CA2742185A1 - Container cover - Google Patents

Abstract

A cover suitable for use on a liquid containing reservoir. The cover is composed of an envelope of porous material. The envelope is subdivided into discrete independent compartments. The compartments each have access to the internal volume for purposes of receiving a charge of hollow spheres. A centrally disposed collection member is positioned at the intersection of the independent compartments. This position is effectively the centre of mass of the cover once charged with spheres and permits expedited positioning and adjustment of the cover on the surface of the liquid container.
The independent compartments facilitate controlled consolidation of the spheres therein and allow for simple positioning and removal of the cover which was challenging with prior art arrangements. The latter typically had to be folded or rolled causing manipulation difficulties and causing potentially hazardous situations during manipulation.
Advantageously, the present invention provides all of the benefits typically associated with spherical geometry in terms of precipitation run off and further provides for significant insulation capacity for the cover.

Description

CONTAINER COVER

The present invention relates to a cover for a reservoir or container which is adapted to hold a liquid material for storage purposes and more particularly, the present invention is directed to a cover which has improved insulation capacity and is easily positioned and removed from a reservoir.

The prior art is replete with covers for reservoirs or containers as well as those which are adapted to act as a water fowl deterrent. In the case of the latter, a number of companies have proposed the use of floating spheres for this purpose as well as for general coverage of a water body. An example of this can be found in the Torex company which provides floating ball pond covers with the purpose for preventing birds from landing on ponds. Typically, the balls or spheres are composed of high density polyethylene (HDPE) which have impregnated therein carbon black for purposes of UV stabilization.
The balls have been found to be particularly useful, since the spherical surfaces can withstand snow, wind and sun with minor to virtually no destruction into the balls themselves.
Other organizations involved in this area include Buromatie which has trademarked the Bird Ball. Others involving this area include Advanced Water Treatment Technologies (AWTT) which provides a high performance floating cover composed of UV
resistant virgin 1-IDPE under the mark Armour Balls.

These spheres have obvious utility, however, all of them suffer from the fact that they are unconsolidated as a mass and therefore can become separated from the group in which they are positioned. Further, the balls can be moved by larger animals and thus become scattered from the main group. This obviously defeats the purpose of having the pond coverage required and also exacerbates costs for replacement of the spheres.

In order to combat these limitations, the art has considered alternatives in terms of the shapes of the floating bodies. One example of this is found in United States Patent No.
3,993,214, issued November 23, 1976 to Usab. The reference teaches an open liquid surface cover composed of a plurality of pentagonal dodecahedrons. The patentee teaches that the dodecahedrons may be hollow or solid, but are made of structural foam having a specific gravity which is approximately one half of the specific gravity of the liquid upon which they are placed. The advantage to this arrangement is that the dodecahedrons clearly provide multiple faces and thus do not present any interstitial volume such as would be the case with spherical bodies. Accordingly, a substantially full, nonpermeable surface is presented for the top of the liquid. Although useful, this arrangement would appear to constitute materials that are quite expensive and further may not operate optimally in situations where there is freezing precipitation.

A variation of that which is taught by Usab is established in U.S. Patent 7,387,473 issued June 17, 2008, to Smith. The patentee provides an apparatus and method for creating a floating cover. The disclosure stipulates that the system has a plurality of buoyant bodies each having a shape defined by a plurality of faces and edges where each edge is formed by two intersecting faces. The bodies, when in use, are partially submerged in a fluid such that at least a portion of a first face of a first body contacts at least a portion of a first face of a second body to form a substantially gapless barrier between the surface of the fluid and the environment. This structure would appear to be limited to the same extent as the structure taught by Usab supra.

In U.S. Patent 7,314,564, issued January 1, 2008, Kruse et al., teach a method for treating liquids. The method incorporates a cover having a plurality of hollow bodies disposed on the surface of the wastewater. Each of the bodies is adapted to float on the wastewater surface and has the contiguous outer surface and is a sufficient mass so that 30% to 70% of the outer surface of the hollow body is exposed to the atmosphere.

There is no discussion regarding a spherical geometry of the bodies or any contemplation that such bodies could be put into a permeable envelope for the purposes of consolidation.

Turning to U.S. Patent Application Publication No. 2006/0005830, published January 12, 2006, to Rosene et al., there is disclosed a floating solar pool heater. The arrangement discussed in the publication is rather conventional in structure and although providing individual openings, there is an absence of any instruction regarding the use of the cover with, for example, hollow spheres, although the cover does provide an insulative capacity.

Fish, in U.S. Patent No. 4,373,462, teaches a fillable structure. In the disclosure, the patentee provides for a floating, flexible structure which can be filled with liquid. The structure is defined by pieces fixed by side seams and the seams are rendered buoyant by trapped balls. A vent is disposed in an upper portion of the container and has thereunder a net bag filled with balls to maintain gas passage, a transverse tube of netting rendered buoyant by balls maintains liquid flow for discharge through a hose. The point of this structure is to recover oil which has been spilled on the surface of a large body of water.

In greater detail, the Fish reference uses the balls for floating attributes, and also to disallow the upper layer of the "lid" to be tightly contacted by the lower layer to promote a "void space" that is proposed to act as a container for floating material on a fluid surface (aimed at recovering oil slicks, etc. on water). The balls are also contained in a tubular netting to disallow "bunching up" in sections between the upper and lower liners. This structure would have no real utility to function as a cover for a reservoir adapted to contain a predetermined volume of liquid. As a further point, the structure is not amenable to expeditious positioning and removal when required from a body of water upon which it is placed. This would be particularly true for a container of liquid.

Further variations on covers and floatable pads include those structures taught in U.S. Patent Nos. 3,102,902, 4,749,606 and 7,789,043.

It is evident that the art has proposed a number of useful structures;
however, these structures are not well adapted for simple positioning and removal from the surface of a liquid reservoir which also provide for surface protection from contamination, insulation capacity and a reduction in evaporation of the liquid to the atmosphere.
Accordingly, it would be desirable to have a cover structure and cover system that overcomes the limitations of the prior art. It would be beneficial to use the netting as the upper and lower barriers simply to contain the balls without any other impermeable membranes surrounding the balls or the containment netting.

Further, using the netting to contain the balls for ease of installation and removal from the fluid container, the balls beneficially can be used for insulation purposes while the netting acts as a deterrent from debris or wildlife/waterfowl from entering the container. The present invention satiates this need.

One object of one embodiment of the present invention is to provide an improved cover adapted for use on a reservoir or container suitable for holding a liquid and a system for covering such structures.

In accordance with a further aspect of one embodiment of the present invention there is provided a cover for a container, comprising means for providing access to each compartment of said compartments, said compartments adapted for retaining hollow spheres to provide insu[ative capacity for said cover.

In respect of the cover, it has been found that the use of FIDPE is particularly effective for the composition of the spheres, netting and the material for releasably opening the netting.

In a preferred embodiment, the cover is composed of a plurality of discrete compartments adapted to receive a charge of hollow spheres which may be 4 inches in diameter by way of example. The individual compartments will provide access points to facilitate charging of the net or mesh material with the spheres. Once the cover is in position, the access point may be sealed with suitable material which does not interfere with the functioning of the cover.

Of particular convenience is the provision of a central connection means which may be disposed at the central intersection of each of the compartments. As an example, where the cover were to contain four compartments the central connection would be positioned centrally at the intersection of all four compartments. This has advantages in terms of manipulation of the cover for placement purposes, since the central point will be effectively the centre of mass of the cover when the same is removed or positioned. ']'his also has a distinct advantage in terms of allowing the cover, when picked up for removal and repositioning, to take the form of a vertically gathered consolidated article as opposed to having to roll the cover as is attributed to prior art arrangements.

The cover is preferably used on reservoir containers, however, the technology is not limited to this environment; the arrangement can easily be used for pond, pool, etc.
applications. In the latter scenario, it is contemplated that several manageably sized cover structures could be grouped together to form a large cover for an open body of water where the features of the instant invention are required.

In accordance with a further aspect of one embodiment of the present invention, there is provided a surface cover for covering a surface of contained liquid, comprising:

a first layer and a second layer of porous flexible material in overlying relation and joined about the periphery and therebetween to define a plurality of discrete compartments, said compartments adaptive for retaining hollow spheres to provide insulative capacity for said cover; and independent access means in each compartment to provide access thereto; and hollow spheres disposed within each compartment to provide insulative capacity to said cover, said porous flexible material and said spheres having a specific gravity less than water to enable flotation in a container of water.

With respect to the spheres for use in the instant invention, the spheres manufactured by the Torex company discussed herein previously are adequate for the purposes of this invention. With respect to the porous material, i.e. netting or mesh, the same will obviously have a pore size less than the diameter of the spheres for purposes of retention. The pore size or mesh size of the porous material can be any suitable range hi size from, for example, 1 millimetre to 10 millimetres or more. This will depend on the diameter of the spheres charged into the envelope of the mesh material. The spheres have been bound to be particularly useful for purposes of insulation. This has a dramatic effect on storage of, for example, water at a work site. It is desirable to maintain water temperature for certain purposes at, for example, a mine site or a hydrocarbon processing site to avoid additional costs of reheating the water.

In order to augment the insulative capacity of the cover containing the spheres, it is contemplated herein that differently sized spheres may be used to provide a spherical distribution where the interstitial volume is reduced. In the vernacular, if one were to use only a single diameter sphere for charging the porous material envelope, then there Would be a significant amount of interstitial volume which, of'course, contributes to potential evaporation of the liquid and heat loss by passive radiation. By providing differently sized spheres, the interstitial volume can be reduced and thus the coverage area increased. This is in contrast to the structures discussed in the prior art, namely those set forth in U.S.
Patent Nos. 3,993,214 and 7,387,473. In the latter arrangements, the degree of flexibility between adjacent bodies would not be as free as it would be with spherical bodies. The dodecahedron situation is believed to be quite inefficient, since parallel faces contact one another and where freezing precipitation is involved, the faces could effectively sheer one another and potentially damage the body itself and lead to large areas of the bodies being frozen together due to the fact that they do not have the benefit of the spherical surface which would otherwise dissipate the precipitate.

Having thus generally described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments and in which:

Figure I is a perspective view of a first embodiment of the cover structure according to the present invention;

Figure 2 is an alternate embodiment of Figure 1;

Figure 3 is a perspective view of one embodiment of the present invention where the cover is in situ; and Figure 4 is a perspective view of the cover structure during positioning in situ as a pool cover;

Figure S is a perspective view of yet a further embodiment of the present invention where the cover is disposed on the surface of a pond; and Figure 6 is a perspective view of an alternate embodiment of the embodiment shown in Figure 1.

Similar numerals employed in the drawings denote similar elements.
Referring now to Figure 1, shown is a first embodiment of the cover, globally denoted by numeral 10. The cover includes a first layer of porous flexible material 12 which overlies a second layer of porous flexible material 14. The first layer 12 and second layer 14 are joined about the periphery 16 by suitable fastening means (not shown). A
suitable fastening means could be stitching, etc.

A plurality of discrete compartments are provided by the inclusion of stitching 18.
The stitching may be a continuous stitching or intermittent stitching. This divides the liner 10 into individual compartments 20, 22, 24 and 26. In the example shown in Figure 1, there is a quartet of compartments of 20 through 26. Each of the compartments 20 through 26 includes independent access via, for example, a slit 30, 32, 34 and 36, respectively relative to the compartments 20 through 26. The independent access slits 30 through 36 are recloseable with suitable stitching as noted with respect to member 18, defined herein previously as stitching 18.

Disposed within the individual compartments 20 through 26, via access slits 30 through 36 respectively, are disposed buoyant members 38, shown in the example as spheres. The spheres 38, by way of example, may comprise hollow carbon black four inch diameter spheres. It has been found that by providing a spherical surface, that a high insulation value is achieved and that precipitation does not adhere as would be the case with conventional cover arrangements. The buoyant members 38, may also take the form of polygons, depicted by numeral 40 in Figure 1.

The cover 10 includes in a centrally disposed position and, more particularly, at the intersection point of each of the individual compartments 20 through 26, a connection area 42. The connection area 42 includes a connector 44, shown in the example as a ring which can be used to position the liner 10 on the top surface of a layer of liquid to be covered as is illustrated in Figures 3 through 5 to be discussed hereinafter.

Advantageously, by providing the connection area 42 at a central position in the cover, the cover 10 is more easily manipulated. The central area 42 is effectively a centre of mass of the cover 10. As such, when the cover 10 is picked up, the entire unit folds into a downward draped position as an orderly consolidated unit. The fact that the cover 10 includes the individual compartments 20 through 26 also contributes to the ease of manipulation. The individual compartments 20 through 26 allow for more consolidated retention of the spheres 38. This is in marked contrast to a system that would not incorporate individual compartmentalization. In the absence of compartments, the buoyant members 38 or spheres, when the cover is picked up for repositioning, would have the tendency to bunch together in the form of an inverted bulb shape, as opposed to an individual draped unit. This has ramifications in terms of control of the cover 10 during movement as the inverted bulb type situation would provide a concentrated mass of spheres at a relatively localized point which could prematurely stress the flexible material leading to premature wear or breakage. Further, it will be appreciated by those skilled in the art that the inverted bulb shape, during high wind conditions, presents a very large surface area for the wind to contact and thus become somewhat challenging to move.
These disadvantages are avoided by providing compartmentalization which distributes the mass of the buoyant bodies 38 in a more efficient manner to avoid high stress points with the flexible material 12 and 14.

It has been found that the material of which the cover may be made in terms of the flexible material 12, 14 as well as the stitching 18 may comprise HDPE. Other suitable examples will include polypropylene, high impact polystyrene (HIPS), and polyethylene.
These materials are suitable owing to the fact that they have properties that are desirable for the cover structure, namely a specific gravity less than water. The ability to retain UV
stabilizers to prevent premature oxidation by the exposure to sun and durability in use conditions where the temperature fluctuates from high temperatures to temperature below freezing.

It has also been found that by making use of the flexible material 12 and 14 of the cover 10 with the buoyant members 38, that freezing precipitation does not have any proclivity to be retained on the flexible material or spheres 38. This is due to the fact that precipitation will effectively be transferred through the porous material 12 and 14 onto the spheres 38. Since the spheres obviously have a round surface, there is a tendency for the precipitation to simply run off the surface of the spheres 38. As is illustrated in Figure 1, the buoyant members or spheres 38 may also be substituted with a polygonal shaped 40.
The polygonal shaped 40 also has the similar attributes of the spheres concerning precipitation run off, etc.

Turning to Figure 2, shown as a further embodiment of the present invention, where the cover structure 10 is shown in a generally rectangular form, as opposed to the circular form shown in Figure 1.

Turning to Figure 3, shown as a perspective view of the cover 10 as positioned in situ in a liquid holding container 46.

In respect of Figure 4, the rectangular version of the cover 10 is shown as positioned on the top surface of a pool, globally denoted by numeral 48.

Figure 5 illustrates an embodiment where the cover 10 has an asymmetrical shape in order to cover a pond 50.

Regarding Figure 6, shown is a further variation of the overall structure of Figure 1.

As depicted, the buoyant bodies 38 in this embodiment illustrate two differently sized spheres. Although the single diameter spheres have obvious utility in adding insulative capacity to the cover 10, the provision of a second or plurality of differently sized spheres also has significant advantage. This advantage is realized by the fact that where a single diameter sphere is used, there is interstitial volume between the spheres.
By providing differently sized spheres, the interstitial volume may be filled to thus provide a surface that has an even greater insulative capacity. This is due to the fact that there are no open areas; the differently sized spheres will interstitially fill the entire area to be covered.

It is known by those skilled in the art that maximum spherical packing can be achieved by making use of a particle size distribution where there are a number of sphere sizes within a given distribution. This provides the greatest possible degree of spherical packing and thus a minimal amount of interstitial volume. It is contemplated that the cover 10, according to the present invention, can include a plurality of diameters for the buoyant bodies in the case of spherical geometry. In respect of the polygonal geometry, a similar situation exists; depending on the specific geometry of the polygon, differently sized polygons can contribute to the interstitial contribution.

As has been indicated herein previously, the stitching 18 between compartments through 26 may be continuous or discontinuous. In the case of the latter, it will be appreciated that the stitching will be sufficient to maintain the buoyant bodies 38 such that they do not transmigrate from one compartment to another.

In terms of the material of which the flexible layers 12 and 14 are made, it has been discussed what suitable materials may be used. In terms of the porosity, any suitable netting or mesh size may be incorporated as long as it is sufficiently dimensioned to retain the buoyant bodies 38 within each individual compartment 20 through 26.

Although embodiments of the invention have been described above, it is not limited thereto and it will be apparent to those skilled in the art that numerous modifications form part of the present invention insofar as they do not depart from the spirit, nature and scope of the claimed and described invention.

Claims (25)

1. A cover for a container, comprising:

a first layer and a second layer of porous flexible material in overlying relation and joined about the periphery and therebetween to define a plurality of discrete compartments, said compartments adaptive for retaining hollow spheres to provide insulative capacity for said cover; and independent access means in each compartment to provide access thereto; and hollow spheres disposed within each compartment to provide insulative capacity to said cover, said porous flexible material and said spheres having a specific gravity less than water to enable flotation in a container of water.

2. The cover as set forth in claim 1, including buoyant independent members disposed within said compartments.

3. The cover as set forth in claim 2, wherein said buoyant members comprise hollow spheres.

4. The cover as set forth in claim 1, wherein said flexible material comprises net material.

5. The cover as set forth in claim 1 or 2, wherein the layers are joined discontinuously while retaining said spheres.

6. The cover as set forth in any one of claims 2 through 5, wherein the layers are joined continuously about the periphery.

7. The cover as set forth in any one of claims 1 through 5, wherein said access means comprises a reclosable opening in each compartment.

8. The cover as set forth in any one of claims 1 through 7, further including connection means at an intersection of said compartments for facilitating positioning and removal of said cover.

9. The cover as set forth in any one of claims 3 through 8, said net material comprises HDPE.

10. The cover as set forth in any one of claims 2 through 8, wherein said spheres comprise HDPE.

11. The cover as set forth in claim 10, wherein said spheres have a similar diameter.

12. The cover as set forth in claim 10, wherein said spheres have a dissimilar diameter for the maximum filling of interstitial volume between spheres.

13. The cover as set forth in any one of claims 1 through 12, wherein said cover comprises a quartet of compartments.

14. The cover as set forth in claim 2, wherein said cover and spheres are composed of a material having a specific gravity of less than water.

15. The cover as set forth in claim 2, in combination with a container containing water.

16. The cover as set forth in claim 2, in combination with a pond containing water.

17. The cover as set forth in claim 2, in combination with a pool containing water

18. A surface cover for covering a surface of contained liquid, comprising:

a first layer and a second layer of porous flexible material in overlying relation and joined about the periphery and therebetween to define a plurality of discrete compartments, said compartments adapted for retaining hollow spheres to provide insulative capacity for said cover;

independent access means in each compartment to provide access thereto; and hollow spheres disposed within each compartment to provide insulative capacity to said cover, said porous flexible material and said spheres having a specific gravity less than water to enable flotation in a container of water.

19. The cover as set forth in claim 18, wherein said cover includes a quartet of compartments.

20. The cover as set forth in claim 18, wherein said compartments are substantially rectangular.

21. The cover as set forth in claim 18, wherein said compartments are substantially square.

22. The cover as set forth in claim 18, wherein said compartments are generally sectors of an arc.

23. The cover as set forth in claim 18, in combination with a container for containing water.

24. The cover as set forth in claim 18, in combination with a pond containing water.

25. The cover as set forth in claim 18, in combination with a pool.