Filter element and method for producing filter element

Abstract

Disclosed is a filter element (10) comprising: a folded pack (2) comprising a flat filter media (1) folded in a zigzag shape, the folded pack (2) further comprising an upstream fold (2A) and a downstream fold (2B); frame elements (3A, 3B, 4A, 4B) at least partially surrounding the folding bag (2), the frame elements (3A, 3B, 4A, 4B) being attached to the lateral folding profiles (5A, 5B) and the end folding sections (6A, 6B) of the folding bag (2); a cover element (7) attached to the frame element (3A, 3B, 4A, 4B) so as to form an internal volume (8) defined by the folded filter media (1), the frame (3A, 3B, 4A, 4B) and the cover element (7); and a filler (14) comprising a particulate adsorbent material (9) within the internal volume (8) and at least partially covering a folded edge (15) of the upstream fold (2A) facing the cover element (7).

Description

Technical Field

[0001] This disclosure relates to a filter element and its manufacture. Although the invention is applicable to any filter element and filter assembly, the invention and its potential problems will be described below with respect to the internal air filter of a motor vehicle.

[0002] Increasing air pollution (especially in large cities) and the use of modern air conditioning equipment make it necessary to purify the air drawn from the outside of motor vehicles into the interior and then treated or conditioned by means of appropriate filters. For this purpose, for example, it is conceivable to use particulate filters, odor filters, or combinations thereof to filter or adsorb as much suspended matter, particulate matter, and odor contained in the ambient air as possible.

[0003] To filter the air inside motor vehicles, folded or pleated filter materials are typically used, such as nonwoven filter fabric formed into folded pouches. For this purpose, the initially flat filter material sheet is folded in a zigzag pattern. The folded pouch is held in place, for example, by side strips and a top strip or another frame. This filter element can be replaced and secured in the filter receiver. The resulting filter assembly can then be installed in the air conditioning system of the corresponding motor vehicle.

[0004] Air conditioning systems for passenger compartments in electric vehicles typically draw in as little fresh air as possible, instead recirculating and conditioning the air in the passenger compartment. The recirculated air needs to be treated and cleaned to ensure passenger safety. In particular, carbon dioxide and moisture contained in exhaled air can accumulate in the passenger compartment and may cause occupant inattention or even health problems. To improve both safety and health, it is desirable to reduce the content of unwanted gases and particulate matter in the air. Background Technology

[0005] US 5,129,929 discloses a filter element that combines a pleated particulate filter medium with an adsorbent filter pad for removing unwanted gases. The adsorbent filter pad includes a flat downstream surface and an upstream surface having multiple ridges with flat sections between the ridges. The adsorbent pad is combined with the pleated particulate filter medium such that the ridges of the adsorbent pad are inserted into hollow pleats on one side of the particulate filter medium. The adsorbent pad is a tangible object.

[0006] US 4,514,197 discloses a filter that combines particulate filter media and adsorbent filter media. The filter includes a foam-type pre-filter and a carbon-type main filter. The main filter holds activated carbon between a flat screen of mesh material and a corrugated screen of mesh material. The activated carbon layer is contained within triangular segments defined by alternating peaks of the corrugated screen attached to the flat screen.

[0007] US Patent 5,354,365 discloses an air filtration assembly combining particulate filter fabric and adsorbent material. A first layer of filter fabric is shaped into a parallel, elongated semi-cylindrical surface, which is connected to a second layer of filter fabric at a common parallel edge. The parallel semi-cylindrical gaps between the fabric layers have a semi-elliptical cross-section and contain gas-adsorbing material. US Patent 5,354,365 excludes triangular designs for gaps containing adsorbent.

[0008] US 5,423,903 discloses an air filter comprising a fine mesh screen and an air-permeable fiber cover, the fine mesh screen and the air-permeable fiber cover being added downstream of a conventional air filter. An accordion-shaped filter element is located upstream of the fine mesh screen, and granular filter material such as activated carbon fills the space between the accordion-shaped filter element and the fiber cover. Summary of the Invention

[0009] The object of this invention is to provide an improved filter element.

[0010] According to a first aspect, a filter element is provided. The filter element includes a folded package comprising a flat filter medium folded into a zigzag shape, the folded package further including an upstream fold and a downstream fold. The filter element also includes a frame element that at least partially surrounds the folded package, the frame element being attached to a lateral fold profile and an end fold section of the folded package. The filter element also includes a cover element attached to the frame element, thereby forming an internal volume defined by the folded filter medium, the frame element, and the cover element. The filter element also includes a filler comprising a particulate-adsorbing material within the internal volume and at least partially covering the folded edge of the upstream fold facing the cover element. In an embodiment, the filter element is, for example, an internal air filter element for cleaning the air in a passenger compartment of a vehicle.

[0011] The proposed filter element may contain more particulate filter material than conventional equipment, while remaining relatively compact.

[0012] In this embodiment, the internal volume is completely filled with particulate adsorbent material, thus the internal volume is entirely occupied by the packing. Embodiments in which the packing partially occupies the internal volume (e.g., reaching a predetermined portion or fraction) are also conceivable. Complete filling can result in improved mechanical stability or robustness of the entire filter element. Partial filling can satisfy specific filtration requirements regarding weight, the content of adsorbent material, and the compressibility of the filter element's shape. The proposed filter element allows for a balance between adsorption efficiency and pressure drop along the fluid path through the packing.

[0013] In the following text, the terms "adsorbent material" and "adsorbent material" are used interchangeably.

[0014] The cover element is air-permeable and ensures that the particulate adsorbent material is surrounded within the filter element. Specifically, the cover element is impermeable to the particulate adsorbent material used. In embodiments, the cover element may comprise several layers of material. In embodiments, the cover element also has filtration properties, such as filtering larger particles contained in the fluid to be filtered. The term "fluid" as used herein also refers to a fluid containing particles, such as a contaminated fluid, like air polluted by dust.

[0015] To obtain a folded package, a flat filter medium can be provided as a starting material and folded accordingly. In embodiments, the flat filter medium is implemented to trap unwanted particles from a fluid medium carrying particles. The filter medium is, for example, a filter fabric, a laid filter, or a filter nonwoven. In particular, the filter material can be produced by spunbonding or meltblown methods. Furthermore, the filter medium can be felted or needle-punched. The filter material can include natural fibers (such as cotton) or synthetic fibers such as polyester, polyphenylene sulfide, or polytetrafluoroethylene. The fibers can be oriented along the machine direction, inclined to the machine direction, and / or transverse to the machine direction during production. In embodiments, the filter material can have a single-layer or multi-layer configuration. It can also contain an adsorbent such as activated carbon. In addition, the filter material can include antibacterial and / or anti-allergic properties. Zinc pyrithione or nano-silver are conceivable as antibacterial substances, and polyphenols are conceivable as anti-allergic substances.

[0016] The filter element combines the ability to trap unwanted particles from the fluid medium being filtered (such as air inside a car cabin or recirculated air) with the removal of gaseous components (such as exhaled air, unwanted odors, or exhaust gases) from the medium. No separate filtration equipment is required.

[0017] The edges can be covered with filler material. For this purpose, there is space between the folded edges and the cap element facing those edges for accommodating particulate filler material (i.e., absorbent material). The filler extends along the height of the folded package to allow for flexible filler volume.

[0018] The usable folding package can be unfolded, and suitable frame and cover elements can be attached to form a filter element with an internal volume. The internal volume is then filled with an adsorbent material (e.g., using a loose material containing adsorbent particles).

[0019] In an embodiment, the folded package may have a height equal to the distance between two planes resting on the folded edge of the downstream fold and another folded edge, respectively, the folded edges having opposite orientations. The frame element may extend beyond this height in one or both directions. In addition to the space within the folded region (i.e., the space between folded sections), the distance between the folded edge and the cap element also provides suitable space for filling. Compared to folds that only fill a zigzag pattern of filter media, the frame element extending beyond this height allows for the filling of more adsorbent material into the filter element. The frame element may extend beyond this height along the fluid flow in one or both directions.

[0020] Frame elements, for example, include multiple stabilizing elements, particularly side and top zones, which at least partially stabilize the filter material to maintain its shape, especially during operation. The stabilizing elements, particularly the side and top zones, may form at least a portion of the frame. Alternatively, an integral frame structure surrounding the filter material is conceivable, such as a plastic frame obtained through injection molding.

[0021] In one embodiment, the frame element includes two side strips and two top strips, which are fixedly attached (e.g., glued) to the folded package, particularly by material fusion, and surround the folded package in a frame shape, and may serve as sealing sections. The side strips and top strips are formed, for example, of a nonwoven material, particularly a filter nonwoven, filter fabric, or the laid filter. The nonwoven material of the side strips and top strips may have reduced air permeability and / or higher flexural stiffness compared to the filter medium. In an alternative embodiment, the filter medium forming the folded package and the frame material are the same.

[0022] In an embodiment, the frame element may include a side zone attached to the lateral fold profile and a top zone attached to the end fold section, and the filter element may also include a recess formed by an adjacent fold in the upstream fold, the side zone and a plane resting on the fold edge, and the internal volume may include a first sub-volume between the plane and the upstream fold and a second sub-volume between the cover element and the plane.

[0023] The cavity can be in the form of a triangular prism. More generally, it is formed as a convex hull corresponding to the adjacent fold. The second sub-volume also contains at least some adsorbent material. This allows for the use of a larger amount of adsorbent material compared to filling only the first sub-volume.

[0024] In this embodiment, the filler extends along the height of the folded pack, forming a cubic or block-shaped sub-volume filled with particulate adsorbent material at the top of the folded pack, which defines a prismatic sub-volume filled with particulate adsorbent material. This design ensures that all air passing through the filter must traverse the minimum path of adsorbent material across the thickness of the second sub-volume along the flow direction. This guarantees that every portion of the air undergoes a consistent minimum level of filtration, preventing any portion from bypassing the adsorbent through gaps or thinner sections. The uniform flow thickness enhances the overall efficiency and effectiveness of the filtration process.

[0025] In the embodiments, the filler also includes other particulate adsorbent materials that are different from the specific adsorbent material.

[0026] In the embodiments, the number of adsorbent materials is greater than two, thereby allowing the desired filtration and / or adsorption properties of a variety of different particulate adsorbent materials to be combined.

[0027] In the embodiments, different adsorbent materials are mixed or blended together. Combining different adsorbent materials in the filter in this manner offers several advantages. By integrating multiple adsorbents (each with unique properties and affinity for various pollutants), the filter can effectively target a wider range of pollutants. This synergistic approach enhances overall adsorption capacity and efficiency because each material can more effectively capture specific types of molecules.

[0028] Furthermore, the diverse pore structures and surface chemistry of adsorbents that are mixed or blended together create a more complex and effective filtration matrix, thereby reducing the likelihood of channel effects and ensuring more uniform contact between air and the adsorbent surface. This integrated filtration mechanism not only improves pollutant removal but also extends filter lifespan because the workload is distributed across different materials. Ultimately, the strategic integration of various adsorbents results in a more robust, versatile, and efficient filtration system.

[0029] In alternative embodiments, other particulate adsorbent materials may be present within the internal volume and at least partially cover the folded edges of the upstream fold, and the internal volume may include regions containing particulate adsorbent materials and other particulate adsorbent materials separately without mixing them. A region can refer to a distinct segment or area where a particular adsorbent material is used independently and is locally separated from other adsorbent materials. Regions can take various forms, such as layers, compartments, or segments. Additionally, the combination of these regions (where multiple segments are combined but still distinct from other materials) is also considered a region. Combining regions of different adsorbent materials in a filter, such as through layering or other configurations, without mixing them, offers several advantages. This method allows each adsorbent to function independently, thereby optimizing its specific properties for different pollutants. By arranging adsorbents in separate regions, the filter can sequentially treat various pollutants, thereby enhancing overall filtration efficiency. This separation prevents potential negative interactions between different adsorbents, such as one material interfering with the performance of another. It also avoids the problem of one adsorbent potentially degrading or dissolving another, thus ensuring the stability and effectiveness of each material. In addition, this method implements a more controlled and predictable filtration process because each adsorbent can be customized for a specific pollutant without compromising the performance of other adsorbents.

[0030] In the embodiments, there are cavities containing more than one type of particulate adsorption material.

[0031] In an embodiment, the filter element may further include another cover element attached to the frame element. The frame element may include a side zone attached to the lateral fold profile and a top zone attached to the end fold section. The filter element may also include a recess formed by an adjacent fold in the upstream fold, the side zone, and a plane resting on the fold edge, and other recesses formed by an adjacent fold facing the cover element in the downstream fold, the side zone, and a plane resting on the fold edge of the downstream fold. The recesses contain particulate adsorbent material, and other recesses contain other specific adsorbent materials. For example, alternating filling may exist, such that every other recess is filled with the same adsorbent, but adjacent recesses contain different adsorbent materials. The other cover element may be at least partially fixedly attached to the downstream fold of the folded package.

[0032] In an embodiment, at least two layers of adsorbent material in the direction between the upstream and downstream sides of the folded package can form a region. For example, a conventional zigzag particle filter element with a frame can be filled with a first adsorbent and then filled with a second adsorbent to form an adsorbent layer.

[0033] In embodiments, the filler may include loose materials, such as activated carbon, silica gel, etc. Loose materials refer to granular, powdery, or particulate matter characterized by its flowability and the ability to be handled without individual packaging. Loose materials can exhibit fluid-like behavior under certain conditions, including solid particles that can flow and conform to the shape of their container, similar to the behavior of a fluid. This flowability is due to the movement and rearrangement of individual particles within the loose material.

[0034] In this embodiment, the adsorbent material can be compacted. This compaction can be achieved by using adhesives, resins, slurries, etc., to fix the filler and prevent the flow of particles. Compaction refers to the process of reducing the volume and increasing the density of a material by applying pressure, binders, or other means. This process can reduce voids, rearrange particles into a tightly packed structure, and generally reduce the flow properties of the material. The main effects include increased density, enhanced mechanical strength, and reduced flowability. However, compacting the filler allows the fluid medium to be filtered (e.g., air) to still pass sufficiently through the filler.

[0035] In the embodiments, particulate adsorbents and other particulate adsorbents are implemented to adsorb any one or any combination of gaseous components, including carbon dioxide (CO2), water (H2O), volatile organic compounds (VOCs) (such as benzene, toluene, and formaldehyde), and nitrogen oxides (NOx). x The pollutants include sulfur dioxide (SO2), ammonia (NH3), hydrogen sulfide (H2S), methane (CH4), ozone (O3), particulate matter (PM) (including PM2.5 and PM10), heavy metals (such as mercury (Hg) and lead (Pb)), radon (Rn), chlorofluorocarbons (CFCs), polychlorinated biphenyls (PCBs), dioxins and furans, pathogenic microorganisms (including bacteria, microorganisms, viruses, and fungi), aromatic hydrocarbons (such as naphthalene and phenanthrene), polycyclic aromatic hydrocarbons (PAHs), silica dust, asbestos fibers, odors, liquids, and fluids. Various adsorbent materials can be used to effectively remove these pollutants, such as, for example, activated carbon, zeolite, silica gel, metal-organic frameworks (MOFs), and carbon nanotubes. This can be achieved by combining suitable adsorbent materials with appropriate adsorption properties.

[0036] In embodiments, the packing may comprise a carbon dioxide adsorbent and a moisture adsorbent, with the moisture adsorbent disposed downstream of the carbon dioxide adsorbent. In the adsorption modes described below, downstream refers to the downstream direction. These embodiments have the advantage that, in the regeneration mode (described below), the adsorbed moisture supports the regeneration of the carbon dioxide adsorbent when air, for example, having a predetermined regeneration temperature, flows in the opposite direction (opposite to the airflow direction during the adsorption mode). The predetermined regeneration temperature triggers the adsorbent to release the adsorbed material into the surrounding medium (e.g., hot air).

[0037] Adsorption is considered the process by which atoms, ions, or molecules from a gas, liquid, or dissolved solid attach to a surface, forming a thin film of adsorbate on the adsorbent. Desorption is considered the process by which atoms, ions, or molecules detach from the surface, reversing the adsorption process. This involves the adsorbate leaving the adsorbent surface, typically requiring energy to overcome binding forces. For example, by applying heat to the adsorbent, the adsorbed substance can be released from the adsorbent.

[0038] In adsorption mode, the filter, particularly the particulate filter media with adsorption / desorption properties, adsorbs various substances such as carbon dioxide and / or water. In desorption mode, the enriched substances can be released from the filter. This allows the filter to be regenerated. In desorption mode, heat can be applied to the particulate filter media, particularly the adsorbent. Desorption mode can also be referred to as regeneration mode.

[0039] In an embodiment, the filter element may include an upstream cap element and a downstream cap element, thereby forming an upstream internal volume and a downstream internal volume. Both the upstream and downstream internal volumes may contain particulate adsorption material. In an embodiment, the upstream and downstream internal volumes may contain different adsorption materials.

[0040] In this embodiment, both the upstream internal volume and the downstream internal volume include first and second upstream / downstream sub-volumes, as previously described. In this embodiment, the volume of the filler in the upstream internal volume is greater than that of the first upstream sub-volume, and / or the volume of the filler in the downstream internal volume is greater than that of the first downstream sub-volume.

[0041] In this embodiment, the four different sub-volumes (first / second upstream / downstream sub-volumes) contain different adsorbent materials, meaning that not all sub-volumes have the same adsorbent material as their filler. This produces and even improves upon the advantages described above regarding the use of different adsorbent materials, as greater flexibility in the arrangement of the adsorbent is achieved due to the double-sided filling (upstream and downstream). Double-sided use saves space because the gaps on both sides of the folded package can be used to store the adsorbent material.

[0042] In one embodiment, the cover element may be at least partially fixedly attached to the upstream fold of the folded package. In another embodiment, this can create different chambers within the internal volume. This can improve the stability of the filter element.

[0043] In embodiments, the folded package can form an annular folded bellows, i.e., a zigzag-shaped filter medium, such that the two end folds are connected, for example by means of adhesive, and the filter medium forms a cylindrical bellows. Therefore, in these embodiments, at least one cap element also has a cylindrical shape. This configuration enables radial flow, where air or fluid can move perpendicular to the axis of the cylinder, thus passing through the folds. The cylindrical cap element can be positioned on the outside or inside of the bellows as part of a framework surrounding the adsorbent material inside the folds.

[0044] According to a second aspect, a filter element is provided. The filter element includes a pleated package comprising a flat filter medium folded in a zigzag pattern, the pleated package including an upstream pleat and a downstream pleat. A frame element at least partially surrounds the pleated package, wherein the frame element is attached to a lateral fold profile and an end fold section of the pleated package. At least one cover element is attached to the frame element, thereby forming an internal volume defined by the pleated filter medium, the frame, and the cover element. The filler within the internal volume comprises at least one particulate adsorption material.

[0045] According to a third aspect, a filter element is provided. The filter element includes a pleated package comprising a flat filter medium folded into a zigzag shape, the pleated package including an upstream pleat and a downstream pleat. A frame element at least partially surrounds the pleated package, wherein the frame element is attached to a lateral fold profile and an end fold section of the pleated package. At least one cover element is attached to the frame element, thereby forming an internal volume defined by the pleated filter medium, the frame, and the cover element. The filler within the internal volume comprises at least two particulate adsorption materials.

[0046] According to a fourth aspect, a filter element is provided. The filter element includes a pleated package comprising a flat filter medium folded in a zigzag shape, the pleated package including an upstream pleat and a downstream pleat. A frame element at least partially surrounds the pleated package, wherein the frame element is attached to a lateral pleat profile and an end pleat section of the pleated package. An upstream cap element and a downstream cap element are attached to the frame element, thereby forming an upstream internal volume defined by the pleated filter medium, the frame, and the upstream cap element. A downstream internal volume is also formed, defined by the pleated filter medium, the frame, and the downstream cap element. The upstream and downstream internal volumes include a filler comprising at least one particulate adsorption material.

[0047] According to a fifth aspect, a method of manufacturing a filter element according to any of the described embodiments is provided. The method includes: providing a folded package; attaching a frame element to a lateral fold profile and an end fold section of the folded package, thereby at least partially surrounding the folded package; placing a particulate adsorbent material as a filler between upstream folds such that the filler at least partially covers the fold edges of the upstream folds; and attaching a cover element to the frame element, thereby forming an internal volume defined by the folded filter medium, the frame element, and the cover element.

[0048] Optionally, the method further includes filling the top of the fold on the opposite side with particulate adsorption material and attaching a cover element to the frame element on that side, thereby enclosing the added particulate adsorption material between the folded filter medium, the frame, and the cover element.

[0049] In an embodiment, instead of the first method step, a conventional filter element with a flat filter medium and frame in a zigzag pattern for trapping particles can be used.

[0050] Other possible embodiments or alternative solutions of the invention include combinations of features not expressly mentioned herein that are described above or below with reference to the embodiments. Those skilled in the art can also add individual or isolated aspects and features to the most basic form of the invention.

[0051] It should be understood that features of the embodiments disclosed above with respect to one aspect or below with respect to the drawings and claims may also be used in conjunction with other aspects of this disclosure. Attached Figure Description

[0052] Further embodiments, features, and advantages of the invention will become apparent from the accompanying drawings, the following description, and the dependent claims.

[0053] Figure 1 This is a schematic diagram of a motor vehicle equipped with an internal air filter.

[0054] Figure 2 A perspective view of a flat particulate filter medium used in embodiments of the disclosed filter element is shown.

[0055] Figure 3 An exploded view of a filter element according to a first embodiment of the filter element is shown.

[0056] Figure 4 A perspective view is shown of a folded package containing particulate filter media folded into a zigzag shape.

[0057] Figure 5 A perspective view of a folded bag with a top and side stripe attached is shown.

[0058] Figure 6 A schematic cross-sectional view of the first embodiment is shown.

[0059] Figure 7 A schematic cross-sectional view of the first embodiment is shown.

[0060] Figures 8 to 11 A schematic cross-sectional view showing another embodiment of the filter element.

[0061] Figure 12 A flowchart is shown, including the method steps involved in the method for manufacturing a filter element.

[0062] Figure 13 An exploded view of a filter element according to an alternative embodiment of the filter element is shown.

[0063] Figure 14 A perspective view of a filter element according to another alternative embodiment of the filter element is shown.

[0064] In the figures, unless otherwise specified, similar or functionally similar elements are marked with the same reference numerals. Detailed Implementation

[0065] Figure 1 A motor vehicle 101 is shown with an air conditioning system including a filter element 102. For example, the air conditioning system may be designed as a heating / air conditioning system. The air conditioning system draws in outside air 103 and directs it through the filter element 102, then releases the cleaned air 104 into the passenger compartment or cabin 105 of the motor vehicle 101. In some operating modes, the recirculated air needs to be filtered and taken back from the passenger compartment 105. The latter is indicated by dashed arrow 106. Filtration is carried out by means of the filter element 102, which is implemented as an internal air filter. The internal air filter 102 includes the filter element described below with respect to embodiments.

[0066] Figure 2 It is shown that it can be individually processed into a foldable bag 2 (e.g., as shown below). Figure 4 The diagram shows a perspective view of a flat filter medium 1. The filter material is, for example, a nonwoven filter, a fabric filter, a laid filter or filter felt, particularly needle-punched felt. Specifically, the filter medium 1 can be produced by a melt-blowing method. The filter material can include natural fibers (such as cotton) or synthetic fibers such as polyester, polyphenylene sulfide, or polytetrafluoroethylene. The fibers can be stretched in the spatial direction. The filter material can be designed as a single layer or multiple layers.

[0067] Specifically, open-type filter media can be designed to remove particles of test dust A4 according to ISO 12103-1 from an airflow at a filtration rate of 0.10 to 0.30 m / s, with an air permeability greater than 3,000 l / m² relative to the filter media surface. 2s (determined at 200 Pa according to ISO-9237). Filter characteristics can be determined, for example, according to DIN71460-1.

[0068] Specifically, high-separation filter media can be designed to remove particles of test dust A2 according to ISO 12103-1 and NaCl aerosol particles according to DIN 71460-1 from an airflow at a filtration rate of 0.10 to 0.30 m / s, with an air permeability greater than 600 l / m² relative to the filter media surface. 2 s (determined at 200 Pa according to ISO-9237). Filter characteristics can be determined, for example, according to DIN71460-1.

[0069] In this embodiment, the filter medium is manufactured as a synthetic medium with a multilayer structure. The basis weight of the filter material preferably reaches 50-150 g / m³. 2 .

[0070] The filter media preferably corresponds to the efficiency class E10-14 of DIN EN 1822-3 as of the date of submission of this application.

[0071] The flat filter medium 1 has a boundary comprising peripheral edges 22A, 22B, 22C, and 22D. To form the folded package 2, the flat filter medium is folded along the indicated dashed and dotted lines 15B and 15C, such that the dashed and dotted lines 15B and 15C become oppositely oriented folded edges (15) and (15A) in the folded package 2 (see...). Figure 4 The folds can be created by folding along sharp edges or by a corrugated configuration of the filter medium 1. The filter element can be designed to be self-supporting, i.e., as shown in the image. Figure 3 The upstream fold 2A and downstream fold 2B generated by the folded package (through folding, etc.) shown in the diagram are shape-stable for the expected flow during the filtration operation. Figure 4 The diagram below shows the resulting folded bag in more detail. Due to the folding, fold lines 15B and 15C become folded edges 15 and 15A.

[0072] Figures 3 to 7 The illustration shows a filter element according to an embodiment, illustrating different perspective and cross-sectional views of the embodiment or a portion thereof.

[0073] Figure 3 An exploded view of the filter element 10 according to the first embodiment is shown. (The image is folded as shown.) Figure 2 The flat filter medium 1 shown is positioned within the frame element 12 and covered by the cover element 7 having lateral flanges 13A, 13C. Figure 3Arrow RF represents the raw fluid (e.g., the air to be filtered), and arrow CF represents the cleaning fluid. Figure 3 In terms of orientation, the air to be cleaned or filtered flows from the top to the bottom of the page, thereby defining the upstream and downstream sides of the filter element 10.

[0074] The filter element 10 includes a pleated package 2, which includes a flat filter medium 1 folded in a zigzag shape. The pleated package 2 includes an upstream pleat 2A and a downstream pleat 2B. A frame element 12 includes side zones 3A, 3B and top zones 4A, 4B, and surrounds the pleated package 2. The frame element 12 is attached to the lateral fold profiles 5A, 5B and end fold sections 6A, 6B of the pleated package 2 (see [link to documentation]). Figure 4 The cover element 7 is attached to the frame element, thereby forming an internal volume defined by the folded filter medium (folded package 2), the frame 12, and the cover element 7. The internal volume 8 is filled with adsorbent material 9, as described below.

[0075] The folded package 2 includes an upstream fold 2A and a downstream fold 2B with opposite orientations. The folds 2A and 2B of the folded package form a recess 11 (see...). Figures 4 to 7 The upstream fold 2A, together with the side zones 3A and 3B and the cover element 7, forms the internal volume 8. The internal volume 8 contains a filler 14, which includes a particulate absorbent material 9 covering at least one fold edge 15; that is, the filler 14 is also present on the outside of the recess 11 (see also...). Figure 6 The frame includes opposing top zones 4A and 4B and opposing side zones 3A and 3B, thus forming the side surfaces of the cube.

[0076] The folding bag 2 has end folding sections 6A and 6B, which are two folding sections adjacent to the top sections 4A and 4B of the frame 12. The term folding section refers to a section between two consecutive folding edges; or, for an end section, it refers to a section between the corresponding folding edge of the folding bag and the corresponding end 22A or 22B. Lateral folding profiles 5A and 5B perpendicular to the folding edge 15 are adjacent to the side sections 3A and 3B. The folding bag 2 has a height h1, which is given as the vertical distance from the bottom to the top of a complete zigzag unit, where the zigzag unit is considered, for example, as a triangle. The frame has a height h2, which is given as the length of the shorter of the two side sections of the top section (4A).

[0077] Figure 4The folded package 2 is shown in more detail, particularly the filter medium 1 folded along fold edges 15 and 15A to form the folded package 2, illustrated as including an upstream fold 2A and a downstream fold 2B. The upstream fold is the section of the folded package surrounding two adjacent fold edges, where these edges are oriented opposite to the flow direction of the original fluid. Similarly, the downstream fold is the section of the folded package 2 surrounding two adjacent fold edges, where these edges are oriented along the flow direction of the original fluid RF. The folded package 2 has a height h1, as described above. It has lateral fold profiles 5A and 5B formed in a zigzag shape. The two outermost folded sections of the folded package 2 are two end fold sections 6A and 6B. The upstream fold 2A and downstream fold 2B can be created by folding along sharp fold edges or by corrugation of the filter medium 1. Folds with different heights are also possible. Furthermore, the fold distance A between corresponding fold edges 15 with the same fold orientation can vary within the embodiment and also between different embodiments.

[0078] The filter medium 1 can be designed to be self-supporting, meaning that the folds are shape-stable for the expected flow during orientation operations. The filter medium 1 is defined by end fold sections 6A and 6B. Figure 2 The flat filter medium 1 shown in the figure has a rectangular shape. However, triangular, pentagonal, polygonal, circular, or oval shapes are also conceivable.

[0079] In variations, the folding distance is less than 5 mm. Examples of filter elements as HEPA filters are conceivable. The thickness of the filter medium 1, particularly the HEPA filter material, is, for example, between 0.2 mm and 1 mm. In other embodiments, significantly thicker filter materials 1 can also be used, for example, so-called composite filter media, which include a gas adsorption filter layer in addition to at least one particulate filter layer. Here, the thickness can reach up to 2 mm, or even up to 3 mm. Accordingly, the folding distance is also chosen to be larger, particularly greater than 5 mm.

[0080] Figure 5A filter element 10 without a cap and filler is shown to illustrate the available internal volume for filling. A folded package 2 is placed within a frame 12. The frame 12 encloses the folded package 2 within a three-dimensional boundary conforming to a cuboid shape, thereby providing structural support and defining the spatial limits of the filter element. The frame 12 includes opposing side zones 3A and 3B and opposing top zones 4A and 4B. The frame has a height h2 that extends beyond the height h1 of the folded package 2. To manufacture the filter element, circumferential frame elements are attached to the folded package 2. For example, side zones 3A and 3B are attached to lateral fold profiles 5A and 5B, and top zones 4A and 4B are attached to end fold sections 6A and 6B. This can be accomplished by means of adhesives, welding, etc. In embodiments, particularly but not limited to, auxiliary materials that ensure a strong bond are used at the thin lateral fold profiles 5A, 5B. These auxiliary materials may include reinforcing strips, adhesives, or support structures to enhance adhesion and stability.

[0081] Next, we will describe in more detail the internal volume of the filter element.

[0082] Figure 6 Show Figures 3 to 7 The diagram shows a partial cross-sectional view of the filter element 10, in which a folded package 2 is positioned within a frame 12, which includes a cover element 7, an optional cover element 7A, and a top zone 4B. Cover elements 7 and 7A are attached to the top and side zones and may be partially attached to the folded package. This can be accomplished using adhesives, welding, etc. In embodiments, auxiliary materials are used to ensure a strong bond. These auxiliary materials may include reinforcing strips, adhesives, or support structures to enhance adhesion and stability. The folded package 2 has been folded along the fold edge 15 to form a recess 11. Particulate adsorption material 9 is positioned between the fold 2A facing the cover element 7, the top zone 4B, and the cover element 7. The filler 14 comprises particulate adsorption material 9 covering the fold edge 15. The folded package 2 has a height h1, and the frame has a height h2, where h2 is greater than h1.

[0083] It should be understood that the entire internal volume between the upstream cover 7 and the folded package 2 is occupied by the filler 14 (dashed area). The filler 14 (e.g., a compacted loose material with absorbent properties) extends on or above the folded edge 15 facing the cover 7. The cover 7 is securely attached to the frame by a laterally projecting flange 13B. Figure 6 The side zone 4B is sealed to the interior relative to the particulate filler 14. This also applies to the optional downstream cover element 7A relative to the flange 21B.

[0084] During operation, the air to be filtered passes through at least the area above the fold or recess 11. This achieves a minimum flow path of length h2 - h1, along which unwanted gaseous components are removed from the air.

[0085] Figure 7 Show Figure 6 An extended cross-sectional view of the embodiment illustrated herein. The folded package 2 is positioned within a rectangular frame 12, which includes a cover element 7, an optional cover element 7A, and top zones 4A and 4B. A filler 14, comprising particulate adsorbent material 9, largely fills the space between the upstream fold 2A, top zones 4A and 4B, and cover element 7. The folded package 2 is folded along fold edges 15 and 15A. The zigzag upstream fold 2A and downstream fold 2B form recesses 11. Figure 7 In the perspective view, the zigzag lateral fold outline 5A is drawn as a front view of the drawing plane. Two planes, E1 and E2, are drawn as dashed lines resting on the folds with different orientations. E1 divides the entire upstream internal volume into a first sub-volume (above E1, upstream relative to the filter medium) and a second sub-volume (below E1, upstream relative to the filter medium). This embodiment shows that both sub-volumes will be filled with adsorbent material.

[0086] Figure 8 A second embodiment of the filter element 110 is shown, which differs from the filter element 110 in the following respects. Figure 7 :exist Figure 8 In this embodiment, the filler 14 includes additional particulate adsorbent material 9A, which fills the space between the downstream fold 2B, the top zones 4A and 4B, the side zones (not shown), and the cover element 7A (which is not optional in this embodiment). The two different filler materials 9, 9A achieve sequential adsorption along the airflow path. Furthermore, the available space within the frames 4A, 4B and the covers 7, 7A is efficiently used to adsorb unwanted gases.

[0087] To illustrate different adsorbent materials 9 and 9A, in Figures 8 to 11 Different dot or line patterns are used. In the embodiments, the particulate adsorption materials 9 and 9A are the same material.

[0088] Figure 9 A third embodiment of the filter element 111 is shown, which differs from the filter element 111 in the following ways. Figure 7Instead of a single adsorbent, two different adsorbent materials 9 and 9A are used. In the illustrated third embodiment, these adsorbents are arranged in alternating layers represented by different textures. Each recess 11 contains two different adsorbent materials 9 and 9A, and furthermore, the filling material positioned outside the recess also comprises two different adsorbent materials 9 and 9A. The adsorbents used may include activated carbon and zeolite. Activated carbon is well-suited for adsorbing organic compounds and odors, while zeolite effectively captures smaller molecules such as ammonia and nitrogen oxides. However, in different embodiments, the adsorbents may include silica gel and activated alumina. Silica gel effectively adsorbs moisture, and activated alumina can adsorb a variety of gases and vapors, including fluorides and sulfur compounds. In yet another embodiment, the adsorbents used may include carbon nanotubes and metal-organic frameworks (MOFs). Carbon nanotubes provide high surface area and good adsorption properties for a wide variety of pollutants, while MOFs can be tailored for specific target gases.

[0089] Figure 10 A fourth embodiment of the filter element 112 is shown, which differs from... Figure 8 The key feature is that the height h2 of the frame 12 extends beyond the height h1 of the folded package 2 in both directions. This increases the space available for the filler 14 on the downstream side.

[0090] Figure 11 A fifth embodiment of the filter element 113 is shown, which differs from the following in that... Figure 9 The filling material 14 inside the recesses 11 and 11A includes only one particulate adsorbent material 9A, and the filling material 14 outside the recesses 11 includes only one (but different) particulate adsorbent material 9.

[0091] Figure 12 The illustration shows an example of a method for manufacturing a filter element (e.g., any of the previously disclosed embodiments). First, in step S0, a flat filter medium 1 is folded into a zigzag shape to form a folded package 2. As described above, the folds can be created by folding along sharp edges or by a wavy configuration of the flat filter medium 1.

[0092] S1 refers to the method steps of providing a folded package 2 (e.g., a folded package generated in S0). The folded package 2 is a flat filter medium 1 folded into a zigzag shape, and the folded package 2 includes an upstream fold 2A and a downstream fold 2B.

[0093] S2 refers to the method steps of attaching frame 12 to folding bag 2. This may include attaching frame elements 3A, 3B, 4A, 4B to the lateral folding contours 5A, 5B and end folding sections 6A, 6B of the folding bag, thereby at least partially surrounding the folding bag 2 (see [link to product description]). Figure 4 and Figure 5 ).

[0094] Next, in step S3, the particulate adsorbent material 9 is placed as a filler between the folds 2A. Specifically, the filler 14 at least partially covers the folded edges of the folds.

[0095] Then, in step S4, the cover element 7 is attached to the frame (elements 3A, 3B, 4A, 4B) to form an internal volume defined by the folded filter medium, the frame 12 (3A, 3B, 4A, 4B) and the cover element 7.

[0096] S5 refers to the following optional method step: filling the top of the folded portion on the opposite side with particulate adsorption material, and attaching the cover element to the frame element on that side, thereby enclosing the added particulate adsorption material between the folded filter media, frame, and cover element. This results in... Figure 8 or Figure 10 The configuration of the filter elements shown.

[0097] Figure 13 An exploded view of an alternative embodiment of filter element 114 is shown, and it differs from the following in that... Figure 3 The height h1 of the folded bag 2 is equal to the height h2 of the frame 12. Figure 13 The diagram also illustrates a downstream cover element 7A, which includes protruding flanges 21A, 21B, 21C, and 21D. Filler may be provided upstream and / or downstream of the folded package 2 and may include one or more absorbent materials.

[0098] Figure 14 Another alternative embodiment of the illustrated filter element 115, which differs from... Figure 13 The embodiment illustrated in the figure is characterized in that, Figure 14 In the middle, the recesses 11 and 11A on both sides (upstream and downstream) are filled with filling material 14, especially filling material 14 including different particulate adsorption materials 9 and 9A.

[0099] List of reference numerals 1. Flat filter media 2 Folding Bag 2A Upstream Fold Section 2B Downstream Fold Section 3A Side Zone 3B Side Zone 4A Top Zone 4B Top Zone 5A Lateral Folding Profile 5B Lateral fold profile 6A End Folding Section 6B End Folding Section 7. Cover element 7A Cover Component 8 Internal volume 9. Particulate Adsorption Materials 9A Particulate Adsorbent Material 10 Filter elements 11. Depression 11A has a concave cavity with a different orientation compared to 11. 12 Framework 13A Protruding flange 13B Protruding flange 13C Protruding flange 14. Filler 15 Folded edges 15A Folded Edge 15B Folded Line 15C Folded Line 20. Dashed lines surrounding the depression 21A Protruding flange 21B Protruding flange 21C Protruding flange 21D Protruding flange 22A Peripheral edge of filter media 22B Peripheral edge of filter media 23A Peripheral edge of filter media 23B Peripheral edge of filter media 101 Motor Vehicles 102 Filter element 103 Outside air 104 Cleaned air 105. The carriage of a motor vehicle 106 Airflow of recirculated air 110 Filter element 111 Filter element 112 Filter element 113 Filter element 114 Filter element 115 Filter element E1 The flat surface resting on the fold section E2 The flat surface resting on the fold section RF raw fluid CF Cleaned Fluid FD flow direction A. Width between folded edges h1 Height of the folded bag The height of the h2 frame

Claims

1. A filter element (10) comprising: The folding package (2) includes a flat filter medium (1) folded into a zigzag shape, and the folding package (2) also includes an upstream fold (2A) and a downstream fold (2B). The frame elements (3A, 3B, 4A, 4B) at least partially surround the folded bag (2), and the frame elements (3A, 3B, 4A, 4B) are attached to the lateral folding profile (5A, 5B) and end folding sections (6A, 6B) of the folded bag (2). A cover element (7) is attached to the frame elements (3A, 3B, 4A, 4B) to form an internal volume (8) defined by the folded filter medium (1), the frame elements (3A, 3B, 4A, 4B), and the cover element (7); and The filler (14) comprises a particulate adsorbent material (9) within the internal volume (8) and at least partially covers the folded edge (15) of the upstream fold (2A) facing the cover element (7).

2. The filter element (10) according to claim 1, wherein The folded package has a height (h), which is the distance between two planes (E1) and (E2) resting on the folded edge (15) and another folded edge (15A) of the downstream fold (2B), respectively, the folded edge (15) and the other folded edge (15A) having opposite orientations, and The frame elements (3A, 3B, 4A, 4B) extend beyond the height (h).

3. The filter element (10) according to claim 1, wherein The frame elements (3A, 3B, 4A, 4B) include side sections (3A, 3B) attached to the lateral folding profiles (5A, 5B) and top sections (4A, 4B) attached to the end folding sections (6A, 6B). The filter element (10) further includes a recess (11) formed by the adjacent fold in the upstream fold (2A), the side zones (3A) and (3B), and the plane (E1) resting on the fold edge (15), and The internal volume (8) includes a first sub-volume between the plane (E1) and the upstream fold (2A), and a second sub-volume between the cover element (7) and the plane (E1).

4. The filter element (10) according to any one of claims 1 to 3, wherein The filler (14) also includes other particulate adsorbent materials (9A) that are different from the particulate adsorbent material (9).

5. The filter element (10) according to claim 4, wherein The other particulate adsorbent material (9A) is within the internal volume (8) and at least partially covers the folded edge (15) of the upstream fold (2A), and The internal volume (8) includes regions containing the particulate adsorbent material (9) and the other particulate adsorbent material (9A), respectively.

6. The filter element (10) according to claim 4, further comprising another cover element (7A) attached to the frame elements (3A, 3B, 4A, 4B). in, The frame elements (3A, 3B, 4A, 4B) include side sections (3A, 3B) attached to the lateral folding profiles (5A, 5B) and top sections (4A, 4B) attached to the end folding sections (6A, 6B). The filter element (10) further includes: A recess (11) formed by the adjacent fold in the upstream fold (2A), the side zones (3A) and (3B), and the plane (E1) resting on the fold edge (15); and Other recesses (11A) formed by the adjacent folds of the downstream fold (2B) facing the cover element (7A), the side zones (3A) and (3B), and the plane (E2) resting on another fold edge (15A) of the downstream fold (2B), and The cavity (11) contains the particulate adsorbent material (9), and the other cavity (11) contains the other particulate adsorbent material (9A).

7. The filter element (10) according to claim 6, wherein, The folded package has a height (h), which is the distance between two planes (E1) and (E2) resting on the folded edge (15) and another folded edge (15A) of the downstream fold (2B), respectively, the folded edge (15) and the other folded edge (15A) having opposite orientations, and The frame elements (3A, 3B, 4A, 4B) extend beyond the height (h) in both directions.

8. The filter element (10) according to claim 6, wherein, The other cover element (7A) is at least partially fixedly attached to the downstream fold (2B) of the folded bag (2).

9. The filter element (10) according to any one of claims 4 to 8, wherein, The particulate adsorbent material (9) and the other particulate adsorbent material (9A) are compacted.

10. The filter element (10) according to any one of claims 4 to 9, wherein, The particulate adsorbent material (9) and the other particulate adsorbent material (9A) are configured to adsorb any one or any combination of gaseous components, including carbon dioxide, water, hydrocarbons, VOCs, odors, microorganisms, and liquids.

11. The filter element (10) according to any one of the preceding claims, wherein, The filler (14) comprises loose material.

12. The filter element (10) according to any one of the preceding claims, wherein, The filler (14) comprises a carbon dioxide adsorbent and a moisture adsorbent, the moisture adsorbent being disposed downstream of the carbon dioxide adsorbent.

13. The filter element (10) according to any one of the preceding claims, wherein, The cover element (7) is at least partially fixedly attached to the upstream fold (2A) of the folded bag (2).

14. The filter element (10) according to any one of the preceding claims, wherein, The folded package (2) forms an annular folded corrugated tube.

15. A method of manufacturing a filter element (10) according to any one of the preceding claims, the method comprising: Foldable bags are provided (2); The frame elements (3A, 3B, 4A, 4B) are attached to the lateral folding profiles (5A, 5B) and end folding sections (6A, 6B) of the folding bag (2) to at least partially surround the folding bag (2). A particulate adsorbent material (9) is placed between the upstream folds (2A) as a filler (14), such that the filler (14) at least partially covers the folded edge (15) of the upstream fold (2A); and The cover element (7) is attached to the frame elements (3A, 3B, 4A, 4B) to form an internal volume (8) defined by the folded filter medium (1), the frame (3A, 3B, 4A, 4B) and the cover element (7).

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