AU2010201315A1 - Distillation - Google Patents

Abstract

A distillation device 10 for producing fresh water from other water. The device includes a substantially transparent structure 12 and one or more supports 14 for supporting the transparent structure to, together with the surface of the other water, 5 define a closed gas space. A collector 26 for collecting condensation from the gas space.

Description

P/00/01 I Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Distillation The following statement is a full description of this invention, including the best method of performing it known to us: 2 Distillation Field of the invention The invention relates to the production of fresh water from other water. Background of the invention 5 Much of the earth's surface is covered in saline water. Whilst saline water is abundant, fresh (ie drinkable or 'pottable') water is sometimes scarce. As the earth's population expands, the need for fresh water is increasing. From time to time certain areas are affected by drought. Fresh water sometimes becomes scarce in 10 localised areas due to a traumatic event such as an earthquake. Saline water can be heated to form vapour and cooled to form fresh water condensation. This process is known as distillation. It is an object of the invention to provide an improved device for producing fresh water from saline water, or at least to provide an alternative for those conceded with the 15 production of fresh water. It is not admitted that any of the information in this specification is common general knowledge, or that the person skilled in the art could reasonably be expected to have ascertained, understood, regarded it as relevant or combined it in any way at the priority date. 20 Summary of the invention Accordingly, in its various aspects, the invention provides desalination devices, various components therefor and methods of producing fresh water.

3 In one aspect the invention provides a distillation device for producing fresh water from other water, the device including a substantially transparent structure; one or more supports for supporting the transparent structure to, together with 5 the surface of the other water, define a closed gas space; and a collector for collecting condensation from the gas space. A wall, optionally in the form of a downwardly depending weighted skirt, may be provided to define a periphery of a volume of other water under the transparent structure. 10 Preferably the transparent structure is predominantly formed of transparent polymer, e.g. Perspex, and most preferably carries or consists of lenses, e.g. the lenses might be carried in pockets. The gas space above the surface of the other water may contain a growth inhibitor which might include ozone. 15 The support(s) may include one or more floats. Optionally the collector includes one or more gutters. Preferably these gutter(s) extend along a lower portion of one or more interior surfaces of the transparent structure to collect condensation therefrom. Preferably the device is connected to a mains water grid to deliver fresh water thereto. 20 Brief description of the drawings / figures Figure 1 is a perspective view of a desalination device in accordance with an embodiment of the invention; Figure 2 is a side view of the device of Figure 1; and 4 Figure 3 illustrates a pocket containing a lens. Detailed description of the embodiments Figure 1 illustrates a desalination device 10 forming a solar powered distillation device. The device includes a transparent structure in the form of a greenhouse 12 and 5 supports in the form of floats 14. The floats 14 support the greenhouse 12 above the surface 5 of the saline water. The greenhouse 12 includes 2 planar rectangular panels at 28 and 30. The panels 28 and 30 are joined at right angles to each other along a respective long edge of each panel. The short edges of the rectangular panels 28 and 30 extend downwardly away 10 from their perpendicular joint to floats 14 which run along the other long edge of each panel 28, 30. As such the greenhouse 12 has a triangular prismic form, wherein the perpendicular join between the panels 28, 30 forms an upward apex. The end faces of the greenhouse 12 are capped by sheet material which extends from the apex down to the surface 5. As 15 such, the lower portions of the sheet material caps together with the floats 14 contact the surface 5 to define a rectangular surface region on top of the water, and the greenhouse 12 defines a gas space, in the form of a triangular prismic shaped volume, above the defined region of surface 5. The gas space is closed as in substantially sealed to prevent the to-be-described water vapour and growth inhibitor escaping. 20 The greenhouse 12 is predominantly formed of transparent material such as perspex. Alternatively polycarbonate is another suitable material. Such transparent materials allow light from the sun to pass therethrough to heat the gas space and the water below. Another characteristic of such transparent materials is that they tend to impede the transmission of heat re-radiated from below. As such the greenhouse 12 serves to 25 trap energy from the sun within the gas space. Of course the skilled person will appreciate that whilst it is desirable that at least a large proportion of the greenhouse 12 is transparent, that workable embodiments of the invention might include some opaque portions. The greenhouse 12 need only be in 5 substance transparent as in a significant proportion of the structure being transparent for trapping heat. Indeed preferred forms of the invention are contemplated to include opaque framing materials supporting transparent panels. The trapped thermal energy elevates the temperature within the greenhouse 12 and 5 tends to vaporise the saline water. As warm air within the greenhouse 12 carrying water vapour contacts the exterior surface of the greenhouse 12 it is cooled by the outside environment. In turn the carried vapour condenses on the interior surfaces of the green house 12. This embodiment of the invention includes collectors in the form of gutters 12 running 10 along a lower portion of the panels 28, 30 upwardly adjacent from the floats 14. The gutters 26 take the form of upwardly open channels which are inclined slightly towards one end of the device 10. Turning to figure 2; in this embodiment the gutters 26 feed water towards a conduit 28 which in turn carries the collected condensate to a mains water grid. 15 The gas space of greenhouse 12 is warm and moist and therefore prone to growths, such as fungus, bacteria and algae, some of which are potentially unhealthy. Preferred embodiments of the invention incorporate a growth inhibitor. In the described embodiment the gas space of the greenhouse 12 contains ozone. The Ozone also functions as a disinfectant killing off virus and bacteria to further improve the quality of 20 the produced water. A wall in the form of a flexible skirt extends downwardly from the floats 14 and the transparent capping faces of the greenhouse 12 to define a wall about the periphery of a rectangular prismic space under the defined region of surface 5. The skirt 16 is formed of flexible sheet material and carries a reinforcing wire 20 along its lower edge. 25 The reinforcing wire 20 inturn carries weights which tend to hold the skirt 16 down in its deployed position. As previously mentioned, the greenhouse 12 serves to capture heat from the sun and to vaporise water within the gas space. The skirt 16 serves to restrain a volume of water 6 thereby reducing the amount of non-vaporised heated water escaping from the device. Non-vaporised heated water carries away energy and thus represents a loss of efficiency. It has been found that the efficiency of the device 10 is improved by the incorporation of 5 lenses 24 ie by using lenses more fresh water can be produced. The lenses focus the sun's rays into the greenhouse 12. The lenses are preferably plastic disks carried in pockets 20. In this embodiment the lenses are formed of perspex. Each pocket 20 is formed by a flexible rectangular web of material 22 welded along 3 of its edges to an external surface of the green house 12 so that its fourth, unwelded, edge is upwardly 10 disposed. Preferred embodiments of the invention are thought to be inexpensive to construct, own and operate. It is contemplated that the device could be built in a large range of sizes to suit a variety of purposes. By way of example large permanent installations could be built to form a permanent water supply. On the other hand small disposable units could 15 be employed in disaster relief operations. Whilst the described embodiment includes floats, other forms of support are contemplated. By way of example, the transparent structure might be supported by posts extending from the sea or lake bed. It is also contemplated that the one or more supports might take the form of an upwardly open vessel. Such a device could be land 20 based and used without a standing body of water, e.g. dirty water, say from a bore, could be supplied to (e.g. pumped) to the vessel. It will be appreciated that the invention might be applied to purifying non-saline but otherwise contaminated water. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features 25 mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims (12)

1. A distillation device for producing fresh water from other water, the device including a substantially transparent structure; 5 one or more supports for supporting the transparent structure to, together with the surface of the other water, define a closed gas space; and a collector for collecting condensation from the gas space.

2. The device of claim 1 further including a wall defining a periphery of a volume of other water under the transparent structure. 10

3. The device of claim 2 wherein the wall is a downwardly depending skirt.

4. The device of claim 1, 2 or 3 wherein the transparent structure is predominantly formed of transparent polymer.

5. The device of any one of claims 1 to 4 wherein the transparent structure carries lenses. 15

6. The device of claim 5 wherein the lenses are carried in pockets.

7. The device of any one of claims 1 to 6 wherein the gas space contains a growth inhibitor.

8. The device of claim 7 wherein the growth inhibitor includes ozone.

9. The device of any one of claims 1 to 8 wherein the support(s) includes one or 20 more floats. 8

10. The device of any one of claims 1 to 9 wherein the collector includes one or more gutters.

11. The device of claim 10 wherein the gutter(s) extend along a lower portion of one or more interior surfaces of the transparent structure to collect condensation therefrom. 5

12. The device of any one of claims 1 to 11 when connected to a mains water grid to deliver fresh water thereto.