Filter housing for housing a filter element for filtering a liquid, as well as filter cartridge with the same

Abstract

A filter housing 1 for housing a filter element (10) for filtering a liquid, for example water, with two housings (2, 5), which each have inner and outer tube sections (21, 51, 30, 61) extending in a longitudinal direction, which can each be inserted telescopically into one another, is disclosed. This results in the formation of an inner flow channel (48) and of at least one outer flow channel (40, 44), which are separated from one another and sealed respectively against the central interior space (10d) of the filter element (10). The filter housing is characterized by a simple and cost-effective structure, which can facilitate the installation of filter cartridges of different lengths and, after installation in a filter cartridge for filtering a liquid, for example water, ensures the formation of suitable flow conditions therein.

Description

[0001] PFP-PA-22558-DEWO

[0002] Filter housing for housing a filter element for filtering a liquid, as well as filter cartridge with the same

[0003] FIELD OF THE INVENTION

[0004] The present invention generally relates to filters for filtering liquids, in particular water and, in particular, for providing drinking water with a high purity, and relates, in particular, to a filter housing for housing a filter element, for use in a filter cartridge, as well as a filter cartridge with such a filter housing and a filter element housed therein, in particular for filtering water.

[0005] PRIOR ART

[0006] US 20070246417 Al discloses a filter housing for housing a filter element for filtering a liquid according to the preamble of claim 1, with an upper and a lower housing for supporting an upper and / or lower end of a filter element designed as a hollow cylinder, wherein an inner tube section projects vertically from a base of the respective housing and the two inner tube sections are inserted telescopically into one another, in order to form an inner flow channel. However, the inner flow channel is not sealed in a liquid-tight manner against the central interior space of the filter element, but rather is provided with a plurality of openings, though which water, which flows through the filter element from outside it, enters the flow channel and leaves it again at a lower end of the flow channel.

[0007] DE 102013 004284 Al discloses an air filter with a hollow cylindrical filter element, which has a three-piece structure, with two tube sections arranged opposite one another and a rotating tube, which surrounds one of the two tube sections and stabilizes the structure. The one tube section has elements securing the direction of rotation, which engage in recesses in the other tube section, such that the two tube sections can be moved relative to one another in a longitudinal direction, in order to compensate for fluctuations in the operating conditions and tolerances.

[0008] Further support structures for hollow cylindrical filter elements are disclosed in CN 208 839202 U and CN 217015 781 U.PFP-PA-22558-DEWO

[0009] SUMMARY OF THE INVENTION

[0010] The object of the present invention is to provide a filter housing for housing a filter element for filtering a liquid, which is constructed simply and cost-effectively and can be used in a filter cartridge for filtering a liquid, in particular water. A further obj ect is to provide a corresponding filter cartridge for filtering a liquid, in particular water, with a such a filter housing with a filter element housed therein.

[0011] These objects are achieved by a filter housing with the characteristics according to claim 1, as well as by a filter cartridge with the characteristics according to claim 10. Further advantageous embodiments form the subject of the dependent claims.

[0012] According to the present invention, a filter housing for housing a filter element for filtering a liquid, in particular water, is provided, wherein the filter element has a central interior space and comprises the filter housing: an upper housing with a base for supporting an upper end of the filter element, a lower housing with a base for supporting a lower end of the filter element, wherein an inner tube section is provided respectively on the base, which projects vertically from the base, and the two inner tube sections are inserted telescopically into one another, in order to form an inner flow channel. According to the invention, the inner flow channel is sealed against the central interior space of the filter element, wherein an outer tube section is further provided respectively on the base, which projects vertically from the base, and wherein the two outer tube sections are inserted telescopically into one another, in order to form an outer flow channel, which is sealed against the central interior space of the filter element.

[0013] After arranging the filter element on one of the two housings and pressing the two housings together, the respective tube sections situated opposite one another, namely the two inner and outer tube sections, are also automatically inserted into one another. A filter for a filter cartridge can be cost-effectively produced in this way. As, after putting the two housings together, the resulting inner and outer flow channel is sealed respectively against the interior space of the filter element, the flow conditions in a filter for a filter cartridge can be reliably specified. It is possible to ensure, in particular, that there is no undesirable mixing between incoming untreated water, which flows in, for example, through the inner flow channel and is further distributed by the latter, and the filtered water, which flows through the filter element from the outside, isPFP-PA-22558-DEWO

[0014] filtered in the process and subsequently enters the outer flow channel and is further distributed by the latter.

[0015] The necessary sealing of the inner and outer flow channel can be achieved by direct contact of the elements involved, for example, by direct contact of side wall sections on the front free ends of the two inner tube sections and / or by contact of an inner perimeter wall of the filter element on an outside of the two outer tube sections. A suitable seal can be created in other ways, in particular by arranging circumferentially formed, elastic sealing elements, in particular O-rings, between the elements involved. A seal can be formed, in particular, in a direction perpendicular to the longitudinal direction of the filter housing, as well as in the longitudinal direction of the filter housing.

[0016] Simple insertion of the inner and outer tube sections into one another may be sufficient for a reliable housing of the filter element, in particular if their front free ends are compatible, such that they can be tightly inserted into one another, in order to create sufficiently stable frictional engagement. However, after installing the filter element, the two housings can also be pretensioned against one another, in particular by applying force from the outside, for example, after installation in a seat in a filter cartridge with a predetermined axial length. According to a further embodiment, the two ends of the filter element can also be suitably materially connected with the insides of the two housings, for example, by bonding or thermal welding or ultrasonic welding.

[0017] A filter housing according to the present invention also facilitates easy recycling, as a used filter element can simply be removed and replaced, in particular for embodiments in which the filter element is not firmly connected to the upper and lower housing.

[0018] A filter housing according to the present invention can also be used as an adjustable length identical part for housing filter elements with different axial lengths. According to a further embodiment, to this end, the two inner tube sections and the two outer tube sections can overlap each other in a longitudinal direction of the filter housing over a predetermined length, and this overlap can be used to compensate for different lengths. The adjustable length region essentially corresponds to the length of the overlap region between the two tube sections, if they are inserted to a maximum into one another, provided an adequate seal is ensured at the front free ends of the two tube sections inserted into one another.PFP-PA-22558-DEWO

[0019] However, a length adjustment can also be achieved for an adjustable length filter housing according to the present invention in another way, for example, by at least one of two tube sections inserted into one another in the longitudinal direction of the housing being flexibly designed, for example, in the manner of bellows, the front free end of which is secured on the front free end of the opposite tube section, for example, by a suitable form fit.

[0020] According to a further embodiment, at least one peripheral seal is provided between an outer perimeter wall of one of the two inner tube sections and an inner perimeter wall of the other of the two inner tube sections, in order to suitably seal the inner flow channel, as mentioned above.

[0021] According to a further embodiment, at least one peripheral seal is provided between an outer perimeter wall of one of the two outer tube sections and an inner perimeter wall of the other of the two outer tube sections, in order to suitably seal the outer flow channel, as mentioned above.

[0022] According to a further embodiment, the inner flow channel communicates with the environment via a central inlet and a central outlet of the inner tube section of the upper and lower housing. This can be used, for example, after installation in a filter cartridge for filtering drinking water, for routing untreated water arriving via the inlet (water to be filtered) via the outlet to an ion exchanger arranged below the filter housing.

[0023] According to a further embodiment, the outer flow channel communicates with the environment via at least one opening, which is formed in the base of the lower and / or upper housing. This can be used, for example, after installation in a filter cartridge for filtering drinking water, for routing filtered water, which flows through the filter element from outside and enters the outer flow channel of the filter housing, to an outlet of the filter cartridge for filtered water.

[0024] By an appropriate arrangement of inlet and / or outlet openings in the two housings, a filter housing according to the present invention can easily be used to establish suitable flow conditions, in particular after installation in a filter cartridge for filtering drinking water.

[0025] According to a further embodiment, in particular in the case of an adjustable length filter housing, the outer flow channel can be divided by the two outer tube sections into a hollow cylindrical inner flow section and a hollow cylindrical outer flow section, wherein the filterPFP-PA-22558-DEWO

[0026] element is supported at a distance from a respective side wall of the two outer tube sections. The additional outer flow section formed in this manner can be used, after installation of a filter housing with a filter element housed therein in a filter cartridge, for example, to provide an additional flow channel for so-called blended water, i.e. for already pre-filtered water, which has been stored unused for a long period outside the filter cartridge, for example in an external water dispenser, and which is intended to be filtered again, in particular in order to remove impurities occurring during storage, for example due to bio-films or the like, by filtering the water again before it is made available to users again.

[0027] To form such an additional outer flow channel, according to a further embodiment, an inner perimeter wall of the filter element can be supported at a first end on a broadened base of one of the two outer tube sections and at an opposite second end on an additional side wall, which is provided outside the other of the two outer tube sections, wherein the broadened base and the additional side wall are formed in alignment with one another in a longitudinal direction of the filter housing.

[0028] To easily seal the at least one outer flow channel, according to a further embodiment, an inner perimeter wall of the filter element can be supported by clamping a respective seal against a respective support section of the two outer tube sections.

[0029] To seal the at least one outer flow channel against the environment, according to a further embodiment, provision can be made for end faces of the filter element opposite one another in the longitudinal direction of the filter housing to be sealed against the respective base of the upper and / or lower housing by means of a respective sealing element. A seal can thus be easily created in an axial direction. As a firm, in particular materially connected, connection of the filter element with the two housings is not necessary for a seal, such a filter housing is ideally suited to recycling. Such a filter housing can also be installed in a simple and cost-effective manner by inserting the respective tube sections into one another.

[0030] According to a further embodiment, the filter element is designed as a hollow cylinder, with a circular profile. The resulting rotational symmetry can be used for particularly easy and reliable sealing of the relevant sections and flow channels.PFP-PA-22558-DEWO

[0031] According to a further embodiment, the filter element is made from a pressed or extruded activated carbon element, which ensures a certain stability, both in a radial and axial direction, and can further encourage suitable sealing of the relevant sections.

[0032] According to a further aspect of the present invention, a filter cartridge for filtering a liquid, in particular water, is provided, with an upper cartridge body and a lower cartridge body, which are connected to one another, in order to form a closed interior space, and with a connecting body with an inlet for unfiltered untreated water, an inlet for blended water, which is a mixture of unfiltered untreated water and pre-filtered water, and an outlet for filtered water, and with a filter element for filtering the liquid arranged in the interior space. According to the invention, a filter housing with a structure, as disclosed above, is arranged in the filter cartridge, wherein the filter element is housed in the filter housing, the inner flow channel communicates with the inlet for unfiltered untreated water of the filter cartridge, and the outer flow channel communicates with the inlet for blended water or with the outlet for filtered water. As mentioned above, the filter element facilitates an establishment of suitable flow conditions in the filter cartridge.

[0033] According to a further embodiment, the filter housing is arranged with the filter element in the upper cartridge body, wherein an ion exchanger section is arranged in the lower cartridge body, and the inner flow channel is extended by a flow tube, such that incoming untreated water flows onward to the ion exchanger section and water flows through the filter element after flowing through the ion exchanger section, in order to be filtered thereby, and arrives in the outer flow channel, in order to be further distributed by the latter.

[0034] According to a further embodiment, the filter element is axially supported on a separating disc, which supports the filter housing, and, for example, presses against the upper cartridge body and is supported on the upper cartridge body, wherein a liquid permeable non-woven fabric is preferably provided between an upper side of the separating disc and the lower housing of the filter housing.PFP-PA-22558-DEWO

[0035] SUMMARY OF THE FIGURES

[0036] The invention is described in more detail below in an exemplary manner and with reference to the accompanying drawings, from which further characteristics, advantages and objects to be achieved are apparent. The Figures show:

[0037] Fig. la a filter housing for a filter cartridge according to the present invention, which houses a relatively short filter element,

[0038] Fig. lb a filter housing for a filter cartridge according to the present invention, which houses a relatively long filter element,

[0039] Fig. 2a the filter housing for a filter cartridge according to Fig. la in a perspective partial section,

[0040] Fig. 2b the filter housing for a filter cartridge according to Fig. lb in a perspective partial section,

[0041] Fig. 3a a perspective side view from above of a filter cartridge according to the present invention, in which a filter housing with a relatively short filter element and a relatively short ion exchanger element are housed,

[0042] Fig. 3b a perspective side view from above of a filter cartridge according to the present invention, in which a filter housing with a relatively long filter element and a relatively long ion exchanger element are housed,

[0043] Fig. 4a a schematic sectional view of the adjustable length filter housing for a filter cartridge according to Fig. la with an illustration of the relevant flow paths, and Fig. 4b a schematic sectional view of a filter cartridge for filtering water, in which a filter housing with a filter element and an ion exchanger element are housed, with an illustration of the relevant flow paths.

[0044] In the Figures, identical reference symbols refer to the same or essentially equivalently acting elements or groups of elements.

[0045] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0046] The basic structure of a filter housing for a filter element 10 referred to overall with the reference symbol 1 is described below with reference to Figures la and lb. The filter element 10 is formed circumferentially and as a hollow element, in particular as a hollow cylindricalPFP-PA-22558-DEWO

[0047] element with a circular profile. The filter element 10 is used, in particular, for filtering water, and is made, in particular, from a pressed or extruded activated carbon element, which has a certain stability, in particular in an axial direction. The filter element 10 is housed in the filter housing 1 between an upper housing 2 and a lower housing 5. To this end, the upper end 10a of the filter element 10 is supported on a flat section on the inside 20a of the base 20 of the upper housing 2 and accordingly supports the lower end 10b of the filter element 10 on a flat section on the inside 50a of the base 20 of the lower housing 5. As explained below, the filter housing 1 with the filter element 10 housed therein is designed to be used in a filter cartridge, in order to filter untreated water (unfiltered water) entering the filter cartridge.

[0048] A respective inner tube section 21, 51 is preferably provided centrally on the base 20a, 50a, which projects vertically from the respective base 20a, 50a and which are inserted into one another such that the two inner tube sections 21, 51 together form an inner flow channel 48, which is sealed against the central interior space lOd of the filter element 10. The inner flow channel 48 is formed from two subsections 27, 57 of the respective inner tube section 21, 51. To seal the inner flow channel 48, a sealing region is formed in the transition region between the front free end 23 of the inner tube section 21 and the front free end 53 of the inner tube section 51. This can basically be achieved by direct contact of the two front ends 23, 53, if the two front ends 23, 53 are designed to be compatible and are tightly inserted into one another.

[0049] Practically, a peripheral seal 12 made from a soft elastic material, for example an O-ring made from a rubber material, can also be provided in the aforementioned sealing region, in order to suitably seal an annular gap between the two front ends 23, 53. In order to suitably compress and position the seal 12, a radially inwardly recessed step 26 can be formed at the front end 23 of the inner tube section 21 of the upper housing 2, from which the front end 23 of the inner tube section 21 with an outlet opening 29 formed therein extends in the direction of the lower end 10b of the filter element 10. Alternatively, a peripheral recess (not shown) for housing the seal 12 can be formed on the inner perimeter wall of the inner tube section 51.

[0050] When used as intended, the inner flow channel 48 is intended to be used to first route the untreated water arriving via the inlet opening 28 in the upper housing 2 in a filter cartridge via the outlet opening 59 in the lower housing 5 to a space below the filter element 10, where an ion exchanger can be arranged, for example. The rear end 22, 52 of the inner tube section 21,PFP-PA-22558-DEWO

[0051] 51 is preferably designed to be cylindrical, to connect with tubular, correspondingly shaped connecting pieces.

[0052] As illustrated further in Figures la and lb, the inner perimeter wall 10c of the filter element 10 is supported respectively at its ends 10a, 10b on an outer tube section 35, 62, which projects vertically in the same way from the respective base 20, 50. The total length of the two outer tube sections 35, 62 in an axial direction is lower than the total length of the two inner tube sections 21, 51, such that, when viewed in an axial direction, an open space remains between the two outer tube sections 35, 62, through which water can flow from outside the filter element 10 inwards into an outer flow channel 44, which communicates suitably via outlet openings 45, 66 with a volume outside the filter housing 1. To establish suitable flow conditions, for example in a filter cartridge, this outer flow channel 44 is sealed against the central interior space lOd of the filter element 10.

[0053] For suitable sealing of the outer flow channel 44, a peripheral seal 11 made from a soft elastic material, for example an O-ring made from a rubber material, can be provided on the outer perimeter wall of the outer tube section 35, which rests on the inner perimeter wall 10c of the filter element 10 and is preferably housed and positioned in a circumferentially formed recess 36. In a corresponding manner, a peripheral seal 14 made from a soft elastic material, for example an O-ring made from a rubber material, can be provided on the outer perimeter wall of the outer tube section 62, which rests on the inner perimeter wall 10c of the filter element 10 and is preferably housed and positioned in a circumferentially formed recess 63. Such sealing of the outer flow channel 44 can basically also be achieved by direct contact of the inner perimeter wall 10c of the filter element 10 on the outer perimeter wall of the outer tube section 35, 62.

[0054] In order for such a filter housing 1 to be suitable for housing filter elements 10 of different lengths, further characteristics are provided, which are most clearly apparent in Fig. lb. To this end, a central tube section 30 is provided between the outer tube section 35 and the inner tube section 21, which extends vertically from the base 20 and is longer than the outer tube section 35.

[0055] It is basically sufficient, to create a telescopic adjustable length filter housing 1, for the radially inwardly recessed central tube section 30 to be inserted directly in the outer tube section 62 ofPFP-PA-22558-DEWO

[0056] the lower housing 5 and for sealing of the outer flow channel 44 against the central interior space lOd of the filter element 10 to be ensured in the contact region.

[0057] However, in order to facilitate greater length adjustability of the filter housing 1, it is preferable for a tube section 61 with a smaller outer diameter to extend further from the outer tube section 62 in the direction of the upper end 10a of the filter element 10, with the outer tube section 62 thus forming the base for the tube section 61 with a smaller outer diameter. As illustrated in Fig. lb, the two tube sections 30, 61 are inserted telescopically into one another, in order to form a further outer flow channel 40, which is sealed against the central interior space lOd of the filter element 10. This can basically be achieved by direct contact of the two front ends 31, 64 of the two tube sections 30, 61, if the two front ends 31, 64 are designed to be compatible and are tightly inserted into one another.

[0058] Practically, a peripheral seal 13 made from a soft elastic material, for example an O-ring made from a rubber material, can also be provided in the aforementioned sealing region, in order to suitably seal an annular gap between the two front ends 31, 64. In order to suitably compress and position the seal 13, a peripheral recess 32 can be formed on the outer perimeter wall of the central tube section 30 of the upper housing 2 at its front end 31, such that the seal 13 rests directly on the inner perimeter wall of the outer tube section 61 of the lower housing 5.

[0059] The two outer flow channels 40, 44 formed in this manner can basically communicate with one another, for the purpose of which holes or the like can be provided in the two tube sections 30, 61.

[0060] However, more preferably, the two outer flow channels 40, 44 are separated from one another and communicate with the environment via separate outlet / inlet openings. As illustrated in Fig. lb, the outer flow channel 44 communicates with the environment via at least one opening 45, which is formed respectively in the base 20 of the upper housing 2, and via a section 46 between the outer side wall 35 and the central side wall 30. Basically, at least one corresponding opening can also be provided in the base of the lower housing 5. Furthermore, the outer flow channel 44 can communicate with the environment via at least one opening 41, which is formed respectively in the base 20 of the upper housing 2, and via at least one opening 66, which is formed in the base 50 of the lower housing 5. The openings 41, 66 can be used as an inlet and / orPFP-PA-22558-DEWO

[0061] outlet of the outer flow channel 44, in order to ensure suitable flow conditions for an intended use in a filter cartridge, as explained below by way of example with reference to Fig. 4b.

[0062] As is evident from a comparison of Figures la and lb, filter elements 10 of different lengths can be housed with an adjustable length filter housing 1 according to the present invention, wherein a maximum adjustable length region is defined by the length of the overlap in an axial direction of the two inner tube sections 21, 51, if these are inserted to a maximum into one another, as illustrated in Fig. la.

[0063] Figures 2a and 2b show such an adjustable length filter housing 1 in the maximum end positions in a perspective partial section, i.e. in a maximum retracted end position and maximum extended end position. In particular, by way of an example, the arrangement of the openings 41, 45 in the upper housing 2 and the openings 66 in the lower housing 5 is also evident from the partial sections.

[0064] It may basically be sufficient, for housing the filter element 10, for the two ends 10a, 10b of the filter element 10 to be glued to the corresponding base 20, 50 of the lower and / or upper housing 2, 5 or materially connected to the latter in another way, for example by thermal welding or ultrasonic welding. Alternatively, a sealing washer can also be provided between the ends 10a, 10b of the filter element 10 and the corresponding base 20, 50 of the lower and / or upper housing 2, 5. Alternatively, as illustrated in Fig. 4a, a peripheral recess 33, 67 can also be formed respectively in the base 20, 50 of the lower and / or upper housing 2, 5, in which a peripheral seal 15, 16 made from a soft elastic material, for example an O-ring made from a rubber material, is respectively housed. In the process, the two housings 2, 5 can also pressed against one another by an external force and thus held together.

[0065] Fig. 3b shows the basic outer form of a filter cartridge 7, into which a filter housing according to the present invention is integrated. The filter cartridge 7 is preferably designed as a cylinder, with a lower cartridge body 77 and a, by comparison, shorter upper cartridge body 75, which is connected to the lower cartridge body 77 via a peripheral connecting section 78 and on the upper end of which a cover 76 is provided, in which a connecting body 79 with at least one inlet and outlet for the interior space of the filter cartridge 7 is provided. When using a structurally identical filter housing 1 and an upper cartridge body 75 with a connecting body 79 but different length filter elements and a lower cartridge body 77, different filter cartridges 7 with differentPFP-PA-22558-DEWO

[0066] lengths, as shown by way of an example in Figures 3a and 3b, and different filter and ion exchanger characteristics can be cost-effectively produced.

[0067] The structure of a filter cartridge according to the present invention is described below with reference to Fig. 4b. The lower housing 5 of the filter housing 1 is located on a separating disc 85, which can be supported, for example, on a section of the upper cartridge body 75 or on the connecting section 78, in order to seal the filter housing 1 against the upper cartridge body 75 and to this ensure a seal of the upper volume 760 against a lower volume 750 of the upper cartridge body 75. To this end, a correspondingly formed recess and / or a seal (not shown) is provided in the contact area between the upper housing 2 and the inside of the upper cartridge body 75. The upper housing 2 can also be materially connected with the upper cartridge body 75, for example by bonding or a welded joint.

[0068] Beveled sections (not shown) can be provided on the upper side of the separating disc 85, in order to suitably center the latter on this fitted filter housing 1.

[0069] The separating disc 85 is permeable to liquids in an axial direction and can have, for example, a plurality of axial bars and / or ribs 86 and ducts 87 for liquid formed between them. A liquid-permeable non-woven fabric can be provided between the upper side of the separating disc 85 and the lower housing 5, in order to retain particles in the respective half space of the filter cartridges 7. The rear end 52 of the lower housing 5 is inserted in a flow tube 91, such that the inner flow channel 48 of the filter housing (see Fig. la) communicates directly with the flow channel 92 of the flow tube 91. The upper end of the inner flow channel 48 of the filter housing is connected to the inlet 790 of the connecting body 79, via which untreated water, i.e. unfiltered water, can flow, which is routed via the flow channel 92 to the base 81 of the lower cartridge body 77. A support body 95 sits thereon, on which a generally cylindrical ion exchange body 18 is supported, which is intended to be used to adjust the hardness of the water in the known manner. The untreated water enters the ion exchange body 18 via the channel 96, flows through the latter and enters the lower volume 750 of the upper cartridge body 75 via the separating disc, from where it finally enters the filter element 10. The flow path of the unfiltered untreated water is indicated by broad, white flow arrows in Fig. 4b.PFP-PA-22558-DEWO

[0070] After flowing through the filter element 10, the water enters the outer flow channel 44, from where the filtered water can then flow into the connecting body 79 to the outlet 795 via a flow channel.

[0071] The connecting body 79 has a further inlet 791, via which the so-called blended water can flow. This can be, for example, pre-filtered water, which has been stored unused for a long period in a water dispenser, and which is intended to be filtered again, before it is made available to users again. To this end, the blended water enters the other outer flow channel 44 of the filter element via the 793. In order to ensure controlled flow conditions, the two outer flow channels 40, 44 are sealed against one another in the filter element, as described above. The incoming blended water flows via the outlets 66 of the lower housing 5 (see Fig. la) into an open space 90 above the ion exchange body 18, from where it can then flow into the lower volume 750 of the upper cartridge body 75 and can flow from there, in the manner described above for the untreated water, through the filter element 10, the outer flow channel 44 and the flow channel into the connecting body 79 to the outlet 795. The flow path of the blended water is indicated by dark flow arrows in Fig. 4b.

[0072] The corresponding flow paths for a filter housing 1 with a filter element 10 with a maximum length housed therein are shown in Fig. 4a.

[0073] A filter cartridge according to the present invention can be modular and made using identical parts, in order to simply provide different lengths for different filter performances by using filter elements. Although a vertical arrangement of the filter cartridge has been disclosed above, it can also be arranged differently in use, for example horizontally.

[0074] As is evident to a person skilled in the art on studying the above disclosure, a filter housing according to the present invention can be used to form suitable flow paths in a filter cartridge, wherein it may be sufficient, to this end, for the inner and / or outer tube sections of the upper and / or lower housing to be inserted directly into one another, in order to ensure a suitable seal of the flow channels against one another. Additional peripheral seals can naturally be provided in the contact areas, as described above.

[0075] The upper and lower housings of a filter housing according to the present invention are preferably respectively produced in one piece from a synthetic material, in particular byPFP-PA-22558-DEWO

[0076] injection molding. If necessary, seals needed for sealing can also be molded using a two-component injection molding process (2K) in suitable positions.

[0077] The filter element can be sealed in a radial direction and / or axial direction against the upper and / or lower housing of a filter housing according to the present invention. The filter element can naturally also be glued directly on the upper and / or lower housing of a filter housing according to the present invention.

[0078] The simple structure of a filter housing according to the present invention facilitates easy recycling, as a used filter element can be easily removed after separating the upper and lower housings from one another by simply pulling them apart and a new, unused filter element can be re-attached to one of the two housings, and the two housings reconnected to one another. This is the case, in particular, if the filter element is not firmly connected to the base of the upper and / or lower housing, for example by gluing or a thermally welded joint. Otherwise, such connections must be dissolved before removing a used filter element.

[0079] Most preferably, a filter housing according to the present invention and at least the upper cartridge body of a filter cartridge according to the present invention are made from the same synthetic material, for example from polypropylene (PP). After separating the filter cartridge in the connecting section 78 (see Fig. 4b) and removing the filter element, the filter housing 1 and the upper cartridge body 75 can then be disposed of together, whereby sorted recycling is basically possible. After replacing the ion exchange body 18, the lower cartridge body 77 can be reused. Provided the filter housing 1 is not connected directly to the upper cartridge body 75, the upper cartridge body 75 can also be reused.

[0080] As is evident to a person skilled in the art on studying the above description, the two tube sections inserted telescopically into one another do not necessarily need to be rigid. For example, it may be sufficient for one of the two tube sections to be rigid and the other of the two tube sections to be formed flexibly in an axial direction, for example in the manner of bellows. Such an arrangement can also be used for the aforementioned length adjustability of the filter housing, wherein the front end of the bellows are connected to the front end of the opposite tube section, for example by a suitable form fit, and the bellows can then be used to compensate for differences in length, if the same filter housing is intended to be used to house different length filter elements and the two housings need to be pulled apart for this purpose.PFP-PA-22558-DEWO

[0081] Alternatively, the two tube sections can also each have a rigid tube section, wherein opposite inner and / or outer tube sections are connected respectively to one another via a bellows section, which ensures a length adjustment on adjusting the distance between the two housings and also a seal

[0082] In summary, the present invention presents a filter housing for filter material (e.g. carbon blocks), which is designed to house a circumferentially formed filter material, in particular a cylindrical filter material, for example a block made of or with activated carbon. Using a two-piece design with a telescopic structure, it is possible to adapt the length of the filter housing to the length of the respective filter element. Two concentrically arranged, central flow channels are provided inside the filter housing, which can be used, for example, after installation in a filter cartridge, to route blended water and / or untreated water to the inside of a filter cartridge and / or further distribute it there. A seal structure for sealing the filter housing against the filter element, i.e. the two housings of the filter housing against one another, ensures that suitable flow channels are formed inside the filter housing.PFP-PA-22558-DEWO

[0083] LIST OF REFERENCE SYMBOLS

[0084] 1 Filter housing

[0085] 2 Upper housing

[0086] 5 Lower housing

[0087] 7 Filter cartridge

[0088] 10 Filter element

[0089] 10a Upper end of filter element 10

[0090] 10b Lower end of filter element 10

[0091] 10c Inner perimeter wall of filter element 10 lOd Central interior space of filter element 10 11 Seal

[0092] 12 Seal

[0093] 13 Seal

[0094] 14 Seal

[0095] 15 Seal

[0096] 16 Seal

[0097] 18 Ion exchanger

[0098] 20 Base

[0099] 20a Inside of base 20

[0100] 21 Inner tube section of upper housing 2 22 Rear end of inner tube section 21

[0101] 23 Front end of inner tube section 21

[0102] 24 Recess

[0103] 25 Stepped section

[0104] 26 Stepped section

[0105] 27 Inner flow channel

[0106] 28 Inlet opening of inner flow channel 27 29 Outlet opening of inner flow channel 27PFP-PA-22558-DEWO

[0107] 30 Side wall of the central tube section

[0108] 31 Front end of side wall 30

[0109] 32 Recess

[0110] 33 Recess

[0111] 35 Side wall of the outer tube section

[0112] 36 Peripheral recess

[0113] 40 Outer flow channel in upper housing 2

[0114] 41 Inlet opening to central flow channel 40

[0115] 44 Additional flow channel on upper housing 2

[0116] 45 Outlet / inlet opening of additional flow channel 44 on upper housing 2 46 Subsection of additional flow channel 44

[0117] 48 Inner flow channel

[0118] 50 Base

[0119] 50a Inside of base 50

[0120] 51 Inner tube section of lower housing 5

[0121] 52 Rear end of lower tube section 51

[0122] 53 Front end of lower tube section 51

[0123] 54 Recess

[0124] 55 Stepped section

[0125] 56a Base of recess 54

[0126] 56b Side wall of recess 54

[0127] 57 Inner flow channel

[0128] 58 Inlet opening of flow channel 57

[0129] 59 Outlet opening of flow channel 57

[0130] 61 Side wall of the outer tube section

[0131] 62 Base of side wall 61

[0132] 63 Recess

[0133] 64 Front end of side wall 61

[0134] 65 Compensating volume for the central flow channel in lower housing 5PFP-PA-22558-DEWO

[0135] 66 Outlet opening of central flow channel 40

[0136] 67 Recess

[0137] 68 Compensating volume for the additional flow channel in lower housing 5

[0138] 75 Upper cartridge body

[0139] 750 Lower volume of upper cartridge body 75

[0140] 76 Cover of upper cartridge body 75

[0141] 760 Upper volume of upper cartridge body 75

[0142] 77 Lower cartridge body

[0143] 78 Connecting section

[0144] 79 Connecting body

[0145] 790 Inlet for untreated water

[0146] 791 Inlet for blended water

[0147] 792 Flow channel for untreated water

[0148] 793 Flow channel for blended water

[0149] 795 Outlet for filtered water

[0150] 80 Edge of lower cartridge body 77

[0151] 81 Base of lower cartridge body 77

[0152] 85 Separating disc

[0153] 86 Bar of separating disc 85

[0154] 87 Duct

[0155] 90 Open space

[0156] 91 Flow tube

[0157] 92 Flow channel

[0158] 93 Outlet from flow channel 92

[0159] 94 Lower support body

[0160] 95 Upper side of lower support body 94

[0161] 96 Open space

[0162] 100 Central axis

Claims

PFP-PA-22558-DEWOCLAIMS1. Filter housing (1) for housing a filter element (10) for filtering a liquid, in particular water, which has a central interior space (lOd), comprising:an upper housing (2) with a base (20) for supporting an upper end (10a) of the filter element (10),a lower housing (5) with a base (50) for supporting a lower end (10b) of the filter element (10), whereinan inner tube section (21, 51) is provided respectively on the base (20, 50), which projects vertically from the base (20, 50), andthe two inner tube sections (21, 51) are inserted telescopically into one another, in order to form an inner flow channel (48), which is sealed against the central interior space (1 Od) of the filter element (10),characterized in that the inner flow channel (48) is sealed against the central interior space (lOd) of the filter element (10), whereinfurthermore, an outer tube section (30, 51) is provided respectively on the base (20, 50), which projects vertically from the base (20, 50), andthe two outer tube sections (30, 61) are inserted telescopically into one another, in order to form an outer flow channel (40, 44), which is sealed against the central interior space (1 Od) of the filter element (10).

2. Filter housing according to claim 1, whereinthe two inner tube sections (21, 51) and the two outer tube sections (30, 61) overlap each other in a longitudinal direction (100) of the filter housing (1) over a predetermined length, such that filter elements (10) with different axial lengths can be housed in the filter housing (1).

3. Filter housing according to any one of the preceding claims, whereinat least one peripheral seal (12) is provided between an outer perimeter wall of one of the two inner tube sections (21, 51) and an inner perimeter wall of the other of the two inner tube sections (51, 21), in order to seal the inner flow channel (48), and / orat least one peripheral seal (13) is provided between an outer perimeter wall of one of the two outer tube sections (30, 61) and an inner perimeter wall of the other of the two outer tube sections (61, 30), in order to seal the flow channel (40, 44).PFP-PA-22558-DEWO4. Filter housing according to any one of the preceding claims, whereinthe inner flow channel (48) communicates with the environment via a central inlet (28) and a central outlet (59) of the respective inner tube section (21, 51), andthe outer flow channel (40, 44) communicates with the environment via at least one opening (41, 45, 66), which is formed in the base (20, 50) of the lower and / or upper housing (2, 5).

5. Filter housing according to claim 4, wherein the outer flow channel is divided by the two outer tube sections (30, 61) into a hollow cylindrical inner flow section (40) and a hollow cylindrical outer flow section (44), wherein the filter element (10) is supported at a distance from a respective side wall (30, 61) of the two outer tube sections.

6. Filter housing according to claim 5, wherein an inner perimeter wall (10c) of the filter element (10) is supported at a first end (10b) on a broadened base (62) of one of the two outer tube sections (30, 61) and at an opposite second end (10a) on an additional side wall (35), which is provided outside the other of the two outer tube sections (30, 61), wherein the broadened base (62) and the additional side wall (35) are formed in alignment with one another in a longitudinal direction (100) of the filter housing (1).

7. Filter housing according to any one of the preceding claims, wherein an inner perimeter wall (10c) of the filter element (10) is supported by clamping a respective seal (11, 14) against a respective support section (35, 62) of the two outer tube sections (30, 61).

8. Filter housing according to any one of the preceding claims, wherein end faces (10a, 10b) of the filter element (10) opposite one another in the longitudinal direction (100) of the filter housing (1) are sealed against the respective base (20, 50) of the upper and / or lower housing (2, 5) by means of a respective sealing element (15, 16).

9. Filter housing according to any one of the preceding claims, wherein the filter element (10) is designed as a hollow cylinder, in particular made from a pressed or extruded activated carbon element.

10. Filter cartridge (7) for filtering a liquid, in particular water, withPFP-PA-22558-DEWOan upper cartridge body (75) and a lower cartridge body (77), which are connected to one another, in order to form a closed interior space,a connecting body (79) with an inlet (790) for unfiltered untreated water, an inlet (791) for blended water, which is a mixture of unfiltered untreated water and pre-filtered water, and an outlet (795) for filtered water, anda filter element (10) for filtering the liquid arranged in the interior space, characterized bya filter housing (1) according to any one of the preceding claims, in which the filter element (10) is housed, whereinthe inner flow channel (48) communicates with the inlet (790) for unfiltered untreated water, andthe outer flow channel (40, 44) communicates with the inlet (791) for blended water or with the outlet for filtered water.

11. Filter cartridge according to claim 10, whereinthe filter housing (1) is arranged with the filter element (10) in the upper cartridge body (75), andan ion exchanger section (18) is arranged in the lower cartridge body (77), wherein the inner flow channel (48) is extended by a flow tube (91), such that incoming untreated water flows onward to the ion exchanger section (18) andafter flowing through the ion exchanger section (18), water flows through the filter element (10), in order to be filtered, and enters the outer flow channel (40, 44).

12. Filter cartridge according to claim 11, wherein the filter element (10) is axially supported on a separating disc (85), which presses the filter housing (1) against the upper cartridge body (75) and is supported on the upper cartridge body (75), wherein a liquid-permeable non-woven fabric is preferably provided between an upper side of the separating disc (85) and the lower housing (5) of the filter housing (1).

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