WO2001027034A1

WO2001027034A1 - Water purification device

Info

Publication number: WO2001027034A1
Application number: PCT/IL2000/000641
Authority: WO
Inventors: Meir Fitoussi
Original assignee: Meir Fitoussi
Priority date: 1999-10-11
Filing date: 2000-10-11
Publication date: 2001-04-19
Also published as: AU7815400A; IL132316A0

Abstract

A device for purifying water which maintains the integrity of a filtering medium contained therein. The device comprises a filter housing containing a purification medium and having a port positioned below the purification medium, and a vessel having a port at the base of the vessel, the vessel port being in communication with the filter housing port. Also disclosed is a water purification apparatus comprising the device and a method for purifying water.

Description

WATER PURIFICATION DEVICE

FIELD OF THE INVENTION

This invention relates in general to a device for filtering water, and particularly to a device for maintaining the integrity of a filtering medium.

BACKGROUND OF THE INVENTION In recent decades, a general awareness of problems with the quality of drinking water has increased enormously. In addition, purified water is necessary for a number of applications other than drinking, such as for medical needs, vehicle batteries, pressing irons, aquatic plants and laboratories.

A multitude of water purification devices is commercially available, including both portable devices as well as devices which may be attached in-line to a domestic, commercial or industrial water supply system. These devices usually contain various purification media which remove impurities from the water either by passive filtering or by active binding of the impurities. One example of such a device is a water dispenser (available commercially under the name Britta Filter") in the form of a pitcher having an upper and a lower compartment, with unpurified water flowing from the upper to the lower compartment through a filtering channel containing a purification medium. The purified water in the lower compartment may then be poured out of the dispenser for drinking.

A drawback in the use of some of these purification media is that after the active material is wetted, it is necessary to retain the media in a moist state. Drying out of the wetted media impairs its performance and supports growth of various types of microorganisms, which subsequently contaminate the filtered water. Manufacturers of devices using such purification media usually instruct the consumer to keep the media moist, but consumers do not always heed these instructions, with the result that instead of drinking purer water, they may be drinking more contaminated water.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a device which uses a purification medium for purifying water.

It is a further object of the invention to provide a device for maintaining the purification medium in a water filtering device in a moist state.

The present invention therefore provides a device for purifying water comprising:

(a) a filter housing containing a purification medium and having a port positioned below the purification medium, the purification medium having a height h relative to the filter housing port, and

(b) a vessel having a port at the base of the vessel, the vessel port being in communication with the filter housing port.

The vessel is positioned lateral to the filter housing and has a height of at least h relative to the filter housing port so that when water is present in the device, the water in the filter housing is at the same height as the water in the vessel, thereby maintaining the purification medium in a moist state The present invention is based on the application of the principle of communicating vessels to a water purification device. As is well known, if a number of vessels of different shapes containing a liquid are connected by conduits at their bottoms (or any other height below the liquid level), the liquid will reach the same level in all of them. The invention uses this principle to maintain the purification medium contained in a filter housing in a moist state, by inserting at least one additional vessel (or 'hydraulic lock') in line with the filter housing.

An additional advantage of the device of the invention is that water obtained from the device is uniformly purified, with limited differences between the initial use of the purification medium and a latter use, since the purifying quality of the medium is maintained. This leads to a longer effective life of the medium and improved quality control.

The vessel may be connected either to the inlet or to the outlet port of the filter housing, as long as it is connected below the purification medium of the housing and is positioned laterally to the filter housing. The term "below the purification medium" is to be understood in a functional sense, i.e. down-stream or following the medium, rather than in a spatial sense, i.e. under the medium. For example, the port of the filter housing may be on the lower lateral side of the housing, rather than at its bottom side. It is to be also understood that the term "below the purification medium" includes below a substantial portion of the medium, and not necessarily below its entirety.

In one, preferred embodiment of the invention, the filter housing port is an outlet for the water, and the vessel port is an inlet for the water, whereby the water flows from the filter housing to the vessel, usually by gravity or by water pressure. In another embodiment of the invention, the filter housing port is an inlet for the water, and the vessel port is an outlet for the water, whereby the water flows from the vessel to the filter housing. In this embodiment, the water flow is induced, e.g. by a pump or other flow-inducing mechanism.

In a still further embodiment, the device of the invention may be installed in-line with a water system to purify the water issuing from the system. Thus, the invention also provides a water system comprising a device according to the invention connected in-line thereto.

The vessel may be of any shape or material which does not interact with water. Preferably, the vessel will be long and narrow, in order to minimize the amount of water held in it.

The purification medium may be any medium which is known to purify, clean, filter, soften, improve the taste of, change the pH of, recycle and/or remove impurities from water. Preferably, the medium is of a type whose performance is impaired when it dries out after wetting. Non-limiting examples of such media are: (a) a mixture of activated charcoal, calcite and Portlandite; (b) a medium comprising Clinoptilolite;

(c) a medium comprising a cation exchanger;

(d) a medium comprising an anion exchanger;

(e) a medium comprising activated charcoal, optionally with silver; (f) Dolomite;

(g) a medium comprising zeolites; (h) a medium comprising alumina; (i) a passive filter such as a membrane or paper filter; (j) a medium comprising a cation exchanger imparting to the water a pH of approximately 5.5; and

(k) a medium comprising a cation exchanger imparting to the water a pH of less than 5.5. Other purification media will be apparent to the skilled man of the art. The device of the invention may be used in any apparatus or application which purifies, cleans, filters, softens, improves the taste of, changes the pH of, recycles and/or removes impurities from water for domestic, institutional, commercial or industrial use. Some non-limiting examples of such apparatuses and applications are pH 5.5 water filters; distilled water for domestic or laboratory use; water nozzle for washing the hair, face, hands, legs or feet; water for washing babies; Jacuzzi; prefilter for vehicle water systems; ice cube former; portable water container; personal water bottles; and agricultural watering systems.

The invention further provides a method for purifying water comprising causing the water to flow through a device, wherein the device comprises:

(b) a vessel having a port at the base of the vessel, the vessel port being in communication with the filter housing port. The vessel is positioned lateral to the filter housing and has a height of at least h relative to the filter housing port so that when water is present in the device, the water in the filter housing is at the same height as the water in the vessel, thereby maintaining the purification medium in a moist state.

BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and to see how it may be carried out in practice, preferred embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 is a perspective sectional view of a portable water purification apparatus comprising one embodiment of the device of the invention; Fig. 2 is a perspective sectional view of an enlargement of the device of Fig.

1 :

Fig. 3 is a front sectional view of the apparatus of Fig. 1; Fig. 4 is a front sectional view of another portable water purification apparatus comprising a further embodiment of the device of the invention; Fig. 5 is a front sectional view of a still further embodiment of the device of the invention; and

Fig. 6 is a partial front sectional view of a water purification apparatus comprising a further embodiment of the device of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to Fig. 1, there is illustrated a portable water purification apparatus, generally designated 2, which comprises an upper compartment 4 for receiving the water to be purified, and a lower compartment 6 for receiving the water from the upper compartment after it has been purified. A partition 8 separates the upper 4 and lower 6 compartments, and an aperture 10 in the center of the partition allows water to flow from the upper to the lower compartment.

The device 12 of the invention is placed through the aperture 10 so that the water from the upper compartment 4 must flow through the device 12 in order to reach the lower compartment. Extending outwardly from the upper end of the device 12 is an annular rim 14 whose bottom surface rests on the upper surface of the partition 8. The attachment of the rim 14 to the partition 8 may be made water impermeable, as is well known to the skilled man of the art, so that the flow of water is through the device only. Purified water may be poured out of the lower compartment through a spout 16 located on the side of the apparatus and 5 communicating with the lower compartment.

The device 12, which may be more clearly seen in Fig. 2, has an upper 18 and a lower 20 end, and a generally cylindrical body 22. An annular inlet groove 24 is cut in the upper end of the device, and leads through an annular passageway 26 to an annular filter housing 28 which extends along the length of the device

10 body 22. The filter housing has at its respective ends an upper inlet port 30 and a lower outlet port 32. The outlet port 32 may be under the purification medium or on its lower lateral side, as long as it receives the water flowing therethrough. The housing 28 is filled with a purification medium 34, which may be held in place by upper and lower gratings (not shown) through which the water may flow.

15 Encircled by and in parallel to the filter housing is an annular fluid vessel 36 in the form of an extended annular channel. The vessel 36 has at its respective ends an upper outlet port 38 and a lower inlet port 40. The outlet port 32 of the filter housing is in communication with the inlet port 40 of the vessel through an annular space 42.

20 The body of the device has a centrally located bore 44 running along the longitudinal axis of the device and having an upper 46 and lower 48 end. The upper end 46 of the bore is closed off by the upper end 18 of the device, but communicates with the upper outlet port 38 of the vessel 36 through a cavity 50 located under the central section of the upper end 18 of the vessel. The lower end

25 48 of the bore opens out of the device through the central section of its lower end 20.

The operation of the device of the invention may be understood with reference to Fig. 3, in which the numbering used in Figures 1 and 2 has been retained in order to facilitate understanding. Unpurified water is poured into the upper compartment 4 of the water purification apparatus 2. The water flows by gravity into the inlet groove 24, through the passageway 26 and upper inlet port 30 into the filter housing 28. The water passes through the purification medium 34 contained in the housing and is purified thereby. The purified water then exits the filter housing through the outlet port 32 and passes to the inlet port 40 of the fluid vessel 36 through the space 42. The water flows up through the vessel 36 and exits through the upper outlet port 38, cavity 50 and upper end 46 of the bore 44, down through the bore and out of the device through the lower end 48 of the bore into the lower compartment 6 of the apparatus. The addition of the passageway 26 allows the water over the purification medium to be retained even when the apparatus is tilted during pouring. The passageway 26 is optional and may be dispensed with, for example in the case of a sealable portable water container.

In the event that a conventional filtering device is used, and the water in the lower compartment has been poured out and not replenished by the addition of new water in the upper compartment, the purification medium will dry out. In the device of the invention, however, water remains in the filter housing 28 and vessel 36. Due to the principle of communicating vessels, the level of water in the filter housing will be equal to the level in the vessel. If the height of the purification medium 34 in the filter housing relative to the outlet port 32 is h, and the height of the vessel relative to the outlet port is at least h, the water level will completely cover the purification medium. Deviations from equal heights in the filter housing and vessel may occur due to external forces such as capillary action of the purification medium, but these will be minimal. Another embodiment of the invention is illustrated in Fig. 4, which shows a squeezable water bottle 60, such as for drinking water or for purified laboratory water, containing another embodiment of the device of the invention. The device includes a filter housing 62 having an upper inlet port 64 and a lower outlet port 66, and a vessel 68 in the foπn of a tube 68 which is positioned lateral to the filter housing. The lower end of the vessel is in communication with the outlet port 66, while the upper end 70 extends out of the bottle in the fonn of a dispenser of the purified water. The dispenser may be sealable. A feed tube 72 extends from the bottom of the bottle to the inlet port 64. The filter housing contains a purification medium 74 having a height h, while the vessel has a height greater than h. A cap 76 seals the bottle.

In operation, the bottle is filled with unpurified water. When it is desired to withdraw filtered water from the bottle, it is squeezed causing the water to enter the feed tube 72 and flow through the filter housing 62 and vessel 68 and out of the bottle through the dispenser 70. On release of the pressure on the bottle, the water remaining in the feed tube flows back into the bottle. However, water remains in the filter housing and vessel at equal water heights 78. Thus, the purification medium is retained in a moist state.

Of course, the water may be caused to flow by other mechanisms such as pumping or suction. The skilled man of the art will understand that the vessel may be located either before or after the filter housing, as long as it communicates with the filter housing under the water level.

Fig. 5 illustrates a further embodiment of the invention in which the vessel is located before the filter housing. The device 80 comprises a filter housing 82 containing a purification medium 84 which is held in place by upper and lower screens (not shown). An inlet port 86 is positioned below the purification medium and an outlet tube 87 extends from the upper side of the housing. A vessel 88 is positioned lateral to the filter housing 82 and has an outlet port 90 at its base and a feed tube 91 connected to its upper end. The outlet port 90 of the vessel is connected to the inlet port 86 of the filter housing by a conduit 92.

In operation, water is fed into the feed tube 91 under pressure and flows through the vessel 88, conduit 92 and filter housing 82, and then out through the outlet tube 87. If the water pressure is reduced, the water level remains at the top of the vessel and filter housing, so that the purification medium is retained in a moist state. Another embodiment of the invention is illustrated in Fig. 6, which shows a partial view of a water purification apparatus 100 comprising an upper 102 and a lower 104 compartment, a partition 106 and an aperture 108, all similar to the apparatus illustrated in Fig. 1. A cylindrical reservoir 110 extends downwardly from the aperture 108 into the space of the lower compartment 104. The reservoir has a closed off bottom end 112, an open upper end and a cylindrical lateral wall 114. The circumference of the upper end of the reservoir is molded to the border of the aperture 108 so as to be watertight, and a slot 116 opens in the lateral wall 114 of the reservoir near its upper end, to allow the egress of water therethrough. A filter housing 118 may be inserted into the reservoir 110. The filter housing contains a purification medium and has an inlet port 120 at its upper end and an outlet port 122 at its bottom end below the purification medium. The filter housing further comprises an annular rim 124 below the inlet port so as to allow the housing to be supported on the edge of the aperture 108. Thus, water poured into the upper compartment 102 may flow into the filter housing through the inlet port. One or more legs 126 are located at the bottom of the housing in order to space the outlet port 122 from the bottom end 112 of the reservoir, and allow a free flow of water out of the housing.

Insertion of the filter housing 118 into the reservoir 110 creates an annular interspace 128 between the outer lateral wall 130 of the filter housing and the inner lateral wall 114 of the reservoir. This interspace, which is positioned laterally to the filter housing, acts as a vessel or hydraulic lock having an inlet port 132 at its base in communication with the outlet port 122 of the filter housing. The height of the interspace is defined by the position of the slot 116 in the wall of the reservoir, and is at least even with the height of the purification medium in the filter housing.

In operation, water poured into the upper compartment 102 enters the filter housing 118 through the inlet port 120 and exits the housing from the outlet port 122. The water flows up through the interspace 128 and out through the slot 116 into the lower compartment 104. Even when no water remains in the upper compartment of the apparatus, the purification medium in the filter housing remains moist due to the retention of water in the interspace which acts as a communicating vessel to the filter housing.

It will be clear to the skilled artisan that various modifications of the illustrated embodiments may be made within the scope of the invention, which is defined by the following claims.

Claims

CLAIMS:

1. A device for purifying water comprising:

(a) a filter housing containing a purification medium and having a port positioned below said purification medium, said purification medium having a height h relative to said filter housing port, and

(b) a vessel having a port at the base of said vessel, said vessel port being in communication with said filter housing port; wherein said vessel is positioned lateral to said filter housing and has a height of at least h relative to said filter housing port so that when water is present in the device, the water in said filter housing is at the same height as the water in said vessel, thereby maintaining said purification medium in a moist state.

2. A device according to Claim 1 wherein said filter housing port is an outlet for the water, and said vessel port is an inlet for the water, whereby the water flows from said filter housing to said vessel.

3. A device according to Claim 1 wherein said filter housing port is an inlet for the water, and said vessel port is an outlet for the water, whereby the water flows from said vessel to said filter housing.

4. A device according to Claim 1 wherein the perfoπnance of said purification medium is impaired when it dries out after wetting. 5. A device according to Claim 1, wherein said purification medium is selected from the group consisting of:

(a) a medium comprising a cation exchanger;

(b) a medium comprising an anion exchanger;

(c) a medium comprising activated charcoal, optionally with silver; (d) a mixture of activated charcoal, calcite and Portlandite;

(e) a medium comprising Clinoptilolite;

(f) Dolomite;

(g) a medium comprising zeolites; (h) a medium comprising alumina; (i) a passive filter;

(j) a medium comprising a cation exchanger imparting to the water a pH of approximately 5.5; and (k) a medium comprising a cation exchanger imparting to the water a pH of less than 5.

5.

6. A device according to claim 1 wherein said filter housing further comprises an enclosed space positioned over said purification medium for retaining water above said purification medium even when said device is tilted.

7. A water purification apparatus comprising a device according to Claim 1.

8. A portable apparatus according to Claim 7 comprising an upper compartment for receiving unpurified water and a lower compartment for receiving purified water, said device being positioned between said compartments, wherein said unpurified water flows from said upper compartment to said lower compartment through said device.

9. A portable apparatus according to Claim 8 further comprising a reservoir extending into said lower compartment and being in communication with said upper compartment, wherein said filter housing is placed in said reservoir, thereby creating said vessel in the interspace between the lateral walls of the housing and the reservoir.

10. A portable apparatus according to Claim 7 being a container comprising an outlet tube and containing said device therein, wherein water may flow from within said container through said device and said outlet tube out of said container.

11. A water system comprising a device according to Claim 1 connected in-line thereto.

12. A method for purifying water comprising causing the water to flow through a device, wherein said device comprises:

(a) a filter housing containing a purification medium and having a port positioned below said purification medium, said purification medium having a height h relative to said filter housing port, and (b) a vessel having a port at the base of said vessel, said vessel port being in communication with said filter housing port; wherein said vessel is positioned lateral to said filter housing and has a height of at least h relative to said filter housing port so that when water is present in the device, the water in said filter housing is at the same height as the water in said vessel, thereby maintaining said purification medium in a moist state.