FILTER CARTRIDGE

Abstract

A gravity-based filter cartridge having a cup-shaped upper part and a cup-shaped lower part, the upper part having a main axis (X), a first rim at a first axial end, a hole-free section at a second axial end, and at least one water inlet between the hole-free section and the first rim, the lower part having a second rim and at least one water outlet, wherein filter media is arranged in the lower part, the filter cartridge further including a mesh fixated to the upper part along a closed path, wherein the mesh is further fixated to the hole-free section radially inwards of the closed path as well as a method for manufacturing the same.

Claims

1. A method for manufacturing a gravity-based filter cartridge, comprising the following steps: forming a cup-shaped upper part having a main axis X, a first rim at a first axial end, a hole-free section at a second axial end, and at least one water inlet between the hole-free section and the first rim, drawing a mesh material over the first rim, pushing the mesh material into the cup-shaped upper part towards the hole-free section, thereby forming a dome-shaped mesh, fixating the mesh material along a closed path to the first rim, fixating the mesh material radially inwards of the closed path to the hole-free section, cutting the mesh from the mesh material along a path radially outward of the closed path, forming a cup-shaped lower part having a second rim and at least one water outlet, inserting filter media into the lower part, and mounting the upper part onto the lower part with the second rim contacting the first rim.

2. The method according to claim 1, wherein the upper part comprises a circumferential outer wall that is closed at the second axial end by an end wall, wherein the end wall together with an adjacent section of the outer wall forms the hole-free section.

3. The method according to claim 1, wherein the hole-free section comprises a support to which the mesh material is fixated at a distance to the end wall along the main axis X.

4. The method according to claim 3, wherein the support has a flat area perpendicular to the main axis X and in that the mesh material is fixated to the area.

5. The method according to claim 1, wherein the mesh material is fixated to the first rim and/or the hole-free section integrally.

6. The method according to claim 1, wherein the mesh material is fixated to the first rim and/or the hole-free section by ultrasonic welding.

7. The method according to claim 1, wherein the mesh material is fixated to the rim and the hole-free section consecutively.

8. The method according to claim 3, wherein the support is a pin extending from the end wall along the main axis X towards the first axial end.

9. The method according to claim 8, wherein the pin has a circular or x-shaped cross-section.

10. The method according to claim 8, wherein the pin has a length L of at least 5 mm, and particularly preferred of at most 20 mm.

11. The method according to claim 1, wherein the mesh material comprises polyethylene terephthalate (PET).

12. The method according to claim 1, wherein the mesh material is fixated to the hole-free section at a position axially above the at least one water inlet.

13. A gravity-based filter cartridge comprising: a cup-shaped upper part and a cup-shaped lower part, the upper part having a main axis X, a first rim at a first axial end, a hole-free section at a second axial end, and at least one water inlet between the hole-free section and the first rim, the lower part having a second rim and at least one water outlet, wherein filter media is arranged in the lower part, the filter cartridge further comprising a mesh fixated to the upper part along a closed path, wherein the mesh is further fixated to the hole-free section radially inwards of the closed path.

14. A gravity-based filtration device having an inlet funnel with a seat as well as the filter cartridge according to claim 13 arranged in said seat.

15. The method according to claim 2, wherein the hole-free section comprises a support to which the mesh material is fixated at a distance to the end wall along the main axis X, and wherein the support has a flat area perpendicular to the main axis X and in that the mesh material is fixated to the area.

16. The method according to claim 15, wherein the mesh material is fixated to the first rim and/or the hole-free section integrally, and wherein the mesh material is fixated to the first rim and/or the hole-free section by ultrasonic welding.

17. The method according to claim 16, wherein the mesh material is fixated to the rim and the hole-free section consecutively, and wherein the support is a pin extending from the end wall along the main axis X towards the first axial end.

18. The method according to claim 17, wherein the pin has a circular or x-shaped cross-section, and wherein the pin has a length L of at least 5 mm, and particularly preferred of at most 20 mm.

19. The method according to claim 18, wherein the mesh material comprises polyethylene terephthalate (PET), and wherein the mesh material is fixated to the hole-free section at a position axially above the at least one water inlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The invention is described by way of example with reference to the drawings showing the following:

[0043] FIG. 1 a side view of a filter cartridge according to the invention;

[0044] FIG. 2 sectional view A-A of FIG. 1;

[0045] FIG. 3 a top view of the filter cartridge of FIG. 1;

[0046] FIG. 4 a bottom view of the filter cartridge of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0047] The gravity-based filter cartridge 2 shown in FIGS. 1 to 4 comprises a cup-shaped lower part 4 and a cup-shaped upper part 6. The upper part 6 is arranged on top of the lower part 4 along a main axis X.

[0048] At a first axial end 8 the upper part 6 comprises a first rim 10 having the shape of a ring running around the main axis X. The first rim 10 comprises a first contact area 12 that is generally flat perpendicular to the main axis X and that defines the first axial end 8.

[0049] The upper part 6 with its cup-shape is arranged upside down on the lower part 4. The upper part 6 comprises a circumferential outer wall 14 that is closed at a second axial end 16 opposite to the first contact area 12 by an end wall 18. The end wall 18 together with an adjacent section of the outer wall 14 forms a hole-free section 20 of the upper part 6.

[0050] The lower part 4 comprises an elongated body 22 that transitions into four feet 24 at a bottom end 26 of the lower part 4. At the bottom end 26 the lower part 4 is closed except for water outlets 28 that are arranged in bottom walls 30 of the feet 24 (see FIG. 4). The feet 24 are separated by grooves 32, of which one groove 32 is shaped differently from the other grooves 32 such that it functions as a positioning groove 34 for correctly aligning the filter cartridge 2 in an inlet funnel (not shown) of a filtration device (not shown).

[0051] The lower part 4 has a second rim 40 at an upper end 42. The second rim 40 comprises a generally flat second contact area 44 onto which the first contact area 12 of the upper part 6 is arranged.

[0052] Several water inlets 46 are located in the outer wall 14 of the upper part 6 located in axial direction in between the first rim 10 and the hole-free section 20 (see FIG. 1). Water may enter into the upper part 6 via these water inlets 46. In the embodiment shown all water inlets 46 are of a similar shape and are arranged at the same height along the main axis X. The water inlets 46 have their highest point at a maximum inlet height H2 (vertical distance from the bottom walls 30).

[0053] The upper part 6 further comprises a mesh 50 that is dome-shaped (see FIG. 2). The mesh 50 is affixed to the first rim 10 along a closed path that extends around the main axis X.

[0054] The hole-free section 20 of the upper part 6 further comprises a pin 52 that extends from the end wall 18 along the main axis X towards the first axial end 8. The mesh 50 is affixed to the pin 52 in an area 54 radially inwards of the closed path, at which the mesh 50 is affixed to the first rim 10. The mesh 50 is thus held in a dome-shaped form.

[0055] The pin 52 has its lowest point at a minimum pin height H1 (vertical distance from the bottom walls 30, see FIG. 2). The minimum pin height H1 is larger than the maximum inlet height H2. This ensures that the mesh 50 will extend to a region above the maximum inlet height H2. As a result air will be able to pass through the mesh 50 easily and accumulate in the hole-free section 20 thereby not blocking the water inlets 46.

[0056] The lower part 4 and the mesh 50 define a cartridge volume 56, in which filter media (not shown) is arranged.

[0057] Water entering into the filter cartridge 2 via the water inlets 46 first enter into a top volume 58 defined by the outer wall 14 and the end wall 18 of the upper part 6 together with the mesh 50. The water will then wet the mesh 50 and will additionally pass through the mesh 50 into the cartridge volume 56 defined by the lower part 4 and the mesh 50. Air present in said cartridge volume 56 may escape upwards through the mesh 50 to the top volume 58. Said air will then not block the water from passing through the mesh 50. The water may then be treated by the filter media and may subsequently exit the filter cartridge 2 through the water outlets 28 into a space 60 below.

[0058] The embodiment of the filter cartridge 2 shown in the drawings is manufactured as follows: first, the cup-shaped upper part 6 having the main axis X, the first rim 10 at the first axial end 8, the hole-free section 20 at a second axial end 16, and the water inlets 46 between the hole-free section 20 and the first rim 10, is formed by injection-molding. Next, a PET mesh material is drawn over the first rim 10. The mesh material is then pushed into the upper part 6 towards the hole-free section 20, thereby forming the dome-shaped mesh 50. The mesh 50 is then fixated to the first rim 10 along a closed path. Further, the mesh 50 is fixated radially inwards of the closed path to the area 54 of the pin 52 of the hole-free section 20. The mesh 50 is then cut from the mesh material along a path radially outwards of the closed path. The lower part 4 having the second rim 40 and the water outlets 28 is also formed by injection molding. Hereafter, ion exchange resin and active coal (both in granular form) is inserted into the lower part 4 as filter media. The upper part 6 is then mounted upside down onto the lower part with the second rim 40 contacting the first rim 10.