WO1992019552A1

WO1992019552A1 - Improvements in or relating to water treatment devices

Info

Publication number: WO1992019552A1
Application number: PCT/GB1992/000802
Authority: WO
Inventors: Christopher Julian Tyler
Original assignee: Waymaster Limited
Priority date: 1991-05-01
Filing date: 1992-05-01
Publication date: 1992-11-12
Also published as: GB9109421D0; GB2255771B; AU1664392A; GB2255771A

Abstract

The disclosure relates to a water treatment device having a chamber (10) through which water to be treated may flow, the chamber containing a water treatment agent in the granular form to act on the water flowing through the chamber, the water treatment agent being contained between spaced water permeable walls (20) formed from sintered granular plastics material.

Description

IMPROVEMENTS IN OR RELATING TO WATER TREATMENT DEVICES

This invention relates to water treatment devices.

Our U.K Patent No. 2,197,647 describes a water treatment device comprising upper and lower water containers with a cartridge containing a water treatment agent mounted in the bottom of the upper container to extend into the lower container to receive water from the upper container which passes through the water treatment agent contained in the cartridge and is then released to the lower container. The cartridge has upper and lower grid form end closures to permit water to pass through the cartridge whilst retaining the water treatment agent therein.

The grid form ends of the cartridge are manufactured in a plastics material by injection moulding. It is obviously necessary to maintain strict tolerances in relation to the spacing of the guide elements and because of tool wear and plastics shrinkage it has not always proved possible to maintain the tolerances sought.

The invention provides a water treatment device having a chamber through which water to be treated may flow, the chamber containing a water treatment agent in the granular form to act on the water flowing through the chamber, the water treatment agent being contained between spaced water permeable walls formed from sintered granular plastics material.

The following is a description of a specific embodiment of the invention, reference being made to the accompanying drawings in which:-

Fig. 1 is an elevation view of a cartridge for a water treatment device with a lid of the cartridge removed;

Fig. 2 is a plan view of the cartridge as shown in Fig. 1;

Fig. 3 is an underplan view of the cartridge; Fig. 4 is a section on the line 4-4 on Fig. 1; Fig. 5 is a section on the line 5-5 on Fig. 1; Fig. 6 is a section on the line 6-6 on Fig. 2; Fig. 7 is a detailed view of an area of the upper part of the cartridge indicated by the arrow 7 on Fig. 2;

Fig. 8 is a cross-sectional view through a top/bottom cap for the cartridge; and

Fig. 9 is a similar view to Fig. 4 showing a modified construction.

The drawings illustrate a cartridge suitable for use with a domestic water treatment device of the type described and illustrated in our U.K. Patent No. 2,197,647.

Referring now to Figs. 1 to 3 of the drawings, there is shown a new form of cartridge for containing the active water treatment material comprising a moulded plastics (e.g. polypropylene) upright cylindrical container 10 having a shallow taper towards its lower end. The upper end of the container is formed with an encircling integral outwardly projecting rim 11 and the container has an integral re-entrant base 12 which is of inverted funnel-shaped cross-section having an upwardly open tapered spout 13 at the center thereof. Fig. 5 of the drawings illustrates the shape of the base in detail.

The shape of the encircling rim at the top end of the container 10 is shown in detail in Figs. 4 and 6 and comprises an inverted channel section peripheral rim 14 to overlie the base of the upper container around the hole in the base through which the body of the container extends downwardly into the lower container. The rim is formed with a recess 15 around its inner periphery having an upwardly facing shoulder 16 to receive and support a lid for the container as described below. The channel form rim reduces the amount of plastics in this region to avoid sinkage after moulding.

The inner wall of the container is formed with three equi-spaced integral ribs 17 to prevent the bottom of one container from "nesting" in the top of another container when stacked for filling. The ribs have tapered sides to give a draft angle to facilitate separation in the moulding operation of the container.

The top and bottom of the container are closed by similar form top and bottom caps 20 illustrated in Fig. 8. Each cap is of inverted funnel section having an outer peripheral flange 21, a domed shaped central portion 22 and an integral upstanding spigot 23 at the center thereof. The caps are formed by sintering suitably sized plastic (e.g. polypropylene) granules in a mould which is passed through a microwave oven at a suitable speed to allow the granules to fuse together but to maintain their shape to create an integral but porous structure which will allow the through flow of water whilst retaining the water treatment medium in the container. By way of example. the caps may be formed from a mixture of granules comprising 70% G.S.E.16 0-1200 and 30% Spheripol and may have a thickness of 2-3 mm. G.S.E. and Spheripol are trade names. The bottom cap is press-fit in the lower part of the container over the similarly shaped base and the top cap is press-fitted into the recess 15 around the inner periphery of the rim 14 and is secured to the shoulder 16 by ultrasonic welding. The top cap is fitted after the container has been charged with a supply of a granular water treatment device such as a mixture of activated carbon and ion exchange resins as indicated at 30.

In use, water enters the cartridge from the top and exits from the aperture formed at the center of the re-entrant base form at the bottom. The re-enterant base form ensures that a certain amount of water is retained in the bottom part of the cartridge to maintain the water treatment material wet which enhances the life of the water treatment material.

Figure 9 of the drawings shows a modified form of the rim 14 for the container in which the inverted channel is dispensed with and the rim of the L-section providing the recess 15 to receive the periphery of the top cap.

Claims

1. A water treatment device having a chamber through which water to be treated may flow, the chamber containing a water treatment agent in the granular form to act on the water flowing through the chamber, the water treatment agent being contained between spaced water permeable walls formed from sintered granular plastics material.

2. A water treatment device as claimed in Claim 1, wherein the chamber comprises a hollow cylindrical cup-shaped container having a sintered granular plastics lid to provide an inlet to the container, an opening at the base of the container for water to exit from the container and a sintered granular plastics bottom cap extending over the base to prevent the loss of the granular water treatment agent from the opening in the base of the container.

3. A water treatment device as claimed in Claim 2, wherein the base of the container has a central outlec raised above the periphery of the base so that water is retained in the container up to the level of the outlet to maintain the water treatment agent at the bottom of the container wet.

4. A water treatment device as claimed in Claim 3, wherein the base has an inverted funnel-shaped form with a central upwardly extending spout with an outlet for water from the container at its upper end and the bottom cap has an inverted funnel-shape to extend over the base.

5. A water treatment device as claimed in any of Claims 2 to 4, wherein the lid has an inverted funnel-shaped form.

6. A water treatment device as claimed in Claim 5, wherein the lid and base cap are of similar form.