WO2011109867A1

WO2011109867A1 - Evaporation controlling platform

Info

Publication number: WO2011109867A1
Application number: PCT/AU2011/000266
Authority: WO
Inventors: Philip Paul Jeffries
Original assignee: Philip Paul Jeffries
Priority date: 2010-03-09
Filing date: 2011-03-09
Publication date: 2011-09-15

Abstract

Disclosed herein is a platform capable of assembly with other like platforms to form a cover for reducing evaporation of water from reservoirs and the like, the platform comprising a floatable body and a plurality of first and second interconnecting lug arrangements extending peripherally therefrom, wherein the first and second interconnecting lug arrangements are positioned alternately about the periphery of the floatable body.

Description

EVAPORATION CONTROLLING PLATFORM

This patent application claims priority from Australian Provisional Patent Application No. 2010900977 titled "Evaporation Controlling Platform" and filed 9 March 2010, the entire contents of which are hereby incorporated by reference.

FIELD

The present invention relates to covers for reducing evaporation from water bodies such as reservoirs and specifically to platforms that can be assembled on the surface of a reservoir to provide an evaporation reducing cover therefor. The invention also relates to methods for reducing evaporation from reservoirs.

BACKGROUND

The quantity of water in lakes and reservoirs is dependent, in part, on the gain from incident rainfall falling into them and the losses from them by evaporation. Evaporation from reservoirs is significant because it represents a loss of water to the atmosphere. Therefore, methods and devices for reducing evaporation losses from reservoirs are needed.

Numerous methods and devices for reducing evaporation losses from reservoirs have been suggested. These generally involve covering the surface of the reservoir in some manner. Suggested methods include forming chemical monolayers on the surface, sheet coverings such as shade cloth, rafts of floating balls, and modular covers. These methods lead to varying results, depending on local conditions and the size of the reservoir or the like. Practical difficulties include the cost of covering and the stability of the covers, especially on larger areas. Chemical monolayers create a layer that is just one molecule thick on the surface and wind tends to spoil the layer. Chemical monolayers also tend to need frequent re-application. Sheet coverings can be difficult to handle as tethering them is difficult and water proof covers tend to pond rainwater on top. In contrast, floating covers that are formed in situ from a plurality of individual modules nested together on the surface provide a solution that is relatively simple to implement.

United States patent 4,270,232 (Ballew) discloses a cover for swimming pools comprising a plurality of small hexagonal segments that can be assembled together on the water surface to form a thermal cover. The segments disclosed therein are designed for use in swimming pools and it is doubtful that they could be used on larger water bodies such as reservoirs due to the sheer number of segments required and the difficulty in assembling them so as to form a cover over a large area. International patent application WO 98/12392 (Thoresen) discloses a floating body for reducing water evaporation from a fresh water reservoir. The floating body is a hexagonal shape having vertical side faces that are partly submerged when the body is afloat. A number of the floating bodies are positioned side by side on the surface of the water in a honeycomb pattern. The floating bodies are said to be difficult to move once they are in place because the submerged lower part of the side faces draw a water volume when they are displaced. Support legs extending from the bottom of the floating body into the water are also disclosed for use in areas exposed to the elements. ·

The two aforementioned prior art arrangements may not be suitable for use on reservoirs that are exposed to high winds. In these areas, the segments or floating bodies may be pushed into one area of the reservoir by the prevailing winds and/or may be blown away from the surface under such conditions.

Australian patent application 2004202873 (Water Innovations) discloses an octagonal floating module with fixings on four opposing sides that allows for the joining of modules. Modules can be

interconnected with one another to form a tessellation. The joining of the modules prevents movement of individual modules with respect to one another. However, the tessellation that is formed has substantial gaps between the modules such that 30% of the water surface remains exposed.

Covers of the type described need to be stable enough to be resistant to movement by prevailing wind conditions, they need to provide sufficient surface coverage in order to reduce evaporation, and they also need to allow for the capture of rain that falls on the reservoir.

There is a need for covers for reservoirs that minimise problems with the prior art covers and/or provide an alternative to prior art covers. SUMMARY

In a first aspect, the present invention provides a platform capable of assembly with other like platforms to form a cover for reducing evaporation of water from reservoirs and the like, the platform comprising a floatable body and a plurality of first and second interconnecting lug arrangements extending peripherally therefrom, wherein the first and second interconnecting lug arrangements are positioned alternately about the periphery of the floatable body.

The first and second interconnecting lug arrangements are engageable with one another to form a coupling between adjacent platforms. In a second aspect, the present invention provides a cover for reducing evaporation of water from reservoirs and the like, the cover comprising a plurality of platforms of the first aspect of the invention, wherein each platform is coupled to at least one adjacent platform. In a third aspect, the present invention provides a method for reducing evaporation of water from reservoirs and the like, the method comprising forming a cover of the second aspect of the invention on the reservoir or the like.

BRIEF DESCRIPTION OF THE FIGURES

Illustrative embodiments of the present invention will be discussed with reference to the accompanying drawings wherein:

Figure 1 shows a plan view of a platform of a first embodiment of the invention;

Figure 2 shows a side view of a platform of a first embodiment of the invention;

Figure 3 shows a cross sectional plan view of a platform of a first embodiment of the invention; Figure 4 shows a plan view of a cover comprising a plurality of interconnected platforms of a first embodiment of the invention;

Figure 5 shows an isometric view of a cover comprising a plurality of interconnected platforms of a first embodiment of the invention;

Figure 6 shows a plan view of a platform of a second embodiment of the invention;

Figure 7 shows a side view of a platform of a second embodiment of the invention; Figure 8 shows a cross sectional view of a platform of a second embodiment of the invention;

Figure 9 shows a cross sectional view of a platform of a second embodiment of the invention;

Figure 10 shows a plan view of a cover comprising a plurality of interconnected platforms of a second embodiment of the invention; and Figure 11 shows an isometric view of a cover comprising a plurality of interconnected platforms of a second embodiment of the invention.

In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings.

DESCRIPTION OF EMBODIMENTS

Figures 1 through 5 show a first embodiment of the invention whilst Figures 6 through 1 1 show a second embodiment of the invention. In Figures 1 through 11 there is illustrated a platform 10 capable of assembly with other like platforms to form a cover for reducing evaporation of water from reservoirs and the like. The platform 10 comprises a floatable body 12 having a plurality of first 14 and second 16 interconnecting lug arrangements extending peripherally therefrom. The first 14 and second 16 interconnecting lug arrangements are positioned alternately about the periphery of the floatable body 12.

The platform 10 may be used in conjunction with other platforms to form a cover for reducing evaporation from reservoirs, lakes, ponds, dams, pools and other similar water bodies. The term

"reservoir" as used herein is intended to include these water bodies. The floatable body 12 may be any suitable planar geometric shape. In some embodiments, the floatable body 12 is polygonal. In these embodiments, the polygonal floatable body 12 may have an even number of sides so that the first 14 and second 16 lug arrangements are disposed alternately about the periphery of the floatable body 12. In the illustrated embodiments, the floatable body 12 is a regular hexagon. The hexagonal shape may be advantageous as it allows for a plurality of platforms to be arranged in a honeycomb arrangement (as best seen in Figures 5 and 10) which minimises the amount of uncovered area between platforms. However, it is contemplated that other shapes, such as circular, oval, square and octagonal, could also be used.

The floatable body 12 comprises a top wall 18, a bottom wall 20 and a plurality of side walls 22a-f. The top wall 18 and bottom wall 20 are spaced from one another and each of the side walls 22a-f extends therebetween. The floatable body 12 may be a unitary construction or it may be assembled from a plurality of parts that are fastened together. In either case, the floatable body 12 is sealed so as to be substantially water tight. The floatable body 12 has a central aperture 23. The aperture 23 is defined by a central wall 25 that extends between the top wall 12 and the bottom wall 20. The central wall 25 is circular in cross section although it could also be any other suitable cross sectional shape (eg. hexagonal). The aperture 23 allows for drainage of water from the top of the platform 10 to the underlying reservoir and/or prevents or minimised the entrapment of air under the platform 10 when it is placed on a water surface. The central wall 25 also provides structural strength in the central part of the platform. In^' the illustrated embodiments, the floatable body 12 is substantially hollow (see Figure 9). However, it is also contemplated that the floatable body 12 may be filled with a buoyant material, such as closed cell foam or polystyrene, to provide additional structural strength. For example, closed cell foam packing may be incorporated within the floatable body 12 and this may prevent or minimise damage caused by any pressure placed on the top wall 18 or bottom wall 20, such as when a person stands on the platform. A range of closed cell foams are available commercially and may be used.

In the illustrated embodiments, each platform 10 has a plurality of open channels 24 in the top wall 18. Each channel 24 extends outwardly -from the centre 26 of the platform to the periphery 28 thereof. Each channel 24 is rectangular in cross section and is defined by channel side walls 30 and 32 and a channel bottom wall 34. The channel bottom wall 34 slopes downwardly from the centre 26 toward the periphery 28. The channels 24 collect water incident on the top of the platform 10, such as rain water, and funnel it directly into the gap between the platforms.

The first 14 and second 16 interconnecting lug arrangements are engageable one with respect to the other to form a coupling 18 between adjacent platforms. As can be seen from the Figures, the platform body 12 illustrated in the first embodiment shown Figures 1 through 5 is substantially the same configuration as the platform body 12 illustrated in the second embodiment shown in Figures 6 through 1 1. However, the configuration of the first 14 and second 16 lug arrangements differs between the two embodiments.

Whilst two embodiments are illustrated, other configurations of the first 14 and second 16 lug

arrangements are also suitable and are contemplated.

In the first illustrated embodiment shown in Figures 1 through 5, the first interconnecting lug arrangement 14 comprises a unitary lug that extends substantially horizontally and outwardly from a side wall 22. The second interconnecting lug arrangement 16 comprises two lugs 16a and 16b that extend outwardly from a side wall 22. The lugs 16a and 16b are spaced with respect to one another. A bar 36 extends substantially horizontally between the lugs 16a and 16b. As shown in Figure 1 , the spacing x between the lugs 16a and 16b of the second interconnecting lug arrangement 16 is greater than the width of the first interconnecting lug arrangement 14. The first interconnecting lug arrangement 14 is in the form of a tab that extends substantially horizontally < and outwardly from a side wall 22. The tab contains a substantially horizontal planar underside face and a curved upper face that extends in an arcuate manner from the side wall to join the underside face at an outer edge of the tab. The tab contains a channel 38 on the underside face. The channel extends the across the width of the tab. The channel is complementary in shape to the bar 36 which, in the illustrated embodiments, is circular in cross section. The channel 38 is able to snap fit over the bar 36 to allow the first interconnecting lug arrangement 14 and the second interconnecting lug arrangement 16 to be snap fitted together. Advantageously, the channel 38 is on an underside face of the lug arrangement 14 and this means that the first lug arrangement 14 can be placed over the bar 36 and a person merely needs to push down with a foot or suitable implement to snap fit adjacent platforms 10 together.

The first 14 and second 16 interconnecting lug arrangements are positioned alternately about the periphery of the floatable body 12. In other words, adjacent sides of the floatable body 12 contain different lug arrangements. This allows for adjacent platforms to be connected to one another all of the way around a platform.

In the second illustrated embodiment shown in Figures 6 through 11 , the first interconnecting lug arrangement 14 comprises two lugs 14a and 14b that extend outwardly from a side wall 22. The lugs 14a and 14b are spaced with respect to one another. The second interconnecting lug arrangement 16 comprises two lugs 16a and 16b that extend outwardly from a side wall 22. The lugs 16a and 16b are spaced with respect to one another. As shown in Figure 6, the spacing x between the lugs 14a and 14b of the first interconnecting lug arrangement 14 is less than the spacing y between the lugs 16a and 16b of the second interconnecting lug arrangement 16. The lugs 14a and 14b of the first lug arrangement 1 fit between the lugs 16a and 16b of the second lug arrangement 16, as shown in Figures 5 and 6, so that respective lugs 14a, 16a and 14b, 16b abut one another.

Each lug 14a, 14b, 16a, and 16b contains an aperture 40 through which a pin 42 or other suitable fastener can be inserted. The apertures 40 in abutting pairs of lugs 14a, 16a and 14b, 16b are aligned so that the fastener can be inserted therethrough to connect adjacent platforms 10 together. In the illustrated embodiments, the fastener is a pin 42. A single pin may be used in abutting pairs of lugs 14a, 16a.

Alternatively, a single pin may be used to extend between all of the lugs 14a, 16a,-14b, and 16b. The apertures 40 are recessed on the surface of the lug so that a head of the pin 42 sits flush with the surface of the lug 14.

The first 14 and second 16 interconnecting lug arrangements are positioned alternately about the periphery of the floatable body 12. In other words, adjacent sides of the floatable body 12 contain different lug arrangements. This allows for adjacent platforms to be connected to one another all of the way around a platform. The platform 10 may be formed from any suitable material. For example, a suitable plastic may be used. Suitable plastics include polyethylene, polypropylene, polyvinyl chloride, polycarbonate, acrylonitrile butadiene styrene, acetal, acrylic, epoxy, polybutylene, polyester, polyurethane, etc. In some embodiments, the platforms are formed from polyethylene. The polyethylene may be cross-linked polyethylene (PE), linear low density polyethylene (LLDPE) or high density polyethylene (HDPE).

The plastic may contain one or more additives. For example, the plastic may contain a pigment or dye. In some embodiments, the plastic contains a white pigment so that the platform 10 is white. This assists in reflecting UV radiation away from the surface of the reservoir. The plastic may also contain UV stabilisers or filters to reduce the damaging effects of UV radiation on the plastic.

The platform 10 may be formed using any suitable moulding technique. For example, it may be formed as a unitary construction by rotational moulding. Other moulding techniques known in the art could also be used. -

If a buoyant material is included internally in the platform 10 it may be introduced post moulding by introducing a precursor material into the internal cavity of the platform 10 through an aperture formed in the top wall, bottom wall and/or side wall(s). The precursor material is then cured or set and the aperture covered.

'

The platform 10 may be any size. However, for ease of assembly over a large water area, it is preferable for the platform 10 to be of a size that allow for a person to stand on whilst it is floating and for the platform to stay afloat. For example, the distance between parallel sides of the floatable body 12 may be between about 500mm and about 1500mm. In some embodiments, the distance between parallel sides of the floatable body 12 is about 1200mm. In some other embodiments, the distance between parallel sides of the floatable body 12 is about 900mm. The lugs may extend about 150mm out from the side wall(s) 22 and the side wall(s) 22 may be about 150mm high.

The present invention also provides a cover for reducing evaporation of water from reservoirs and the like, the cover comprising a plurality of platforms of the first aspect of the invention, wherein each platform is coupled to at least one adjacent platform.

The cover may be formed by placing the plurality of platforms 10 on the surface of a reservoir. In some cases, due to wind and/or water movements, the platforms 10 may tend to self assemble into a honeycomb structure. In any event, an operator is able to stand on one platform 10 and connect an adjacent platform either by pressing the channel 38 into engagement with the bar 36 or by inserting the pin 42 through the aperture 40. The operator may then step over onto an adjacent platform and connect the next platform. This process can be repeated until the platforms are interconnected to form the cover. Alternatively, the assembly can be carried out on land and the assembled or partially assembled structure can then be moved onto the water surface. The interconnecting lug arrangements 14 and 16 act as spacers between adjacent platforms 10 and this leads to the formation of an uncovered zone 44 between adjacent platforms. Sunlight reaches the water surface in the uncovered zone 44 and this means that evaporation may take place in these areas.

However, it will be appreciated that it is usually necessary for water bodies to be exposed to some sunlight in order to control the microorganism populations in the water. Therefore, there is a balance between having too much area uncovered, in which case water loss due to evaporation will be greater, and too little area uncovered, in which case populations of undesirable microorganisms may increase due to a lack of UV radiation on the water surface. In the present case, the uncovered zone 40 may be between about 5% and about 20% of the surface area of the cover. The amount of surface area uncovered will be determined, at least in part, by the distance the lug arrangements 14 and 16 extend from the side walls 22 and/or the position of the apertures 40 in the lugs. In the illustrated embodiments, the uncovered area 44 comprises about 1 1% of the total surface area of the cover. This is in contrast to the prior art cover disclosed in Australian patent application 2004202873 which has a significantly greater area uncovered and the prior art covers disclosed in United States patent 4,270,232 in which the adjacent hexagonal segments abut one another so that there is relatively little uncovered area.

When adjacent platforms 10 are connected, they are able to rotate with respect to one another about the bar 36 or pin 42. In this way, the plurality of connected platforms form a flexible sheet like arrangement that is able to adapt to different surface shapes such as when wind blows across a reservoir. Also, the interconnected platforms form a large mass that minimises the possibility of the wind blowing the platform off of the surface of the water.

In use, the outer surface of the top wall 18 will be exposed to sunlight throughout the day. The radiant energy incident upon the top wall may be captured by one or more solar cells (not illustrated) fitted to the top wall. The platform 10 may then have the dual function of reducing evaporation from the surface of the reservoir and also generating electricity.

The present invention also provides a method for reducing evaporation of water from reservoirs and the like, the method comprising forming a cover of the second aspect of the invention on the reservoir or the like.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Throughout this specification the word "comprise", or variations such as "comprises"- or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

All publications mentioned in this specification are herein incorporated by reference. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of each claim of this application.

Claims

1. A platform capable of assembly with other like platforms to form a cover for reducing evaporation of water from reservoirs and the like, the platform comprising a floatable body and a plurality of first and second interconnecting lug arrangements extending peripherally therefrom, wherein the first and second interconnecting lug arrangements are positioned alternately about the periphery of the floatable body.

2. The platform of claim 1 , wherein the first and second interconnecting lug arrangements are engageable with one another to form a coupling between adjacent platforms.

3. The platform of any one of claims 1 and 2, wherein the first interconnecting lug arrangement comprises a unitary lug that extends substantially horizontally from the periphery of the floatable body.

4. The platform of claim 3, wherein the second interconnecting lug arrangement comprises two lugs that extend outwardly from a side wall of the floatable body.

5. The platform of claim 4, wherein the lug of the first interconnecting lug arrangement of one platform fits between the lugs of the second interconnecting lug arrangement of an adjacent platform.

6. The platform of any one of claims 3 to 5, wherein the second interconnecting lug arrangement further comprises a bar that extends substantially horizontally between the two lugs.

7. The platform of claim 6, wherein the first interconnecting lug arrangement contains a channel on an underside face, said channel configured to be snap fitted over the bar of the second interconnecting lug arrangement.

8. The platform of any one of claims 1 and 2, wherein the first interconnecting lug arrangement comprises two lugs that extend outwardly from a side wall of the floatable body.

9. The platform of claim 8, wherein the second interconnecting lug arrangement comprises two lugs that extend outwardly from a side wall of the floatable body.

10. The platform of claim 9, wherein the lugs of the second lug arrangement of One platform fit between the lugs of the first lug arrangement of an adjacent platform so that respective lugs abut one another.

11. The platform of claim 10, wherein each lug contains an aperture through which a pin can be inserted to connect adjacent platforms together.

12. The platform of any one of claims 1 to 11 , wherein the floatable body is polygonal.

13. The platform of claim 12, wherein the floatable body is hexagonal.

14. The platform of any one of claims 1 to 13, wherein the floatable body has a central aperture therethrough.

15. The platform of any cine of claims 1 to 14, wherein the platform has a plurality of open channels in a top wall.

16._, A cover for reducing evaporation of water from reservoirs and the like, the cover comprising a plurality of platforms of any one of claims 1 to 15, wherein each platform is coupled to at least one adjacent platform.

17. A method for reducing evaporation of water from reservoirs and the like, the method comprising forming a cover of claim 16 on the reservoir or the like.

18. A platform substantially as hereinbefore described with respect to the accompanying Figures.