Device and method for protecting drinking water from microorganisms

Abstract

A water filter comprises an ultrafilter or microfilter, in particular a membrane stack for ultrafiltration or microfiltration, which has a direction of flow (D) and contains an alkalinizing and/or oxidative material that is placed upstream of or within the membrane stack when viewed in the direction of flow.

Claims

1.-15. (canceled)

16. A water filter (1), comprising: a membrane filter with a filtration membrane, which has a direction of flow (D) and comprises an alkalinizing and/or oxidative material (3).

17. The water filter as in claim 16, wherein the membrane filter is an ultrafilter or microfilter having a membrane.

18. The water filter as in claim 17, wherein the alkalinizing and/or oxidative material (3) is placed upstream of the ultrafilter or microfilter when viewed in the direction of flow, and/or in contact with the membrane of the ultrafilter or microfilter.

19. The water filter as in claim 16, wherein the alkalinizing and/or oxidative material (3) is placed directly upstream of or within a membrane stack (5) and in contact therewith.

20. The water filter (1) as in claim 16, wherein the membrane filter is a membrane stack (5) for ultrafiltration or microfiltration.

21. The water filter (1) as in claim 16, wherein the alkalinizing and/or oxidative material (3) contains at least one material selected from the group consisting of oxides, carbonates, and peroxides.

22. The water filter (1) as in claim 16, wherein the alkalinizing and/or oxidative material (3) comprise one or more of magnesium peroxide, calcium peroxide, sodium peroxide, potassium peroxide, and zinc peroxide.

23. The water filter (1) as in claim 16, wherein the alkalinizing and/or oxidative material (3) comprise calcium carbonate and/or magnesium carbonate.

24. The water filter (1) as in claim 16, wherein the alkalinizing and/or oxidative material (3) comprise calcium oxide and/or magnesium oxide.

25. The water filter (1) as in claim 16, wherein the alkalinizing and/or oxidative material (3) comprises particles having a particle size in the range between 0.5 millimeters and 2.5 millimeters.

26. The water filter (1) as in claim 20, wherein the alkalinizing and/or oxidative material (3) is arranged in form of a loose bed upstream of or within the membrane stack (5) and in contact therewith.

27. The water filter (1) as in claim 16, wherein the water filter comprises a loose bed of alkalinizing and/or oxidative material (3), and a membrane stack (5).

28. The water filter (1) as in claim 16, wherein the water filter has an inlet side (8) and an outlet side (7), wherein the inlet side is configured for being connected to a water pipe or a water tank.

29. The water filter (1) as in claim 16, wherein the water filter is configured for being used as a filter cartridge for a machine for preparing hot and/or cold beverages, and/or for an under-sink water filter.

30. A method for treating drinking water, comprising: providing the drinking water in a water source; causing, during a stagnation phase, the drinking water to not emerge from the water source; extracting and replenishing, during an extraction phase, the drinking water from the water source; and passing, during the extraction phase, the drinking water through an alkalinizing and/or oxidative material (3) and subsequently passing the drinking water through a membrane filter.

31. The method as in claim 30, wherein the water source is a water pipe or a water tank, and wherein the membrane filter is an ultrafilter, a microfilter, or a membrane stack (5) for ultrafiltration or microfiltration.

32. The method as in claim 30, wherein the alkalinizing and/or oxidative material (3) is selected from the group consisting of oxides, carbonates, and peroxides.

33. The method as in claim 31, further producing a hot or cold beverage with the drinking water.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 shows a first embodiment of a water filter.

[0043] FIG. 2 shows a second embodiment of a water filter

DETAILED DESCRIPTION

[0044] The invention will be illustrated in more detail by way of exemplary embodiments as schematically shown in the drawings of FIGS. 1 and 2.

[0045] FIG. 1 shows an embodiment of a water filter 1 in the form of an ultrafilter.

[0046] This water filter comprises a housing with an inlet 8 and an outlet 7, thereby defining a direction of flow D.

[0047] A membrane stack 5 comprising a plurality of hollow-fiber membranes 4 is arranged inside the housing.

[0048] The membrane stack 5 is folded over, and the open ends of the hollow-fiber membranes 4 are retained in a potting compound 6 on the outlet side. Hence, downstream of the inlet 8 the water flows into the hollow-fiber membranes 4 from the outside and exits therefrom at the open ends thereof.

[0049] A granular alkalinizing and/or oxidative material 3 is placed directly upstream of the membrane stack 5 and in contact with the membrane stack 5.

[0050] Towards the inlet side, the granular material is held back by a screen or retention grid 2.

[0051] The water to be filtered flows through the alkalinizing and/or oxidative material 3, then enters the membranes 4 from outside and exits therefrom through the open ends of the capillary membranes.

[0052] During stagnation phases, the membranes 4 are protected from contamination on the inlet side by the material 3 which has an alkalinizing and/or oxidizing effect. More particularly, it counteracts the formation of a biofilm that might be caused due to a growth of the germs which are held back by the membranes 4.

[0053] FIG. 2 shows another embodiment, in which the alkalinizing and/or oxidative material 3 is placed upstream of the open ends of the membrane stack 5 or in contact therewith.

[0054] The water to be filtered flows through the alkalinizing and/or oxidative material 3 and enters the membranes through the open ends of the capillary membranes 4 and exits therefrom through the outer surface of the capillary membranes 4.

[0055] The embodiment according to FIG. 2 is therefore similar to the embodiment shown in FIG. 1, while the water filter 1 is operated in the opposite direction of flow. This embodiment, too, comprises a retention grid on the inlet side.

LIST OF REFERENCE NUMERALS

[0056] 1 Water filter [0057] 2 Retention grid [0058] 3 Alkalinizing and/or oxidative material [0059] 4 Capillary membrane [0060] 5 Membrane stack [0061] 6 Potting compound [0062] 7 Outlet [0063] 8 Inlet [0064] D Direction of flow