TANK LINER
A liquid-tight tank liner for use with elongate tanks with rounded end walls is disclosed. The liner is configured to carry the hydrostatic pressure loading which would otherwise be applied to longer side walls of the tank when the tank is filled with water or other liquid.
The present invention relates to a tank liner and more particularly to a liner for a tank for holding a liquid such as water, rainwater for example.
The present invention also relates to a tank, such as a water tank, that includes the liner.
Tanks for holding water, such as rainwater, in domestic and urban situations may, due to space limitations, need to be of a shape other than circular. For use where only confined space is available, a tank may be of an oblong or elongated shape with straight side walls and narrower end walls which are usually rounded, particularly when the tank is fabricated from corrugated steel panels. Tanks of this general shape require internal reinforcement to prevent the side walls from bowing outwardly under the hydrostatic pressure of the water stored within the tank.
For steel tanks, an approach which has been used is to install steel baffles between the two side walls, the baffles acting as ties to connect the two side walls and thereby to prevent them from distorting under load. The baffles are installed at the time of manufacture. The baffles are normally riveted to the side walls and care does need to be taken to ensure that the riveted connection is sealed against water leakage. Moreover a significant disadvantage with this construction is that the tank cannot be stored and transported in demounted condition to be assembled on site; accordingly significant storage and transportation costs can arise with tanks of this construction.
The present invention provides a liquid-tight tank liner for use with tanks of the general shape indicated above with the liner being configured to carry the hydrostatic pressure loading which would otherwise be applied to the longer side walls of the tank when the liner is filled with water or other liquid.
According to the present invention there is provided a liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid and the liner having a structure such that when the liner is installed within the tank shell and filled with liquid, the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
Typically, the opposed sides of the liner will only slightly contact or will be spaced inwardly from the side walls of the tank shell so that the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
The above-described liner, when installed in a tank shell and filled with water or other liquid is essentially self-supporting in the sense that it does not rely substantially, if at all, on the tank shell to structurally support the liner.
According to the present invention there is also provided a liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid, the liner providing a series of interconnected tubular cells extending from a base of a tank to the top of the tank shell, the configuration of the liner in its uninstalled state being such that when the liner is installed within the tank shell and is filled with water or other liquid, the cells at the respective ends of the liner will engage the adjacent end wall of the tank shell and will be deformed into a non-cylindrical shape, and the or each cell intermediate the end cells will be deformed into an elongate shape transversely of the side walls of the tank, the or each intermediate cell having part-cylindrical end walls which are positioned in relation to the side walls of the tank shell when in the installed state whereby the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
The cells may be fabricated as separate cells each with an upstanding wall and a base when installed in the tank shell, the adjacent cells being interconnected to provide water or liquid flow between the cells.
The liner may be constructed from panels of sheet material welded or glued together to form the cells such that adjacent cells share a common upstanding wall provided by a single panel and a base sealed to the lower ends of the panels forming the cells when installed in the tank shell. Advantageously, the connections are between parts of the panels directed transversely to the side walls of the tank shell whereby the connections are subject principally to a shear loading.
The liner may be constructed so that the upstanding wall and the base of each cell are separate components that are welded or glued or otherwise connected together. With such an arrangement, preferably the shape of the base is the shape required when the cell is installed in the tank shell and filled with water.
According to the invention there is also provided a liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid, the liner having an upstanding peripheral wall, a base sealed to the peripheral wall, and a series of spaced baffles extending between opposed sides of the peripheral wall lying adjacent the sides of the shell when the liner is installed in the tank shell, the sheet material forming the baffles being connected to the inside face of the peripheral wall by welding or gluing, and the baffles being of such a length that when the liner is installed in the tank shell and subject to the hydrostatic pressure of water or other liquid stored within the tank, the baffles will maintain the opposed sides of the liner in relation to adjacent sides of the tank shell whereby the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
According to the invention there is also provided a liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid, the liner providing a series of interconnected tubular cells and is such that when installed within the tank and filled with water or other liquid the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
The liner may be formed with water inlet and water outlet openings for when the liner is installed in a tank shell.
The liner may also be formed with fittings located in the openings to allow the liner to be coupled to water inlet and water outlet fittings when the liner is installed in a tank shell.
The liner may comprise clips or other members at an upper end of the liner that can hook onto a rim of a tank shell or otherwise connect the liner to the tank shell to facilitate hanging the liner in the tank shell in a desired orientation.
According to the invention there is also provided a liner as described above in a flat-packed form suitable for transport to an assembly site for a tank.
According to the invention there is also provided a tank for water or another liquid that includes a tank shell and the above-described liner installed in the tank shell, wherein the tank shell is an elongated shape with straight side walls and narrower end walls, wherein the liner has an upstanding wall which conforms approximately to the wall of the shell and a base sealed to the wall of the liner, and wherein opposite end wall sections of the wall of the liner are braced against the curved end walls of the shell and are thereby supported by the shell and whereby side wall sections of the wall of the liner can carry hydrostatic pressure loading of water or other liquid in the liner uniformly around the periphery of the cells without subjecting the side walls of the shell to substantial, if any, loading tending to cause the side walls to distort.
Preferably the liner comprises a series of separate cells having cylindrical upstanding walls that can carry hydrostatic pressure loading of water or other liquid in the liner uniformly around the periphery of the cells without subjecting the side walls of the shell to substantial, if any, loading tending to cause the side walls to distort.
Preferably the end cells of the series of cells are braced against the end walls of the shell and cause intermediate cells in the series of cells to be compressed so that the cells are elongated transversely to a longitudinal axis of the shell.
The end walls of the shell may be any suitable shape. Suitable shapes include part-cylindrical and squared.
Typically, the cells are interconnected at their upper and lower ends to permit water flow between the series of cells.
Typically, the tank shell is fabricated from corrugated steel panels.
The invention will now be further described with reference to the accompanying drawings, in which:
In principle, this provides a solution to the problems discussed at the outset as the tank shell itself does not require to be constructed with side walls which are reinforced to carry the hydrostatic pressure loading. It is noted that the arrangement can include contact between the liner 4 and side walls of the tank shell 2, provided the contact is such that a substantial part of the hydrostatic pressure loading is carried by the liner. The tank can therefore be transported in prefabricated sections assembled on site. The liner is fabricated from flexible sheet plastics material which is folded into a compact flat pack form for transportation and is then fitted into the outer shell. However, with the configuration shown in
Although it will be seen that the overall peripheral shape of the liner is broadly similar to that shown in
Instead of forming the liner from a series of separate tubular cells which are then assembled together in the manner shown in
The cells formed by the assembled panels are closed at the bottom by a base layer of sheet material welded to the panels. To provide intercommunication between the cells, the individual panels in the zone of the walls 44 common to two adjacent cells may remain unsealed to the base panel to permit passage of water, and the lower edge of the panel in this zone may be profiled to provide a large area flow port.
Instead of forming the liner with a series of individual cells, the peripheral configuration of the liner with a scalloped shape of tight radius as shown in
Although reference has been made herein to welded connections between various components forming the liner, the connections may alternatively be glued connections and to an extent this will be determined by the nature of the fabric used.
In all embodiments of the invention the walls of the liner and the baffles (if present) are fabricated from flexible sheet material of appropriate characteristics to ensure it has sufficient strength to withstand the hydrostatic pressure loading to which it will be subjected in use. The fabric must be able to support tension loads over a prolonged period of time without stretching while having resistance to abrasion and to temperature to withstand solar heating via the shell of portions of the liner above water level. Suitable materials may be composed of a scrim or woven fabric having an impervious coating on one or both sides and such materials are already commonly used for tarpaulins and tank liners of other types. In situations where the tank is to be used for storing water, the impervious coating should be a food grade quality material.
When a base is used to close the cells, as it is not subject to the same tension loading as the walls and baffles, it may not necessarily need to be fabricated from the same material as the walls of the liner. Similar considerations apply for a top closure (if present) at the upper ends of the cells. The base may alternatively be of a semi-rigid material and which may be cut to the same shape as the shell, thereby making it easy to drop the liner into the shell and self-locate, as described above in relation to the
Although the preferred embodiments have been described with reference to a liner for an elongate tank shell having rounded ends, a liner in accordance with the broad principles of the invention could also be fabricated for use with an elongate shell having squared or any other shaped ends provided that the ends are of a size and/or construction such that they will not deform outwardly when subject to hydrostatic pressure loading.
In addition, although the preferred embodiments have been described with reference to a tank shell formed from corrugate steel, the invention also extends to tank shells formed from other materials.
The embodiments have been described by way of example only and modifications are possible within the scope of the invention.
Throughout this specification and claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers.
Claims
1. A liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid, the liner providing a series of interconnected tubular cells extending from a base of the tank to a top of the tank shell, the configuration of the liner in its uninstalled state being such that when the liner is installed within the tank shell and is filled with water or other liquid, the cells at the respective ends of the liner will engage the adjacent end wall of the tank shell and will be deformed into a non-cylindrical shape, and the or each cell intermediate the end cells will be deformed into an elongate shape transversely of the side walls of the tank, the or each intermediate cell having part-cylindrical end walls which are positioned in relation to the side walls of the tank shell when in the installed state whereby the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
2. A liner according to claim 1 designed for use with a tank shell in which the end walls of the tank shell are of part-cylindrical shape.
3. A liner according to claim 1, wherein the cells are fabricated as separate cells each with an upstanding wall and a base when installed in the tank shell, each cell being interconnected to an adjacent cell to provide water or other liquid flow between the cells.
4. A liner according to claim 1, wherein the liner is constructed from panels of the sheet material welded or glued together to form the cells such that adjacent cells share a common upstanding wall provided by a single panel and a base sealed to the lower ends of the panels forming the cells when installed in the tank shell.
5. A liner according to claim 4, wherein the welds connecting the adjacent panels are between parts of the panels directed transversely to the side walls of the tank shell when the liner is installed in the tank whereby the welded or glued connections are subject principally to a shear loading when water or other liquid is in the liner.
6. A liner according to claim 5, wherein the upstanding wall and the base of each cell are separate components that are welded or glued or otherwise connected together.
7. A liner according to claim 6, wherein the shape of the base is the shape required when the cell is installed in the tank shell and filled with water.
8. A liner according to claim 1 formed with water inlet and water outlet openings for when the liner is installed in a tank shell.
9. A liner according to claim 8 formed with fittings located in the openings to allow the liner to be coupled to water inlet and water outlet fittings when the liner is installed in a tank shell.
10. A liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid, the liner having an upstanding peripheral wall, a base sealed to the peripheral wall, and a series of spaced baffles extending between opposed sides of the peripheral wall lying adjacent the sides of the shell when the liner is installed in the tank shell, the sheet material forming the baffles being connected to the inside face of the peripheral wall by welding or gluing, and the baffles being of such a length that when the liner is installed in the tank shell and subject to the hydrostatic pressure of water or other liquid stored within the tank, the baffles will maintain the opposed sides of the liner in relation to adjacent sides of the tank shell whereby the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
11. A liner according to claim 10, wherein the part of the inside face of the peripheral wall to which each baffle is connected is directed transversely to the side walls of the tank shell when the liner is installed in the tank whereby the connections are subject principally to a shear loading when water or other liquid is in the liner.
12. A liner according to claim 10, wherein the baffles are spaced longitudinally of the liner.
13. A liner according to claim 10, wherein the baffles are spaced vertically of the liner.
14. A liner according to claim 10, wherein the opposite ends of the liner when installed in the tank are engaged with the ends of the tank shell.
15. A liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid, the liner providing a series of interconnected tubular cells and is such that when installed within the tank and filled with water or other liquid the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
16. A liner according to claim 15, wherein the cells are fabricated as separate cells, each cell being interconnected to an adjacent cell to provide liquid flow between the cells.
17. A liner according to claim 15, wherein the cells are directed in the liner with the axis of each cell extending substantially vertically.
18. A liner according to claim 15, wherein the cells are directed in the liner with the axis of each cell extending substantially horizontally.
19. A liquid-tight liner for installation into a tank shell of elongate shape having opposed end walls and opposed side walls, the liner being fabricated from flexible sheet material impervious to passage of water or other liquid and the liner having a structure such that when the liner is installed within the tank shell and filled with liquid the side walls of the tank shell will not be subject to substantial, if any, water or other liquid pressure tending to distort the side walls.
20. A tank for water or another liquid that comprises a tank shell and a liner according to any one of the preceding claims installed in the tank shell, wherein the tank shell is an elongated shape with straight side walls and narrower end walls, wherein the liner has an upstanding wall which conforms approximately to the wall of the shell and a base sealed to the all of the liner, and wherein opposite end wall sections of the wall of the liner are braced against the end walls of the shell and are thereby supported by the shell and whereby side wall sections of the wall of the liner can carry hydrostatic pressure loading of water or other liquid in the liner around the periphery of the cells without subjecting the side walls of the shell to substantial, if any, loading tending to cause the side walls to distort.
21. A tank according to claim 20, wherein the liner comprises a series of separate cells having cylindrical upstanding walls that can carry hydrostatic pressure loading of water or other liquid in the liner uniformly around the periphery of the cells without subjecting the side walls of the shell to substantial, if any, loading tending to cause the side walls to distort.
22. A tank according to claim 21, wherein the end cells of the series of cells are braced against the end walls of the shell and cause intermediate cells in the series of cells to be compressed so that the cells are elongated transversely to a longitudinal axis of the shell.
Type: Application
Filed: Mar 13, 2008
Publication Date: Jul 1, 2010
Applicant: BLUESCOPE BARTLETT LINERS PTY LTD (Melbourne, Victoria)
Inventors: Maxwell Charles Bartlett (Victoria), Vivian Riddell (Victoria)
Application Number: 12/530,876