GB2260132A

GB2260132A - Water treatment apparatus

Info

Publication number: GB2260132A
Application number: GB9121146A
Authority: GB
Inventors: Robert Brian Myring
Original assignee: TRENT VALLEY WATER SYSTEMS LIM
Current assignee: TRENT VALLEY WATER SYSTEMS LIM
Priority date: 1991-10-04
Filing date: 1991-10-04
Publication date: 1993-04-07
Anticipated expiration: 2011-10-04
Also published as: GB2260132B; GB9121146D0

Abstract

Apparatus for the treatment of water by subjecting it to ultra-violet (UVc) radiation, to render it potable or ensure that it is potable, in which at least one channel (17) is provided for flow of water, open at the top for access of the radiation and having at least one boundary surface reflective of the radiation. The channel may be of zig zag configuration, defined by a number of partitions (16) provided in an open tray (10). <IMAGE>

Description

Title: Water Treatment Apparatus Description of Invention This invention relates to apparatus for the treatment of water by subjecting it to ultra-violet radiation to render it or ensure that it is potable.

It is known that ultra-violet radiation, particularly in the range of wavelengths from 100nm to 280nm, known as the UVc band, is effective in destroying or rendering non-harmful certain micro organisms, particularly bacteria and other organisms which are common contaminants in water supplies. The use of UVc radiation, e.g. from a suitable lamp, is known in the treatment of potable water supplies.

UVc radiation capable of acting on micro organisms is a constituent of sunlight, but the use of sunlight in the treatment of water requires careful control of the conditions under which it takes place in order to ensure that the treatment is effective. It is broadly the object of the present invention to provide apparatus for facilitating such treatment.

According to one aspect of the present invention, we provide apparatus for the treatment of water by subjecting it io UVc radiation, comprising means defining at least one channel for flow of water and having an open top for access of the radiation to the water, the channel having at least one boundary surface which is reflective of the radiation.

Preferably the channel is defined in a member in the form of a tray having a base, an upstanding peripheral wall, inlet and outlet means for flow of water respectively to and from the tray member, and at least one partition within the tray to define at least one channel of serpentine form extending between the inlet and outlet means.

Preferably there is provided a plurality of partitions extending generally parallel to one another to define a plurality of generally parallel channel portions, each partition affording, or cooperating with the tray member to afford, means for communication between adjacent channel portions at or adjacent an edge of the tray, said means for communication afforded at adjacent partitions being at opposite parts of the tray member from one another so that water is constrained to flow successively along said channel portions in a zig-zag path between the inlet and outlet means.

Conveniently, the tray member is generally of rectangular shape in plan view and the inlet and outlet means are provided at or adjacent opposite corners thereof, so that the channel portions defined by the partitions are of substantially the same length as one another.

To afford the means for communication between adjacent channel portions, each partition may have a corner which is chamfered or otherwise relieved to define an aperture between adjacent channel portions at the junction between the base and peripheral wall of the tray member.

Preferably each of the partitions has both sides provided with a surface which is reflective of the radiation, as is the base of the tray member. Water flowing in the channels is thus subject to radiation of the maximum possible intensity. The intensity of the radiation treating the water is not diminished by having to penetrate any covering over the channels nor any condensation which may form on a covering over a channel.

The partitions may be of glass having a known type of mirror finish on both sides. Of course, such mirror finish must be of a nature such as to remain unaffected by prolonged contact with water and exposure to air and sunlight.

The base of the tray member preferably also carries a reflective surface or a member having a reflective surface.

The tray member may be made of fibre, e.g. glass, -reinforced plastics material.

The depth to which UVc radiation penetrates water is limited and varies with the clarity of the water. Therefore the apparatus preferably has associated therewith valve means for controliing the rate of flow of water through the apparatus so that the depth of water in the channels does not exceed that which ensures that the water is effectively treated in its passage through the apparatus. By way of example, the flow of water through the apparatus may be controlled to limit depth of water in the channels to less than 6mm if the water is clear, or less than 4mm if the water is cloudy. The time of exposure of each molecule of water, flowing in the channels, to sunlight should exceed 15 seconds.

There may be provided valve means responsive to sunlight and operable to prevent flow of water through the apparatus if there is no or insufficient sunlight to ensure effective treatment by the apparatus. Such valve means may include a temperature-responsive element positioned so as to be heated by sunlight impinging on the apparatus, and operable to open the valve means for flow of water when the temperature of the element is indicative of a sufficient intensity of sunlight to ensure effective water treatment. By way of example, such a temperature responsive element may be of the known type incorporating a wax-filled capsule and producing a mechanical output which is operative on the valve means.It would be possible to provide a valve means operable to control the flow of water in proportion to the intensity of the sunlight falling on the apparatus or in some other relation thereto.

To provide protection for the apparatus when it is not in use, there may be provided removable or openable cover means for the channel or channels thereof.

Apparatus according to the first aspect of the invention as above set forth may be used in apparatus which further includes storage means for water prior to treatment and water after treatment, and means for causing flow of water through the water treatment apparatus between the two such storage means. The means for storage of water prior to treatment may include filter means for filtering the water before it passes through the treatment apparatus, to ensure adequate penetration of UVc radiation for effective treatment of the water, as above referred to.

The apparatus may include pump means for causing flow of water from the first storage means, through the treatment apparatus, to the second storage means.

According to another aspect of the invention, we provide a method of treatment of water to render it or ensure that it is potable, comprising causing the water to flow in an open topped channel exposed to UVc radiation, the channel having at least one boundary surface which is reflective of the radiation.

Preferably the radiation is provided by sunlight.

These and other features of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of apparatus according to the first aspect of the invention; Figure 2 is a section through apparatus according to the second aspect of the invention as above set forth; Figure 3 is a plan view of the apparatus of Figure 2.

Referring firstly to Figure 1 of the drawings, the apparatus there illustrated comprises a member 10 which is generally in the form of a tray, having a base 11 which is rectangular and an upstanding peripheral wall comprising a first pair of opposed wall portions 12a, 12b and a second pair of opposed wall portions 13a, 13b. The uppermost end of the peripheral wall has an out turned peripheral flange 14. The base 11 is reinforced by a number of ribs 15 extending parallel to one another therebeneath. The member 10 is made of glass-reinforced plastics material.

Within the member 10 and extending between the first opposed wall portions 12 thereof there is provided a number of partitions 16 so as to divide the interior of the tray member into a number of parallel channel portions 17. Each of the partitions 16 has a chamfered corner 18 to define an aperture for flow of water between the channel portions 17 on opposite sides of the partition, and alternate ones of the partitions 16 have such chamfered corner immediately adjacent the wall portion 12a. The other alternate partitions have their chamfered corners adjacent the wall portion 12b. An inlet 19 communicates with the channel portion 17 immediately adjacent the wall portion 13a, while an outlet 20 communicates with the channel portion 17 immediately adjacent the wall portion 13b.It will be appreciated that the arrangement of the partitions 16 with their chamfered corners 18 alternately adjacent the opposite wall portions 12a, 12b defines a zig-zag path for flow of water between the inlet and outlet of the apparatus.

The base 11 of the member 10, the inwardly facing sides of the upstanding peripheral wall thereof, and opposite sides of the partition 16 are all provided with a mirror finish so as to be reflective of light and in particular of UVc radiation. The partitions 16 may be of glass having a mirror finish on opposite sides; the base and peripheral wall of the member 10 may have a reflective finish or support respective mirror panels to provide the necessary reflective quality.

Referring now to Figures 2 and 3 of the drawings, the apparatus shown in these figures comprises a structure which is predominantly of fibre-reinforced plastics material and has a base 30 and an upstanding peripheral wall 31. A horizontal wall 32 extends parallel to the base 30 at a distance approximately two-thirds the way from the base to the top of the wall 31, and is supported from the base by a number of pillar formations 33 extending upwardly from the latter.

A cylindrical tank is thus defined in the lower part of the apparatus; access to this tank is possible by way of a manhole and cover 34 at the centre of the apparatus. A cylindrical wall 35 extends upwardly from the horizontal wall 32 at a distance from the outer wall 31 to define an annular area as described hereafter.

The annular area defined between the walls 31, 35 can be considered as comprising four quadrants in the first of which quadrants are disposed several strainer baskets 36. The next two quadrants comprise an empty channel 55 for flow of water and in which settlement of suspended solid matter can take place, and in the final quadrant a number of filter plates are disposed. These filter plates comprise regions 38, 39, 40 for first, second and third stages of filtration to remove particles of decreasing size. After the third stage of filtration, a fitting 41 in the wall 32 leads to a pipe 42 extending through an outermost part of the tank defined in the lower part of the apparatus and to a wall connector in the wall 31 connected to a hand pump 43.The pump 43, manually operable by a handle 44, has an output by way of a filter 45 to a valve 46 and thence, by a pipe 47, to the inlet 48 of an apparatus as illustrated in Figure 1 and above described. Such apparatus, indicated generally at 49 in Figure 2, is mounted horizontally at the top of the apparatus substantially at its centre, supported by upstanding support members 50. Means, not shown, is provided for levelling the apparatus 49, e.g.

a number of levelling screws. The outlet (51) from the apparatus 49 leads downwardly into the cylindrical tank defined at the lower part of the apparatus.

A pair of pivoted cover members 52 are provided, pivoted adjacent opposite sides of the apparatus 49 and pivotable between open positions as illustrated and closed positions in which they cover the apparatus 49 and associated parts including the valve 46.

The valve 46 is arranged to be operated mechanically from a temperature responsive element, e.g. a wax-capsule device of known type, positioned as indicated at 56 for sunlight to fall on it, so as only to permit flow of water through the pipe 47 into the apparatus 49 when the covers 52 are open and the sunlight is sufficiently intense to ensure satisfactory treatment of the water flowing through the apparatus 49. Desirable exposure times and depths of water flowing in the channels are as mentioned above.

In use of the apparatus, water for treatment can be poured, e.g. by hand from buckets, into the strainer baskets 36. The strainer baskets remove coarse solid matter from the water, after which the water flows around the halfannular settlement channel 55 to the filtration stages 38, 39, 40 and thence to the pump 43. Operating the pump causes the water to be pumped through the filter 45 (which may be a replaceable-cartridge type of filter of 25 micron mesh size, in order to render the water sufficiently clear for effective treatment) through the apparatus 49 as shown in Figure 1, for treatment by the UVc radiation in sunlight to render it potable. The treated water is stored in the tank forming the lower part of the apparatus of Figures 2 and 3, and may be drawn off for drinking or other purposes at a tap 54.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. Apparatus for the treatment of water by subjecting it to UVc radiation, comprising means defining at least one channel for flow of water and having an open top for access of the radiation to the water, the channel having at least one boundary surface which is reflective of the radiation.

2. Apparatus according to Claim 1 comprising a member in the form of a tray having a base, an upstanding peripheral wall, inlet and outlet means for flow of water respectively to and from the tray member, and at least one partition within the tray to define at least one channel of serpentine form extending between the inlet and outlet means.

3. Apparatus according to Claim 2 comprising a plurality of partitions extending generally parallel to one another to define a plurality of generally parallel channel portions, each partition cooperating with the tray member to afford means for comniunicailon between adjacent channel portions at or adjacent an edge of the tray.

4. Apparatus according to Claim 3 wherein said means for communication afforded at adjacent partitions are at opposite parts of the tray member from one another so that water is constrained to flow successively along said channel portions in a zig-zag path between the inlet and outlet means.

5. Apparatus according to Claim 4 wherein the tray member is of rectangular shape in plan view, and the inlet and outlet means are provided at or adjacent opposite corners thereof, so that the channel portions defined by the partitions are of substantially the same length as one another.

6. Apparatus according to any one of Claims 2 to 5 wherein each partition has a corner which is shaped to define an aperture between adjacent channel portions at the junction between the base and the peripheral wall of the tray member.

7. Apparatus according to any one of Claims 2 to 6 wherein each partition has both sides provided with a surface reflective of the radiation,

8. Apparatus according to any one of Claims 2 to 7 wherein the base of the tray member also has a reflective surface.

9. Apparatus according to any one of Claims 2 to 8 wherein the or each partition is of glass having a mirror finish on both sides.

10. Apparatus according to any one of Claims 2 to 9 wherein the tray member is of fibre-reinforced plastics material.

11. Apparatus according to any one of the preceding Claims further comprising valve means for controlling the rate of flow of water through the channel.

12. Apparatus according to any one of the preceding Claims further comprising valve means responsive to sunlight and operable to prevent flow of water through the apparatus if there is insufficient sunlight to ensure effective water treatment by the UVc radiation in the sunlight.

13. Apparatus according to Claim 12 comprising a temperature responsive element positioned so as to be heated by sunlight impinging on the apparatus, and operable to open the valve means for flow of water when the temperature of the temperature-responsive element is indicative of a sufficient intensity of sunlight to ensure effective water treatment.

14. Apparatus according to Claim 13 wherein said temperature responsive element comprises a wax-filled capsule producing a mechanical output operative on the valve means.

15. Apparatus according to any one of the preceding Claims comprising openable cover means for the at least one channel.

16. Apparatus according to any one of the preceding Claims further comprising storage means for water prior to treatment, storage means for water after having been treated, and means for causing flow of water between the two storage means, through the at least one channel.

17. Apparatus according to Claim 16 wherein the means for storage of water prior to treatment includes filter means.

18. Apparatus according to Claim 16 or Claim 17 including pump means for causing said flow of water.

19. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.

20. A method of treating water for potability, comprising causing the water to flow in the at least one channel of apparatus according to any one of the preceding Claims.

21. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.