AU2005270741B2

AU2005270741B2 - Water purifier

Info

Publication number: AU2005270741B2
Application number: AU2005270741A
Authority: AU
Inventors: William John Allender
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-09
Filing date: 2005-08-08
Publication date: 2010-03-25
Anticipated expiration: 2025-08-08
Also published as: AU2005270741A1

Description

1 WATER PURIFIER TECHNICAL FIELD This invention relates to water purification and more particularly to a solar desalinater or water purifier. 5 BACKGROUND ART Water can be evaporated by the sun (as in solar energy) or waste heat from any convenient source, such as cooling towers, steam engines and the like. Water vapour so produced can be condensed on a cool surface and drinkable water then collected, and the remaining concentrate discharged in 10 any convenient way. However, such a process, whilst operating effectively in nature, has yet to be efficiently harnessed commercially. The prolonged drought conditions in some parts of the world and the changing world climate have made drinkable water a valuable resource. The diminution of drinkable water supplies in many parts of the world has brought forward the need to 15 preserve or recycle water. One process commonly used is reverse osmosis, but this is expensive, complex to operate and contributes to "greenhouse" gases. It is an object of the present invention to provide an improved yet simple water purifier which is operated by solar energy or heat from other sources. 20 SUMMARY OF THE INVENTION According to one aspect of the invention there is provided a water purifier comprising a housing which is located over a reservoir of impure water, the housing having at least one collector surface upon which water vapour is condensed, a water collection gutter below the or each collector surface, and 25 an outlet from the collection gutter, wherein the housing is in the shape of a pyramid having a square base with four sides being north, east, south and west facing, the east and west facing sides being clear or transparent to allow 02/02/2010 2 the passage of sunlight to the impure water in the reservoir and the north and south facing sides being silvered or aluminised to allow the reflection of the sunlight and respectively provide two collector surfaces. The housing may be made of any convenient material, such as glass or 5 clear UV-capped polycarbonate plastic. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a water purifier according to one embodiment of the invention, Fig. 2 is a cross sectional view taken through 11-11 of the 10 water purifier shown in Fig. 1, Fig. 3 is a perspective view of the water purifier shown in Fig. 1 with the housing separated from a pool for containing impure water, Fig. 4 is a view similar to that of Fig. 3 but further showing 15 a serpentine arrangement of tubing for conveying waste heat, and Fig. 5 is a view of a scaled up water purification system employing a plurality of preferred water purifiers of the invention. DETAILED DESCRIPTION OF THE INVENTION 20 The water purifier 10 shown in the drawings comprises a housing 11 which, in this instance, is in the shape of a pyramid having a square base and four triangular sides 13, 14, 15 and 16 which, for the sake of convenience, will be called the north facing side 13, the east side facing side 14, the south facing side 15 and the west facing side 16. The sides of the housing 11 are 25 made from UV-capped polycarbonate plastic, but other convenient, transparent and stable materials may be used. 09/029910 WO 2006/015433 PCT/AU2005/001197 3 The east and west facing sides 14 and 16 are clear or transparent to allow the passage of sunlight. The north and south facing sides are silvered or aluminised to allow the reflection of the sunlight from their outside surfaces and to provide two collector surfaces at their respective inside surfaces. 5 Around the internal periphery of the square base, there is a water collection and flow gutter 17 defined between the sides of the housing 11 and an endless inner wall 12. The peripheral gutter 17 has an outlet 18. The portion of the base confined by the inner wall 12 is open and, in use, the housing 11 is placed over a reservoir of impure water which, in this case, is a 10 trough or pool 19, but may be a pond. The walls of the pool 19 may be made of a black, water impervious material, such as black plastic or black tiles to improve heat absorption. The pool 19 has a ledge 24 upon which the housing 11 rests, a supply pipe 25 and a drain pipe 26. Water vapour resulting from evaporation of water in the reservoir is 15 condensed on the two collector surfaces of the north and south facing sides 13, 15 and runs down those surfaces into the peripheral gutter 17. The cooling and condensation of the water vapour could be further enhanced by double glazing the sides of the housing 11 and passing waste coolant water between the two layers of glazing. 20 By way of example, the square base of the housing 11 is 80cm x 80cm and each triangular side 13, 14, 15 and 16 has a base to apex height of 80cm and is 6mm in thickness. The peripheral gutter 17 could be 5cm wide and 10cm high as determined by the vertical height of the inner wall 12. The outlet 18 may be connected to a suitable storage container and the 25 concentrate remaining in the pool or pond can be returned to its source or otherwise responsibly discharged.

WO 2006/015433 PCT/AU2005/001197 4 Although the invention has been described with reference to a housing in the shape of a pyramid, other shapes such as a rectangular prism, a dome, or an inverted cone could be used. 5 Purifiers according to the present invention could be used with or without modification in domestic applications. For example, a purifier of the present invention may be attached to the roof of a building or modified to follow the slope of an east west roof in order to catch the sun. A scaled up version could be used in industrial applications to process many litres of sea water or 10 contaminated water so as to supply drinkable or potable water to towns and other users. As well as being operated by solar energy in the manner as described above, the operation and yield of water purifiers of the present invention may be improved by the use of heat (particularly waste heat) from other sources that is used to increase the temperature of the reservoir of 15 impure water to between 500C and 800C. Fig. 4 shows a serpentine arrangement of tubing 20 located on or over the floor of the pool 19 and adapted to convey waste heat, say, in the form of warm effluent from an industrial process, therethrough whilst submerged in the reservoir of impure water. The warm effluent enters the tubing 20 through an 20 entry port 21 and exits through an egress port 22. At a pool temperature of 500C, the yield of drinkable or potable water from the water purifier 10 was just under 1 litre per day. The yield of potable water may be increased by about ten times for each doubling in size of the base of the housing. At higher temperatures, say, up to 800C, there are expected to be even higher yields. 25 A scaled up water purification system 23 employing a plurality of water purifiers of the present invention is shown in Fig. 5, and is suited to operating in WO 2006/015433 PCT/AU2005/001197 5 conjunction with a large industrial plant 24, such as a power plant, where waste heat is a by-product of the plant's industrial process. Each water purifier in this system is constructed of glass panels supported by steel frames over a segmented reservoir (or individual ponds) of 5 water to be purified. Pipes placed in each reservoir are used to conduct waste heat fed through pipes 25 from the plant 24 to the impure water. Impure water from a river or other source is pumped into each reservoir by inflow piping 26, and concentrated impure water may be released (after suitable treatment) back into the source by outflow piping 27. At a pond temperature of 800C, the yield 10 of drinkable or potable water from the water purification system of Fig. 5, would be expected to be sufficient to supply the needs of a small town. Purified water produced from sea water by the water purifier described with reference to Figs. 1 to 3 has been analysed by the National Measurement Institute of the Australian Government, and been found to have very minute 15 trace concentrations of calcium, iron, potassium, sodium, chloride and sulphate, and was of drinkable quality. These concentrations were found to be lower than those in commercially available, bottled drinking water. It will be apparent to persons skilled in the art that various modifications may be made in details of design and construction of the water purifier and 20 system described above without departing from the scope and ambit of the invention.

Claims

1. A water purifier comprising a housing which is located over a reservoir of impure water, the housing having at least one collector surface upon which water vapour is condensed, a water collection gutter below the or each collector surface, and an outlet from the collection gutter, wherein the housing is in the shape of a pyramid having a square base with four sides being north, east, south and west facing, the east and west facing sides being clear or transparent to allow the passage of sunlight to the impure water in the reservoir, and the north and south facing sides being silvered or aluminised to allow the reflection of the sunlight and respectively provide two collector surfaces.

2. The water purifier of claim 1 wherein the housing is made of glass or clear UV-capped polycarbonate plastic.

3. The water purifier of claim 1 wherein the water collection gutter is defined between the sides of the housing and an endless inner wall.

4. The water purifier of claim 3 wherein the portion of the base confined by the inner wall is open.

5. The water purifier of claim 1 wherein the reservoir has a ledge upon which the housing rests.

6. A water purification system comprising a plurality of water purifiers of claim 1, each water purifier being adapted to be located over a reservoir of impure water, pump means for feeding impure water from a source thereof into 02/02/2fn1 0 7 each reservoir through inflow piping, and outflow piping from each reservoir for discharging concentrated impure water back into the source.

7. The system of claim 6 further including pipe means for conducting waste heat from an industrial plant through the reservoir of impure water. 02/02/2010