GB2264295A

GB2264295A - Water purification apparatus

Info

Publication number: GB2264295A
Application number: GB9215343A
Authority: GB
Inventors: Mark Mathieson; Colin Mathieson; Lee Chandler
Original assignee: UV Systems Ltd
Current assignee: UV Systems Ltd
Priority date: 1992-07-18
Filing date: 1992-07-18
Publication date: 1993-08-25
Anticipated expiration: 2012-07-18
Also published as: GB9215343D0; GB2264295B

Abstract

Water purification apparatus has a filtration tank 10 containing a mass of filtration media 12. The apparatus has a water sterilisation chamber 16 fitted on or within an upper part of the tank, a UV source 18 being furnished within the chamber 16. A water inlet 23 connects to the chamber 16 and that chamber is provided with at least one outlet hole 24, through which sterilised water leaves the chamber 16, to be distributed over the filtration media 12. An outlet 13 for sterilised and filtered water is provided in a lower part of the tank 10. <IMAGE>

Description

WATER PURIFICATION APPARATUS This invention relates to water purification apparatus, suitable for use for example in conjunction with garden commercial or other ponds assist in keeping the water clear of algae and the control of bacteria or other harmful micro-organisms.

A common problem with garden ponds is that the water often looses its clarity, especially in the summer months, so reducing the opportunity to view fish which may live within the pond. Other problems may arise with garden ponds or commercial fish-breeding operations, whereby water-borne bacteria or other pathogenic micro-organisms may lead to losses of fish stock through disease.

In an attempt to keep pond water clear, and to control algae and other organisms, it is known to draw water more or less continuously from a pond, and to pass that water through a filter before returning it to the pond. A simple porous filter arrangement may be employed, though it is also known to employ a biological filter, where the water is percolated through a filter bed containing matter having a relatively large surface area, on which appropriate strains of bacteria are encouraged to grow and which can digest organic impurities in the water.

It is also known to treat with ultra-violet light water drawn more or less continuously from a pond, so as to kill live organic matter - such as algae - in the water. It is further known to connect the output of an ultra-violet steriliser to the inlet of a filtration unit, such that the water is serially treated firstly to ultra-violet light (hereinafter referred to as "W") and secondly by filtration (or vice versa), in an attempt to control the clarity of water within a pond.

However, this requires the furnishing of two sets of equipment to perform the two separate functions, which nevertheless must be carefully matched to ensure that there is a correspondence in the optimal water flow rates therethrough. Moreover, a treatment plant consisting of a serially connected UV treatment apparatus and a filtration unit inevitably is very bulky, as well as being complex to install and maintain with optimum efficiency.

The present invention aims at providing a water purification apparatus which is specifically adapted to perform both W treatment and filtration on water which may for example be drawn from a pond, to assist in maintaining the clarity of the water.

According to one aspect of the present invention, there is provided water purification apparatus comprising a filtration tank containing a mass of filtration media, a water inlet for water to be treated, an outlet from the tank for filtered water, and an UV water sterilisation chamber mounted on or within an upper part of the tank above the filtration media, said water inlet leading to the interior of the sterilisation chamber and there being at least one outlet from the sterilisation chamber and arranged to distribute over the surface of the filtration media water leaving the sterilisation chamber.

It will be appreciated that the water purification apparatus of this invention may be used for a variety of purposes, whenever water is to be treated both by UV light and filtration. However, the principal intended use of the apparatus is for the treatment of pond water, and so references will hereinafter be made exclusively to that. Nevertheless, it is to be understood that the invention is not limited thereto.

In a preferred embodiment of water purification apparatus of this invention, the sterilisation chamber includes a separate water tank supported in the upper part of the filtration tank, with an UV tube assembly being mounted within the sterilisation chamber to irradiate water within that separate tank. Such a tube assembly may be disposed partially or even wholly within the confines of the separate tank, so as to be immersed when in use. Alternatively, the UV tube assembly could be arranged within the sterilisation chamber but above the normal water level in the separate tank. In this case, it may be advantageous to provide a reflector above the tube assembly, to maximise the UV radiation directed into the water in the separate tank.

The plurality of outlets from the sterilisation chamber may be formed in at least one elongate water distribution channel associated with the separate tank, and into which water flows from that tank following the treatment thereof, whereby the water may-leave the channel for distribution over the filtration media.

The separate tank may be elongate and extend for at least most of the length of the filtration tank; in this case, two distribution channels may be associated with the separate tank, one to each side thereof. A weir preferably is formed between the separate tank and the or each distribution channel, whereby water supplied to the separate tank will overflow the weir into the or each distribution channel, for subsequent distribution over the filtration media within the filtration tank.

The sterilisation chamber is conveniently formed as a separate unit (for example by a vacuum-forming operation) fitted to the upper region of the side walls of the filtration tank. In this case, the overall area of the sterilisation chamber may correspond to the area of the filtration tank, whereby the separate unit may be fitted to and supported by the side walls of the filtration tank. In such a construction, there may be provided a lid for the sterilisation chamber, which lid fits over the separate unit and so closes the sterilisation chamber. A control circuit may be associated with that lid, whereby removal of the lid inhibits operation of the UV tube assembly contained within the sterilisation chamber.

In an alternative construction, the filtration tank may have a lid, the UV sterilisation chamber being formed as an elongate essentially-closed chamber fitted to said lid and within which is mounted an UV tube assembly, there being a plurality of spaced outlet holes through the wall of the chamber to distribute water over the filtration media water leaving the sterilisation chamber. In such a case, it is convenient for the UV sterilisation chamber to be substantially cylindrical and be mounted with its axis generally horizontal, the UV tube assembly extending along the length of the chamber.

By way of example only, two specific embodiments of water purification apparatus constructed and arranged in accordance with the present invention will now be described in detail, reference being made to the accompanying drawings, in which: Figure 1 is a longitudinal vertical section through a first embodiment of apparatus of this invention; and Figure 2 is a transverse vertical section through a second embodiment of apparatus of this invention.

Referring initially to Figure 1, there is shown a filtration tank 10 of a generally rectangular horizontal cross-sectional shape, and fitted with a lid 11. The tank 10 contains a mass 12 of filtration media, which conveniently takes the form of a biological filtration bed having for example a large number of pieces of short convoluted tubing, on the surfaces of which bacteria are encouraged to grow. The tank 10 is fitted with an outlet 13 at the lower region of the filtration bed, and an overflow pipe 14 the inlet 15 to which is above the normal water level within the tank 10.

Attached to the inside of the lid 11 is an UV sterilisation chamber 16, secured in position for example by means of U-bolts 17. The chamber 16 is of cylindrical shape, and an W tube assembly 18 extends co-axially therethrough. This tube assembly 18 comprises a cylindrical quartz sleeve 19 within which is mounted an W discharge tube 20, powered by wires 21 passing through the lid 11 and through end caps 22 fitted in a water-tight manner to the quartz sleeve 19.

The W sterilisation chamber 16 is provided with a water inlet pipe 23, passing through the lid 11. The chamber 16 further is provided with an array of relatively small diameter water outlet holes 24, through which water may leave the chamber 16.

In order to use the apparatus described above, the UV tube 20 is energised and then water is drawn from a pond by a suitable pump, to be delivered to the inlet 23 of the sterilisation chamber 16. Whilst in that chamber, the water is irradiated with UV light, the water leaving the chamber through the distribution holes 24 in such a way that the water is distributed over the mass of filtration media contained within the filtration tank 10. The sterilised water then passes over the filtration media, to leave the tank 10 through the outlet 13, to be returned to the pond. Should the filtration media or the outlet 13 become blocked, then the water will overflow out of the pipe 14, for return to the pond.

Referring now to Figure 2, there is shown an alternative embodiment of water purification apparatus of this invention. Like parts with those of figure 1 are given like reference numerals and will not be described again here.

Fitted to the top of the side walls 30 of the filtration tank 10 is a vacuum-formed unit 31 defining in conjunction with a lid 32, an UV sterilisation chamber. The unit 31 is shaped to define an UV treatment tank 33, and a pair of distribution channels 34, both the tank 33 and channels 34 being elongate and extending for most of the length of the tank 10.

Mounted within the tank 33 is an UV tube assembly 35, including a quartz outer sleeve 36 and an UV discharge tube 37. As with the previous embodiment, the quartz sleeve 36 is fitted with waterproof end caps (not shown) through which extend wires (also not shown) for energising the discharge tube 37. In addition means (not shown) are provided to support the tube substantially horizontally within the tank 33.

An inlet pipe 38 extends through and is attached to the lid 32, the inlet pipe being disposed to direct in-coming water into the tank 33. The inlet pipe could be located at one end of the tank 33, or mid-way between the ends thereof.

Weirs 39 are formed between the side walls of the tank 33 and the discharge channels 34, whereby water overflowing the tank 33 will run into the discharge channels 34. Each discharge channel is provided with a plurality of holes 40 disposed along the length of the channel and through which water entering the channel is discharged to fall on the filter media 12. The sizes of the holes 40 are selected having regard to the intended water through-put, whereby the channels 34 will be only partially full of water overflowing the tank 33, to ensure distribution out of the holes 40 for the entire length of each channel.

The side walls of the unit 31 are provided with overflow openings 41, above the channels 34. Should the discharge holes 40 become blocked, sterilised water will still be distributed on the filter media 12, through these overflow holes 41, but in a less efficient and less well-distributed manner.

The lid 32 is fitted with a safety device 42 comprising a switch unit coupled to a control circuit for the UV discharge tube 37. The switch 42 has a plunger 43 which extends through an opening in the lip 32 to engage a part of the unit 31. Should the lid 32 be lifted, the switch 42 will open, and inhibit operation of the discharge tube 37.

Claims

1. Water purification apparatus comprising a filtration tank containing a mass of filtration media, a water inlet for water to be treated, an outlet from the tank for filtered water, and an ultra-violet water sterilisation chamber mounted on or within an upper part of the tank above the filtration media, said water inlet leading to the interior of the sterilisation chamber and there being at least one outlet from the sterilisation chamber and arranged to distribute over the surface of the filtration media water leaving the sterilisation chamber.

2. Water purification apparatus as claimed in Claim 1, wherein the sterilisation chamber includes a separate water tank supported in the upper part of the filtration tank, an ultra-violet tube assembly being mounted within the sterilisation chamber to irradiate water within the separate tank with ultra-violet light.

3. Water purification apparatus as claimed in Claim 2, wherein the ultra-violet tube assembly is arranged at least partially within the confines of the separate tank so as to be immersed when in use.

4. Water purification apparatus as claimed in Claim 2, wherein the ultra-violet tube assembly is arranged within the sterilisation chamber so as to be above the water level in the separate tank when in use.

5. Water purification apparatus as claimed in any of claims 2 to 4, wherein there is at least one elongate water distribution channel associated with the separate tank and into which water flows from that tank, the channel having a plurality of spaced distribution holes disposed along the length thereof and out of which the water leaves the channel for distribution over the filtration media.

6. Water purification apparatus as claimed in claim 5, wherein the separate tank is elongate and extends along the length of the filtration tank, there being two distribution channels associated with the separate tank, one to each side thereof.

7. Water purification apparatus as claimed in Claim 5 or Claim 6, wherein a weir is provided between the separate tank and the or each distribution channel.

8. Water purification apparatus as claimed in any of claims 2 to 7, wherein the sterilisation chamber is formed as a separate unit fitted to the upper region of the side walls of the filtration tank.

9. Water purification apparatus as claimed in Claim 8, wherein the sterilisation chamber includes a lid which fits over the separate unit and the open top of the filtration tank.

10. Water purification apparatus as claimed in Claim 1, wherein the filtration tank has a lid and the ultra-violet sterilisation chamber is formed as an elongate essentially-closed chamber fitted to said lid and within which is mounted an ultra-violet tube assembly, there being a plurality of spaced outlet holes through the wall of the chamber to distribute water leaving the chamber over the filtration media.

11. Water purification apparatus as claimed in claim 10, wherein the ultra-violet sterilisation chamber is substantially cylindrical and is mounted with its axis generally horizontal, the ultra-violet tube assembly extending along the length of the chamber.

12. Water purification apparatus as claimed in any of the preceding claims, wherein the ultra-violet sterilisation chamber includes a ultra-violet tube assembly having an ultra-violet tube mounted within a quartz sleeve around which the water to be sterilised flows.

13. Water purification apparatus substantially as hereinbefore described with reference to and as illustrated in Figure 1 or in Figure 2 of the accompanying drawings.