WO2006003350A1

WO2006003350A1 - Liquid treatment filter

Info

Publication number: WO2006003350A1
Application number: PCT/GB2004/002872
Authority: WO
Inventors: Lee Lovelace
Original assignee: Morphy Richards Limited
Priority date: 2004-07-02
Filing date: 2004-07-02
Publication date: 2006-01-12

Abstract

A liquid treatment filter cartridge (108) comprising a chamber (210, 211) for housing a filter material, an inlet (205) to control the flow of liquid through said cartridge and an outlet (200, 1502) formed by at least one projection extending from a chamber wall. The projection, projects either into or out of the chamber, preferably at a base region of the filter cartridge. In particular, the plurality of orifices may be formed as a plurality of slits provided on one or more faces of each projection. The outlet configuration is configured to prevent clogging of the outlet by the granular filter material and may be useable with or without a mesh to cover the plurality of orifices.

Description

LIQUID TREATMENT FILTER

Field of the Invention

The present invention relates to a liquid treatment filter and in particular, although not exclusively, to a liquid treatment filter outlet configured to be resistant to clogging by a granular filter material.

Background to the Invention

Water treatment filters have been used for some years, particularly in the treatment of household tap water. Typically, such filters for use in the home comprise a granular ion exchange resin and activated charcoal which function to remove minerals and chloride from the water prior to consumption.

A common liquid treatment filter, found in the art, comprises a generally cylindrical body provided with an inlet at one end of the cylinder to allow a flow of liquid into an inner chamber housing the filter material and an outlet provided at an adjacent end to allow a flow of liquid out of the chamber. Typically, the filter cartridge is positioned within a water filter jug at a mid-point therein separating an upper non-treated water storage compartment and a lower treated water storage compartment. Examples of such liquid treatment filters are disclosed in WO

98/32705, GB 2269586, WO 98/17582, WO 98/05401 , US 3747767 and EP 0992458.

Common to such known liquid treatment filters is the use of a mesh or similar woven grating positioned at the outlet and configured to prevent loss of the granular filter material from the inner chamber. Water flows under gravity, from the inlet to the outlet in direct contact with the granular liquid treatment material. In some examples, the mesh extends across substantially the whole of the cylindrical base section. Other examples include the separate locating of a mesh over separate orifices provided at the base of the cylinder so as to provide a plurality of independent mesh covered outlets. A considerable disadvantage associated with known liquid treatment filters is the tendency for the outlet to become blocked by the granular filter material following only short or moderate periods of use. For a typical prior art liquid treatment filter, the inventors have observed the onset of outlet clogging following the processing by the filter of as little as 10 litres of water.

A particular problem with prior art liquid treatment filters is the increasing amount of time required to process a single litre of liquid as the outlet becomes blocked. The inventors have observed, in some instances, immediately prior to the outlet becoming completely blocked, approximately 10 minutes are required for a conventional filter to process 1 litre of water. The total lifetime of such a filter being approximately 20 litres of processed liquid.

As a consequence of the above disadvantages a further problem with known liquid treatment filters is the requirement for a user to regularly replace the filter where the outlet has become blocked. This appears particularly wasteful as the granular treatment material is not exhausted when the filter is replaced.

The inventors have therefore realised a need for a liquid treatment filter with an outlet configured to allow the free flow of liquid through the filter avoiding the problems of outlet clogging.

Summary of the Invention

The inventors provide a liquid treatment filter comprising at least one outlet configurable for use in direct contact with the liquid treatment medium avoiding requirement for a mesh or similar webbing covering the outlet.

For prior art filters, the inventors observed a sagging of the mesh, in the region of the outlet in response to the weight of the moistened granular filter material upon the mesh. Accordingly, the inventors provide a substantially rigid or semi-rigid outlet which will not deform over time in response to the force exerted by the moist granular filter material stacked above the outlet.

An outlet is provided being configured to promote a non-compacting distribution of filter granules at the outlet. This is achieved by providing at least one outlet configured with sloping side walls, a plurality of orifices or slits being formed on the sloping side walls of each outlet. In particular, the outlets may take the form of projections or discrete concave regions formed at a base or outer wall of the filter cartridge. The tapering face of the outlet promotes a cascading of the granular filter material across the outlet. Accordingly, the weight of the granules is not concentrated on any particular point of the outlet, the angled surface serving to distribute the force of the filter material thereby preventing outlet blockage.

According to a specific embodiment of the present invention, the plurality of orifices are formed as a plurality of slits being defined by a plurality of ribs at a base region of the filter, the ribs being positioned adjacent to one another. The ribs may be arranged in a step-like configuration being either a repeating peak and trough step-like configuration or a ascending or descending step-like configuration. Additionally, the projections may be formed as conical, triangular prism, truncated prism or pyramid like structures, the slits being provided on the at least one face of the cone, prism or pyramid and in particular at the angles between the contours of the cone, prism or pyramid. In the specific embodiment where the outlet configuration is contoured, two transverse faces are provided adjacent to one another, each side of the slit, to provide a rigid or semi-rigid platform upon which the filter granules maybe stacked.

The orifices or slits maybe configured with a diameter or width being less than the diameter or thickness of the filter material granules so as to prevent the granules from escaping from the treatment chamber within the filter cartridge.

Suitable structural supports maybe provided across the ribs to prevent the ribs from deforming under the force of the moist granules. -A-

According to a first aspect of the present invention there is provided a liquid treatment filter comprising: a chamber capable of housing a liquid treatment medium; at least one inlet configured to allow a flow of a liquid into said chamber; said filter further comprising and characterized by: at least one projection projecting into said chamber; and a plurality of slits being provided on said at least one face, said plurality of slits being configured to allow a flow of liquid out of said chamber.

The outlet maybe formed as a grating or webbing formed by a plurality of elongate members or ribs arranged as either a flat or step-like configuration. According to specific implementations, the grating maybe formed with an alternating peak and trough configuration where adjacent elongate members or ribs are arranged in an alternating raised and lowered position, the slits being provided between each step.

Preferably, the projections comprising the slits are arranged as triangular prisms, truncated pyramids or pyramidal-like structure having inclined faces which taper in an inward direction from the base of the filter towards the chamber. Alternatively, the prism or pyramidal-like structure may project out of the chamber.

The inlet or outlet maybe configured to control the flow of liquid through the filter by a size of the cross-sectional area of the slits or orifices of the outlet and inlet. Preferably, the inlet comprises a total cross-sectional area being less than the cross-sectional area of the outlet. In particular, the filter is configured to control the flow of the liquid through the filter by a width of the orifices or slits without requirement or a mesh or webbing positioned at the outlet.

However, a mesh may be provided at an interior of the filter cartridge positioned over and about the outlets. The mesh is configured to prevent loss of filter material and in particular activated charcoal from the inner chamber. The mesh may extend across substantially a cross section of the inner chamber or may be provided at the specific regions of each outlet.

Where the outlet comprises a plurality of slits defined by a plurality of elongate members, ridges ribs, at least one support rib maybe provided across each of the elongate members or ridges so as to provide structural support, inhibiting separation of the members or ridges due to the force exerted upon the outlet by the moist granulate filter material. The ridges or ribs maybe formed integrally or non-integrally with the main body of the filter.

According to a second aspect of the present invention there is provided a liquid treatment filter comprising a chamber being defined by at least one outer wall, said chamber capable of housing a liquid treatment medium; at least one inlet configured to allow a flow of a liquid into said chamber; said filter further comprising and characterised by at least one projection extending away from said outer wall of said chamber, said projection comprising at least one face being aligned transverse to said outer wall; and a plurality of orifices capable of allowing a flow of said liquid from said chamber, said orifices formed on said at least one face of said at least one projection.

According to a third aspect of the present invention there is provided a water filter cartridge comprising a chamber being defined by a chamber wall and a base section said chamber being configured to house a granular filter material; at least one inlet configured to allow a flow of water into said chamber; said filter further comprising and characterized by a plurality of orifices formed on a projection extending from said base region into said chamber; wherein said orifices provide an outlet configured to allow a flow of water from said chamber.

According to one specific implementation, a width of the orifices or slits of the outlet is in the approximate range 0.125 mm to 0.175 mm. The granules may be sphere-like granules comprising a diameter of approximately 0.3 mm whereby the dimensions of the orifices, slits or slots are configured to prevent passage of the granules out of the chamber. The filter material may comprise an ion exchange resin and carbon-based filter material configured to remove minerals and/or chloride from the liquid, in particular water.

According to a fourth aspect of the present invention there is provided a liquid treatment filter comprising a chamber for housing a granular filter material, said chamber being defined by an outer chamber wall; at least one inlet configured to allow a flow of liquid into said chamber, said filter further comprising and characterised by at least one surface extending from said outer chamber wall into said chamber and transverse to said outer chamber wall; a plurality of orifices formed on said surface, said orifices being configured to allow a flow of liquid out of said chamber.

According to a fifth aspect of the present invention there is provided a liquid treatment filter outlet for a liquid treatment filter, said filter comprising an inlet, and a chamber capable of housing a granulate liquid treatment medium, said outlet comprising and characterised by a plurality of slits comprising a width being less than a diameter of each liquid treatment granule; wherein said slits are in direct contact with the granules and configured to inhibit loss of said granules from said chamber, whilst allowing a flow of said liquid out of said chamber.

According to a sixth aspect of the present invention there is provided a liquid treatment filter outlet for a liquid treatment filter, said filter comprising an inlet, and a chamber capable of housing a liquid treatment medium, said outlet comprising and characterised by at least one projection projecting into said chamber from a chamber wall defining said chamber and a plurality of orifices provided on said at least one projection said plurality of orifices being configured to allow a flow of liquid out of said chamber whilst inhibiting loss of said liquid treatment medium from said chamber.

The liquid treatment filter according to the present invention is usable with any manner of water filter jug, water filter heating or cooling appliance or electric water boiling appliance, such as a kettle and the like involving the treatment of a liquid, in particular water using a granular based liquid treatment medium.

Brief Description of the Drawings

For a better understanding of the invention and to show how the same may be carried into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which:

Fig. 1 herein illustrates a cross-sectional side elevation view of a water filter jug comprising a water filter according to the present invention;

Fig. 2 herein illustrates a cross-sectional side elevation view of the filter cartridge according to a specific implementation of the present invention;

Fig. 3 herein illustrates a cross-sectional side elevation view of a lower portion of the filter cartridge comprising a plurality of outlets according to a specific implementation of the present invention;

Fig. 4 herein illustrates a cross-sectional side elevation view of at least one outlet having an approximate triangular prism-like shape according to a specific implementation of the present invention;

Fig. 5 herein illustrates a perspective view of at least one outlet arranged in a stepped-like configuration comprising a plurality of substantially parallel ribs according to a specific implementation of the present invention;

Fig. 6 herein illustrates a plan view of an interior lower portion of the filter cartridge comprising four outlets according to a specific implementation of the present invention; Fig. 7 herein illustrates a plan view of an exterior lower portion of the filter cartridge comprising four outlets according to a specific implementation of the present invention;

Fig. 8 herein illustrates a cross-sectional side elevation view of the filter cartridge comprising a granular filter material within a first sub-chamber and a second sub-chamber according to a specific implementation of the present invention;

Fig. 9 herein illustrates a filter cartridge outlet according to a specific implementation of the present invention involving a plurality of ribs arranged in a grating where each rib overlaps with a neighboring rib in a substantially vertical plane so as to provide a series of gaps between the ribs;

Fig 10 herein illustrates a plan view of a mesh insert configured for positioning within the filter cartridge according to a specific implementation of the present invention;

Fig 11 herein illustrates a side elevation view of the mesh insert of figure 10 herein;

Fig 12 herein illustrates a side elevation view of the mesh insert configured in a bent configuration suitable for insertion within the filter cartridge;

Fig 13 herein illustrates a side elevation view of the filter cartridge comprising the mesh insert positioned over and about the inwardly projecting outlets;

Fig 14 herein illustrates a plan view of the interior of the filter cartridge in which the mesh insert is installed being configured to cover each of the four outlets. Detailed Description

There will now be described by way of example a specific mode contemplated by the inventors. In the following description numerous specific details are set forth in order to provide a thorough understanding. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the description.

A liquid treatment device is provided and in particular an outlet for a liquid treatment filter or liquid treatment filter cartridge being configured to allow the free flow of a liquid out of the filter avoiding the problems of clogging and relatively short filter cartridge lifetimes.

The outlet comprises a plurality of orifices, in the form of slots or slits configurable to be in direct contact with the liquid treatment material. The outlet slits are defined by a plurality of ribs arranged as a grating whereby liquid is configured to flow out of the filter through the gaps between the ribs forming the outlet. The orifices, slits or slots formed between the ribs comprise a width or diameter being equal to or less than the width or diameter of the granulate filter treatment material whereby passage of the filter material from with the filter cartridge is prevented due to the dimensions and configuration of the outlet orifices. Requirement for a mesh, to prevent loss of the filter material, is thereby avoided, however a mesh may optionally be used as detailed herein below.

Referring to figure 1 herein there is illustrated a cross-sectional elevation view of a liquid treatment jug 100 comprising pre-treated liquid storage chamber 101; post-liquid treatment chamber 102; filter jug body 103; chamber dividing walls 104; handle 105; spout 106; lid 107; and filter cartridge 108.

Jug body 103 defines an inner chamber being divided into two chambers 101, 102 by chamber walls 104 and cartridge 108. The chamber walls 104 and cartridge 108 are positioned substantially midway between jug base 111 and lid 107. Chamber wall 110 being connected to wall 104, in part, defines spout 106 together with main body 103. Lid 107 is moveable between an open and closed positioned allowing the transfer of a liquid into chamber 101. Handle 105 is positioned at an exterior of main body 103 so as to allow a user to grasp the filter jug and decant water therefrom.

Positioned between filter cartridge 108 and inner walls 104 is provided filter securing means 109 configured to releaseably secure the filter cartridge 108 to the jug 100. Securing means 109 may comprise any form of releasable attachment including a snap-fit attachment, bayonet type fitting or the like.

In use, untreated liquid, particularly water, is poured into pre-storage chamber 101 by displacing lid 107. The untreated liquid flows through filter cartridge 108 and into the lower chamber 102 positioned directly underneath chamber 101, the flow of liquid through the filter cartridge from chamber 101 into chamber 102 being under the force of gravity. Housed within filter cartridge 108 is a filter treatment medium (not shown) which functions to remove minerals and/or selected ions, in particular chloride, from the untreated liquid.

Following the transfer of liquid from the chamber 101 to chamber 102, the treated, filtered liquid maybe decanted from the jug 100 via spout 106 being connected directly to chamber 102.

According to the present invention the filter material within the cartridge 108 may be in direct contact with a filter cartridge outlet (not shown) positioned at a base region of the cartridge.

Referring to figures 2 and 3 herein there is illustrated a cross-sectional elevation view of the liquid treatment filter as detailed with reference to figure 1 herein comprising at least one outlet 200; at least one support rib 201; a plurality of elongate members 202; an outer chamber wall 203; an inner chamber wall 204; at least one inlet 205; an inlet support member 206; orifices 207; filter lid 209; chambers 210, 211 and base section 300.

At least one outlet 200 is provided at a base region of the filter 300. The

5 outlets are defined by a plurality of elongate members, or ribs 202 being arranged in a step-like configuration tapering inwardly towards the interior of chamber 210,

211. The elongate members or ribs 202 maybe formed integrally or non- integrally with the exterior wall 203 so as to define a plurality of orifices or slits formed between the elongate members or ribs being configured to allow the flow o of liquid from within chamber 210 out of the filter cartridge.

According to the specific implementation of the present invention the filter comprises an inner wall 204 configured to divert or deflect the flow of liquid between the inlet 205 and outlet 200. The inner chamber wall 204 defines the 5 first chamber 211 and second chamber 210, both chambers being configured to house the granular filter material. Inlet 205 comprises a plurality of orifices or slits configured to allow the flow of liquid from the liquid storage chamber 101 through column 208 and into filter chamber 211. According to the present invention the plurality of orifices formed at the inlet are formed as a plurality of slits on a conical 0 end portion of cylindrical member 206 projecting into an interior of filter chamber

211 and in particular base 300. A plurality of orifices 207 interconnect chambers 211 and 210 allowing the free flow of liquid between the chambers from inlet 205 to outlets 200. Filter lid 209 provides a seal for filter chambers 210, 211 preventing the escape of the liquid treatment material. Accordingly, water stored 5 within chamber 101 is prevented from entering the filter other than by the inlet 205. Similarly, liquid flowing out of chamber 211 is prevented from escaping other than into chamber 210.

The orifices, in the form if slits, are formed at the faces of projections o extending from the base region of the filter cartridge. The inclined surfaces of the outlets in the specific embodiment comprise ribs arranged substantially parallel to one another forming a triangular prism. The support ribs 201 are provided, substantially transverse to the elongate members 202 so as to provide structural support and prevent separation of the ribs and a widening of the outlet slits.

When in use, a granular filter material is housed within chambers 210, 211. Liquid flows into the filter cartridge via inlet 205 and into first chamber 211, in contact with the filter material. The water flows against gravity from the lower region of the inner chamber 211 to an upper region of the chamber towards orifices 207. The liquid then flows through orifices 207 into filter chamber 210 also housing the filter material. The liquid then flows through chamber 210 under gravity towards the plurality of outlets 200. The liquid then flows out of the filter cartridge via the plurality of orifices or slits being the outlets and out of the filter cartridge.

Referring to figure 4 herein there is illustrated a cross-section elevation view of one outlet 200 being defined by a plurality of elongate members 202 arranged in a step-like configuration. The outlet structure 202 maybe formed integrally or non-integrally with the filter body 203 and/or base section 300. According to the specific implementation of the present invention the outlet 200 comprises a plurality of slits formed on at least one face of a triangular prism, at the angle between the steps of the prism. One or more support ribs 201 are provided on each face of the prism, transverse to and in contact with the elongate members so as to provide structural support. The support ribs thereby inhibit separation of the elongate members and a corresponding widening of the slits. The support ribs 201 may extend the full distance across the outlet or may extend over a portion of each outlet face.

The outlet, in the form of a triangular prism projects inwardly from the base of the cartridge towards the inner chamber. Two faces of the triangular prism comprise the substantially parallel aligned plurality of ribs in between which are provided slits to allow the passage of liquid, in particular water, from the inner chamber. Accordingly, each outlet comprises two surfaces being transverse or inclined relative to outer chamber wall 203 and/or filter base 300. According to the specific implementation of the present invention each surface of the triangular prism comprising the ribs and slits, are inclined at an angle of approximately 120° relative to a base section 300.

Referring to figure 5 herein there is illustrated a perspective view of outlet 200 being defined by a plurality of elongate members or ribs 202 arranged in a cascading stepped configuration. Each elongate member 202 comprises a substantially vertical face 502 and a substantially horizontal face 501. A plurality of slits 500 are defined by neighboring elongate members and in particular slits 500 are bordered along their length by a substantially horizontal face 501 of a first elongate member and a substantially vertical face 502 of a neighboring elongate member. The elongate members are held in place, in the step-like arrangement by the at least one support rib 201 (not shown) and suitable structural support means (not shown) positioned at the end regions of the prism-like structure.

According to the specific implementation of the present invention each elongate member is displaced substantially above a lower neighboring elongate member whereby an upper edge 503 of a lower positioned rib is substantially aligned with a lower edge 504 of a neighboring rib as illustrated in Figure 5 herein. The width of the slits or distance between adjacent faces 501 and 502 of neighboring ribs is in the approximate range 0.125 mm to 0.175 mm, the width being less than a diameter or thickness of the granular filter material.

In use, the granular filter material is housed within the filter chamber in direct contact with elongate members 202 and outlet slits 500. Due to the relative positioning of the slits being bordered by substantially transverse faces 501 , 502 the granular material is prevented from packing densely against the slits thereby blocking the outlets. The granules, are stacked, one on top another on faces 501 against 502. According, a network of granules is built directly upon the ribs 202 such that, the force exerted by the moist granular material onto the outlet is distributed across the plurality of faces 501 , 502.

Figure 6 herein illustrates a plan view of the lower region of the filter cartridge from the interior of the cartridge and figure 7 herein illustrates a plan view of the lower region of the filter cartridge from an exterior of the filter cartridge.

Four outlets 200 are provided at a lower base section 300 of the filter cartridge 108. At least one chamber wall 203 connects the base section 300, to a sealing lip 602 positioned at an upper region of the filter cartridge and configured to receive lid 209. Securing means 109 are provided at the sealing lip 602, substantially opposed to one another configured to mate with the securing means

109 so as to secure cartridge 108 to, for example, a water filter jug as detailed with reference to figure 1 herein. A central region of the base is adapted to receive a portion of inner chamber wall 204 whereby a dual chamber cartridge is provided configured to store filter material in at least two separate chambers.

Each of the four outlets 200 are equally spaced from one another providing a plurality of holes or slits through which the liquid flows out of the chamber 210.

According to the specific implementation of the present invention the ribs

200 of each outlet are arranged in a step-like configuration forming an apex projecting into the inner chamber. Further specific implementations include the step-like configuration projecting out of the base of the filter away from the inner chambers.

Referring to figure 8 herein there is illustrated a cross-sectional side elevation view of the filter cartridge 108. In use, the liquid flows from a source of untreated liquid, such as an untreated liquid storage chamber 101 passed the filter lid 209 as indicated by arrows 801 , 802. Both filter chambers 211 and 210 house the liquid treatment filter material being a granulate ion exchange resin. The liquid on passing through the inlet 205 is forced to flow against gravity arrow 803 in an upward direction through the inner chamber, in contact with the ion exchange resin. The liquid flows through the orifices 207, arrow 804 and into the second chamber 210 also housing the ion exchange resin. The liquid flows under gravity down the second chamber, in contact with the filter material and out of the cartridge, arrow 805 via the plurality of orifices 200 at cartridge base 300.

The plurality of slits formed at the outlets are configured to allow the flow of liquid out of the filter whilst preventing passage of the ion exchange resin. In order to avoid clogging of the outlet by the filter material, the outlet is constructed so as to taper inwardly or outwardly with respect to the base of the cartridge so as to distribute the force exherted by the moist granules onto the outlet. Accordingly, the tendency of the outlets to clog is reduced as the granules will tend to cascade down the slopping faces of each outlet.

Referring to figure 9 herein there is illustrated a perspective view of a further specific implementation of a filter cartridge outlet comprising a plurality of elongate members arranged in a step-like configuration. The outlet comprises a plurality of ribs or elongate members 900 arranged in a step-like structure whereby each rib is positioned relative to a neighboring rib so as to overlap in the substantially vertical plane. A plurality of gaps are formed between the ribs serving to allow the passage of liquid but not the granular ion exchange resin 800.

Each rib 900 may comprise a rectangular, square, circular or elliptical cross- section as with the embodiment of figure 5 herein. Where the ribs include a substantially rectangular cross-section, end surface 902 of a first rib is positioned adjacent surface 901 of a neighboring rib so as to define a gap or slit 903 between the ribs 900. An overlap region is provided, in the substantially vertical plane, between adjacent ribs, the overlap region of an adjacent rib in close proximity to surface 902 serving to further restrict and prevent passage of the granular resin material 800 out of the cartridge. In use, liquid flows through the filter cartridge, passed the ribs 900, arrow 904, via channels 903 formed between the ribs 900, and out of the filter cartridge.

Figure 10 herein is a plan view of a mesh insert 1000 comprising separate mesh elements 1001 ; mesh support frame 1002; support frame break 1003; central support 1004; and hinge means 1005.

The mesh insert 1000 is substantially plainer in a non-installed configuration, whereby each of the mesh elements 1001 extend radially outward from central support 1004. Central support 1004 comprises a ring-like configuration whereby each of the mesh elements 1001 extend outwardly from the ring being substantially equally spaced relative to one another.

Each mesh element is housed within a support frame 1002 extending around substantially an entire perimeter of the mesh element forming a border. Breaks or discontinuities are present at selected intervals along the border 1002 allowing the mesh element to bend as detailed with reference to figure 12 herein. Hinge means 1005 are provided at the junction between support frame 1002 and the central ring-like support 1004, hinge means 1005 allowing each of the mesh elements to be hingeably displaced relative to the central support.

Referring to figures 11 and 12 herein, there is illustrated side elevation views of the mesh insert 1000 in a substantially plainer configuration (figure 11 ) and a hinged configuration suitable for installation within the filter cartridge (figure 12).

In order to configure the mesh insert for positioning within the filter cartridge, each mesh element 1001 and border 1002 are bent upwardly relative to central support 1004 via hinge means 1005, as detailed with reference to figure 12 herein. Additionally, each mesh element 1001 is bent at the regions of the breaks 1004 in each border 1002. Figure 13 herein is a side elevation view of the filter cartridge on figure 3 further comprising the mesh insert 1000 positioned over and about each of the outlets. Figure 14 herein is a plan view of the filter interior comprising the mesh insert position over and about each of the four outlets of figure 6 herein.

When assembled within the filter cartridge, the mesh insert is configured to cover the outlet orifices or slits so as to prevent the passage of fine particles from out of the cartridge. For example, the mesh is configured to prevent particulate carbon or fragmented filter material from passing through the gaps between the outlet ribs. The mesh insert is securely located within the base of the filter cartridge by a snap-fit action whereby a seal is formed around each outlet so as to prevent the escape of particulate matter from within the cartridge. The mesh 1001 comprises standard material common to filter cartridges disclosed in the art.

In use, the mesh 1001 lies against the slopping surfaces of the triangular prism outlet projections. Due to this configuration any sagging of the mesh under the weight of the moist granular material is localised at the contours of the outlet. That is, any sagging of the mesh at each step of the slopping outlet face is not of sufficient magnitude to result in a blocking of each slit 500 as detailed with reference to figure 5 herein.

According to a further embodiment of the present invention, figure 15 herein illustrates a perspective view of a lower portion of a filter cartridge 1500 comprising a chamber wall 1501 ; two projections 1502; a base region 1503; a first face of a projection 1504 and a second face of a projection 1505.

Each projection 1502 extends from base region 1503 towards the interior of the filter cartridge. Each projection comprises a length extending a distance over base region 1503, each projection being curved along its length. First and second walls 1504, 1505 taper inwardly from base region 1503 towards the interior of the chamber defined by chamber walls 1501. Accordingly, each face 1504, 1505 is a sloping face being aligned transverse to the base 1503 and walls 1501. Each projection 1502 is formed as a truncated prism having a length corresponding to an arc of a circle.

Figure 16 herein illustrates a perspective view of one projection 1502 as detailed with reference figure 15 herein. Each projection comprises a plurality of ridges 1600 extending across each face 1504 and 1505. The projections extend outwardly away from face 1504 extending between a region of the projection being inner most within the chamber and the base region 1503. As illustrated with reference to figure 16 herein the ridges extend between an upper region of the projection and a lower region of the projection in a plane substantially transverse to a plane of base region 1503. A region of each face 1504 separates each projection. Each projection, in the form of a square based truncated prism, curved along its length, comprises a substantially flat upper surface 1604. Upper surface 1604 is substantially parallel to base section 1503.

A plurality of slits 1601 are provided in close proximity to each projection 1600, each slit being formed on face 1504. In particular, each slit 1601 is positioned at the angle between ridges 1600 and face 1504 and extend a distance of the height of projection 1502, that is from base region 1503 towards the interior of the chamber defined by chamber walls 1501. Slits 1601 may be provided at one side of each ridge or may be provided on both sides at the junction with the face 1504. Alternatively, the slits may be formed at any position along the length of each ridge or in close proximity thereto. As detailed with reference to figure 5 herein the width of slits 1601 is configured to inhibit loss of the granular filter material from the filter cartridge chamber, whilst allowing a flow of liquid out of the chamber.

Figure 17 herein is a cross-section, elevation view of the cartridge outlet as detailed with reference to figure 15 herein. The projection 1502 extends from base region 1503 inwardly towards the cartridge chamber defined by walls 1501.

A width of the projection decreases from base region 1503 to the chamber interior whereby faces 1504, 1505 taper inwardly towards the chamber interior from base 1503. The granular filter material therefore is configured to cascade down the tapering faces of the projection which serves to inhibit blockage of the slits 1601 by the filter material.

Figure 18 illustrates a plan view of the interior of the filter cartridge as detailed with reference to figure 15 herein. Two projections are provided at base region 1503 positioned opposed to one another. Each projection being substantially curved along its length is configured to correspond to the curvature of the perimeter of base section 1503. Accordingly each face of the projection is also curved along its length.

As illustrated with reference to figure 18 herein each ridge extending from faces 1504, 1505 comprises a substantially rectangular or square cross-section. Each face and ridge being terminated at base 1503 and upper surface 1604 of each projection.

According to further specific implementations, projections 1502 may be formed with non-tapering faces 1504, 1505, whereby each face is aligned substantially perpendicular to base section 1503. According to yet further specific implementations, projections 1502 may extend from the chamber walls 1501 where the internal chamber is defined by the chamber walls without inclusion of base section 1503.

Claims

Claims:

1. A liquid treatment filter (108) comprising:

a chamber (210, 211) capable of housing a liquid treatment medium;

at least one inlet (205) configured to allow a flow of a liquid into said chamber;

said filter further comprising and characterized by:

at least one projection (202, 1502) projecting into said chamber; and

a plurality of slits (500, 1601) being provided on said at least one projection, said plurality of slits being configured to allow a flow of liquid out of said chamber.

2. The filter as claimed in claim 1 wherein said slits are formed as a grating on said at least one projection, each slit of said plurality of slits being aligned on said projection so as to extend a distance between a lower and upper region of said projection.

3. The filter as claimed in claims 1 or 2 wherein said slits are configured to control a flow of said liquid through said filter.

4. The filter as claimed in anyone of claims 1 to 3 wherein said slits are configured to be in direct contact with said liquid treatment medium.

5. The filter as claimed in anyone of claims 1 to 4 wherein said filter is configured to control the flow of liquid through the said filter by a width of said slits without requirement for a mesh positioned at said outlet.

6. The filter as claimed in anyone of claims 1 to 5 wherein said inlet is configured to control the flow of said liquid through said filter.

7. The filter as claimed in claim 6, wherein an area of said inlet through which water flows into said chamber is less than a total area of said outlet slits.

8. The filter as claimed in anyone of claims 1 to 7 wherein said filter comprises two projections positioned at a base of said chamber (300, 1503).

9. The filter as claimed in anyone of claims 1 to 8 further comprising a mesh, said mesh being provided at an exterior side of said plurality of slits relative to said chamber.

10. The filter as claimed in claim 8 wherein each projection comprises a plurality of ridges extending a distance between a lower and upper region of each said projection, each slit of said plurality of slits being provided at the angle between each said ridge and a face of said projection.

11. The filter as claimed in claim 10 wherein said ridges comprise a substantially rectangular or square cross-section.

12. A liquid treatment filter (108) comprising:

a chamber (210, 211) being defined by at least one outer wall (203, 1501), said chamber capable of housing a liquid treatment medium;

said filter further comprising and characterised by: at least one projection (202, 1502) extending away from said outer wall of said chamber, said projection comprising at least one face being aligned transverse to said outer wall; and

5 a plurality of orifices (500, 1601) capable of allowing a flow of said liquid from said chamber, said orifices formed on said at least one face of said at least one projection.

13. The liquid treatment filter as claimed in claim 12 wherein said o projection extends into said chamber.

14. The liquid treatment filter as claimed in claim 12 wherein said projection extends out of said chamber.

5 15. The liquid treatment filter as claimed in anyone of claims 12 to 14 comprising two projections, each projection comprising two faces being aligned transversed to said outer wall, said plurality of orifices being provided on each face.

0 16. The liquid treatment filter as claimed in claim 15 wherein said plurality of orifices are formed as a plurality of slits, wherein a width of each slit is configured to inhibit loss of said liquid treatment medium from said chamber.

17. The liquid treatment filter as claimed in claim 16 further comprising 5 a plurality of ridges being formed on each face of each projection, wherein said slits extend along the length of each ridge.

18. The liquid treatment filter as claimed in claim 17 wherein a cross- sectional width of said two projections decreases away from said outer wall. 0

19. The liquid treatment filter as claimed in anyone claims 12 to 18 wherein a width of each orifice or said plurality of orifices is in the approximate range 0.125 mm to 0.175 mm.

20. A water filter cartridge (108) comprising:

a chamber (210, 211) being defined by a chamber wall (203, 1501) and a base region (300, 1503), said chamber being configured to house a granular filter material;

at least one inlet (205) configured to allow a flow of water into said chamber;

said filter further comprising and characterized by:

a plurality of orifices (500, 1601) formed on at least one projection (202,

1502) extending from said base region into said chamber;

wherein said orifices provide an outlet configured to allow a flow of water from said chamber.

21. The cartridge as claimed in claim 20, wherein said orifices are arranged as a plurality of slits, each slit of said slits having a width configured to prevent passage of said filter material from said chamber.

22. The cartridge as claimed in claim 21 , wherein said at least one outlet comprises a plurality of ribs (202) arranged in a cascading step-like arrangement, wherein said slits are positioned adjacent to one another at the region between the steps.

23. The cartridge as claimed in anyone of claims 20 to 22 wherein said at least one projection is arranged as a cone, prism, triangular prism, truncated prism or pyramid-like structure.

24. The cartridge as claimed in anyone of claims 20 to 23 wherein a width of said slits is less than a diameter of a granule of said filter material.

5 25. The cartridge as claimed in claim 24 wherein a width of each slit of said slits is in the approximate range 0.125 mm to 0.175 mm.

26. The cartridge as claimed in claim 25 wherein each granule comprises a diameter of approximately 0.3 mm. 0

27. The cartridge as claimed in anyone of claims 20 to 26 further comprising a mesh element (1000) configured to inhibit loss of said filter material from said chamber, said mesh element being positioned at an exterior of said chamber. 5

28. The cartridge as claimed in anyone of claims 20 to 26 further comprising a mesh element configured to inhibit loss of said filter material from said chamber, said mesh element being positioned at an interior of said chamber.

o 29. The cartridge as claimed in anyone of claims 20 to 28 wherein said inlet comprises at least one orifice, a total area of said at least one orifice of said inlet being less than a total area of said plurality of orifices of said outlet.

30. The cartridge as claimed in claim 39 wherein said flow of water 5 through said cartridge is controlled by a size of said area of said at least one orifice of said inlet.

31. The cartridge as claimed in anyone of claims 20 to 30 wherein said filter material comprises an ion exchange resin. 0

32. A liquid treatment filter (108) comprising: a chamber (210, 211) for housing a granular filter material, said chamber being defined by an outer chamber wall (203, 1501);

at least one inlet (205) configured to allow a flow of liquid into said chamber;

5 said filter further comprising and characterised by:

at least one surface extending from said outer chamber wall into said chamber and transverse to said outer chamber wall; and 0 a plurality of orifices (500, 1601) formed on said surface, said orifices being configured to allow a flow of liquid out of said chamber.

33. The filter as claimed in claim 32 wherein said filter comprises a 5 plurality of surfaces, each surface extending into said chamber from said outer chamber wall, each surface comprising a plurality of orifices, said plurality of surfaces being positioned at a region of said chamber substantially opposed to said inlet.

0 34. The filter as claimed in claims 32 or 33 wherein said plurality of orifices are formed as a plurality of slits comprising a width being less than a diameter of each granular of said granular filter material.

35. The filter as claimed in anyone of claims 32 to 34 further comprising 5 a mesh being positioned over said plurality of orifices at an interior side of said filter.

36. A liquid treatment filter outlet (200) for a liquid treatment filter, said filter comprising an inlet (205), and a chamber (210, 211) capable of housing a o granulate liquid treatment medium, said outlet comprising and characterised by: a plurality of slits (500, 1601) comprising a width being less than a diameter of each liquid treatment granule;

wherein said slits are configured to inhibit loss of said granules from said 5 chamber, whilst allowing a flow of said liquid out of said chamber.

37. The outlet as claimed in claim 36 wherein a width of said slits is configured to control a flow of said liquid through said filter.

o 38. The outlet as claimed in claims 36 or 37 wherein said plurality of slits are formed on at least one projection formed integrally with said filter and projecting into towards said chamber.

39. A liquid treatment filter outlet for a liquid treatment filter, said filter 5 comprising an inlet (205), and a chamber (210, 211) capable of housing a liquid treatment medium, said outlet comprising and characterised by:

at least one projection projecting into said chamber from a chamber wall (203, 1501) defining said chamber; and 0 a plurality of orifices (500, 1601) provided on said at least one projection, said plurality of orifices being configured to allow a flow of liquid out of said chamber whilst inhibiting loss of said liquid treatment medium from said chamber.

5 40. The outlet as claimed in claim 39 further comprising a mesh (1001) positioned over and about said at least one projection.

41. The outlet as claimed in anyone of claims 39 or 40 wherein said inlet is configured to control the flow of liquid through said filter, an area of said o inlet being less than a total area of said plurality of orifices.

42. A liquid treatment jug for treating liquid using a filter (108) according to anyone of claims 1 to 19.

43. A water filter jug comprising a filter (108) as claimed in anyone of claims 1 to 19.

44. A liquid heating appliance comprising a filter (108) as claimed in anyone of claims 1 to 19.

45. A water cooling appliance comprising a filter as claimed in anyone of claims 1 to 19.

46. A liquid treatment jug for treating liquid using a cartridge (108) according to anyone of claims 20 to 31.

47. A water filter jug comprising a cartridge (108) as claimed in anyone of claims 20 to 31.

48. A liquid heating appliance comprising a cartridge (108) as claimed in anyone of claims 20 to 31.

49. A water cooling appliance comprising a cartridge (108) as claimed in anyone of claims 20 to 31.

50. A liquid treatment jug for treating liquid using a liquid treatment filter outlet (200) according to anyone of claims 36 to 41.

51. A water filter jug comprising a filter outlet (200) as claimed in anyone of claims 30 to 41.

52. A liquid heating appliance comprising a filter outlet (200) as claimed in anyone of claims 30 to 41.

53. A water cooling appliance comprising a filter outlet (200) as claimed in anyone of claims 30 to 41.