Liquid Treatment Device, Method of Manufacturing It and Liquid Treatment System

Abstract

A liquid treatment device includes a body. The body includes a container section defining a container for holding liquid to be treated and a liquid treatment section defining a cavity and including at least one liquid treatment part. The body includes at least one liquid-impermeable wall defining at least a bottom of the container and at least one wall enclosing the cavity. These walls are inseparable, any seams in transitions between these walls being between parts of the body joined by bonding. The liquid treatment device is provided with at least one first liquid-permeable window allowing liquid to egress from the device and at least one second liquid-permeable window allowing liquid to flow from an interior of the container to the cavity. The liquid treatment device includes a barrier between the cavity and the container interior, inseparable from the body, the barrier including at least one of the second windows.

Claims

1. A liquid treatment device including a body, the body including: a container section defining a container for holding liquid to be treated and a liquid treatment section defining a cavity and including at least one liquid treatment part, wherein the body includes at least one liquid-impermeable wall defining at least a bottom of the container and at least one wall enclosing the cavity, wherein these walls of the body are inseparable, any seams in transitions between these walls being between parts of the body joined by bonding, and wherein the liquid treatment device is provided with at least one first liquid-permeable window allowing liquid to egress from the device and at least one second liquid-permeable window allowing liquid to flow from an interior of the container to the cavity, wherein the liquid treatment device includes a barrier between the cavity and the container interior, the barrier including at least one of the second windows, wherein the barrier is inseparable from the body.

2. The liquid treatment device according to claim 1, wherein the barrier is a wall section in which at least one of the second windows is provided, and wherein any seams in a transition between the wall section and an adjoining section of the body surrounding the wall section are between parts of the body joined by bonding.

3. The liquid treatment device according to claim 2, wherein the wall section is made in one piece with a wall defining at least the bottom of the container.

4. The liquid treatment device according to claim 2, wherein the wall section is a wall of a housing of the cavity, the housing being joined to the container section to a wall defining at least the bottom of the container, by bonding.

5. The liquid treatment device according to claim 1, wherein the liquid treatment section includes a cavity side wall closed on itself about the cavity, and wherein any seams in a transition between a circumference of the cavity side wall at an end thereof proximal to the container section, and the at least one liquid-impermeable wall defining at least the bottom of the container are between parts of the body joined by bonding.

6. The liquid treatment device according to claim 5, wherein the cavity side wall forms the first liquid-permeable window, wherein the cavity side wall includes at least one layer of sheet material, e.g. pleated.

7. The liquid treatment device according to claim 1, wherein the at least one liquid treatment part includes at least one of a granular and a fibrous liquid treatment medium.

8. The liquid treatment device according to claim 1, wherein the at least one liquid treatment part is arranged in the cavity.

9. The liquid treatment device according to claim 8, wherein an interior surface of a side wall of the cavity bounds the cavity.

10. The liquid treatment device according to claim 9, wherein a liquid treatment medium arranged in the cavity is arranged to contact the interior surface of the cavity side wall.

11. The liquid treatment device according to claim 1, wherein the liquid treatment section has an elongated cross-section.

12. The liquid treatment device according to claim 1, wherein a side wall of the liquid treatment section and one of the barrier and an end wall at an opposite end of the liquid treatment section to the barrier are parts of a beaker-shaped component, integral parts of a beaker-shaped component made in one piece.

13. A liquid treatment system, including a container for collecting treated liquid and the liquid treatment device according to claim 1, suspendable above a base of the container for collecting treated liquid.

14. A method of manufacturing the liquid treatment device according to claim 1, including the steps of: forming the body including at least one of the walls and joining the body and the other walls together.

15. The method according to claim 14, including manufacturing the liquid treatment section and the container section separately and joining the liquid treatment section to the container section.

16. The liquid treatment device according to claim 2, wherein the liquid treatment section includes a cavity side wall, closed on itself about the cavity, and wherein any seams in a transition between a circumference of the cavity side wall at an end thereof proximal to the container section, and the at least one liquid-impermeable wall defining at least the bottom of the container are between parts of the body joined by bonding, and wherein the cavity side wall forms the first liquid-permeable window, wherein the cavity side wall includes at least one layer of sheet material, e.g. pleated.

17. The liquid treatment device according to claim 16, wherein the at least one liquid treatment part includes at least one of a granular and a fibrous liquid treatment medium, and wherein the at least one liquid treatment part is arranged in the cavity.

18. The liquid treatment device according to claim 17, wherein an interior surface of a side wall of the cavity bounds the cavity, and wherein a liquid treatment medium arranged in the cavity is arranged to contact the interior surface of the cavity side wall.

19. The liquid treatment device according to claim 18, wherein the liquid treatment section has an elongated cross-section, and wherein a side wall of the liquid treatment section and one of the barrier and an end wall at an opposite end of the liquid treatment section to the barrier are parts of a beaker-shaped component, integral parts of a beaker-shaped component made in one piece.

20. A liquid treatment system, including a container for collecting treated liquid and the liquid treatment device according to claim 19, suspendable above a base of the container for collecting treated liquid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The invention will be explained in further detail with reference to the accompanying drawings, in which:

[0055] FIG. 1 is a side view of a liquid treatment system;

[0056] FIG. 2 is a cross-sectional view of part of a first replaceable liquid treatment device for the liquid treatment system of FIG. 1;

[0057] FIG. 3 is a cross-sectional view of part of a second replaceable liquid treatment device for the liquid treatment system of FIG. 1;

[0058] FIG. 4 is a cross-sectional view of part of a third replaceable liquid treatment device for the liquid treatment system of FIG. 1;

[0059] FIG. 5 is a cross-sectional view of part of a fourth replaceable liquid treatment device for the liquid treatment system of FIG. 1;

[0060] FIG. 6 is a cross-sectional view of part of a fifth replaceable liquid treatment device for the liquid treatment system of FIG. 1;

[0061] FIG. 7 is a cross-sectional view of part of a sixth replaceable liquid treatment device for the liquid treatment system of FIG. 1;

[0062] FIG. 8 is a cross-sectional view of part of a seventh replaceable liquid treatment device for the liquid treatment system of FIG. 1; and

[0063] FIG. 9 is a cross-sectional view of part of an eighth replaceable liquid treatment device for the liquid treatment system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0064] A liquid treatment system for the treatment of aqueous liquids such as mains drinking water includes a jug 1 as an example of a container for collecting treated liquid. The jug 1 is provided with a pouring spout 2 and a handle 3. The jug 1 is open at an end opposite a base. The jug 1 has an elongated cross-sectional shape for cross-sections perpendicular to an upright axis 4 that is oriented substantially vertically when the jug 1 is stood on its base.

[0065] The open end of the jug 1 is closed by a lid 5 including a fill opening closed by a pivotable closure element 6. A pivotable spout cover 7 is part of the lid 5 and closes the pouring spout 2 when the jug 1 is stood on its base.

[0066] A liquid treatment device in the form of a funnel 8 is suspended within the jug 1. To this end, an exterior ridge 9 at an, in use, upper end of the funnel 8 is supported by a ledge formed on an interior surface of a side wall of the jug 1. The ledge and ridge 9 need not extend all the way around the circumference of the funnel 8. The ledge is at such a level that the funnel 8 is suspended completely within the jug 1. The lid 5 is supported by the jug 1 and covers a mouth of the funnel 8.

[0067] It is possible to define an upright axis of the funnel 8, in this example aligned with the jug axis 4 when the funnel 8 is suspended in the jug 1. Seen in axial direction, the funnel 8 comprises two adjacent sections. One section 10 defines a container for holding liquid to be treated. Another section 11 defines a cavity through which liquid is forced to flow and in which at least one liquid treatment medium may be arranged.

[0068] The container section 10 includes a side wall separating an interior of the container from the environment. This side wall is closed on itself about the funnel axis. An edge at an in use upper end of the funnel 8 defines a mouth of the funnel 8. The exterior ridge 9 is provided at this end. The side wall slopes inwards towards the liquid treatment section 11 defining the cavity, so that the section 10 defining the container for holding liquid to be treated has no clearly defined bottom wall. In a different embodiment (not shown), there may be such a wall transitioning into the side wall at a clearly defined edge.

[0069] The cavity in the liquid treatment section 11 may form a chamber arranged to hold one or more liquid treatment media for treating liquids such as aqueous liquids. An example would be mains drinking water or another aqueous beverage. The liquid treatment media may include liquid treatment media for the treatment of liquid in a diffusive process, e.g. media removing or adding components to the liquid. In particular, the media may include a liquid treatment medium for the treatment of liquid by sorption, which for present purposes includes ion exchange, adsorption and absorption. The media may include activated carbon. They may include an ion exchange resin, e.g. a cation exchange resin. The cation exchange resin may include cation exchange resin in the hydrogen form. In a particular embodiment, a majority of the ion exchange resin is in the hydrogen form. For more effective use of the available volume, the cation exchange resin may be weakly acidic cation exchange resin. The liquid treatment medium will generally be at least partly in granular form.

[0070] At least one of the walls of the funnel 8 is provided with at least one liquid-permeable window allowing liquid, but not any granular matter above a certain size, from the cavity in the liquid treatment section 11 to egress from the funnel 8. At least one of the walls of the funnel 8 is provided with at least one liquid-permeable window allowing liquid, but not any granular matter in the cavity above a certain size, to pass between an interior of the container defined by the section 10 and the cavity. Otherwise, a wall section comprised in a liquid-impermeable wall is situated between the cavity and the container interior, so that these are separated from each other by at least that wall section. The wall section is comprised in one of a set of liquid-impermeable walls that are integral parts of a body of the funnel 8. Each of these walls is either inseparably joined to the remainder of the body or an integral part of a body section made in one piece, so that the wall transitions seamlessly into the remainder of the body.

[0071] Liquid-impermeable walls of the funnel 8 will generally be made of plastic, e.g. styrene-acrylonitrile (SAN), polyethylene polypropylene, styrene maleic anhydride (SMA) or polystyrene. The latter-mentioned two materials, in particular SMA, provide a lasting relatively glossy finish without extensive use of additives. Where the walls are joined, they are bonded, so that a positive material joint is formed. This means that the material of the walls and that of an optional adhesive or filler material is coalesced. They may be joined by welding, soldering or adhesive bonding. The walls are self-supporting, maintaining a substantially stable shape without any need for external reinforcement.

[0072] In a first implementation (FIG. 2) of the funnel 8, the funnel side wall 212 transitions seamlessly into the separating wall section 213, so that they are integral parts of the same body, which is made in one piece. The body may be obtained by injection-moulding, for example. The body also includes a side wall 214 of the liquid-treatment section 211, which surrounds a cavity 215. This cavity side wall 214 is closed on itself about an upright funnel axis 216. The cavity side wall 214 is shaped to provide the cavity 215 with an elongated cross-section (with the cross-sectional plane perpendicular to the funnel axis 216).

[0073] The cavity side wall 214 is provided with a flange 217 at an axial end opposite the transition between the cavity side wall 214 and the funnel side wall 212. A bond 218 of the type mentioned above joins an axial end wall 219 to the flange 217 of the cavity side wall 214 to close the cavity 215. The axial end wall 219 is provided with through-going channels forming liquid-permeable outlet windows.

[0074] Viewed from the cavity 215, the wall section 213 is concave. It is substantially dome-shaped. Venting apertures 220a,b are provided at the apex of the dome. Slits 221a,b form liquid-permeable inlet windows allowing liquid to pass from a container interior 222 to the cavity 215. These slits 221a,b extend substantially to a base of the dome. A mesh 223 is provided between a liquid treatment medium 224 arranged in the cavity 215 and the wall section 213. The liquid treatment medium 224 is granular, fibrous or a mixture of the two. The interior surface of the cavity side wall 214 bounds the cavity 215, so that the liquid treatment medium 224 is free to contact this interior surface.

[0075] To manufacture the funnel in its first implementation, the mesh 223 is joined to the separating wall section 213 along its edge. This assembly is turned upside down to fill the cavity 215 with the liquid treatment medium 224. The axial end wall 219 is then joined to the cavity side wall 214.

[0076] In a second implementation (FIG. 3) of the funnel 8, the funnel side wall 312 also transitions seamlessly into the separating wall section 313, so that they are integral parts of the same body, made in one piece, e.g. by injection-moulding.

[0077] The liquid treatment section 311 includes a beaker-shaped component formed by a cavity side wall 314 and an axial end wall 319 of the liquid treatment section 311 and defining a cavity 315. In this case, therefore, the transition between the axial end wall 319 and the cavity side wall 314 is seamless. The beaker-shaped component may be moulded, e.g. injection-moulded. The cavity side wall 314 is closed on itself about an upright funnel axis 316. The cavity side wall 314 is shaped to provide the cavity 315 with an elongated cross-section (with the cross-sectional plane perpendicular to the funnel axis 316).

[0078] The cavity side wall 314 is provided with a flange 325 at an axial end proximal the funnel side wall 312. A bond 326 of the type mentioned above joins the funnel side wall 312 to the flange 325 of the cavity side wall 314 to close off the cavity 315.

[0079] The axial end wall 319 is provided with through-going channels forming liquid-permeable outlet windows. Viewed from the cavity 315, the separating wall section 313 is concave. It is substantially dome-shaped. Venting apertures 320a,b are provided at the apex of the dome. Slits 321a,b form liquid-permeable inlet windows allowing liquid to pass from a container interior 322 to the cavity 315. A mesh 323 is provided between a liquid treatment medium 324 arranged in the cavity 315 and the wall section 313. The interior surface of the cavity side wall 314 bounds the cavity 315, however. Nothing else separates this interior surface from the liquid treatment medium 324, so that the latter is free to contact this interior surface.

[0080] To manufacture the funnel in its second implementation, the beaker-shaped component is filled with the liquid treatment medium 324. The mesh 323 may be joined to the flange 325 first, before this assembly is joined to the funnel side wall 312. Alternatively, it may be clamped between the funnel side wall 312 and the flange 325, before the bond 326 is formed.

[0081] In a third implementation (FIG. 4) of the funnel 8, the funnel side wall 412 also transitions seamlessly into the separating wall section 413 so that they are integral parts of the same body, made in one piece. A side wall 414 of the liquid treatment section 411 defining the cavity 415 is a separate, e.g. moulded, part. The cavity side wall 414 is closed on itself about an upright funnel axis 416. The cavity side wall 414 is shaped to provide the cavity with an elongated cross-section (with the cross-sectional plane perpendicular to the funnel axis 416). The cavity side wall 414 is provided with a first flange 417 at an axial end distal to the funnel side wall 412 and with a second flange 425 at an axial end proximal to the funnel side wall 412. A first bond 426 of the type mentioned above joins the proximal flange 425 to the funnel side wall 412. A second bond 418 of the type mentioned above joins the flange 418 at the distal axial end to an axial end wall 419, so as to close the cavity 415. The axial end wall 419 is provided with through-going channels forming liquid-permeable outlet windows.

[0082] Viewed from the cavity 415, the wall section 413 is concave. It is substantially dome-shaped. Venting apertures 420a,b are provided at the apex of the dome. Slits 21a,b form liquid-permeable inlet windows allowing liquid to pass from a container interior 422 to the cavity 415. A mesh 423 is provided between a liquid treatment medium 424 arranged in the cavity 415 and the wall section 413. The interior surface of the cavity side wall 414 bounds the cavity 415 with nothing between it and the liquid treatment medium 424, so that the latter is free to contact this interior surface. The liquid treatment medium 424 is granular, fibrous or a combination thereof.

[0083] To manufacture the funnel in its third implementation, the axial end wall 419 may first be joined to the cavity side wall 414. In that case, the remaining steps are the same as those for manufacturing the funnel in its second implementation. Alternatively, it is possible to join the mesh 423 and the cavity side wall 414 together first. In that case, the remaining steps are the same as those for manufacturing the funnel in its first implementation.

[0084] In a fourth implementation (FIG. 5) of the funnel 8, a cartridge with a conventional configuration is manufactured first and joined to the funnel side wall 512 so as to occupy an aperture in a bottom thereof.

[0085] A beaker-shaped component comprises a side wall 514 of the liquid treatment section 511 defining the cavity 515, which side wall 514 is closed on itself about an upright funnel axis 516. The cavity side wall 514 is shaped to provide the cavity 515 with an elongated cross-section (with the cross-sectional plane perpendicular to the funnel axis 516). The beaker-shaped component further comprises an axial end wall 519 of the liquid treatment section 511, so that the transition between the cavity side wall 514 and the axial end wall 519 is seamless. The axial end wall 519 is provided with through-going channels forming liquid-permeable outlet windows.

[0086] The cavity side wall 514 is provided with a flange 525 at an axial end distal to the axial end at which the axial end wall 519 is provided and proximal to the funnel side wall 512.

[0087] A cap-shaped component 527 includes the wall section separating a container interior 522 from the liquid treatment section 511. The cap-shaped component 527 is provided with a circumferential rim by which it is inseparably joined to the flange 525 so as to form an upper bond 528 of the type mentioned above. This closes off the cavity 515. Viewed from the cavity 515, the cap-shaped component 527 is concave. It is substantially dome-shaped. Venting apertures 520a,b are provided at the apex of the dome. Slits 521a,b form liquid-permeable inlet windows allowing liquid to pass from a container interior 522 to the cavity 515. A mesh 523 is provided between a liquid treatment medium 524 arranged in the cavity 15 and the cap-shaped component 527. An interior surface of the cavity side wall 514 bounds the cavity 515 with nothing between it and the liquid treatment medium 524, so that the liquid treatment medium 524 is free to contact this interior surface.

[0088] The flange 525 is also joined to a rim 529 surrounding the aperture defined in the funnel side wall 512 so as to form a lower bond 530 of the type mentioned above. The lower flange bond 530 prevents any bypass of liquid, ensuring that all the liquid in the container interior 522 passes through the cavity 515.

[0089] A fifth implementation (FIG. 6) of the funnel 8 is similar to the fourth implementation. However, in this implementation, the mesh 523 is omitted. Instead, a liquid treatment medium 624 is enveloped in a liquid-permeable bag 631, e.g. made out of liquid-permeable woven or non-woven fabric or a liquid-permeable foil. The liquid treatment medium 624 is granular, fibrous or a mixture of the two. An interior surface of a cavity side wall 614 still bounds the cavity 615 and liquid contacting the liquid treatment medium 624 is also free to contact this interior surface. However, direct contact between the liquid treatment medium 624 and the interior surface of the cavity side wall 614 is substantially prevented.

[0090] An axial end wall is essentially formed by a filter element 632 of the type described more fully in WO 2013/139821 A1 This filter element 632 includes a porous, liquid-permeable body 633. It further includes a rim 634 covering at least a peripheral face of the porous body 633 so as to frame first and second major surface areas thereof. The filter element 632 is joined to a rim 635 of the cavity side wall 614 by a bond 636 of the type mentioned above. Thus, the porous body 633 is comprised in the liquid-permeable window allowing liquid from the cavity 615 to egress.

[0091] It is noted that the filter element 632 need not be combined with liquid treatment medium 624 in a liquid-permeable bag 631. Each of these features can be adopted without the other.

[0092] A sixth implementation (FIG. 7) of the funnel 8 is similar to the fourth and fifth implementation.

[0093] A beaker-shaped component comprises a side wall 714 of the liquid treatment section 711 defining a cavity 715, which cavity side wall 714 is closed on itself about an upright funnel axis 716. The cavity side wall 714 is shaped to provide the cavity 715 with an elongated cross-section (with the cross-sectional plane perpendicular to the funnel axis 716). The beaker-shaped component further comprises an axial end wall 719 of the liquid treatment section 711, so that the transition between the cavity side wall 714 and the axial end wall 719 is seamless. The axial end wall 719 is provided with through-going channels forming liquid-permeable outlet windows. However, these through-going channels are only provided in a peripheral section of the axial end wall 719.

[0094] The cavity side wall 714 is provided with a flange 725 at an axial end distal to the axial end at which the axial end wall 719 is provided and proximal to the funnel side wall 712.

[0095] A cap-shaped component 727 includes the wall section separating an interior 722 of the container for holding liquid to be treated from the liquid treatment section 711. The cap-shaped component 727 is provided with a circumferential rim. A liquid treatment module 737 includes a liquid-impermeable separating wall 738 with a liquid-permeable window in the form of a central aperture. The separating wall 738 is positioned between the cavity 715 and the cap-shaped component 727. The separating wall 738 is also provided with a flange, which is positioned between and in contact with the cap-shaped component 727 and the flange 725 of the cavity side wall 714. Bonds 739,740,730 of the type discussed above join these walls together in a sealed and inseparable manner. The liquid treatment module 737 includes a central channel 741 in sealed liquid communication with the liquid-permeable window through the separating wall 738 at one axial end. The central channel 741 is closed at an opposite axial end. Flow through the liquid treatment module 737 in use is in a radial direction between the central channel 741 and a remainder of the cavity 715.

[0096] This radial flow is through a module liquid treatment medium 742, which may be arranged to effect a purely mechanical filtration and/or may include any of the liquid treatment media discussed above, e.g. arranged in a thermally bonded liquid-permeable porous block.

[0097] In an alternative embodiment (not shown in detail), the separating wall 738 is in sealed liquid communication with a membrane filtration module, e.g. a hollow fibre membrane module. In such an embodiment, the membrane comprises the liquid treatment medium.

[0098] As illustrated, a further liquid treatment medium 724 is arranged in the cavity 15 around the liquid treatment module 737. This liquid treatment medium 724 may be granular in nature, fibrous or a mixture of the two. It may comprise any of the liquid treatment medium types discussed above, e.g. including an ion exchange resin.

[0099] The interior surface of the cavity side wall 714 bounds the cavity 715 with nothing between it and the liquid treatment medium 724, so that the liquid treatment medium 724 is free to contact this interior surface.

[0100] Viewed from the direction of the cavity 715, the cap-shaped component 727 is concave. It is substantially dome-shaped. Venting apertures 720a,b are provided at the apex of the dome. Slits 721a,b form liquid-permeable inlet windows allowing liquid to pass from the container interior 722 into a space between the separating wall 738 and the cap-shaped component 727, and from there into the central channel 741 of the liquid treatment module 737.

[0101] To manufacture the funnel in its sixth implementation, the liquid treatment module 737 and surrounding liquid treatment medium 724 are first placed in the beaker-shaped component. The cap-shaped component 727 is then placed on top. This assembly may either be placed into an aperture in the bottom of the section 10 defining the container for holding liquid to be treated, so that the bonds 739,740,730 may then be formed substantially simultaneously. This would work well if welding is used. Alternatively, upper and lower separating wall bonds 739,740 may be formed before the assembly is placed in the aperture in the bottom of the section 710 defining the container for holding liquid to be treated.

[0102] In all implementations, the whole funnel 8 is replaced at the end of its useful lifetime and the inseparable, sealed connection between the two sections 10,11 ensures that there are no bypass flows of untreated liquid into the jug 1.

[0103] A seventh implementation (FIG. 8) of the funnel 8 also includes a container section 810 and a liquid treatment section 811. The liquid-impermeable funnel side wall 812 transitions seamlessly into a separating wall section 813, so that they are integral parts of the same body, which is made in one piece. The body may be obtained by injection-moulding, for example. In this way, it is impossible for liquid to flow out of a container interior 822 without passing into the liquid treatment section 811.

[0104] The body also includes inner and outer annular depending wall sections 843,844. These are likewise made in one piece with the wall forming at least the bottom of the container section 810.

[0105] The liquid treatment section 811 includes a cavity 815, which in this embodiment is empty. It may contain a granular or fibrous liquid treatment medium of the types mentioned above, or a mixture thereof, in an alternative embodiment.

[0106] In this embodiment, a liquid-permeable cavity side wall 814 is provided. This cavity side wall 814 is closed on itself about an upright funnel axis 816. The cavity side wall 814 is shaped to provide the cavity 815 with an essentially circular cross-section (with the cross-sectional plane perpendicular to the funnel axis 816). The cross-section may be elongated in an alternative embodiment.

[0107] The liquid-permeable cavity side wall 814 includes at least one layer of sheet material. At least one such layer of sheet material may be in the form of a membrane or a woven or non-woven textile arranged to filter microbes. The textile fibres may be functionalised to provide them with chemical or electrophysical properties that enable the sheet material made of these fibres to filter out microbes. For example, the textile material may include silver or a silver salt or compound. It may include electroactive or charge-modified fibres. Such fibres are effective to retain microorganisms through electroadsorption. Material including such fibres may include sites having an electrokinetic potential in the range of 20-75 mV, e.g. 40-70 mV, for example. The fibres of the textile material may include fibres made of or provided with a coating including a metal oxide, e.g. aluminium oxide, aluminium hydroxide or zirconium oxide. A particular example is boehmite (γ-AlO(OH)). The fibres may have a diameter in the range of 2-1000 nm, e.g. in the range of 2-100 nm. They may have a ratio of length to diameter of between 1 and 5, for example.

[0108] Other fibres of one or more layers of sheet material of the cavity side wall 814 may be cellulose fibres, glass fibres, viscose fibres, polyester fibres, polyethylene fibres, polypropylene fibres, cotton fibres or a mixture thereof, optionally with a binder.

[0109] The cavity side wall 814 may include a layer of sheet material comprising activated carbon fibres. Such sheet material is obtainable by heat treatment of a non-woven textile material made of organic fibres to carbonise them, followed by an activation step. Alternatively, a layer of sheet material may include powdered activated carbon, which need not be bound, e.g. powdered activated carbon having a mean particle size (d.sub.50) in the range of 2-10 μm.

[0110] Specific examples of suitable sheet material are provided in WO 03/000407 A1, for example. Compared with a semi-permeable membrane, variants with a functionalised woven or non-woven textile sheet material have a lower resistance to flow whilst still being capable of filtering out microbes.

[0111] Although not shown, a liquid-permeable support tube may be arranged radially inwards of the sheet material. The sheet material may alternatively be arranged on a self-supporting frame. A screen (not shown) arranged radially outwards of the sheet material may protect it in one embodiment.

[0112] Where the sheet material includes a semi-permeable membrane, it may be made of cellulose acetate, polyethersulfone, polyimide, polytetrafluoroethylene, or polycarbonate, for example. The membrane may have porous voids with a mean pore size of between 0.05 and 5 μm, for example, e.g. below 2 μm.

[0113] A liquid-impermeable axial end wall 819 is a separate component, shaped to have an inner and outer annular ridge 845,846 directed towards the container section 810.

[0114] An upper bond 847 sealingly joins the cavity side wall 814 to the container section 810 at one axial end. A lower bond 848 sealingly joins the cavity side wall 814 to the axial end wall 819. In this way, it is impossible for liquid to leave the liquid treatment section 811 without being treated on its way through the cavity side wall 814. The bonds 847,848 may be made with a potting compound such as polyurethane or with a hot-melt adhesive, for example.

[0115] Viewed from the cavity 815, the separating wall section 813 is concave. It is substantially dome-shaped. A venting aperture 820 is provided at the apex of the dome. Slits 821a,b form liquid-permeable inlet windows allowing liquid to pass from a container interior 822 to the cavity 815. These slits 821a,b extend substantially to a base of the dome.

[0116] An eighth implementation (FIG. 9) of the funnel 8 is a variant of the seventh implementation, also including a container section 910 and a liquid treatment section 911. In this variant, the liquid treatment section 911 is first manufactured separately from the container section 910, whereupon the two sections are assembled such as to become inseparable.

[0117] The liquid treatment section 911 includes an assembly of a liquid-permeable cavity side wall 914 and a liquid-impermeable axial end wall 919. The latter is shaped to have an inner and outer annular ridge 945,946 directed towards the container section 910. The cavity side wall 914 is of the same type as the cavity side wall 814 described above in relation to the seventh implementation. It is similarly joined to the axial end wall 919 by a bond 948. The cavity side wall 914 and the axial end wall 919 for a beaker-shaped component.

[0118] The cavity side wall 914 is sealingly joined to a cap-shaped component 927 at its opposite axial end by a bond 947. To this end, the cap-shaped component includes integral inner and outer annular depending wall sections 943,944. The cap-shaped component 927 thus closes off a cavity 915, which in this embodiment is empty. It may contain a granular or fibrous liquid treatment medium of the types mentioned above, or a mixture thereof, in an alternative embodiment.

[0119] The cavity side wall 914 is closed on itself about an upright funnel axis 916. The cavity side wall 914 is shaped to provide the cavity 915 with an essentially circular cross-section (with the cross-sectional plane perpendicular to the funnel axis 916). The cross-section may be elongated in an alternative embodiment.

[0120] The cap-shaped component 927 is self-supporting and made of liquid-impermeable material. Viewed from the cavity 915, the cap-shaped component 927 is concave. It is substantially dome-shaped. A venting aperture 920 is provided at the apex of the dome. Slits 921a,b form liquid-permeable inlet windows allowing liquid to pass from a container interior 922 to the cavity 915. These slits 921a,b extend substantially to a base of the dome.

[0121] The cap-shaped component 927 is formed with a flange by which the liquid-treatment section 911 is joined to the container section 910. Specifically, a bond 949 (adhesive or welded joint) is provided between the flange and a rim 929 surrounding an aperture in a section of the funnel side wall 912 forming the bottom of the container section 910.

[0122] Since any seams in transitions between the cavity side wall 14 and the funnel side wall 912 are between parts joined by bonding, untreated liquid in the container interior 922 cannot bypass the liquid treatment part in the liquid treatment section 911, as is the case for each of the embodiments described above. Moreover, contaminants are unable to enter the cavity 915, so that the liquid treatment part has a longer useful life. Once the end of this useful life is reached, the entire funnel 8 is replaced.

[0123] The invention is not limited to the embodiments described above, which may be varied within the scope of the accompanying claims. For example, the liquid treatment device may be for placement in a beverage machine, e.g. a coffee maker. Such a system need not include a container for collecting the treated liquid, which may pass straight to the section of the machine in which the beverage is prepared. The machine may include a suction pump for drawing the liquid through the section of the liquid treatment device defining the cavity, in which at least one liquid treatment medium may be arranged.

LIST OF REFERENCE NUMERALS

[0124] 1—jug [0125] 2—pouring spout [0126] 3—handle [0127] 4—jug axis [0128] 5—lid [0129] 6—closure element [0130] 7—spout cover [0131] 8—funnel [0132] 9—ridge [0133] 10, 210, 310, 410, 510, 610, 710, 810, 910—container section [0134] 11, 211, 311, 411, 511, 611, 711, 811, 911—liquid treatment section [0135] 12, 212, 312, 412, 512, 612, 712, 812, 912—funnel side wall [0136] 213, 313, 413, 813—wall section [0137] 214, 314, 414, 514, 614, 714, 814, 914—cavity side wall [0138] 215, 315, 415, 515, 615, 715, 815, 915—cavity [0139] 216, 316, 416, 516, 616, 716, 816, 916—funnel axis [0140] 217, 417—flange [0141] 218, 418—bond [0142] 219, 319, 419, 519, 719, 819, 919—axial end wall [0143] 220a,b, 320a,b, 420a,b, 520a,b, 620a,b, 720a,b, 820, 920—venting aperture [0144] 221a,b, 321a,b, 421a,b, 521a,b, 621a,b, 721a,b, 821a,b, 921a,b—slit [0145] 222, 322, 422, 522, 622, 722, 822, 922—container interior [0146] 223, 323, 423, 523—mesh [0147] 224, 324, 424, 524, 624, 724—liquid treatment medium [0148] 325, 425, 525, 625, 725—flange proximal to container section [0149] 326, 426—proximal flange bond [0150] 527, 627, 727, 927—cap-shaped component [0151] 528, 628—upper flange bond [0152] 529, 629, 929—rim [0153] 530, 630, 730—lower flange bond [0154] 631—bag [0155] 632—filter element [0156] 633—porous body [0157] 634—rim [0158] 635—cavity side wall rim [0159] 636—rim bond [0160] 737—liquid treatment module [0161] 738—separating wall [0162] 739—upper separating wall bond [0163] 740—lower separating wall bond [0164] 741—central channel [0165] 742—module liquid treatment medium [0166] 843, 943—inner annular depending wall section [0167] 844, 944—outer annular depending wall section [0168] 845, 945—inner annular ridge [0169] 846, 946—outer annular ridge [0170] 847, 947—upper bond [0171] 848, 948—lower bond [0172] 949—bond