TECHNICAL FFELD
[0001] 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.
BACKGROUND ART
[0002] 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 pounds. 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 Euromatic
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 HDPE under the mark Armour Balls.
[0003] 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.
[0004] 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.
[0005] 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, arc 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 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.
[0006] 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.
[0007] 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.
[0009] 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.
[0010] 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.
[0012] 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
overcornes 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.
[0013] 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.
[0014] 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.
[0015] 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 insulative capacity for said cover.
[0016] In respect of the cover, it has been found that the use of HDPE is particularly effective
for the composition of the spheres, netting and the material for releasably opening
the netting.
[0017] 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 not 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.
[0018] 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.
This 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.
[0019] 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.
DESCRIPTION OF THE INVENTION
[0020] 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
compartment 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.
[0021] 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 in 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 proccessing site to avoid additional costs of reheating the
water.
[0022] 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.
[0023] Having thus generally described the invention, reference will now be made to the
accompanying drawings illustrating preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
Figure 1 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 5 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.
[0025] Similar numerals employed in the drawings denote similar elements.
INDUSTRIAL APPLICABILITY
[0026] The present invention has utility in the container cover industry.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] 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.
[0028] 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.
[0029] 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 3 8, 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.
[0030] 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.
[0031] 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
consolidate 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 c)f 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] Turning to Figure 3, shown as a perspective view of the cover 10 as positioned in
situ in a liquid holding container 46,
[0036] 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.
[0037] Figure 5 illustrates an embodiment where the cover 10 has an asymmetrical shape in
order to cover a pond 50.
[0038] Regarding Figure 6, shown is a further variation of the overall structure of Figure
1.
[0039] 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 sited 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.
[0040] 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 greater 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.
[0041] As has been indicated herein previously, the stitching 18 between compartment!! 20
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.
[0042] 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.
1. A cover for a container,
characterized in that said cover comprises:
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, characterized in that said cover includes buoyant independent members disposed within said compartments.
3. The cover as set forth in claim 2, characterized in that said buoyant members comprise hollow spheres.
4. The cover as set forth in claim 1, characterized in that said flexible material comprises net material.
5. The cover as set forth in claim 1, characterized in that the layers are joined discontinuously while retaining said spheres,
6. The cover as set forth in claim 2, characterized in that said layers are continuously joined about the periphery.
7. The cover as set forth in claim 1, characterized in that said access means comprises a reclosable opening in each compartment.
8. The cover as set forth in claim 1, 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 claim 3, characterized in that said net material comprises HDPE.
10. The cover as set forth in claim 2, characterized in that said spheres comprise HDPE.
11. The cover as set forth in claim 10, characterized in that said spheres have a similar diameter or said spheres have a dissimilar diameter for
the maximum filling of interstitial volume between spheres.
12. The cover as set forth in claim 1, characterized in that said cover comprises a quartet of compartments.
13. The cover as set forth in claim 2, characterized in that said cover and spheres are composed of a material having a specific gravity of less
than water.
14. The cover as set forth in claim 2, in combination with a container containing water
or in combination with a pond containing water or in combination with a pool containing
water.
15. A surface cover for covering a surface of contained liquid,
characterized in that said cover comprises:
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;
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.
16. The cover as set forth in claim 15, characterized in that said cover includes a quartet of compartments.
17. The cover as set forth in claim 15, characterized in that said compartments are substantially rectangular or said compartments are substantially
square.
18. The cover as set forth in claim 15, characterized in that said compartments are generally sectors of an arc.
19. The cover as set forth in claim 15, in combination with a container for containing
water or in combination with a pond containing water or in combination with a pool.