Patent Publication Number: US-2021178305-A1

Title: Adsorber Element for a Filter System and Filter System with an Adsorber Element

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns an adsorber element for a filter system, in particular an air filter system, as well as a filter system with an adsorber element. 
     DE 10 2013 013 390 A1 discloses a filter system with an adsorber element. The adsorber element is movably supported so that the effective flow cross section for the fluid is changeable by a position change of the adsorber element. 
     SUMMARY OF THE INVENTION 
     The invention has the object to provide an adsorber element for a filter system with improved efficiency. 
     A further object is providing a filter system with improved adsorber properties. 
     The aforementioned object is solved according to one aspect of the invention by an adsorber element with at least one adsorber medium for a filter system, wherein the filter system comprises a housing with an inlet and an outlet and the filter system can be flowed through by a gaseous fluid from the inlet to the outlet. A frame is provided comprising a base plate and one or a plurality of rigid support elements projecting away from the base plate, wherein the base plate and the support elements comprise at least in sections thereof the adsorber medium. 
     The further object is solved by a filter system comprising a housing with an inlet and an outlet and a filter element arranged between inlet and outlet, wherein the filter system can be flowed through by a gaseous fluid flowing from the inlet to the outlet, and further comprising at least one adsorber element according to the invention. 
     Beneficial configurations and advantages of the invention result from the further claims, the description, and the drawing. 
     An adsorber element is proposed with at least one adsorber medium for a filter system, wherein the filter system comprises a housing with an inlet and an outlet and the filter system can be flowed through by a gaseous fluid from the inlet to the outlet. A frame comprising a base plate and one or a plurality of rigid support elements projecting away from the base plate is provided, wherein the base plate and the support elements at least in sections thereof comprise the adsorber medium. 
     Advantageously, the adsorber element can be used as an HC trap in a clean air flow, in particular in a motor vehicle, in which back-diffusing hydrocarbons (HC) are to be adsorbed from the clean air when the internal combustion engine is turned off. 
     A large surface of the adsorber medium is available because the base plate as well as the sail-shaped support elements can be covered with adsorber medium. Moreover, the free-standing sails provide the possibility that both sides of the adsorber medium come into contact with the fluid. This provides for an increased adsorption performance and desorption performance of the adsorption element. 
     Since the support elements are rigidly embodied, the fluid flow at the adsorber element is only affected to a small extent, in particular, the adsorber element causes no significant increase of the pressure loss. Due to the rigid arrangement of the support elements, the flow of the fluid does not change in an unpredictable manner so that measured values of an air-mass meter, for example, a hot-film air mass meter, in the fluid flow are not falsified. 
     The frame with base plate and support elements can be produced by injection molding, 3D printing or the like. The configuration provides for good mold removal of the frame of the adsorber element. 
     According to a beneficial configuration of the adsorber element, the base plate can comprise openings, in particular the base plate can be designed in a grid shape. Advantageously, the adsorber medium, for example, an adsorber mat, can be accessible for the fluid flow through the permeable base plate. The base plate can serve as a carrier for the adsorber medium. 
     According to a beneficial configuration of the adsorber element, the adsorber medium arranged on the base plate can be arranged on a side of the base plate which is oppositely positioned to the support elements. This can be the backside of the base plate. In this way, fluid can reach the adsorber medium. The base plate can advantageously be formed by two parts, a top plate and a bottom plate, which enclose the adsorber medium. The support elements project away from the base plate when the latter is of a single plate design or from one of the two plates when the latter is embodied of two plates. The second plate can also have openings so that the fluid can reach the adsorber medium from this side also. In this way, a simple mounting of the adsorber medium can be realized. The latter can be embodied beneficially as a mat or the like. 
     According to a beneficial configuration of the adsorber element, at least one support element can support the adsorber medium of the support element at least at one side. The adsorber medium can be held stably at the support element. 
     According to a beneficial configuration of the adsorber element, at least one of the support elements can comprise a pocket for holding the adsorber medium. The adsorber medium, for example, as a mat, can be pushed simply into the pocket. 
     According to a beneficial configuration of the adsorber element, the base plate on its side oppositely positioned to the support elements can be covered with a fluid-tight cover. In this way, the adsorber medium on the base plate can be protected. In particular, this enables a transportation capability of the adsorber element. 
     According to a beneficial configuration of the adsorber element, the adsorber medium can comprise at least one activated carbon-containing layer, comprising a gas-permeable carrier layer on which an activated carbon layer is arranged. The activated carbon layer can be formed by a fluid-permeable adhesive layer on which activated carbon particles are applied. Advantageously, the adsorber medium can be formed by a plurality of such layers. The number of layers can be selected according to need. 
     According to a beneficial configuration of the adsorber element, the activated carbon layer can be covered by a gas-permeable holding layer. In this way, the activated carbon layer can be fixed securely on the carrier layer and form a self-supporting activated carbon-containing layer. 
     According to a beneficial configuration of the adsorber element, support elements and base plate with adsorber medium arranged thereat can be sealed at their rims. In this way, it can be permanently prevented that activated carbon particles or other particles become detached from the adsorber medium and reach the clean air flow. 
     According to a further aspect of the invention, a filter system is proposed comprising a housing with an inlet and an outlet and a filter element arranged between inlet and outlet, wherein the filter system can be flowed through by a gaseous fluid flowing from the inlet to the outlet, and further comprising at least one adsorber element according to the invention. 
     The adsorber element comprises a frame, comprising a base plate and one or a plurality of rigid support elements projecting away from the base plate, wherein the base plate and the support elements comprise at least in sections thereof the adsorber medium. 
     Advantageously, the support elements can be oriented in the direction toward a clean air socket, i.e., they produce no significant pressure loss and do not impair the flow guiding action and the signal of a possibly present air-mass meter. 
     Beneficially, the base plate can be combined of two parts between which the adsorber medium of the base plate is enclosed. 
     According to a beneficial embodiment of the filter system, the base plate of the adsorber element can be arranged substantially parallel to a region of an outer wall of the housing. The adsorber element can be mounted beneficially, for example, in a clean air hood of a clean air supply of an internal combustion engine. Alternatively, the base plate can also be arranged differently, for example, at a slant to the outer wall. 
     According to a beneficial embodiment of the filter system, the base plate can be arranged at a distance from the region of the outer wall. For example, one or a plurality of spacers can be arranged therebetween. Beneficially, adsorber medium can be arranged on the side of the base plate facing away from the support elements which has openings for this purpose. Due to the distance of the base plate from the region of the outer wall, fluid can reach also the backside of the base plate whereby the adsorber surface of the base plate is practically doubled. 
     According to a beneficial configuration of the filter system, the support elements with their adsorber medium can be arranged substantially parallel to the main flow direction between an outflow side of the filter element and the outlet of the housing. Advantageously, the rigid support elements produce no noteworthy pressure loss and do not impair the flow guiding action and the signal of a possibly present air-mass meter. Also beneficial is a sail-type shape of the support elements. 
     According to a beneficial configuration of the filter system, the adsorber element can be arranged downstream of the filter element between an inlet-side raw side and an outlet-side clean side. In this context, a pressure loss of the filter element is substantially determined only by the filter element. 
     According to a beneficial configuration of the filter system, the adsorber element can be arranged in a clean air region, for example, in a clean air hood. Beneficially, an operation of an air-mass meter can remain unaffected due to the only minimal pressure loss of the adsorber element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages result from the following drawing description. Embodiments of the invention are illustrated in the drawings. The drawings, the description, and the claims contain numerous features in combination. A person of skill in the art will consider the features expediently also individually and combine them to expedient further combinations. 
         FIG. 1  shows a perspective view of an adsorber element according to an embodiment of the invention. 
         FIG. 2  shows a side view of the adsorber element according to  FIG. 1 . 
         FIG. 3  shows in exploded illustration components of the adsorber element according to  FIG. 1 . 
         FIG. 4  shows in exploded illustration components of the adsorber element according to  FIG. 1 . 
         FIG. 5  shows a section view of an adsorber medium according to an embodiment of the invention. 
         FIG. 6  shows a plan view of a clean air hood of an air filter with an adsorber element installed in the clean air hood. 
         FIG. 7  shows a section through a filter system with filter element and adsorber element according to an embodiment of the invention. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the Figures, same or similar components are identified with same reference characters. 
       FIGS. 1 through 4  show various views of an adsorber element  40  according to an embodiment of the invention. The adsorber element  40  is in particular suitable for a filter system with a gaseous fluid flow, in particular for an air filter system, in which hydrocarbons are to be removed at the clean side of the filter system. The adsorber medium  42  adsorbs this foreign matter at the clean gas side. 
       FIG. 1  shows a perspective view of the adsorber element  40 .  FIG. 2  shows a side view of the adsorber element  40 .  FIG. 3  shows in exploded illustration components of the adsorber element  40 , and  FIG. 4  shows in exploded illustration components of the adsorber element  40  in almost assembled state. 
     The adsorber element  40  comprises a frame  30  with a base plate  44  and one or a plurality of, in this example two, rigid support elements  50  projecting away from the base plate  44  and embodied sail-like. The support elements  50  are arranged rigidly on the base plate  44 . The base plate  44  and the support elements  50  each comprise adsorber medium  42 . The adsorber medium  42  is expediently provided in a mat form. 
     The base plate  44  is embodied grid-shaped so that fluid that passes alongside the base plate  44  can reach the adsorber medium  42  through openings  54 , of which some are identified with reference characters. In this example, the base plate  44  comprises a top plate  46  and a bottom plate  48  between which the adsorber medium  42  is arranged. The bottom plate  48  is also embodied grid-shaped so that fluid that passes alongside the backside of the base plate  44  can also reach the adsorber medium  42 . The efficiency of the adsorber surface as well as the inflow surface of the base plate  44  are thus doubled. 
     The two support elements  50  support the adsorber medium  42  of the respective support element  50  at least at one side. In the illustrated embodiment, the two support elements  50  are designed in the form of a pocket  52  into which the adsorber material  42  can be inserted. This can be seen in the  FIGS. 3 and 4 . 
     The two pocket-like support elements  50  project rigidly away from the top plate  46  of the base plate  44  into which a mat-shaped adsorber element  42  can be inserted, respectively. The top plate  46  of the base plate  44  and the support elements  50  are embodied as one piece, for example. The bottom plate  48  of the base plate  44  can be fastened to the top plate  46  and, for example, can be fixedly clipped, screwed, glued, fused thereto. 
     Between the two plates  46 ,  48  of the base plate  44 , a mat-shaped adsorber element  42  is inserted and clamped fixedly by the connected plates  46 ,  48 . The base plate  44  and the support elements  50  comprises closed rims so that the adsorber media  42  in the support elements  50  and the base plate  44  are sealed at the rim and no adsorption material can escape from the adsorber element  40 . 
     The base plate  44  is slightly curved and can be adapted easily to an installation situation in an air filter housing or the like. 
     The base plate  44  can be covered optionally at its side  58  which is oppositely positioned to the support elements  50  by a fluid-tight cover (not illustrated). This permits an improved transportation capability of the base plate  44  so that the adsorber element  40  can be produced at a different location than the air filter system and can then be installed in the latter. 
       FIG. 5  shows a section illustration of an adsorber medium  42  according to an embodiment of the invention. The adsorber medium  42  is embodied, for example, as a single activated carbon layer  80 . The adsorber medium  42  can also be comprised of a plurality of such layers  80 . 
     In the illustrated embodiment, an adsorbent layer  72 , in particular an activated carbon layer  72 , is arranged on a gas-permeable carrier layer  70 . The activated carbon layer  72  is secured in this context by an adhesive layer  74  on the carrier layer  70 . The activated carbon layer  72  is covered by a gas-permeable holding layer  76 . 
     Preferably, the adsorbent layer  72  is laid onto the carrier layer  70 . In this way, it can be ensured that this layer  72  ensures a high fluid permeability. The efficiency can be controlled by type and quantity of the adsorbent. 
     The carrier layer  70  can be comprised, for example, of one or a plurality of flat layers of polyethylene terephthalate (PET). The flat layer can be stamped out. The adsorbent layer  72  can also be applied in several layers onto the carrier layer  70 . 
       FIG. 6  shows a plan view of a clean air hood  102  of an air filter system  100  with the adsorber element  40 , as it is described in the preceding embodiment, installed in the clean air hood  102 .  FIG. 7  shows a section of the filter system  100  with a filter element  104  and an adsorber element  40  according to an embodiment of the invention. The adsorber element  40  is fastened, for example, non-detachably welded, in the housing  10  with tabs at the rim of the base plate  44 . 
     The filter system  100  comprises a housing  10  with an inlet  12  and an outlet  14  and can be flowed through by a gaseous fluid from the inlet  12  to the outlet  14 . The filter element  104  is arranged between raw side  106  and clean side  108 . The fluid flow, for example, air, flows in  FIG. 7  laterally into the housing  10  and upwardly through the filter element  104  to the outlet  14  which is arranged, in turn, laterally at the housing  10 . 
     The base plate  44  of the adsorber element  40  is substantially arranged parallel to a region  16  of an outer wall  20  of the housing  10  and projects with the rigid support elements  50  into the clean side  108 . The support elements  50  are arranged with their adsorber surface  56  substantially parallel to the main flow direction between outflow side of the filter element  104  and the outlet  14  of the housing  10  so that no noteworthy effect on the flow occurs in operation. Furthermore, the support elements  50  and the adsorber element  40  as a whole cause no noteworthy pressure loss. 
     Therefore, an operation of a possibly present air-mass meter, as it is usually arranged at the outlet  14 , is essentially not affected. For various embodiments of the air filter system  100 , the air-mass meter can be used cost-efficiently with unchanged calibration. 
     The depth with which the support elements  50  project into the clean side  108 , their position and their number can be adapted easily to existing boundary conditions of the filter system  100 . 
     The base plate  44  can be arranged at a distance from the region  16  of the outer wall  20 , for example, by means of spacers. Then, the fluid can also flow between base plate  44  and the region  16  of the housing  10  behind the base plate  44  and can come into contact with the backside of the adsorber medium  42  of the base plate  44 .