Note: Descriptions are shown in the official language in which they were submitted.
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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
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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
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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
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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
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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
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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.
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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.
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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
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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
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.
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.
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