Circular filter element and filter system

Abstract

The invention relates to a circular filter element (10) for filtering a fluid, in particular for filtering air, for a filter system (100), in particular for an air filter system of a fuel cell system, comprising: a filter medium body (12) which extends about a longitudinal axis (80) and has a particulate filter medium, said filter medium body enclosing an interior space (14); two end bodies (20, 22) which delimit the filter medium body (12) at end faces (16, 18) facing away from each other, at least one end body (20, 22) being an open end disc (24) and having a through opening (26) in fluid communication with the interior space (14); and a suction element (40) which is arranged in the through hole (26) of the open end disc (24) and is directly or indirectly fixedly connected with the filter medium body (12) or the end disc (24). In the operating state, a fluid can flow through the sorption element (40) in series with the filter medium body (12) in the direction of the longitudinal axis (80), and the sorption element (40) is sealed against the passage opening (26). The invention also relates to a filtration system (100).

Description

[0001] This patent application claims priority to German patent application 102023124081.1, filed on September 7, 2023, at the German Patent and Trademark Office, the content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present invention relates to a circular filter element for filtering a fluid, in particular for filtering air, for a filter system, in particular for an air filter system of a fuel cell system, and to a filter system having a circular filter element. BACKGROUND

[0003] Fuel cell systems usually require a particle filter and a sorption filter to filter out particles and harmful gases from the intake air. The filter media bodies of the different filter stages usually have different sizes.

[0004] US 2018149119 A1 shows a filter device having a circular filter element with a filter media body, in the open end disc of which a sorption element is arranged, which open end disc is provided with an outlet for the filtered fluid. The fluid that has been filtered through the filter media body flows through the sorption element, whereby harmful substances located in the filtered fluid can be adsorbed.

[0005] DE 102016004316 A1 discloses a flat secondary element which is inserted into the open end disc on the clean side of a circular primary filter element and is axially flowed through in operation. The secondary element is separate from the primary filter element and comprises only a particle filter medium. The secondary filter element serves primarily to prevent the original fluid to be filtered from contaminating the clean side of the filter element device when the primary filter element is replaced. SUMMARY

[0006] It is an object of the present invention to provide a circular filter element for filtering a fluid, in particular for filtering air, for a filter system, in particular for an air filter system of a fuel cell system, which is easy to maintain and cost-effective, which has a sorption element.

[0007] It is a further object to provide a filter system having such an easy-to-maintain and cost-effective circular filter element.

[0008] According to an aspect of the present application, the above object is achieved by a circular filter element for filtering a fluid, in particular for filtering air, for a filter system, in particular for an air filter system of a fuel cell system, comprising at least: a filter medium body with a particulate filter medium extending around a longitudinal axis, the filter medium body enclosing an inner space; two end bodies delimiting the filter medium body at end faces facing away from each other, wherein at least one end body is an open end disc and has a through-hole in fluid communication with the inner space; and a sorption element arranged in the through-hole of the open end disc and directly or indirectly fixedly connected with the filter medium body or the end disc, wherein in an operating state the sorption element can be flowed through by a fluid in series with the filter medium body along the longitudinal axis direction, wherein the sorption element is sealed with respect to the through-hole.

[0009] The above object is further achieved by a filter system for filtering a fluid, in particular for filtering air, in particular air of a fuel cell system, having a filter housing with a fluid inlet and a fluid outlet, and having at least one circular filter element arranged between the fluid inlet and the fluid outlet.

[0010] Advantageous embodiments and advantages of the present application result from the other claims, the description and the drawings.

[0011] According to an aspect of the present application, a circular filter element for filtering a fluid, in particular for filtering air, for a filter system, in particular for an air filter system of a fuel cell system, is proposed, comprising at least: a filter medium body with a particulate filter medium extending around a longitudinal axis, the filter medium body enclosing an inner space; two end bodies delimiting the filter medium body at end faces facing away from each other, wherein at least one end body is an open end disc and has a through-hole in fluid communication with the inner space; and a sorption element arranged in the through-hole of the open end disc and directly or indirectly fixedly connected with the filter medium body or the end disc. Wherein in an operating state the sorption element can be flowed through by a fluid in series with the filter medium body along the longitudinal axis direction. The sorption element is sealed with respect to the through-hole.

[0012] The proposed circular filter element has a filter medium body configured as a particulate filter, and a sorption element, which can be configured as a sorption element or an absorption element. The circular filter element and the sorption element can be provided with a common open end disc having a through-hole for the filtered fluid. In this way, the sorption element can be fixedly connected with the filter medium body and / or the open end disc.

[0013] By using a common end disk, the sealing of both elements (filter medium body and adsorption element) can be accomplished in one process step, which has a favorable effect on production costs.

[0014] The particle filter can be configured, for example, as a folded cellulose bellows filter element or a synthetic material bellows filter element.

[0015] For adsorbing harmful gases, the adsorption element can have, for example, activated carbon, wherein the activated carbon can be sandwiched between synthetic medium layers to process an activated carbon medium. This activated carbon medium can be processed as a folded bellows filter element or, alternatively, as a cylindrical wound bellows filter element.

[0016] Other solutions are also conceivable, in which activated carbon is introduced into a fluid-permeable closed hollow body. Another alternative for the adsorption of harmful gases is a coated honeycomb body.

[0017] The common open end disk between the filter medium body and the adsorption element can be composed, for example, of plastic, polyurethane (PUR) foam or a metal sheet.

[0018] The filter medium body, which is configured as a particle filter, is flowed through radially in the circular filter element, while the gas adsorption in the adsorption element takes place in an axial flow direction. The adsorption element can also extend here into the clean air duct of the filter housing and / or into the fluid outlet of the filter housing, i.e. beyond the end disk.

[0019] According to an advantageous embodiment of the circular filter element, the adsorption element can be at least partially embedded in the open end disk with an axially extending outer side. In particular, the circular filter element can be connected with the open end disk material-lockingly. In this way, the adsorption element can be connected tightly to the end disk, so that the filtered fluid of the filter medium body has to flow completely through the adsorption element, so that harmful substances can be adsorbed or absorbed advantageously.

[0020] According to an advantageous embodiment of the circular filter element, the adsorption element can at least partially protrude into the inner space of the filter medium body in the direction of the longitudinal axis. Thereby, a greater adsorption element volume can be provided for adsorbing or absorbing harmful gases.

[0021] According to an advantageous embodiment of the circular filter element, the adsorption element can at least partially protrude from the end face of the open end disk of the filter medium body in the direction of the longitudinal axis. Thereby, a greater adsorption element volume can be provided for adsorbing or absorbing harmful gases.

[0022] According to an advantageous embodiment of the circular filter element, the adsorption element can be bounded in the direction of the longitudinal axis by opposite end faces, wherein one end face of the adsorption element can be flush with the open end disc. In this way, the adsorption element can be arranged flush towards the outer space or towards the inner space of the circular filter element.

[0023] According to an advantageous embodiment of the circular filter element, the adsorption element can have a cuboid-shaped contour, the outer edges of which are oriented essentially in the direction of the longitudinal axis. Here, the diagonal of the end faces of the cuboid-shaped contour corresponds at most to the diameter of the through-hole of the end disc. In particular for adsorption elements having folded activated carbon media, the cuboid-shaped contour represents a cost-effective embodiment of the adsorption element.

[0024] According to an advantageous embodiment of the circular filter element, the adsorption element can have a cylindrical contour, the cylindrical axis of which is parallel, in particular concentrically aligned, to the longitudinal axis. Here, the adsorption element can be arranged radially inside the through-hole. The cylindrical contour can advantageously fill the circular opening of the end disc, in particular in the case of a hollow cylindrical filter medium body, thereby providing the fluid flow through the adsorption element with the largest possible cross section.

[0025] According to an advantageous embodiment of the circular filter element, the adsorption element can comprise a folded adsorption medium, wherein the folded edges of the adsorption medium can be arranged oblique, in particular perpendicular, to the longitudinal axis. In this way, a large adsorption element medium area can be provided for the adsorption or absorption of harmful gases.

[0026] According to an advantageous embodiment of the circular filter element, the adsorption element can comprise an adsorption medium wound around the longitudinal axis. The arrangement of the adsorption medium of such an adsorption element can also be cost-effectively manufactured, while providing the fluid to be filtered with the largest possible adsorption or absorption area.

[0027] According to an advantageous embodiment of the circular filter element, the adsorption element can have a side band on at least one axially extending outer side. Here, the axially extending outer side can also be referred to as axial outer side. In particular, the circular filter element can be sealingly closed with the side band.

[0028] In particular, the side band can be embedded in the open end disc, in particular connected with the open end disc material-lockingly. On the one hand, the outer side of the folds of the adsorption element, in particular of the folded adsorption medium, can be advantageously sealed. On the other hand, the side band can advantageously be used for the connection to the end disc. For example, the side band can be cast into the end disc, thereby being firmly connected with the end disc.

[0029] According to an advantageous embodiment of a circular filter element, the adsorption element may include an adsorption medium constructed as a bulk material. The bulk material can, for example, be arranged in a plastic housing with openings for fluid flow, which is also a very cost-effective embodiment of the adsorption element. For this purpose, the end face of the housing in the longitudinal direction can be covered, for example, with a nonwoven fabric through which fluid can flow.

[0030] According to an advantageous embodiment of the circular filter element, a nonwoven fabric can be arranged on the end faces of the adsorption element. In particular, at least one end face, especially at least one downstream end face, can have reinforcing ribs. The adsorption medium can therefore be advantageously arranged between the two end faces provided with nonwoven fabric. To reinforce against the flow pressure of the flowing fluid, reinforcing ribs, especially cross ribs, can be arranged on at least one end face, especially at least one downstream end face.

[0031] According to an advantageous embodiment of the circular filter element, the adsorption element can have a honeycomb structure with channels open along its longitudinal axis. Here, the honeycomb structure can have an adsorption medium. In particular, the honeycomb structure can be coated with an adsorption medium. Such a honeycomb structure can, for example, be advantageously manufactured as a plastic extrusion. Applying activated carbon can advantageously produce a mechanically stable and lightweight adsorption element for adsorbing or absorbing harmful gases.

[0032] According to another aspect of the invention, a filtration system for filtering fluids, particularly air, especially air in a fuel cell system, is provided, the filtration system having a filter housing with a fluid inlet and a fluid outlet, and having at least one circular filter element arranged between the fluid inlet and the fluid outlet.

[0033] The proposed filtration system advantageously filters particles, particularly dirt particles, from fluids, especially air, and also adsorbs or absorbs harmful gases on the adsorption element. This arrangement of the adsorption element within a circular filter element is a particularly cost-effective and efficient solution because all fluid filtered by the particulate filter must flow through the adsorption element. In this way, the effective adsorption or absorption of harmful gases in the filtration system is ensured. Attached Figure Description

[0034] 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 contain a large number of combined features. Those skilled in the art will also advantageously consider these features individually and generalize them into other meaningful combinations. Exemplary examples are shown below: Figure 1This is an exploded isometric view of a filtration system for filtering fluids, particularly air, especially air for fuel cell systems, according to an embodiment of the present invention. Figure 2 yes Figure 1 A longitudinal sectional view of the filtration system shown. Figure 3 This is an isometric view of a circular filter element according to an embodiment of the present invention; Figure 4 yes Figure 3 A longitudinal sectional view of the circular filter element shown; Figure 5 yes Figure 3 An isometric view of the adsorption element of the circular filter element shown. Figure 6 yes Figure 3 A top view of the circular filter element shown; Figure 7 yes Figure 4 A detail of the longitudinal section view of the circular filter element shown; Figure 8 This is a longitudinal sectional view of a circular filter element according to another embodiment of the present invention; Figure 9 yes Figure 8 An isometric view of the adsorption element of the circular filter element shown. Figure 10 yes Figure 8 A top view of the circular filter element shown; Figure 11 yes Figure 8 A detail of the longitudinal section view of the circular filter element shown; Figure 12 This is a longitudinal sectional view of a circular filter element according to another embodiment of the present invention; Figure 13 yes Figure 12 An isometric view of the adsorption element of the circular filter element shown. Figure 14 yes Figure 12 A top view of the circular filter element shown; Figure 15 This is a longitudinal sectional view of a circular filter element according to another embodiment of the present invention; Figure 16 yes Figure 15 An isometric view of the adsorption element of the circular filter element shown. Figure 17 yes Figure 15 A top view of the circular filter element shown; Figure 18 This is a longitudinal sectional view of a circular filter element according to another embodiment of the present invention; Figure 19 yes Figure 18 An isometric view of the adsorption element of the circular filter element shown. Figure 20 yes Figure 18 A top view of the circular filter element shown; Figure 21 yes Figure 20 A detail of the top view shown; Figure 22 This is a longitudinal sectional view of a circular filter element according to another embodiment of the present invention; Figure 23 yes Figure 22 An isometric view of the adsorption element of the circular filter element shown. Figure 24 yes Figure 22 A top view of the circular filter element shown; Figure 25 yes Figure 22 A detail of the longitudinal section view shown; Figure 26 This is a longitudinal sectional view of a circular filter element according to another embodiment of the present invention; Figure 27 yes Figure 26 An isometric view of the adsorption element of the circular filter element shown. Figure 28 yes Figure 26 A top view of the circular filter element shown; and Figure 29 yes Figure 26 A detail of the longitudinal section view shown. Detailed Implementation

[0035] In the accompanying drawings, identical or similar parts are numbered using the same reference numerals. The drawings are for illustrative purposes only and should not be construed as limiting.

[0036] The directional terms used below, such as "left," "right," "up," "down," "front," "back," and "after," are used only to better understand the drawings and are in no way intended to limit the generality of the invention. The parts and elements shown, their design and uses, can be varied to the extent that those skilled in the art would consider and adapted to their respective applications.

[0037] Figure 1 An exploded isometric view of a filtration system 100 for filtering fluids, particularly air, especially air for fuel cell systems, according to an embodiment of the present invention is shown. Figure 2 A longitudinal sectional view of the filtration system 100 is shown. Figure 3 An isometric view of the circular filter element 10 arranged in the filtration system 100 is shown, whileFigure 4 A longitudinal sectional view of the circular filter element 10 is shown.

[0038] The filtration system 100 includes a filter housing 110 having a tangentially arranged fluid inlet 102 and an axially arranged fluid outlet 104. In the filter housing having a first housing portion 112 and a second housing portion 114, a circular filter element 10 is arranged along a longitudinal axis 80 between the fluid inlet 102 and the fluid outlet 104.

[0039] The circular filter element 10 includes a filter media body 12 extending around a longitudinal axis 80 and containing particulate filter media, the filter media body surrounding an internal space 14. The filter media body 12 may be constructed, for example, as a folded cellulose corrugated filter cartridge or a synthetic material corrugated filter cartridge.

[0040] The circular filter element 10 also includes two end bodies 20, 22, which define a filter media body 12 at opposite end faces 16, 18. One of the end bodies 20 is configured as an open end plate 24 and has a through hole 26 in fluid communication with the internal space 14. Filtered fluid can flow out through the through hole 26 of the end plate to the fluid outlet 104.

[0041] The other end body 22 is also constructed as an end plate 25.

[0042] End plates 24 and 25 may be made of, for example, plastic, polyurethane (PUR) foam, or metal sheet.

[0043] The end plate 24 has a surrounding seal 30 formed of the material of the end plate 24 and oriented along the longitudinal axis 80.

[0044] Since the fluid flows from the radial outside to the inner side through the circular filter element 10, the original fluid region 82 located radially outside the circular filter element 10 can be sealed relative to the clean fluid region 84 located in the internal space 14 of the circular filter element 10 using the seal 30.

[0045] The second end plate 25 has an axially projecting support element 32. When the circular filter element 10 is installed into the filter housing 110, once the first housing portion 112 is connected to the second housing portion 114 (e.g., by threaded connection or clamping), the circular filter element 10 is pre-tightly pressed against the filter housing 110 by the seal 30 and the support element 32.

[0046] Furthermore, the circular filter element 10 includes an adsorption element 40, which is arranged in the through-hole 26 of the open end plate 24 and is directly or indirectly fixedly connected to the filter media body 12 or the end plate 24. In operation, the adsorption element 40 can be connected in series with the filter media body 12 along the longitudinal axis 80 and be flowed through by fluid.

[0047] like Figure 4 As shown, the adsorption element 40 extends at least partially into the interior space 14 of the filter media body 12 along the longitudinal axis 80. The adsorption element 40 is defined by opposing end faces 46 and 48 along the longitudinal axis 80. Here, one end face 46 of the adsorption element 40 is flush with the open end plate 24.

[0048] Figure 5 An isometric view of the adsorption element 40 of the circular filter element 10 is shown. Figure 6 A top view of the circular filter element 10 is shown.

[0049] like Figure 5 and Figure 6 As shown, the adsorption element 40 has a cubic profile 50, with its outer edge 45 oriented substantially along the longitudinal axis 80. Here, the diagonals 52 of the end faces 46, 48 of the cubic profile 50 correspond at most to the diameter 34 of the through hole 26 of the end plate 24. This means that, as shown, the adsorption element 40 can be fitted into the through hole 26 of the end plate 24 using its outer profile.

[0050] To adsorb harmful gases, the adsorption element 40 may, for example, have activated carbon, which may be sandwiched between layers of synthetic media to form an activated carbon medium. This activated carbon medium can be processed into a pleated corrugated filter element. Figures 1 to 7 In this process, the adsorption element 40 has a folded adsorption medium 42, the folded edges 56 of which are arranged perpendicular to the longitudinal axis 80.

[0051] The adsorption element 40 has a side strip 58 on its axially extending outer surface 44. The pleats 55 of the adsorption medium 42 are sealed by the side strip 58.

[0052] Figure 7 It shows Figure 4 A detail of the longitudinal sectional view of the circular filter element 10 is shown. This illustrates how the adsorption element 40 is connected to the end plate 24. The pleats 55 of the adsorption element 40 are sealed at the outermost surface 44 of the axially extending cubic profile 50 using side strips 58. The outermost pleats 55 and side strips 58 are integrated into the material of the end plate 24, and are particularly locked to the material of the end plate 24. For this purpose, the side strips 58 can be cast into the end plate 24, for example.

[0053] In this way, the adsorption element 40 is effectively sealed relative to the through hole 26 of the end plate 24.

[0054] Figure 8 A longitudinal sectional view of a circular filter element 10 according to another embodiment of the present invention is shown. Figure 9 An isometric view of the adsorption element 40 of the circular filter element 10 is shown for this purpose.Figure 10 A top view of the circular filter element 10 is shown. Figure 11 A detail of the longitudinal section view of the circular filter element 10 is shown.

[0055] Figures 8 to 11 The structure of the circular filter element 10 shown is similar to Figures 1 to 7 The illustrated embodiment is similar. The adsorption element 40 also has a folded adsorption medium 42, but has a cylindrical profile 54, whose cylindrical axis is parallel to, and in particular concentrically aligned with, the longitudinal axis 80. Here, the adsorption element 40, radially arranged within the through-hole 26 of the end plate 24, completely fills the through-hole 26.

[0056] This cylindrical profile 54 can be achieved, for example, by using laser cutting to cut the outer edge of a cubical filter bellows cartridge.

[0057] The adsorption element 40 is also sealed on its axially extending outer surface 44 using a side strip 58. Figure 11 As can be seen in the cross-sectional view, the adsorption element 40 is also embedded in the end plate 24 using the outermost pleats 55 and the side strips 58, especially cast together with the end plate 24.

[0058] Figure 12 A longitudinal sectional view of a circular filter element 10 according to another embodiment of the present invention is shown. Figure 13 An isometric view of the adsorption element 40 of the circular filter element 10 is shown for this purpose. Figure 14 A top view of the circular filter element 10 is shown.

[0059] In this embodiment, the adsorption element 40, also having a cylindrical profile 54, includes an adsorption medium 42 wound around a longitudinal axis 80. Activated carbon media can be easily wound into a filter bellows cartridge in this manner. Optionally, the outer surface 44 can also be sealed with a side strip 58, such as... Figure 13 As shown. This adsorption element 40 can be manufactured in a cost-effective manner and can completely fill the through-hole 26 of the end plate 24 without the need for proper cutting.

[0060] Figure 15 A longitudinal sectional view of a circular filter element 10 according to another embodiment of the present invention is shown. Figure 16 An isometric view of the adsorption element 40 of the circular filter element 10 is shown for this purpose. Figure 17 A top view of the circular filter element 10 is shown.

[0061] like Figure 15As shown, the adsorption element 40 extends at least partially from the end face 16 of the open end plate 24 of the filter medium body 12 along the longitudinal axis 80. The adsorption element 40 is therefore partially arranged in the internal space 14 of the circular filter element 10 and partially arranged in its external space.

[0062] Furthermore, the adsorption element 40, constructed with a cylindrical profile 54, has an adsorption medium 42 constructed as bulk material 60. The bulk material 60 can be arranged, for example, within a housing 70 (e.g., a plastic housing), wherein nonwoven fabric 62 can be arranged on the end faces 46, 48 of the adsorption element 40, respectively. The nonwoven fabric 62 retains the bulk material 60 within the housing 70 while still allowing fluid to flow axially through the adsorption element 40. To resist the flow pressure of the flowing fluid, at least one end face 46, 48, particularly at least the downstream end face 46, can have reinforcing ribs 64. These reinforcing ribs 64 can, for example, be arranged on the end face 46 in the form of cross ribs.

[0063] On the outer surface 44, the housing 70 may have a surrounding frame 72, which has at least partially perforations 74, and this frame can be integrated into the end plate 24. In particular, the perforations 74 in the frame 72 allow for the best possible engagement with the end plate 24. By casting the end plate 24 and the frame 72 together, a robust connection can be achieved between the adsorption element 40 and the end plate 24.

[0064] Figure 18 A longitudinal sectional view of a circular filter element 10 according to another embodiment of the present invention is shown. Figure 19 An isometric view of the adsorption element 40 of the circular filter element 10 is shown, while Figure 20 A top view of the circular filter element 10 is shown. Figure 21 It shows Figure 20 A detail of the top view shown.

[0065] like Figure 18 As shown, the adsorption element 40 is flush with the end face 16 of the open end plate 24 of the filter medium body 12 along the longitudinal axis 80. The adsorption element 40 is therefore arranged in the internal space 14 of the circular filter element 10.

[0066] like Figure 19 And especially Figure 21 As shown in the detailed view, the adsorption element 40, constructed with a cylindrical profile 54, has a honeycomb structure 66. This honeycomb structure 66 has channels 68 open along the longitudinal axis 80 through which the fluid to be filtered can flow. For this purpose, the honeycomb structure 66 may have an adsorption medium 42. In particular, the honeycomb structure 66 may be coated with the adsorption medium 42. The honeycomb structure 66 can be effectively manufactured, for example, as a plastic extrusion.

[0067] As in the aforementioned embodiments, the adsorption element 40 also has a frame 72 with perforations 74 extending around the adsorption element 40, which can be suitably embedded, in particular cast into, the end plate 24 of the circular filter element 10.

[0068] Especially Figure 21 In the magnified detail view, it can be seen that... Figures 18 to 21 The honeycomb structure 66 shown in the embodiments has identical channels 68 with square cross-sections for fluid flow. However, as an alternative, the channels may have different, or even irregularly shaped, cross-sections.

[0069] Figure 22 A longitudinal sectional view of a circular filter element 10 according to another embodiment of the present invention is shown. Figure 23 An isometric view of the adsorption element 40 of the circular filter element 10 is shown, while Figure 24 A top view of the circular filter element 10 is shown. Figure 25 It shows Figure 22 A detail of the longitudinal section view shown.

[0070] Figures 22 to 25 The illustrated embodiment has the same characteristics as Figures 18 to 21 The embodiment uses an adsorption element 40 with a honeycomb structure 66. The difference is that... Figures 22 to 25 The adsorption element 40 shown extends at least partially from the end face 16 of the open end plate 24 of the filter medium body 12 along the longitudinal axis 80. The adsorption element 40 is therefore partially arranged in the internal space 14 of the circular filter element 10 and partially arranged in its external space.

[0071] Figure 25 The detailed view, in longitudinal section, shows the connection between the adsorption element 40 and the open end plate 24. In particular, the seal 30 can be foam-molded onto the wall of the adsorption element 40. Figure 25 The longitudinal sectional view shows that the frame 72 of the adsorption element 40 is embedded in the material of the end plate 24. Here, the perforations 74 of the frame 72 are for better engagement with the material of the end plate 24.

[0072] Figure 26 A longitudinal sectional view of a circular filter element 10 according to another embodiment of the present invention is shown. Figure 27 An isometric view of the adsorption element 40 of the circular filter element 10 is shown, while Figure 28 A top view of the circular filter element 10 is shown. Figure 29 It shows Figure 26 A detail of the longitudinal section view shown.

[0073] In this embodiment, the adsorption element 40 is completely arranged in the external space of the circular filter element 10 and extends beyond the end plate 24 along the longitudinal axis 80, extending into the fluid outlet 104 of the filter housing 110.

[0074] The adsorption element 40 is again constructed as a honeycomb structure 66 as in the previous two embodiments. Figure 29 The longitudinal sectional view shows that the frame 72 of the adsorption element 40 is embedded in the material of the end plate 24. Here, the perforations 74 of the frame 72 are for better engagement with the material of the end plate 24.

[0075] List of reference signs 10 Filter elements 12 Filter media 14 Interior Space 16 End Face 18 end face 20 end body 22 end bodies 24 serving trays 25 serving trays 26 Through Holes 28 central tube 30 Seals 32 Supporting elements 34 diameter 40 Adsorption elements 42 Adsorption medium 44. Outer surface 45 Outer edge 46 End face 48 end face 50. Cube-shaped outline 52 diagonals 54. Cylindrical outline 55 pleats 56 Folded edges 58 Side straps 60 Bulk materials 62 Nonwoven fabric 64 Reinforcing Ribs 66. Honeycomb structure 68 channels 70 Housing 72 Frames 74 Perforations 80 Vertical axis 82 Original fluid region 84 Clean Fluid Area 100 Filtration System 102 Fluid inlet 104 Fluid Outlet 110 Filter housing 112 First shell section 114 Second shell section

Claims

1. A circular filter element (10) for filtering fluids, particularly for filtering air, for use in a filtration system (100), particularly for an air filtration system for a fuel cell system, said circular filter element comprising: A filter media body (12) with particulate filter media extending around the longitudinal axis (80) surrounds the interior space (14). Two end bodies (20, 22) define the filter media body (12) at opposite end faces (16, 18), wherein at least one end body (20, 22) is an open end plate (24) and has a through hole (26) in fluid communication with the internal space (14). An adsorption element (40) is arranged in the through-hole (26) of the open end plate (24) and is directly or indirectly fixedly connected to the filter medium (12) or the end plate (24). In operation, the adsorption element (40) is connected in series with the filter medium (12) along the longitudinal axis (80) and is passed through by the fluid. Furthermore, the adsorption element (40) is sealed relative to the through hole (26).

2. The circular filter element according to claim 1, wherein, In operation, the filter medium (12) is flowed through in the radial direction.

3. The circular filter element according to claim 1 or 2, wherein, The adsorption element (40) extends at least partially into the open end plate (24) with its substantially axially extending outer surface (44), and is particularly engaged with the material of the open end plate (24).

4. The circular filter element according to any one of claims 1 to 3, wherein, The adsorption element (40) extends at least partially into the internal space (14) of the filter medium body (12) along the direction of the longitudinal axis (80).

5. The circular filter element according to any one of the preceding claims, wherein, The adsorption element (40) extends at least partially from the end face (16) of the open end plate (24) of the filter medium body (12) along the direction of the longitudinal axis (80).

6. The circular filter element according to any one of the preceding claims, wherein, The adsorption element (40) is defined by opposing end faces (46, 48) in the direction of the longitudinal axis (80), wherein one end face (46) of the adsorption element (40) is flush with the open end plate (24).

7. The circular filter element according to any one of the preceding claims, wherein, The adsorption element (40) has a cubic profile (50) with its outer edge (45) oriented substantially along the direction of the longitudinal axis (80), wherein the diagonal (52) of the end face (46, 48) of the cubic profile (50) corresponds at most to the diameter (34) of the through hole (26) of the end plate (24).

8. The circular filter element according to any one of claims 1 to 6, wherein, The adsorption element (40) has a cylindrical profile (54) with its cylindrical axis parallel to, and in particular concentrically aligned with, the longitudinal axis (80), wherein the adsorption element (40) is radially arranged inside the through hole (26).

9. The circular filter element according to any one of the preceding claims, wherein, The adsorption element (40) has a folded adsorption medium (42), wherein the folded edges (56) of the adsorption medium (42) are arranged inclined, in particular perpendicular to the longitudinal axis (80).

10. The circular filter element according to any one of claims 1 to 8, wherein, The adsorption element (40) includes an adsorption medium (42) wound around the longitudinal axis (80).

11. The circular filter element according to claim 9 or 10, wherein, The adsorption element (40) has a side band (58) on at least one substantially axially extending outer surface (44), which is sealed in particular by means of the side band (58), wherein the side band (58) is embedded in the open end plate (24) and is locked in connection with the material of the open end plate (24).

12. The circular filter element according to any one of claims 1 to 8, wherein, The adsorption element (40) has an adsorption medium (42) constructed as a bulk material (60).

13. The circular filter element according to any one of the preceding claims, wherein, Nonwoven fabric (62) is arranged on the end faces (46, 48) of the adsorption element (40), and / or at least one end face (46, 48), particularly at least one downstream end face (46), has reinforcing ribs (64).

14. The circular filter element according to any one of claims 1 to 8, wherein, The adsorption element (40) has a honeycomb structure (66) with channels (68) open along the longitudinal axis (80), wherein the honeycomb structure (66) has the adsorption medium (42).

15. A filtration system (100) for filtering fluids, particularly air, especially air for a fuel cell system, the filtration system having a filter housing (110) with a fluid inlet (102) and a fluid outlet (104), and having at least one circular filter element (10) according to any one of the preceding claims, the circular filter element being disposed between the fluid inlet (102) and the fluid outlet (104).

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