AU2022221538B1

AU2022221538B1 - Device to mitigate water evaporation

Info

Publication number: AU2022221538B1
Application number: AU2022221538A
Authority: AU
Inventors: Peter Chapman
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-26
Filing date: 2022-08-26
Publication date: 2023-04-27
Anticipated expiration: 2042-08-26

Abstract

The device (1)comprises a rectangular panel (2) of reinforced polypropylene fabric. All four side edges of the panel (2) include sleeves (3) with open corner ends (4) housing elongated polystyrene blocks (5). A further sleeve (11), spanning between opposing longitudinal edges of the panel (2), encloses an elongated block of polystyrene. Lateral (8) and longitudinal (9) steel rods are also housed in the respective sleeves (3) under the blocks (5). Connectors (7,10) enable the device to be connected to ground anchors (15) placed around the periphery of a dam (16) and/or enable adjacent devices (1) to be connected together to form one or more rafts (13). In use, the sleeves (3) fill with water and the rods (8,9) cause the lower surface of each sleeve (3) to deflect downwards providing ballast for the floating panel (2), increasing the resistance of the panel (2) to lifting by any wind blowing across the water surface. The trench of water bounded by the lower surfaces of the sleeves (3) provides further resistance to any device (1) movement through the water.

Description

TITLE: DEVICE TO MITIGATE WATER EVAPORATION

Technical Field

THIS INVENTION relates to the prevention of water evaporation. In particular, it is directed to a device to mitigate evaporation of water from open-topped water storage facilities such as dams and reservoirs.

Definitions

It should be noted that, throughout this specification, unless the contrary is expressly stated, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was, at the priority date, publicly available, known to the public, part of the common general knowledge, or known to be relevant to an attempt to solve any problem with which this specification is concerned.

Unless the contrary is expressly stated, the use of ordinal adjectives such as "first", "second", "third" and the like, to describe objects is not intended to imply that the objects are in any particular sequence, either temporally, spatially, or in any other manner.

The terms "comprising" or"comprises" as used throughoutthis specification and claims are taken to specify the presence of the stated features, integers and components referred to but not preclude the presence or addition of one or more other feature/s, integer/s, component/s or group thereof.

Background Art

Rainfall in certain geographical areas is declining and, simultaneously, as the climate warms, evaporation rates from open storage water facilities are increasing. Further, water demands of consumers from expanding urban developments is also escalating.

Consequently, obtaining and storing water in Government operated reservoirs is increasingly difficult and the consequent cost of its supply to consumers is also increasing. Also, access to sufficient water is a critical issue for farming, not only for the farm household use, but also for maintaining livestock and for the irrigation of crops. The lower rainfall, and higher water evaporation rates, along with other factors such as sandy soils and flat landscapes, all contribute to a lack of abundant runoff and surface water resources. Further, underground water resources can be too saline for stock use, surface water flows are ephemeral, and a farm often has no connection to mains water. As a result, a substantial percentage of food producers are reliant on farm dams to provide the water for livestock, crops and for their own domestic use.

There have been a number of prior art attempts to limit the loss through evaporation once the water has been harvested on properties in dams. One prior art attempt is tree windbreaks planted near dams; however, trees take a significant period to reach an effective size, cannot be planted too close to dam walls as their roots may penetrate and damage the walls, or actually withdraw water from the dam for their own nutrition. A second prior art attempt is the use of a shade cover suspended above the water surface with cables; disadvantages include high winds damaging the shade cover, difficulty in anchoring the support cables in poor quality soils, and the relatively high capital outlay on construction labour costs. A third prior art attempt is the use of covers floating on top of the water surface; these floating covers include (1) continuous floating sheets with internal buoyancy cells covering the entire surface of the dam, (2) modular covers, with the individual modules either restrained or unrestrained, that can move freely across the water surface, and (3) polystyrene-filled motor vehicle tyres; typical disadvantages of these floating covers include (i) excluding natural rainfall from entering the dam if the entire surface is covered, (ii) the large number, and therefore significant cost, of modules required to cover any particular dam, and (iii) the leaching of undesirable chemicals from a floating cover into the water. A fourth prior art attempt is applying a chemical anti-evaporative agent layer to the water surface; disadvantages of this chemical treatment include (i) the layer is significantly effected by strong winds blowing across a dam, (ii) the agent is manufactured from biodegradable materials and therefore require re-application, as often as every 48 hours, particularly if the soil forming the dam is favourable to absorption of the chemical; anti-evaporative agents are therefore ineffective as a long-term solution to water evaporation from a dam.

It is thus a general object of the present invention to overcome, or at least ameliorate, one or more of the above-mentioned disadvantages.

Summary of the Invention

According to a first aspect of the present invention, there is provided a device to mitigate evaporation of water from an open-topped water storage facility, the device comprising:

an impervious polygonal panel; at least one open-ended sleeve around the perimeter of the polygonal panel; a buoyancy means within each of the at least one open-ended sleeve; and a ballast means within each of the at least one open-ended sleeve.

Preferably, the polygonal panel includes at least one bracing member extending substantially across at least one section of the panel.

Preferably, each at least one bracing member is a sleeve enclosing a stiffening means.

Preferably, the impervious polygonal panel is manufactured from a flexible material.

Preferably, the flexible material is a polymeric material.

Preferably, the polymeric material is reinforced polypropylene fabric.

Preferably, the buoyancy means and stiffening means are each manufactured from a polymeric material.

Preferably, the polymeric material of the buoyancy means and stiffening means is polystyrene.

The ballast means may comprise any suitable either granular or less friable materials.

Suitable granular materials include sand and earth or a combination thereof.

Suitable less friable materials include rigid rod- or wire-like metallic materials.

Preferably, the ballast means is manufactured from a rigid rod-like metallic material.

Preferably, the metallic material is steel.

In one embodiment of the present invention, the ballast means comprises a single continuous rod.

In another embodiment of the present invention, the ballast means comprises multiple rods joined by respective coupling means.

Suitable coupling means include (1) ferrules attached to threaded ends of the rods, (2) threaded ends of adjacent rods connected to a complementary internally threaded connector, or (3) bolt-type fasteners.

Optionally, the device includes a first connection means adapted to connect to an adjacent device.

In one embodiment of the present invention, the aforementioned coupling means are further adapted to function as the first connection means to connect to an adjacent device.

In another embodiment of the present invention, the first connection means is a series of spaced "hooks and loops" straps affixed around the perimeter of the polygonal panel.

Optionally, the device includes a second connection means adapted to connect the device to an anchoring means positioned substantially at the periphery of the water storage facility.

In those embodiments of the present invention where two or more of the device are connected together forming a raft, at least one of the device of the raft includes a third connection means adapted to be connected to another adjacent raft.

The third connection means may be either a series of spaced "hooks and loops" straps affixed around the perimeter of an appropriate polygonal panel or a weighted wire adapted to connect the appropriate polygonal panels from each adjacent raft.

Preferably, the polygonal panel is either a rectangular or square polygon.

In those embodiments of the present invention wherein the polygonal panel is either a rectangular or square polygon, the panel includes four sleeves, each open at each end, and positioned at the respective side edge of the panel.

As a second aspect of the present invention, there is provided a system to mitigate evaporation of water from an open-topped water storage facility, the system comprising:

one or more of the device as hereinbefore described; and

at least one anchoring means comprising a ground anchor for positioning substantially at the periphery of the open-topped water storage facility and adapted to be connected to the respective second connection means.

In one embodiment of the present invention, each anchoring means includes a slide anchor adapted to be connected at one end to the ground anchor by a cable, the other end of the slide anchor being adapted to be connected to the second connection means.

A third aspect of the present invention is a method of mitigating evaporation of water from an open-topped water storage facility, the method comprising:

providing a system as hereinbefore described; affixing one or more of the anchoring means substantially at the periphery of the water storage facility; and connecting the one or more device to a respective anchoring means.

Brief Description of the Drawings

The present invention will now be described with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic top plan view of a device of the invention;

FIG. 2 is a schematic plan view of certain components of the device of FIG. 1;

FIG. 3 is a schematic cross-section view of part of the device of FIGS. 1 & 2;

FIG. 4 is a schematic plan view of multiple devices of FIGS. 1 to 3 coupled together; and

FIG. 5 is a schematic plan view of the device of FIGS. 1 to 3 in use.

Detailed Description of the Preferred Embodiment

Referring to the FIGS., the device (1) (FIG. 1) comprises a rectangular panel (2) of reinforced polypropylene fabric. All four side edges of the panel (2) are folded over and welded to the underside of the panel (2) to create sleeves (3). Each end of the sleeves (3) are cut to create open corner ends (4). An elongated block (5) of polystyrene is inserted into each sleeve (3) (FIG. 3). Multiple steel rods with threaded ends are connected together by complementary internally threaded connectors (7) to create appropriate length lateral (8) and longitudinal (9) rods which are inserted into the respective sleeves (3) under the blocks (5) (FIGS. 2 & 3). The threaded ends of adjacent lateral (8) and longitudinal (9) rods are connected together with complementary threaded corner connectors (10) (FIG. 2). The connectors (7,10) include plates (7a,1Oa) - each having at least one hole therein extending outwards from the edges of the panel (2) to which a shackle or similar (not illustrated) can be attached. A sleeve (11) (FIG. 1), spanning between opposing longitudinal edges of the panel (2), encloses an elongated block of polystyrene (not illustrated) and is welded to the upper surface of the panel (2). A series of "hooks and loops" straps (12) (FIG. 1) are fixed to the longitudinal edges of the panel (2) enabling adjacent devices (1) to be connected together to form a raft (13) (FIG. 4) if required. Also, if required, weighted wires (14) (FIG. 4) can be connected to respective connectors (7,10) between adjacent rafts (13) to create an array of interconnected rafts over any required area (FIG. 4).

In use (FIG. 5), ground anchors (15) are placed around the periphery of a dam (16), slide anchors (17) are connected between their respective ground anchors (15) and the respective connector plates (7a,10a) of the device (1) with cables (18) by any suitable means known in the art. When placed into the dam (16), the sleeves (3) fill with water and the weight of the rods (8,9) cause the lower surface of each sleeve (3) to deflect downwards (FIG. 3). By appropriate selection of the blocks (5) and the rods (8,9), the necessary buoyancy for the device (1) can be achieved. The sleeve (11) functions as a stiffening rib assisting to prevent the panel (2) from folding.

Although not wishing to be bound by theory, the rods (8,9) provide ballast for the floating panel (2) thereby increasing the resistance of the panel (2) to lifting by any wind blowing across the water surface. Different rod (8,9) diameters provide differing ballast weights. Further, the trench of water bounded by the lower surfaces of the sleeves (3) provides further resistance to any device (1) movement through the water due to wind gusts. With the lower surfaces of the sleeves (3) below water, any wind gust would have to displace water to create a sufficient depression on the water surface for wind to pass under and lift the panel (2). For typical dimensions of the panel (2) (10m x 1Om or 1Om x 5m), such a depression would have to be approximately 100mm deep, a condition which is rarely, if ever, reached by natural wind gusts. When a dam (16) is full, the system of the present invention has exposed water surfaces around the edges of the system and in the small gaps between devices (1), allowing natural aeration of the water. As the water level in the dam (16) progressively drops, the surface areas of these spaces decrease thereby reducing exposure of the remaining water to evaporation and hence increasing the overall efficiency of the system. The interconnection of rods (8,9) and the connector plates (7a,10a) creates a load bearing grid-like network beneath the water surface transferring wind force to the anchor system.

The present invention offers a number of advantages which include:

the floating panels can be connected together to maximise coverage over a water surface;

the panels remain in full contact with the water as the water surface level fluctuates;

the system is substantially unaffected by wind gusts across the water surface;

the system minimises water surface exposure to wind and sun;

the system is simple to construct, not requiring extensive trade skills.

It will be appreciated that the above described embodiments are only exemplifications of the various aspects of the present invention and that modifications and alterations can be made thereto without departing from the inventive concept as defined in the following claims.

Claims

1. A device to mitigate evaporation of water from an open-topped water storage facility, the device comprising:

an impervious polygonal panel; at least one open-ended sleeve around the perimeter of the panel; a buoyancy means within each of the at least one open-ended sleeve; a rigid ballast means within each of the at least one open-ended sleeve; and a connection means adapted to connect the device to an anchoring means positioned substantially at the periphery of the water storage facility.

2. A device as defined in Claim 1 wherein, the ballast means is sufficient to maintain the lower surface of the at least one open-ended sleeve beneath the surface of the water when the device is in use.

3. A device as defined in Claim 1 or Claim 2 wherein, the ballast means is manufactured from rod-like metallic material.

4. A device as defined in Claim 3 wherein, the ballast means comprises a single continuous rod.

5. A device as defined in Claim 3 wherein, the ballast means comprises multiple rods joined by respective coupling means.

6. A device as defined in Claim 5 wherein, the coupling means is selected from the group comprising ferrules attached to threaded ends of the rods, threaded ends of adjacent rods connected to a complementary internally threaded connector, or bolt-type fasteners.

7. A device as defined in any one of Claims 1 to 6 wherein, the polygonal panel includes at least one bracing member comprising a sleeve enclosing a stiffening means and extending substantially across at least one section of the panel.

8. A device as defined in any one of Claims 1 to 7 wherein, the polygonal panel comprises either a rectangular or a square polygon having four sleeves, each open at each end, and positioned at the respective side edge of the polygonal panel.

9. A device as defined in any one of Claims 1 to 8 wherein, the polygonal panel is manufactured from a flexible polymeric material.

10. A device as defined in any one of Claims 1 to 9 wherein, the buoyancy means is manufactured from a polymeric material.

11. A device as defined in any one of Claims 7 to 10 wherein, the stiffening means is manufactured from a polymeric material.

12. A device as defined in any one of Claims 1 to 11 further adapted for connection to an adjacent device.

13. A device as defined in Claim 12 wherein, two or more of the device are connected together forming a raft.

14. A device as defined in Claim 13 wherein, at least one of the device of the raft is further adapted for connection to another adjacent raft.

15. A system to mitigate evaporation of water from an open-topped water storage facility, the system comprising:

one or more of the device as defined in any one of Claims 1 to 14; and at least one anchoring means comprising a ground anchor for positioning substantially at the periphery of the open-topped water storage facility and adapted for connection to a respective device.

16. A system as defined in Claim 15 wherein, each anchoring means includes a slide anchor adapted to be connected at one end to the g round anchor by a cable, the other end of the slide anchor being adapted for connection to a respective device.

17. A method of mitigating evaporation of water from an open-topped water storage facility, the method comprising:

providing a system as defined in Claim 15 or Claim 16; affixing one or more of the anchoring means substantially at the periphery of the open-topped water storage facility; and connecting the one or more device to a respective anchoring means.