AU2020100801A4 - Floating evaporation control device - Google Patents

Abstract

Disclosed is device (10) to reduce evaporation of water from a water storage area (30), the device (10) including: a body (11) having an upper surface (12), a lower surface (14), and a side surface (16) extending between the upper (12) and lower surfaces (14); the side, upper and lower surfaces (16, 12, 14) defining a cavity (18) leading to an opening (21); at least one flotation instrument (20) having two opposite ends and a longitudinal axis extending between the two opposite ends, the flotation instrument located within the body to prevent the device from sinking below a water-level when the device is positioned on said water storage area, wherein the flotation instrument (20) is retained within the cavity (18) by the ends expanding apart from each other toward the side surface (16). 2/5 / 4. V / 7 / / ~~g2 Pt 4> /t/J -~ '¾ >~ ~7 it Au - (I K. // ¾ -- V.', /1 Jo

Description

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FLOATING EVAPORATION CONTROL DEVICE

Field

[0001] The present invention relates to reducing the rate of evaporation from water storage areas exposed to the environment.

Background

[0002] One of the most important resources for all life on Earth is water. Water, however, can at times be scarce and often has to be moved or stored to be useful to humans. Humans construct water storage areas both small and vast, to capture precipitation water when it occurs, or capture water from land run off for later use.

[0003] Extreme weather events such as increased heat and dryness put pressure on the availability of fresh water. Due to increased heat and dryness, evaporation is a major mechanism for water loss from water storage areas artificial and naturally occurring. In Australia, for example, some areas experience evaporation loss of greater than 2 metres per year. This represents 2 cubic metres of water for every square metre of exposed surface. This is a significant water loss.

[0004] There have been attempts to mitigate water loss through evaporation from large bodies of water such as dams. In urban environments for example, a plastic sheet may be used to cover a pool to reduce the rate of water evaporation. However, this would be impractical for covering a vast water storage area such as a dam. Another example is a device that involves filling the cavity of an end-of-life car tyre with solid foam to make the tyre float on water. Thousands of these foam-filled tyres are then placed on a body of water, such as a dam, to cover the surface, thereby reducing evaporation. It has however been noted that in some examples, trees and grass germinate in them, negating their usefulness. A further example is a hexagonal shaped shell which is also used in a similar manner to cover the surface of the dam. These shells made from polypropylene fit together and take on board 80kg of water ballast to hold them to the water surface during adverse weather. However, when used on farm dams, which typically have sloping sides (about 40 degrees to the horizontal), water levels generally drop during a dry season, the hexagonal devices become stranded on the dam walls, the 80 kg of water ballast flows out, leaving a very large, light (3-4kg) object which is easily blown away by wind.

[0005] Also, the cost of filling tyres completely with solid foam, or manufacturing and installing the hexagonal polypropylene shells is very high. Therefore, it would be desirable to provide a device which is easy to manufacture, handle, install and is of lower cost. It is even more desirable if a large community waste stream can be re-purposed to save evaporation.

[0006] It is an object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages.

Summary of Invention

[0007] An aspect of the present invention provides a device to reduce evaporation of water from a water storage area, the device including:

a body having an upper surface, a lower surface, and a side surface extending between the upper and lower surfaces;

the side, upper and lower surfaces defining a cavity leading to an opening;

at least one flotation device fastened to the body to prevent the device from sinking below water level, when positioned on said water storage area.

[0008] Preferably, the body is a tyre, preferably in the form of a used or recycled tyre.

[0009] Preferably, the flotation device is a section of polyethylene foam, preferably in the form of a pool noodle.

[0010] Preferably, the flotation device is made from polyethylene, preferably in the form of a used or recycled milk bottle.

[0011] Preferably, the flotation device is fastened by one or more fasteners at least partially within the cavity adjacent the lower surface, when placed on said water storage area.

[0012] Preferably, the body has one or more apertures for receipt of said one or more fasteners to secure the flotation device to the body.

[0013] Preferably, said one or more fasteners is a cable-tie having an end that is received by said one or more apertures, about the flotation device, and returned back to a head of the cable-tie.

[0014] Preferably, the cable-tie is made from various polymeric materials, preferably nylon.

[0015] Preferably, the upper and lower surfaces are sidewalls of the tyre, and the side surface is a tread of the tyre.

[0016] Preferably, the device includes a lid to cover the opening and protect the flotation device from exposure to ultraviolet light and wind.

[0017] Preferably, the body further includes additional apertures to fasten the lid to the body.

[0018] Another aspect of the present invention provides a method of reducing evaporation of a water storage area, the method including placing a plurality of said devices on said water storage area.

[0019] Preferably, the method further comprises the step of tethering said plurality of devices by passing a rope through an aperture in the lids of said plurality of devices, thereby connecting said plurality of devices.

[0020] Another aspect of the present invention provides a device to reduce evaporation of water from a water storage area, the device including:

a body having an upper surface, a lower surface, and a side surface extending between the upper and lower surfaces;

the side, upper and lower surfaces defining a cavity leading to an opening;

at least one flotation instrument having two opposite ends and a longitudinal axis extending between the two opposite ends, the flotation instrument located within the body to prevent the device from sinking below a water-level, when the device is positioned on said water storage area, wherein the flotation instrument is retained within the cavity by the ends expanding apart from each other toward the side surface.

[0021] Preferably, the flotation instrument has longitudinally extending cells that force the ends apart from each other, when the flotation instrument is located within the cavity.

Brief Description of Drawings

[0022] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

[0023] Figure 1 is a perspective view of a floating evaporation control device according to an embodiment of the present invention;

[0024] Figure 2 is an "in use" view of several floating evaporation control devices on a body of water;

[0025] Figure 3 is another perspective view of the floating evaporation control device, showing a flotation device;

[0026] Figure 4 shows the evaporation control device with a lid; and

[0027] Figures 5a and 5b show the evaporation control device in tethered configurations.

Description of Embodiments

[0028] Figure 1 shows a floating evaporation control device 10 according to an embodiment of the present invention. The device 10 is used to reduce the rate of evaporation of a water storage area (such as a dam) and primarily includes a body 11 having an upper surface 12, and a lower surface 14. The body 11 is preferably in the form of a used or recycled car tyre and has a side surface 16, which extends between the upper and lower surfaces 12, 14. The side, upper and lower surfaces 16, 12, 14 define a cavity 18 which leads to an opening 21.

[0029] Figure 1 also shows a flotation device or flotation instrument 20, which is contained within the body 11. The flotation device 20 is preferably in the form of a custom made polyethylene section or extrusion, similar to a pool noodle, for example. However, any closed cell foam section or extrusion is envisaged. Importantly, the flotation device 20 is fastened such that it is positioned at least partially within the cavity 18 and adjacent the lower surface 14. In some embodiments, the flotation device 20 may be positioned adjacent to the side surface 16 as well.

[0030] The body 11, in the form of a car tyre, has tyre tread defined by the side surface 16, and side walls defined by the upper and lower surfaces 12, 14.

[0031] Figure 2 shows several floating evaporation control devices 10 bunched together, floating on a water storage area 30. When many tyres are placed on the water storage area 30, they "self-align" and tight pack under wind forces as indicated in Figure 2. Most of the water storage area 30 is then covered, leaving small spaces 32 between the tyre bodies 11.

[0032] Figure 3 shows fasteners 22 and 24 which secure the flotation device 20 to the cavity 18 of the body 11. The fasteners 22 and 24 may be in the form of a zip-tie or cable-tie or a similar fastening means. In this way, the fasteners 22 and 24 are secured to apertures (not numbered) in the side surface 16 of the body 11.

[0033] Also shown in Figures 3 and 4 is a lid 26 in the form of a circular disk which is fastened to the upper surface 12 of the body 11 in the same manner as the flotation device 20. Again, there are apertures in the upper surface 12 of the body 11 which are not numbered in the figures. The lid 26 may be of a diameter that is similar to the diameter of the main opening 21 (or inner annulus) of the tyre body 11, as shown in Figure 4. Alternatively however, the lid 26 has a larger diameter that is equal to or similar in diameter to the entire flotation device 10 (that is the outer annulus of tyre body 11). The lid 26 is preferably made from any durable and ultraviolet resistant material such as an aluminium sheet. However, injection moulded recycled polyethylene or polypropylene is preferred. A larger lid 26 provides more reflectivity of sun radiation and less absorbance of radiation by the black tyre itself, especially if aluminium is used. Such a configuration may help to limit dam water temperature variation.

[0034] Turning to Figures 4, 5a and 5b, the floating evaporation control device 10 is shown with an aperture 27 in the lid 26. The purpose of the aperture 27 is to enable multiple evaporation control devices 10 to be tethered together via a rope, cable or the like, indicated by 28 in Figures a and 5b. This is to prevent multiple devices 10 from floating away from each other.

Specifically, Figure 5a shows the rope 28 in a slack configuration and the devices 10 have floated away from each other. Figure 5b shows the rope 28 pulled taught and the devices 10 floating closer together. Such an arrangement can be used to confine the devices to a particular dam section or to prevent the devices from leaving the dam, such as during a flood, for example.

[0035] The invention in relation to a specific embodiment will now be described.

[0036] The floating evaporation control device 10, in the form of a passenger vehicle tyre will typically reach the end of its legally usable life on a road car after about 3 to 5 years. These tyres are generally made to fit wheels of 15 to 19 inches in diameter. When selecting a used car tyre for use in the present invention, width (i.e. the width of side surface 16) is not material and the tyre should be in good condition (not cut open or with metal rods or cables exposed). Tyres with worn tread (i.e. side surface 16) are acceptable, but no fabric used in tyre construction should be visible as this may act as a water conduit to the tyre rubber matrix.

[0037] For the flotation device 20 shown in Figure 1, a swimming pool noodle is ideal. A standard pool noodle is made from polyethylene foam with a diameter of 70mm and a length of 1500mm. To fit the most common 17-inch car tyre, a length of 1700mm of foam is required to make a full, tight loop within the cavity 18. The standard pool noodle has a central void of mm diameter. This needs to be sealed or eliminated to optimize floating stability. This may be achieved by using stoppers or by heat sealing with a device such as a heat gun or hot plate or by using a noodle manufactured without a central void, for example. However, in a preferred embodiment, discussed in further detail below, the flotation device 20 is 100mm in diameter which is notably larger than a standard pool noodle.

[0038] Turning to the lid 26, approximately 460 mm or 700 mm in diameter is required. The lid 26 is fitted to the upper surface 12, being the "non-water" side of the tyre, using the cable-ties described earlier. Alternatively, threaded fasteners in the form of three standard metal self tapping screws, such as those used for metal roof construction may be used. The screws are totally covered with a multi-layer moisture protection system.

[0039] In a second embodiment of the present invention, the evaporation control device 10 is still in the form of a passenger vehicle tyre having the tyre body 11 with side surface 16 and side walls defined by the upper and lower surfaces 12, 14. However, rather than a flotation device or flotation instrument in the form of a standard swimming pool noodle 20, as described earlier, a noodle, commercially known as a "jumbo noodle" having a diameter of about 100mm, and a length of about 2100mm and a central void of about 25mm may be used. The jumbo noodle may be fed by hand or machine into the tyre cavity 18 to lie close to the side surface 16 of the tyre 11 and the upper surface 12. Locating the noodle close to the upper surface 12 and partially above the water-line, allows the evaporation control device 10 to quickly stabilize itself, as compared to if there was no part of the noodle above the water-line. A portion of the noodle above the water-line provides an effective "turning moment" to counteract any downward displacement of the floating evaporation control device 10.

[0040] The cells of the jumbo noodle run longitudinally which causes the ends of the noodle to expand apart from each other towards the side surface like a spring and lock in place within the cavity 18, without the need for additional fasteners. The noodle resists bending in this position. When the jumbo noodle is out of the tyre cavity 18, the jumbo noodle is substantially straight and has first and second ends with a longitudinal axis extending therebetween. The cells of the jumbo noodle run along the longitudinal axis. When the noodle is in a seated position within the tyre cavity 18, the jumbo noodle resists bending by exerting a force perpendicular to the longitudinal axis of the noodle, which in turn exerts a force onto the inside of the tyre cavity 18. The force exerted by the jumbo noodle on the inside of the tyre cavity 18 is enough to maintain the position of the noodle in the tyre, even when the tyre is placed on a body of water. The flotation device 20 in the form of a jumbo noodle can be between 2 to 3 meters in length and cut to size to suitably fit various tyre sizes.

[0041] Assembly of the invention will now be described.

[0042] For both the first and second embodiment, the tyre body 11 should be lightly washed to remove excess grime from all surfaces. The inside of the tyre body 11, that is the cavity 18, should be in excellent condition already. Warm water, detergent and a rag is sufficient to clean the tyre.

[0043] For the first embodiment, the polyethylene foam noodle 20 should be warmed to increase the flexibility and thus aid assembly. The noodle 20 should be attached to the cavity 18, adjacent the lower surface 14, which is the water side of the tyre body 11. This will require four holes drilled into the tyre body 11, specifically the bead of the tyre between the metal cable of the bead and the major part of the tyre. It is important to avoid drilling into the metal cable as the tyre matrix itself prevents the metal from exposure to water and the atmosphere. A cable tie is then threaded through the drilled hole and around the noodle and back to the cable-tie head. This cable-tie head is larger than the aperture and therefore unable to pass through said aperture. This prevents the noodle moving from its position when the device is placed on a body of water. As described above, the lid 26 is attached to the upper surface ("non-water side") of the tyre.

[0044] For the second embodiment, no holes need to be drilled in the tyre body 11 and no attachments are required to keep the noodle in position. The jumbo noodle is bent and is fed into the cavity 18 of the tyre body 11. Due to the longitudinal direction of the jumbo noodle cells, the jumbo noodle resists bending and pushes against the surface 16. The bending force created by the jumbo noodle keeps the jumbo noodle in position within the cavity 18. Importantly, the jumbo noodle needs to be of a length such that the end that is fed into the cavity meets the other end of the jumbo noodle, approximately. The installer may be required to trim the length of jumbo noodle with a saw or the like.

[0045] The tyre with the jumbo noodle fitted, is then positioned to fit a protective cover on the top. The cover may be aluminum or polypropylene. The protective cover has three, equidistant, pre-cut slots sufficiently wide to allow free passage of the fastening screws and long enough to allow the assembler to locate the narrow section between steel cables (which are invisible within tyre matrix) able to accept the screws. The ends of the slots themselves are semi-circles. There is no need to specially orient the cover disc and the tyre (as both are circular). To satisfy customer or marketplace demands, it is also envisaged that the flotation device of the second embodiment may not have a protective cover. This will reduce costs and simplify construction, but may reduce the overall performance of the device.

[0046] Advantages of at least a preferred embodiment of the present invention will now be described.

[0047] The lid 26 provides six protections to the device: Protection of the flotation device 20 (i.e. the pool noodle) from ultraviolet radiation. Protection of the flotation device 20 from any attack by animals such as birds or foxes. The lid 26 prevents bird nesting within the cavity 18 of the body 11, or any bird deaths within the body 11 which may pollute the body of water. The lid 26 prevents any tree, shrub or grass seeds from entering and germinating within the cavity 18. The lid or protective cover 26 reduces the evaporation of water significantly by aiding the development of a heavy water vapor micro-environment within the device 10. Importantly, the lid 26 gives added protection of each device and the whole array of devices from wind. Wind is a major factor in evaporation of water from farm dams.

[0048] A used tyre provides at least the following advantages: The tyre can withstand all types of weather and high stresses, yet they are soft and flexible when touching and floating near each other. The tyres are lightweight when aided by the flotation device and thus float. However, if the water level drops, the tyres on the outside of the array may become stranded. As the device has a low profile and weights about 10kg, it is unlikely to blow away in adverse weather. The amount of waste tyres is growing - currently about 22 million waste passenger car tyres per year in Australia. The present invention puts these waste tyres to constructive use and may even help reduce illegal dumping of tyres. The evaporation prevention device is of low cost to manufacture and assemble. The tyre in conjunction with the lid covers the body of water to protect from the effects of sun and wind. Shading the water both within the tyre and between tyres reduces the temperature of the water, thereby reducing evaporation. The tyres alone cover about 47% of the water surface, whilst the tyres and lid in combination cover about 77% of the water surface. When the flotation device 20 is secured to the lower surface 14 and in some embodiments, substantially adjacent the side surface 16, the flotation device 20 is at the lowest possible position in the cavity 18 of the tyre 11 and thus its maximum flotation effect is achieved with a minimum volume of total foam flotation, reducing cost and weight. This particular arrangement however, is not essential.

[0049] Advantageously, only having a fraction of the tyre filled with the foam floating device reduces cost and weight. For example, when a pool noodle that has a cavity extending from one end to the other is used, the device 10 floats on the water storage area 30 with 85mm of the tyre body 11 above the water, and about 135mm of the tyre body 11 below the water. In other words, 85mm of the side surface 16 is out of the water and 135mm of the side surface 16 is under the water. This is due to the positioning of the noodle within the cavity 18 of the tyre body 11. Moreover, the level of flotation above the water can be adjusted by altering the density or diameter of the polyethylene foam flotation device, or even removing the abovementioned noodle cavity, effectively increasing the density or size of the noodle. When the flotation device , in pool noodle form, is secured in the position described above, and the device 10 is floating in the manner described above, the flotation device 20 is completely submerged. This means that the minimum amount of flotation material is used, calculated to be approximately 5.7 litres of polyethylene pool noodle foam. In stark contrast, this amount of foam is half the amount of polystyrene foam used if the entire cavity 18 of the tyre body 11 is filled. Accordingly, the position of the flotation device is important to save cost and weight. The flotation device may be positioned adjacent the top surface 12 or the bottom surface 14, within the tyre cavity 18.

[0050] Another advantage of the preferred embodiment of the present invention is that the pool noodle will not degrade because it is covered by a lid, and also because the foam noodle is not a "particulate foam', like polystyrene foam. Unprotected polystyrene foam allows seeds of grasses, brush and trees to germinate and this produces a water "pump" from their roots to their leaves (transpiration). This negates the usefulness of that device.

[0051] The preferred embodiment of the present invention is also advantageous in that evaporation loss may be reduced by up to 8 0 - 9 0 %, which may provide about 40% more useable water from the average water storage area, over a year long cycle.

[0052] The second embodiment is advantageous because when sufficient noodle volume is submerged, the noodle flotation effect will balance the downward pull of gravity of the tyre and an equilibrium is reached (floating). This allows approximately 70-100 mm of tyre free-float above the water line. This free-float, in conjunction with self-alignment and tight pack of the devices allows the uncovered water between the devices to be partially protected from evaporation utilising several principles (shading, wind protection and micro-climate development.)

[0053] As mentioned earlier, a portion of noodle, inside the tyre cavity 18, but above the water line provides an effective 'turning moment' to counteract any downward displacement of the device. This may be referred to as 'device stability' and it returns the device to its original, level, floating position very rapidly.

[0054] Another advantage of the second embodiment is that it costs less to produce due to the reduced amount of time required to assemble.

[0055] In an alternative embodiment, the flotation device 20 may be a recycled 3L plastic resin milk bottle or similar air containing device typically made from polyethylene or another similar empty beverage container, of any such size sufficient to float the tyre 11 as described above. Such containers must be securely sealed for long life, preferably by using the original milk bottle cap and seal. Another method of sealing the milk bottle is to apply a small quantity (2ml to 5ml) of paint into the milk bottle cap which is then screwed to the bottle. This allows the paint film to spread over a large distance of the threaded area, providing the seal strength and permanence. The milk bottle may be attached within the cavity 18 to the body 11 in the same manner described above. However, longer cable-ties may be required. It is also envisaged that instead of plastic milk bottles, plastic containers may be used and may even be wedged into place within the tyre cavity without cable-ties.

[0056] In alternative embodiments it is envisaged that the device 20 as described above, may have a solar panel instead of a lid 26, or the solar panel may be attached to the lid 26 using one or more brackets and fasteners. When a plurality of these devices are spread over a water storage area, clean solar energy is created whilst reducing water evaporation.

[0057] The embodiment of device 20 shown in Figure 1 may also include a tracking feature such as GPS, to give the user a location of device 20. Tracking features are helpful to the user in the event of theft or movement on a large water course. Other forms of technology may be fitted to the device 20, including, but not limited to: water temperature sensor; air temperature sensor; oxygen level sensor; wind speed sensor; and an air quality sensor. These sensors can provide information to the user, giving an indication of dam water level, dam water quality, and threat of a bush fire, for example.

[0058] The embodiment of device 20 shown in Figure 1 may also include advertising or logos on the lid 26. Such advertising may be permanent or designed to fade in ultraviolet light in a certain amount of time. Alternatively, the lid 26 may be coated in a superior reflective finish to reflect more sunlight.

[0059] The embodiment of device 10 shown in Figure 1 may include an electro-magnetic signal reflector to provide or improve internet connections in rural areas or even small wind turbines extending from the device.

[0060] Although the present invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims (5)

1. A device to reduce evaporation of water from a water storage area, the device including:

a body having an upper surface, a lower surface, and a side surface extending between the upper and lower surfaces;

the side, upper and lower surfaces defining a cavity leading to an opening;

at least one flotation instrument having two opposite ends and a longitudinal axis extending between the two opposite ends, the flotation instrument located within the body to prevent the device from sinking below a water-level when the device is positioned on said water storage area, wherein the flotation instrument is retained within the cavity by the ends expanding apart from each other toward the side surface.

2. The device of claim 1, wherein the body is a passenger car tyre, and further wherein, the upper and lower surfaces are the sidewalls of the tyre, and the side surface is a tread of the tyre.

3. The device of claim 2, wherein the flotation instrument is a pool noodle having a diameter of about 100mm and further wherein, the cellular structure of the flotation instrument forces the ends apart from each other, when the flotation instrument is located within the cavity.

4. The device of claim 3, further including a lid to cover at least the opening of the tyre to protect the cavity from any one of: wind; ultraviolet light; birds; animals; and to prevent plants from growing from the device.

5. The device of claim 4, wherein the lid is secured to the body of the device by at least one threaded fastener.

Australian Electric Car Manufacturing Pty Ltd. Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON