GB2408997A

GB2408997A - Collapsible water storage tank

Info

Publication number: GB2408997A
Application number: GB0426954A
Authority: GB
Inventors: James Gordon Tucker
Original assignee: CORROSION PROT SYSTEMS Ltd
Current assignee: CORROSION PROT SYSTEMS Ltd
Priority date: 2003-12-09
Filing date: 2004-12-08
Publication date: 2005-06-15
Anticipated expiration: 2024-12-08
Also published as: GB2408997B; GB0328552D0; GB0426954D0

Abstract

A tank comprises a base and a plurality of sides, each side comprising outer support panels (11) and inner panels (26, Figure 7), the tank further comprising a liner. Preferably the outer panels are in the form of two metal mesh panels secured together by coiled wire (14, Figure 2) and on each side, the inner support panels are preferably in the form of two insulating panels. The panels may be folded to fit through a gap smaller than the assembled size of the tank, such as a loft hatch. The tank may further comprise a lid (32, Figure 9a), where the base and the lid are each made from two smaller panels. A series of hoops (21 Figure 6) may be provided around the assembled tank to strengthen the structure.

Description

LIQUID STORAGE TANK

The present invention relates to a liquid storage tank.

Liquid storage tanks are large and unwieldy and are inconvenient in respect of storage before installation, or manoeuvring during installation.

A particular problem arises in replacement water tanks in the roofs of buildings. Sometimes such tanks are built into the roof of the building during construction of the building and there is no means of access which is sufficiently large to allow a replacement tank to be moved into the roof space. Typically, the loft hatch is much smaller than the tank in the roof space. When the original tank becomes corroded, problems arise and typical solutions include simply restoring the existing tank by providing, for example, a waterproof coating or lining within the tank or, where the original tank is corroded to too great an extent, a smaller tank is installed in place of the large original tank.

Particularly where a number of buildings of the same age require these tanks replaced, there is a particular problem in replacing those tanks, that is in providing tanks of similar size to the original tanks, and storing the tanks before installation and actually handling the tanks during installation.

The present invention provides an arrangement for reducing or meeting all of these problems.

The present invention provides a liquid storage tank comprising a base and a plurality of sides, each side comprising a plurality of outer support panels and plurality of inner panels and a liquid proof liner being provided within the tank formed by the inner panels. The liner may comprise a single piece flexible liner or may in some circumstances comprise tape extending between adjacent inner panels and/or a waterproof sealant.

i IRW- Specification as liled Dec 2004.doc

Thus, for example, in a preferred arrangement the outer support panels comprise metal mesh panels. The inner panels may provide heat insulation as is frequently required by law, and so the inner panels may comprise rigid panels of insulating material which may include fibre, such as glass reinforced plastic material which may include a layer of expanded polystyrene or other insulating material.

It is clearly necessary to connect the various outer support panels together and a simple means is provided to do so. It is particularly convenient where the outer support panels are of a mesh material, to join all of the outer support panels together, that is the two outer support panels for each side, and each side together, by means of a series of loops which may be separate or may be conveniently provided by a wire spiral.

In a particular convenient arrangement, where the liquid storage tank is a IS rectangular tank and all of the panels are flat, the outer support panels for each side may comprise two outer support panels and similarly the inner panels for each side may comprise two panels. Thus if the overall dimensions of the relevant side are A x B then the support panels may be A x i/: B or 'if: A x B. Thus it is possible to more readily store the panels as they are half the width they would otherwise be and also it is readily possible to pass the support panels up through a loft hatch into the roof space.

In a preferred arrangement the base of the tank may be similarly constructed, that is may comprise a plurality (e.g. 2) of outer support panels which may preferably be of mesh and a plurality (e.g. 2), of inner panels which may be of insulating material. The outer support panels of the base may be joined to the outer support panels of the sides in the same way, that is, for example, by means of a wire spiral.

Thus if the tank is cubic in shape, the side walls and base may be provided by ten identical support panels and ten identical outer inner panels, held together by a relevant number of wire spirals.

IIRW- Specification as fled Dec 2004.doc

One of the difficulties in providing a tank which is built of a plurality of panels is that the pressure of the water within the tank provides an outward hydrostatic force and this needs to be resisted. The outer support panels and inner panels may not be sufficiently strong to resist that outward force.

In order to provide further hoop strength, there may be provided an outer frame mounted intermediate of the top and bottom edges of each side surrounding the outer support panels and preferably a second frame, which surrounds the upper edges of the sides of the tank.

The liquid storage tank may be completed by means of a lid having a lip which engages around the top edge of the other support panels so as to provide further hoop strength. The lid may in turn be made of two panels which are either hingedly or rigidly connected together.

A preferred embodiment of the invention will now be described by way of example and with reference to the accompanying drawings in which: Figure I shows a perspective view of a first stage of assembly of a liquid 20storage tank in accordance with a preferred embodiment of the invention, showing the relative positions of all of the outer support panels for the sides and base of the tank, Figure 2 shows for a first embodiment of the invention, the next stage of assembly, showing pairs of outer support panels forming the sides and the base connected to one another by a wire spiral connector, Figures 2A -2C showing the 25engagement of the wire spiral with the panels, Figure 3 shows for the first embodiment of the invention, the next stage of assembly in which base panel and side panels are connected by means of a wire spiral, Figure 4 shows for the first embodiment of the invention, the next stage in which the lower halves of the side panels connected together by means of a more 30relevant wire spirals, HRW- Specifcabon as filed Dec 2004.doc Figure 5, 5A, 5B, 5C show for the first embodiment of the invention, various illustrations of the following stages in which a intermediate frame is mounted around the side panels of the tank to provide hoop strength, Figure 6 shows for the first embodiment of the invention, the next stage in which wire spirals connect the upper halves of the side panels, Figure 7 shows for the first embodiment of the invention, the next stage in which inner panels are inserted into the outer support panels of Figure 6, Figure 7A, 7B show details of the inner panels of Figure 7, Figure 8, 8A, 8B show details of an upper intermediate frame located around the upper edge of the sides of the tank to provide further hoop strength, Figure 9, 9A, 9B, 9C show details of a lid for mounting and engaging the upper edge of the tank, Figure 10 shows for the first embodiment of the invention, a perspective view of the completed tank' Figure 11 shows a second embodiment of the invention in which two intermediate frames is mounted around the side panels of the tank to provide hoop strength, Figures 12 to 15 show the steps of assembling the second embodiment of the invention, Figures 16, 16A and 16B show details of the intermediate frames of the second embodiment of the invention, Figures 17, 1 7A, 1 7B and 1 7C show details of the second embodiment of the invention, and Figure 18 shows for the second embodiment of the invention, a perspective view of the completed tank Often water storage tanks (typically rectangular of overall dimensions lm, x lm x lm) are originally sited in buildings where replacement is impossible due to the size of the access. In most cases the "loft" or access hatch is 0.5m x 0.5m.

HRW- Specification as filed Dec 2004.doc

Commonly these tanks are designed to house "service" water (toilets, wash basins, showers etc. etc.) and in this instance the tank has to have a number of inherent features to comply with current water by-laws.

Although sectional tanks generally can be assembled within a confined space, they do not have a continuous internal water-tight seal (lining) and are prone to leakage. Installation of these tanks also requires skilled personnel. They also require tank supports and internal stiffening.

We will describe a "flat pack" tank with dimensions not exceeding a standard loft hatch, although this dimension is not necessarily limiting. The pack is light weight with simple instructions to enable easy assembling of the tank within.

The tank comprises of an outer frame in the form of joined outer support IS panels. This frame supports and provides dimensional stability for inner insulated sectional glass reinforced plastic (composite) panels. These panels provide the inner structure of the tank.

These composite panels are joined together by interconnecting locating pins which assist in dimensional stability and hoop stress resistance.

Both the outer panels (which are preferably made of a mesh of metal such as galvanised steel) joined together and the rigid inner panels joined together provide some hoop resistance but we also provide a frame which provides further strength.

At the top of the tank there is a composite lid which can engage the upper edges of the tank and provide further hoop strength.

The tank is designed to be modularized and as such similar tanks may be interconnected to provide additional storage capacity.

HRW- Specification as filed Dec 2004.doc s

We now refer in detail to Figures l - 10. Figures I - 9 in particular show the construction of a liquid storage tank l O of cubic shape having dimensions A x A x A. An outer framework is assembled from ten identical outer support panels 11, each outer support panel 11 comprising an outer steel rod 12 forming a rectangular frame to which is welded steel mesh 13 (see Figure 2A). For ease of illustration, only some of the panels 11 have the mesh 13 drawn in. The material of the mesh and the frame will be chosen so as to provide a suitable strength for the application. Thus in a typical arrangement in which the tank 10 is of dimension Im x lm x lm, the rod of the frame in 12 may comprise a steel wire of 2 to 4mm, preferably 3mm diameter, and the mesh may be a steel wire of and the spacing between adjacent strands of the wire mesh is 50mm to 1 OOmm, preferably 75mm. The steel of the mesh panels 11 may be galvanised or otherwise protected.

Each outer support panel 1 1 is of overall dimension A x i/z A. (Throughout we will refer to all of the panels as being of dimension of A or i/z A, but clearly the inner panels will need to be slightly smaller than the outer panels so as to be fitted inside).

It will be noted that all of the outer support panels 11 are identical in size and shape.

To assemble the two outer support panels 1 1a and 1 lb to form the base of the tank are positioned side by side in the position shown in Figure 1. They should be joined together as follows. Two long edges 12a, 12b (i.e. of length A) of the two panels 1 la and I lb are situated to abut one another. Aa wire spiral 14a (see Figure 2, 2A, 2B, 2C) of galvanised steel wire is rotated and engages with the two rods forming the long edges 12a, 12b of the two panels 1 la, 1 lb starting at one end of the two edges. As the wire spiral rotates, the free end passes around the rods forming the edges 12a 12b of the two panels 1 la and 1 lb and the mesh of the two panels 11a, 1 lb. This rotation drives the wire spiral to engage with the mesh and hence to move from the initial position of Figures 2A and 2B along into further engagement with the

I IRW- Specification as fiend Dec 2004.doc

relevant edges 1 2a, 1 2b of the panels I I a and 1 lb (see Figure 2C) until the free end of the spiral has moved along the long edges 12a, 12b to the opposite end. The wire spiral 14 should be a little less than A in length. Typical dimensions of the spiral are 2-4mm wire diameter, preferably 3mm diameter, and spiral diameter 25-35mm, S preferably 30mm.

In alternative arrangements, the two edges 12a, 12b of the two outer support panels 1 la, 1 lb may be simply mounted together by means of any suitable clips or rings, for example plastic ties, but the use of a wire spiral means that the edges of the two panels I la and 1 lb are engaged with one another along their length instead of only at selected points along their length.

The diameter of the wire spiral is chosen so as to enable it to freely engage with the edges of the two outer support panels 1 1 a, 1 1 b but at the same time to urge them into close engagement. In a preferred arrangement the wire spiral may be arranged so as to be of different diameter along its length, the free end which first engages with the mesh of the two outer support panels 1 la, l lb may be of greater diameter so as to readily engage with the panels l la, 1 lb but away from the free end of the spiral, the diameter may reduce so as to urge the two mesh panels l la, 1 lb closely into engagement with one another.

The wire spiral may be rotated by hand or by a power tool such as an electric drill with a suitable connector.

Each side 15 -18 of the storage tank 10 may be similarly constructed from two outer support panels 11 in the same way as the base, the arrangement being that the wire spirals which joins each of the two mesh panels 11 forming each outer side panel will extend horizontally. (See Figure 2) Having assembled the base 15 and the four sides 16 - 19, the four sides are then engaged with the base 15. Thus a wire spiral 14 of length (a little less than) A,

I IRW- Specification as filed Dec 2004.doc

typically 990mm, is used to join the lower edge of the lowermost outer support panel forming each side 16 - l 9 to the relevant edge of the base 15 (See Figure 3.) Then the vertical edges of each adjacent lowermost outer support panel forming each side 16 - l9 are joined initially by wire spirals of length 'it: A typically 450mm. (See Figure 4).

The next stage is to assemble an outer frame 21 (or hoop) around the sides of the tank lO to provide hoop strength and help resist the hydrostatic pressure of the liquid within the tank.

The outer frame 21 comprises four frame members 22 - 25 which may be in the form of metal rods, for example, steel rods of, for example, a rectangular closed box section, or an "L" section of length approximately A with means to connect them together at their ends. In a preferred embodiment, however, the frame members are of composite fibre reinforced plastic material. In Figure 5B it will be seen that the section of the frame members 22 - 25 a "U" section of typical dimensions 46mm x 36mm x 3mm thickness. The four frame members 22 - 25 (two of length 1060mm and two of length 1070mm) are bolted together at their ends and are disposed immediately above the wire spirals 14 which engage the upper most and lower most outer support panels 11. The arrangement of the outer frame 21 is clear from Figure 5.

As is clear from Figure 6, the next step is to connect the vertical edges of the upper most outer support panels 11 by means of wire spirals. This completes the assembly of the mesh panels 11 to provide an outer framework.

There are provided 10 inner insulating panels 26. The inner insulating panels are divided into pairs and the pairs of insulating panels 26 are connected along their long edges. The dimensions of each inner insulating panel is approximately A x I/ A

I IRW- Specification as filed Dec 2004.doc

(or at least a little less so as to allow them to be readily inserted within the outer frame).

The inner insulating panels are preferably formed of fibre reinforced plastic material, or may be formed of an insulating material such as an expanded plastic material such as expanded polystyrene surrounded by a water proof skin in the form of a plastic skin such as ABS. The panels are typically 25-35mm thick, preferably 28mrn thick, and of 500mm x lOOOmm overall dimensions. They include integral joining pegs or dowels or pins. The frame members 29 - 32 of the upper frame 28 are connected at their ends to each other either by means of a releasable connection such as a bolt or the upper frame 28 may be a single piece moulding or may be attached to one another by adhesive.

Each pair of inner insulating panels 26 are engaged with one another along their long edges by means of some kind of connector which may be, at its simplest, fabric reinforced adhesive tape or be in the form of pins 27 as illustrated in Figure 7B or both. In this way each pair of inner insulating panels may then be inserted in to the outer frame already provided, the first pair being laid down on to the mesh panels 11 forming the base of the tank 10, and each successive pair then being engaged with the sides provided by each pair of mesh panels 11. The long edges of each pair of insulating panels 26 is arranged vertically, that is in the opposite direction to the joint between each adjacent pair of outer support panels 11.

The pins 27 have a further purpose. As well as joining part of panels together they also help resist the hydrostatic pressure in the tank.

To further assist in resisting hydro-static pressure, there is provided around the upper most edges of each side of the tank 10 an upper frame 28 formed of four "U" section frame members 29 - 32 which, as is clear from Figure 8a, has dimensions so as to engage over the upper most edge of the relevant outer support panel and inner insulating panel 26. The frame members 29 - 32 may be of galvanised steel but in a

I{RW- Specification as filed Dec 2004.doc

preferred arrangement they are formed of fibre reinforced plastic material of cross- section dimensions 46mm x 36mm x 3mm thick. Two will be 1030mm length and two 990mm.

To provide full waterproofness for the tank, there is mounted within the tank a prefabricated inner liner 41 which may be of welded plastic material such as a welded flexible polymeric material such as polyurethane, which is long, lasting and will not leak, of a thickness, typically 2-4mm, preferably 3mm. The form of the liner 41 when expanded, will be an open-topped box of dimensions approximately A x A x A (typically 940mm x 940mm around the open top and of 1050mm length to allow sufficient material to be laid over the upper edges of the tank. The material around the open top is laid over the upper edges of the inner insulating panels 26 and outer support panels 11 and below the upper frame member 28 whereby the upper frame member and the relevant panels may trap the liner as is clear from Figure 8B.) The open upper surface of the tank 10 may be closed by means of a lid 32 which may be in the form of two parts joined to one another, each part being of approximate dimensions A x i/: A (515mm x 1020mm). The lid is illustrated in Figure 9. As is clear, the two parts 33, 34 of the lid 32 may have along a longer edge an upright lip 36, 37, the two lips being engaged with a flexible seal therebetween by, for example, bolts or other releasable coupling or by a permanent coupling such as adhesive.

One of the lid parts 33 includes an access hatch 38 and the other 34 includes a vent 39. The lid 32 includes around its outer edge a downwardly extending lip 40 which engages around the outside edge of the upper frame 28 thereby increasing its resistance to hoop stress.

As is clear from Figure 9A, apart from the area where the lid 32 engages with the upper frame 28, the lid includes an insulating layer which may be provided between an upper and lower skin. The insulating layer may be of any known

I IRW- Specification as filed Dec 2()04.doc

insulating material such as expanded plastic, such as expanded polystyrene or expanded polyurethane, and the skin may be provided by a glass reinforced plastic material.

It will be understood that as all of the inner and outer panels of each side and the base have two opposite short edges (I/2A) and two opposite longer edges (A) all of the components for the tank 10 including the panels may easily be passed through a restricted opening such as an access hatch which is only slightly larger in maximum dimension of i/z A. The tank is readily assembled in situ. Pipes for providing water access to the inside of the tank have to be provided through one or more of the sidewalls of the tank and the mesh may include cutaway portions in standard positions to allow the ready cutting through the relevant inner insulating panel to provide access for pipes.

A second embodiment of the invention is now described. In some circumstances, the single intermediate frame around the side panels of the tanks is insufficient and the second embodiment provides two such intermediate frames, an upper intermediate frame 211 being mounted around the middle of the upper set of side panels, and a lower intermediate frame 212 being mounted around the middle of the lower set of side panels.

The assembly has to be revised to take this into account. In Figure 12 it illustrates how the vertical edges of the outer support panels forming each side 16-19 are joined. There is provided a quarter length wire spiral 213-216 for each vertical edge starting at the bottom.

The lower intermediate frame 212 is then mounted around the lower set of side panels above the wire spirals 213-216 (see Figure 13). Figure 14 shows wire spirals, 217-220 engaged from the top edge of the side panels down to engage with the lower intermediate frame 212.

IlRW- Specification as liled Dee 2004.doc

The upper intermediate frame 211 is then engaged as shown in Figure 15.

Upper short wire spirals 221-224 are then engaged with the edge of the side panels and extend from the uppermost edge of the tank to the upper support ring 21 1.

Figures 167 1 6A, 1 6B show the construction of the lower and upper intermediate frames 210-21 1 and Figures 17, 17A, 17B, 17C show how the wire spirals are provided in the spaces between insulating panels 26. Figure 1 7C is a plan view of a corner showing how the spiral is mounted within a space between the ends of the inner insulating panels 26.

The invention is not restricted to the details of the foregoing examples.

For example, a range of materials may be used depending upon the circumstance which the tank is to be used.

Although we have described the tank with regard to a facility which it may be passed through a confined access hatch, because of its construction it is readily provided in the form of a "flat pack" and so the construction is particularly useful where a tank is to be provided for example, for temporary or permanent storage of water elsewhere other than in the roof space. For example, in a farm or perhaps in an emergency situation where water is to be provided at a particular point, the tank may be delivered and assembled quickly without skilled labour or complex tools and will then provide a strong permanent or temporary tank. Furthermore because of the use of mesh and relatively lightweight insulating panels rather than solid steel panels, the weight of individual packs within the flat pack may be kept to a minimum for easy transport and storage.

HRW- Specificabon as filed Dec 2004.doc

Claims

1. A liquid storage tank comprising a base and a plurality of sides, each side comprising a plurality of outer support panels and plurality of inner panels and a liquid proof liner within the tank formed by the inner panels.

2. A tank as claimed in claim I in which the liner comprises a single piece flexible liner 3. A tank as claimed in claim I in which the outer support panels comprise metal mesh panels.

4. A tank as claimed in claim I in which the inner panels comprise rigid panels of insulating material 5. A tank as claimed in claim I in which the inner panels are of glass reinforced plastic material 6. A tank as claimed in claim I in which the inner panels include a layer of expanded polystyrene or other insulating material.

7. A tank as claimed in claim 1 in which the outer support panels are of a mesh material, 8. A tank as claimed in claim 7 in which the outer support panels are joined together by means of a series of loops 9. A tank as claimed in claim 8 in which the loops are provided by wire spirals.

10. A tank as claimed in claim 1 in which where the liquid storage tank is a rectangular tank and all of the panels are flat, the outer support panels for each side

I IRW- Specification as filed Dec 2004.doc

comprises two outer support panels and the inner panels for each side comprise two panels, each panel having two opposite short edges and two opposite longer edges whereby to allow the panels to pass through a restricted opening.

1 1. A tank as claimed in claim 10 in which the base of the tank is constructed of two outer support panels and two inner panels, each panel having two opposite short edges and two opposite longer edges whereby to allow the panels to pass through a restricted opening.

12. A tank as claimed in claim 11 in which the outer support panels of the base are joined to the outer support panels of the by means of a wire spiral.

13. A tank as claimed in claim 1 in which to provide hoop strength, there is provided at least one outer frame mounted intermediate of the top and bottom edges of each side surrounding the outer support panels 14. A tank as claimed in claim 13 in which there is provided a frame, which surrounds the upper edges of the sides of the tank.

15. A tank as claimed in claim 1 in which the liquid storage tank includes a lid having a lip which engages around the top edge of the other support panels so as to provide further hoop strength.

16. A tank as claimed in claim I in which the lid comprises two panels which are either hingedly or rigidly connected together, each panel having two opposite short edges and two opposite longer edges whereby to allow the panels to pass through a restricted opening 17. A liquid storage tank comprising a plurality of rectangular sides and a rectangular base formed of panels, and a liquid proof liner within the tank formed by the panels, wherein all of the panels are flat, the panels for each side each comprises

HRW- Specification as filed Dec 2004.doc 1)

two panels, each panel having two opposite short edges and two opposite longer edges whereby to allow the panels to pass through a restricted opening of smaller dimensions than the tank 18. A tank as claimed in claim 17 in which each side and the base of the tank is constructed of two outer support panels and two inner panels, each panel having two opposite short edges and two opposite longer edges whereby to allow the support panels to pass through a restricted opening 19. A tank as claimed in claim 18 in which the outer support panels are of a mesh material, A tank as claimed in claim 19 in which the outer support panels of the sides and the base are joined to each other by means of a wire spiral.

21. A tank as claimed in claim 17 in which to provide hoop strength, there is provided at least one outer frame mounted intermediate of the top and bottom edges of each side surrounding the outer support panels 22. A tank as claimed in claim 21 in which there is provided a frame, which surrounds the upper edges of the sides of the tank.

23. A tank as claimed in claim 17 in which the liquid storage tank includes a lid having a lip which engages around the top edge of the other support panels so as to provide further hoop strength.

24. A tank as claimed in claim 23 in which the lid comprises two panels which are either hingedly or rigidly connected together, each panel having two opposite short edges and two opposite longer edges whereby to allow the support panels to pass through a restricted opening.

HRW- Specification as filed Dec 2004.doc