side filter media body 20 includes circumferential lateral strips 38 arranged transversely to the outflow surface 36 at its end faces 22, 24, 26, and 28. In this case, the safety filter 50 is tightly and sealingly connected to the outflow-side edge 40 of the lateral strips 38, particularly by gluing or welding.

[0037] For this purpose, the edge 40 of the lateral band 38 protrudes at least partially along the flow direction 80 beyond the outlet surface 36 of the outlet-side filter media body 20. The protrusion length need not be very large; for example, a protrusion length of 1-2 mm is sufficient to arrange the safety filter 50 inside the protruding edge 40 of the lateral band 38 and to glue or fuse it to the edge 40 of the lateral band 38, as shown below. Figure 3 and 4 As can be seen in the image. In this case, the safety filter 50 rests directly on the end of the fold of the filter medium 30.

[0038] In this way, the safety filter 50 can be incorporated into the junction of the side belt 38 and the filter medium 30 of the outflow side filter medium body 20, and in particular, it can be directly glued to it.

[0039] like Figure 1 and 4 As can be seen, in order to seal the safety filter at the end of the corrugated part, a portion 44, 46 of the side band 38 can protrude beyond the outlet surface 36 of the filter media body 20 at two opposite end faces 22, 26 on the outlet side. In this case, the protruding portions 44, 46 can advantageously fold over the safety filter 50 along the flow direction 80 on the outlet side and be tightly and sealably bonded to the safety filter 50 in this way. In this way, the safety filter 50 is tightly and sealably bonded to the side band all around and reliably seals the outlet surface 36 of the filter media body 20, preventing the discharge of activated carbon particles.

[0040] Figure 5 A schematic cross-sectional view of a filter element 100 according to another embodiment of the present invention is shown.

[0041] Filter element 100 includes and Figures 1 to 4The filter element 100 shown has a basically the same configuration, which has two filter media bodies 10, 20.

[0042] and Figures 1 to 4 Compared to the illustrated embodiment, here the safety filter 50 is glued or fused to the end face 42 of the protruding edge 40 of the side belt 38. In this way, a reliable circumferential seal can be achieved between the side belt 40 and the safety filter 50.

[0043] exist Figure 6 The figure shows a schematic cross-sectional view of a filter element 100 according to another embodiment of the present invention.

[0044] In this configuration, the safety filter 50 covers the end faces 22, 24, 26, and 28 of the outflow-side filter media body 20 and is tightly and sealably connected to the seal 62. In this way, the safety filter 50 can be directly embedded in the seal 62.

[0045] Advantageously, the safety filter 50 can therefore be circumferentially pulled downward around the activated carbon corrugations of the filter media body 20 during the manufacturing process of the filter media body 20 until it can be incorporated into the seal 62. For example, the safety filter 50 can be foamed directly during the foaming process of the seal 62.

[0046] Advantageously, the safety filter 50 can be formed into the shape of the outflow side filter media body 20 by deep drawing. Subsequently, the deep-drawn safety filter 50 can be placed on the activated carbon corrugated part and can be foamed together with the seal 62.

[0047] Figure Labels 10 Filter Media 12 Filter Media 14. Inflow surface 16 Outflow surface 18 Lateral bands 20 Filter media 22 End face 24 end face 26 End face 28 end face 30 Filter Media 34. Flow surface 36 Outflow surface 38 Lateral bands 40 Edge 42 End face Part 44 46 parts 50 Safety Filters 60 Connection Area 62 Seals 80 Flow direction 100 Filter element.

Claims

1. A filter element (100) for filtering, in particular, gaseous fluids, especially air, particularly for filtering air for a fuel cell system, comprising at least two filter media bodies (10, 20) that can be flowed through sequentially in a flow direction (80), each filter media body comprising an inflow surface (14, 34) and an outflow surface (16, 36). in, At least one of the at least two filter media bodies (10, 20) includes an adsorption filter media (30) having granular adsorption material. The safety filter (50) covers the outflow surface (36) of the filter medium body (20) located on the outflow side of the at least two filter media bodies (20) and prevents the granular adsorbent material from being discharged from the outflow side.

2. The filter element according to claim 1, wherein, The outflow side filter media body (20) includes a circumferential lateral band (38) at its end faces (22, 24, 26, 28) arranged transversely to the outflow surface (36), wherein the safety filter (50) is tightly and sealingly connected to the outflow side edge (40) of the lateral band (38), particularly by gluing or fusion.

3. The filter element according to claim 2, wherein, The edge (40) of the lateral strip (38) protrudes at least partially along the flow direction (80) beyond the outflow surface (36) of the outflow side filter media body (20).

4. The filter element according to claim 3, wherein, The safety filter (50) is glued or fused to the end face (42) of the protruding edge (40) of the lateral strip (38).

5. The filter element according to claim 3, wherein, The safety filter (50) is disposed within the protruding edge (40) of the lateral strip (38) and is glued or fused to the edge (40) of the lateral strip (38).

6. The filter element according to any one of the preceding claims, wherein, The safety filter (50) is bonded to the junction of the side strip (38) and the filter medium (30) of the outflow side filter medium body (20), and is in particular glued.

7. The filter element according to any one of the preceding claims, wherein, At least a portion (44, 46) of the lateral strip (38) protrudes beyond the outflow surface (36) of the filter media body (20) at at least two opposite end faces (22, 26) on the outflow side, and folds over the safety filter (50) along the flow direction (80) on the outflow side, particularly tightly and sealably to the safety filter (50).

8. The filter element according to any one of the preceding claims, wherein, The two filter media bodies (10, 20) are arranged to overlap each other in a region, wherein the outflow surface (16) of the inflow-side filter media body (10) is arranged opposite to the inflow surface (34) of the outflow-side filter media body (20) and connected to a common seal (62) that radially surrounds the connection region (60) of the two filter media bodies (10, 20).

9. The filter element according to claim 8, wherein, The safety filter (50) covers the end faces (22, 24, 26, 28) of the outflow side filter media body (20) and is connected to the seal (62), particularly embedded in the seal (62).

10. The filter element according to claim 9, wherein, The safety filter (50) is formed into the shape of the outflow side filter media body (20) by deep drawing.

11. The filter element according to any one of the preceding claims, wherein, The inflow-side filter media (10) is configured as a particulate filter, and the outflow-side filter media (20) is configured as an adsorption filter, particularly an activated carbon filter.

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