Patent Application
20120309604
The present invention relates to a liner and more particularly, the present invention relates to an improved liner for use in a holding container or reservoir and a method of lining such a reservoir or container.
Synthetic plastic liners have been used to line above and below ground reservoirs. The simplest example of this is a conventional swimming pool which provides an inground opening which is prepared and levelled and subsequently lined with a polyethylene and the like material. In industrial applications, for purposes of handling landfill, hazardous waste disposal, infer cilia, more sophisticated liners are required in order to comply with environmental regulations. In situations related to the latter, geomembranes composed of synthetic plastics are regularly used. One material that has been particularly useful in providing liners is high density polyethylene (HDPE). This material is particularly useful since it generally includes and retains UV stabilizers so that it does not prematurely degrade when exposed to the sun and conventionally has a very lengthy useful life span. Another useful material is linear low density polyethylene (LLDPE).
Returning to industrial applications, conventional liners are typically formed in segments which provides for adjacent segments being fusion welded in an imbricated manner to provide a fairly large liner. The liners are then manually installed by several workers and then custom fitted to the area which the liner will serve.
Examples of liners in the prior art include, for example, U.S. Pat. No. 4,065,924, issued Jan. 3, 1978 to Young. The patentee teaches a method of lining a waterway or reservoir. There are a number of steps taught for forming the membrane which comprises a laminate of a butyl sheet with a layer of synthetic fibres bonded thereto.
A conventional “drop in” style liner is described in U.S. Pat. No. 7,574,834, issued Aug. 18, 2009 to Murray. The liner is designed for above ground water storage and provides for a plurality of modular walls coupled together to form a continuous perimeter. Each of the walls is inclined relative to the horizontal. A liner covers an internal side of the modular walls and an area encompassed by the perimeter.
In terms of larger storage vessels, U.S. Patent Publication No. 2009/0139633, published Jun. 4, 2009, provides a method for lining a container and the liner itself. In the method, the patentee teaches a reservoir tank or basin having a waterproof layer of plastic where, in a first step, at least one of the fastening elements comprised of Velcro™ is fastened to the inner side of the container and in a second step, at least one sealing sheet of plastic is fastened to the first fastening member. There is no real challenge in handling the liner in this publication as it is a modular type liner.
Additional examples of existing technology in the liner field are taught in U.S. Pat. No. 3,683,628, issued Aug. 15, 1972 to Tabary and in U.S. Patent Reissued Pat. No. 35,272, reissued Jun. 11, 1996 to Mathieson, et.al.
The liner that is incorporated in the instant technology is used in the storage tanks which are illustrated, as an example, in the websites of Royal Liner and Fab-Seal.
In greater detail, the liner system that is contemplated by the present invention is specifically used in reservoirs designed to hold a liquid. In the case where the liquid is water, specific guidelines need to be followed and specific materials used to line the container.
The receptacles or containers containing the water are typically assembled on site. This is where the complication arises with the conventional arrangements. As discussed hereinabove, the liners are fairly large, i.e. greater than 50 feet in diameter or greater and accordingly, the size of the liner for use in lining such a structure is very large and difficult to manipulate. Generally speaking, in conventional methodology the liner is transported to the site. The receptacle or container is assembled, many of which are of a cylindrical geometry. Once assembled, the onerous task of lining the receptacle is undertaken. The problem is that the liner, owing to the size, is extremely difficult to manipulate and it must be dropped into position and then subsequently placed so that the vertical walls are covered and the liner extends over the top of the vertical walls. This is not without complications under the best of circumstances; the exercise is grossly encumbered during inclement weather conditions. Under wind conditions, the liner effectively becomes a sail and even a slight wind can become a potentially fatal situation to workers attempting to position and fasten down the liner to the structure. It has been known in the field that the liner can become completely disengaged from the container and drift down several properties away from its initial intended position. There have also been a significant number of injuries to the workers where the liner flails in the wind and can easily slap or even worse, transport a worker purely under the force of the wind with the liner.
Given the problems with the existing arrangements and the systems used to line containers presently employed, there exists a need to have a system that is efficient and is not affected by inclement weather conditions. The present invention is directed to solving the limitations of the prior art arrangements.
One object of the invention is to provide an improved liner system and method of lining a container.
A further object of one embodiment of the present invention, there is provided a liner for a tank adapted to retain liquid, comprising: a liner body adapted to form a base and at least one vertical wall in a continuous structure; said at least one vertical wall of said liner adapted for folding over a supporting wall section; and stabilizing means integral with and positioned about the base of said base of said liner for stabilizing motion of said liner during assembly of said wall section when said wall section is positioned on top of said stabilizing means.
Conveniently, the stabilizing means may be simple, discrete extensions from the existing liner. These are preferably radially disposed about the periphery of the underside of the liner.
Of particular advantage is the fact that the material of which the liner is made is HDPE or LLDPE. The attributes of these materials are well documented in the art and it is further known by those skilled that these materials, once they have served a useful lifespan as a liner, can be reclaimed and used for further article formulation, an example of which is lawn furniture. In this manner, the liner technology of the instant invention has a “green” aspect and is not wasteful to the extent of existing arrangements.
Once the liner is in position over the top edges of the wall segments of which the container is composed, suitable fastening means may be used for securement.
In terms of positioning the liner within the receptacle, it has been found that by making use of the stabilizing members which are integral with the base of the liner body, all of the inherent dangers and complications attributed to the prior art are overcome.
The stabilizing members briefly described herein previously are of particular advantage, since the liner can be transported to the site, put into position where the receptacle is to be placed and then the container effectively built around the liner. This is in marked contrast to the existing methodology which builds the container first and subsequently drops the liner over and into the receptacle. As will be appreciated in the case of the latter, it is extremely difficult to position a large disc like article (the liner) into the substantially cylindrical container. This requires continuous manipulation in order to centre the liner within the cylindrical container, which is not only time consuming, but extremely challenging.
In the case of the instant technology, the stabilizing members have on the top thereof the wall segments of the cylindrical container. In this manner, the liner is placed, the sides of the liner lifted substantially vertical to the base of the liner as the wall segments of the container are positioned on the stabilizing members. This eliminates the possibility of any movement from wind of the liner since the stabilizing members are integral, i.e. fixedly secured to the underside of the liner base. The corollary advantage to this structure is that the liner is effectively maintained in a pretentioned state so that no adjustment manipulation is required for purposes of centering the liner within the cylindrical container.
Accordingly, a further object of another embodiment of the present invention is to provide a method stabilizing movement of a liner body during the lining of a container adapted to store a liquid comprising: providing a liner body having a base and walls folding to a substantially orthogonal position relative to said base; providing integrally connected stabilizing means separate from said walls for extending perpetually from said base when said walls are folded; positioning wall segments for forming said container on top of solid stabilizing means; and folding and securing liner walls over said wall segments, whereby said liner body and walls are stabilized against lift and movement during assembly of said container.
Although it is preferred that the material of which the liner is made comprise HDPE or LLDPE, other suitable materials will be readily apparent to those skilled in the art. Additional materials may include polyethylene terephthalate (PET), bisphenol polyethylene, polyvinyl chloride (PVC), and acrylonitrile butadiene styrene (ABS).
In an alternative embodiment instead of providing individual stabilizing members about the periphery of the base of the liner, the number of stabilizing members projecting from the base may be significantly reduced and include a ring of material (around HDPE or LLDPE material). In this manner, the stabilizing members would act as spacer members for spacing coaxially disposed ring for purposes of receiving the cylindrical wall members and thus achieving the same result of the stabilizing members when they are positioned about the perimeter in spaced relation and in significant quantity.
Having thus generally described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments.
Similar numerals employed in the drawings denote similar elements.
Referring now to
The liner is typically formed of a plurality of independent rectangular sections, shown in dashed line in
In
As an option, the stabilizing members 14 may be positioned within a pouch 16 similarly located on the under surface of the liner at 10. This is to provide an area into which the individual stabilizing members 14 may be tucked in for storage. To this end, the pouches 16 are also integral with the liner and maintain the stabilizing members 14 in an orderly fashion.
Referring to the remaining Figures and specifically
With respect to specific reference to
Once the sidewalls 22 are folded as indicated in
It has been found that this structure and method for assembling a container to hold a liquid and the liner therein is particularly effective and obviates all of the dangers typically associated with workers attempting to “drop-in” a liner into a premade container composed of sidewalls 26. By providing the stabilizing members 14 about the periphery of the liner, the tension of the liner can always be maintained at the base 18 and the stability of the liner during assembly of the container sidewalls 26. It will be clear to those skilled in the art that this structure and method of assembly prevents the possibility of air currents coming underneath the liner which would otherwise create billowing and a dangerous manipulation situation. The sidewalls 26, due to the weight thereof, retain the liner in position and do not allow air current or air flow under the base. With respect to the flexible sidewalls 22 of the liner 10, these are unaffected by any type of air flow or wind currents, since they are within the body of the container being formed and are thus essentially unaffected by air flow over the top of the sidewalls 26.
In terms of a method using the liner of the present invention, the description for
Turning to
Referring to
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.
