GB1596293A

GB1596293A - Storage tanks and constructional units therefor

Info

Publication number: GB1596293A
Application number: GB780877A
Authority: GB
Original assignee: PRECOLOR SALES Ltd
Current assignee: PRECOLOR SALES Ltd
Priority date: 1978-02-23
Filing date: 1978-02-23
Publication date: 1981-08-26

Description

(54) IMPROVEMENTS IN OR RELATING TO STORAGE TANKS AND CONSTRUCTIONAL UNITS THEREFOR (71) We, PRECOLOR SALES LIMITED a British Company, of Unit A4, Rosehill Industrial Estate, Rosehill, Market Drayton. Shropshire, new address Newport Road. Market Drayton, Shropshire, do hereby declare the invention, for which we prav that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to constructional units for use in the construction of storage or other tanks, to tanks comprising such units and to methods of producing the constructional units and tanks.

Storage tanks, for example for water or other liquids, are known which comprise a number of constructional units connected together in liquid-tight arrangement. The use of a number of units which can be transported as such and assembled on the site where the tank is required greatly facilitates the construction of the tanks, especially where the latter are of large capacity.

However, where the known tanks are ones having tall walls (for example six feet or more) the lower portions of the walls are subjected to large pressures when the tank is full, and they require separate internal or external reinforcement. This reinforcement which can be provided, for example, by internal cross-braces or "external corsetry", results in expense of money and time in assembly over that which would otherwise be required. This problem is becoming increasingly important now that very large tanks are required for the storage of water in desert countries. There is therefore a demand for storage tanks which can be constructed from constructional units without the need for a separate reinforcing structure for the lower portion of their walls.

In a first aspect the invention provides a storage tank whose walls comprise a single row of upstanding constructional units each of said units comprising a panel of square or other rectangular shape having flanges extending outwardly with respect to the tank from at least two opposed respective edge regions thereof and said panel having one or more reinforcing members extending across it, said flanges providing means by which adjacent units are connected together, and the units being arranged relative to one another so that said two flanges of each unit are vertically aligned with respect to the tank.

In a second aspect the invention provides a constructional unit for assembly with like units to form the walls of a storage tank according to the first aspect of the invention, the constructional unit comprising a glass fibre-reinforced plastics material panel of square or other rectangular shape having flanges extending from two edge regions thereof, said flanges providing means by which the constructional unit can be connected to like units to form the walls of the storage tank, the panel having two reinforcing members extending from an edge region thereof to an opposite edge region thereof.

Constructional units of the present invention can readily be assembled with like or other constructional units to provide storage tanks without the need for separate reinforcing structure for the lower wall portions, either inside or outside the tank.

The invention is concerned particularly with the use of panels of an overall planar profile, which together with their flanges are of moulded plastics material, for example, glass-reinforced plastics material (referred to hereinafter simply as "glass-reinforced plastic"). It is with reference to such panels that the following description particaularly relates.

The panel of the constructional unit can have a flange extending from one or more further edge regions, and it conveniently has flanges extending from all of its edge regions.

The panel has one or more reinforcement members, for example elongated members arranged substantially parallel to the panel.

The reinforcement members can be, for example, metal bars especially ones having an angular cross-section. Lengths of angle iron have been found to be particularly suitable. Where the panel is of rectangular shape, two angle irons are conveniently used. spaced apart on the panel so that one web of each, i.e. one side of the angle, is attached to the panel and the other web extends outwardly at a right-angle from the panel. The angle irons in the unit are preferably parallel to each other. They are preferably so arranged with respect to the panel that in the assembled tank they extend substantially vertically.

The panel preferably has additional reinforcement by providing it with convex or other dished portion. This conveniently protrudes from a generally planar profile of the panel in the direction in which the flanges extend. Where the panel has two or more elongated reinforcement members, the dished portion conveniently lies in the area bounded, at least on two sides thereof, by said members. The dished portion, where it of an elongated shape. is preferably orientated so that in the assembled tank it extends in a substantially vertical direction.

Adjacent units of the invention are conveniently connected together by means of nuts and bolts or other connecting members.

Where nuts and bolts are used the units have suitable apertures formed therein to accommodate the bolts. The location of these apertures depends on the position in the assembled tank the unit will take. For example. units intended for the walls will normally have apertures in the side flanges which will be adjacent side flanges of other wall units. Connection of wall units with base units will normally require apertures in the end portions of the panels of the wall units for connection to apertures in the flanges of the base units.

Storage tanks of the invention can consist of units of the invention, or only a part can be of such units. For example, the base can be of separate construction.

Where thc units are intended for storage tanks of considerable depth, for example six feet or more, the thickness of the panels intended for the walls can be such that it increases from top to bottom. For example, where the panels are of glass-reinforced plastics, the amounts of glass fibre used can increase progressively from a weight in the range 4 to 10 oz./sq.foot at the top of the panel to a weight in the range 10 to 16 oz./sq. foot at the bottom.

Where the units of the invention are of plastics material, they can conveniently be made by a moulding process in which the panel and its flanges are moulded as an mtegral member. Moreover, a moulding process provides a means of attaching the reinforcing members by bonding to the panel and/or to the flanges. For example, where angle irons are used as reinforcement. they can be embedded in the plastics material by forming the latter in a mould containing the angle irons so that a part of the angle irons, for example one of the angle portions, is covered by the plastics material when it has set. A moulding process also provides a very convenient way of obtaining a dished portion in the panel.

There is now described, by way of example, with reference to the accompanying drawings a constructional unit which is one embodiment of the first aspect of the invention, and a water storage tank which is one embodiment of the second aspect of the invention.

In the drawings: Figure 1 is a perspective view of the constructional unit; Figure 2 is a cross-section of the constructional unit along the line .I-II of Figure l; Figure 3 is a perspective view of the water storage tank; and Figure 4 is cross-section on an enlarged scale showing the connection through adjacent flanges of two of the constructional units forming part of one of the side walls of the water storage tank.

Referring first to Figures 1 and 2, the constructional unit is of a generally tray-shaped configuration, and comprises a rectangular panel 11 having extending from the respective edges side flanges 12, 13 and end flanges 14, 15, the panel and flanges being an integral rigid plastics moulding, for example of glass-reinforced plastic. The flanges extend at right angles from the panel. and the flanges extending from opposite edges are parallel to each other. Suitable dimensions for the panel are, for example, a length twice as great as the width, for instance a length of eight feet and a width of four feet. The flanges, which are normally all of the same width, are conveniently four inches wide where the panel has the dimensions referred to above.

On the side of the panel from which the flanges extend there are fixed two reinforcement members 16, 17 parallel to each other and to the flanges 12, 13 and spaced apart so that each of them lies approximately midway between the midlongitudinal axis of the panel and one of the flanges 12, 13. These reinforcement members are of angle iron and they extend from flange 14 to flange 15. The angle irons are firmly attached, for example by bonding, so that one of the webs of the angle is held against the face of the panel and the other extends at a right angle from that face. The width of the two webs of the angle iron can be the same or different. In the embodiment shown in the drawings the width of the web contacting the face of the panel is three inches and the width of the other web is four inches or more.

In the rectangular portion of the panel defined by the angle irons and the flanges 14, 15 there is a shallow dished area 18 protruding from the plane containing the remainder of the panel and in the Same general direction as the flanges. This dished portion serves to enhance the strength of the uilit.

Where the unit is designed to be attached by means of bolts or like connecting members to adjacent units to form a tank, the flanges of the unit can have formed therein a number of apertures 19 to receive said connecting means. For example, the apertures can conveniently be in a row along the length of each of the flanges carried by the longer side edges of the panel, the rows running parallel to the planar portion of the panel.

As indicated above, the panels and flanges of the units of the invention are conveniently made of glass-reinforced plastic material. There is now described a method by which such constructional units, for example that described immediately above as an embodiment of the invention, can be made.

A female steel mould whose internal profile corresponds to the external profile required of the unit is polished, treated with a mould release agent, and then coated with a thin layer of a gel composition which is allowed to set hard. This gel composition for example that sold under the Trade Mark Uragel 34/308A, conveniently contains any colouring matter required in the unit. When the gel coat layer has set hard, there is laid down on it, in one or more stages, a laminate of fibre glass and a polyester resin, for example the isophthalic resin sold by Synthetic Resins Limited under the Trade Mark Resin 1368A, and the laminate is allowed to set hard. The two angle irons or other reinforcement members are located in the mould in positions corresponding to the positions they are intended to have in the unit.

A further amount of glass fibre and polyester resin is laid down on top of the hardened first laminate so that the new layer covers the web of the angle iron in contact with the first layer of laminate. The second layer is then allowed to set hard thereby bonding the angle iron in the laminate, and then the moulded product can be lifted from the mould. If holes or other apertures are required in the unit they can now be formed, for example, by drilling.

A water storage tank which is one embodiment of the second aspect of the invention can be assembled using the unit described above, and similar units as follows, though it will be appreciated that tanks of other dimensions could be made by using a different number of units.

Referring now to Figure 3, the tank is assembled from ten units 30 which constitute the two longer (side) walls and four units 31 which constitute the end walls these units being constructional units according to the invention. The bottom of the tank is provided by the flat concrete base 32. It will be appreciated that units 31 differ slightly from units 30 with regard to their apertures for receiving the connecting members, and this difference is referred to in greater detail below.

Five of the units described above with reference to Figures 1 and 2 are connected together by means of nut and bolt assemblies 33, each assembly engaging corresponding apertures 19 in the adjacent flanges.

With reference to Figure 4, in connecting adjacent units the preferred procedure is to apply a mastic or other sealing composition to the adjacent flanges around the corresponding apertures which are to accommodate the bolts, so that when the nut and bolt assemblies are tightened the mastic forms a water-impermeable layer between the flanges. A bolt 35 carrying a washer 36 of diameter greater than that of the apertures is passed through the corresponding apertures, and another washer 37 is passed over the end of the bolt protruding from the flanges and a nut 38 threaded onto the bolts, and tightened thereon so as to draw the adjacent flanges tightly together. Preferably, further quantities of sealing composition are applied between the washers and the flanges to promote a good seal. The procedure is followed for the other bolts and their nuts.

In the embodiment shown in Figure 3 the constructional units constituting the end walls of the tank differ from the units constituting the side walls as follows. Whereas each of the units 30 of the side walls has a row of apertures in each of its side flanges, as shown in Figure 3, the end wall units do not. They each have a row of apertures in one side edge flange, whereby the two end wall units can be connected together in similar fashion as are adjacent side wall units, but each end wall unit is connected to the adjacent side wall unit by means of nut and bolt assemblies passing respectively through the apertures in the adjacent side flange of the side unit and through a row of apertures 39 in the edge region of the panel of the respective end wall unit.

The lower end flanges 15, 15a of the respective side wall units and end wall units are sealed where they contact the concrete base 32 by means of a mastic or other sealing composition.

The upper end flanges 14, 14a of the side wall and end wall units together for a support for a cover 40 for the tank.

The bottom for the tank can comprise a plurality of constructional units of the invention illustrated in Figures 1 and 2 of the drawings. In that case the units comprising the bottom (bottom units) can be laid on the ground side by side so that together they form a rectangle of the required shape, and adjacent units are firmly connected to one another, for example, by means of nut and bolt assemblies. The units are preferably laid so that their flanges are directed upwardly. Where units of this invention having upwardly directed flanges are used, they are conveniently connected by means of nut and bolt assemblies passing through apertures in their side flanges (or end flanges as the case may be) and through apertures (not shown) in the bottom edge regions of the panels of the side wall and end wall units.

The nut and bolt assemblies are conveniently augmented by the use of mastic or other sealing compositions in the manner described above with reference to the connection together of adjacent side wall units.

Where the tank is one having tall side walls, it will normally require some supplementary support to prevent the top edges of the walls from being distorted by the pressure exerted by the contents of the tank.

Such support can be, for example, one or more cross braces extending across the tank, or angle irons extending across the tank, or angle irons extending along the top edges of the walls and connected together at the corners of the tank. However, such supplementary support is not to be confused with the internal or external reinforcement required for the lower portions of the tanks of the prior art. The former can be so positioned that it is out of contact with the contents of the tank, even when the latter is full. Normally it is above the level of the contents.

This is important in obviating corrosion of the supplementary support which would otherwise occur if the supports were immersed in contents having a corrosive effect on it, for example galvanised steel stays in contact with water.

The supplementary support can take the form of a cover for the tank provided that it is so positioned with respect to the walls of the tank that it provides the necessary support. The cover, for example, can be constructed from units of this invention or it can be of conventional construction.

The panels can be in the shape of triangles or other polygons. Depending on the shape, it may be necessary to use 'filler' units to provide a straight edge where side and end walls are connected together.

WHAT WE CLAIM IS: 1. A storage tank whose walls comprise a single row of upstanding constructional units each of said units comprising a panel of fibrous reinforced hardenable material having flanges extending outwardly with respect to the tank from at least two opposed respective edge regions thereof, said flanges providing means by which adjacent units are connected together, and the units being arranged relative to one another so that said two flanges of each unit are vertically aligned with respect to the tank.

2. A storage tank according to Claim 1, in which each of said panels has a further flange extending outwardly from its bottom edge region.

3. A storage tank according to Claim 1 or 2. in which the panels are formed integrally with their associated flanges.

4. A storage tank according to Claim 3, in which the panels and their associated flanges are of glass-fibre reinforced plastics material.

5. A storage tank according to any of the preceding claims, in which the panels have integral reinforcing members parallel to each other and extending from an edge region to an opposite edge region of the panel.

6. A storage tank according to Claim 5.

in which the reinforcing members are parallel to the vertical flanges of the respective panels.

7. A storage tank according to Claim 5 or 6, in which the reinforcing members are elongated members of L cross-section.

9. A storage tank according to Claim 4 and Claim 7, in which the respective reinforcing members have been moulded into the glass-fibre reinforced plastics material.

9. A storage tank according to any of the preceding Claims, in which the panels are formed with convex or other dished regions therein, which stiffen the respective constructional units.

10. A storage tank according to Claim 5 and Claim 9, in which said convex regions lie between said two reinforcing members of the respective panels.

11. A storage tank according to any of the preceding Claims, which has a bottom constituted by a plurality of constructional units each comprising a panel having flanges extending from at least two respective edge regions thereof, said flanges providing the means by which adjacent units of the bottom are connected together.

12. A storage tank according to Claim 1, which has two side walls parallel to each other and two end walls parallel to each other, said side walls each comprising a plurality of upstanding constructional units each unit comprising a panel of elongated rectangular shape having flanges extending outwardly with respect to the tank from each edge thereof, the two flanges extending from the elongated side edges each having turned therein and extending longitudinally thereof a row of apertures by means of which the unit is connected to corresponding apertures in adjacent constructional units; and said end walls each comprising a plurality of upstanding constructional units each unit comprising a panel of elongated rectangular shape having flanges extending

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. form a rectangle of the required shape, and adjacent units are firmly connected to one another, for example, by means of nut and bolt assemblies. The units are preferably laid so that their flanges are directed upwardly. Where units of this invention having upwardly directed flanges are used, they are conveniently connected by means of nut and bolt assemblies passing through apertures in their side flanges (or end flanges as the case may be) and through apertures (not shown) in the bottom edge regions of the panels of the side wall and end wall units. The nut and bolt assemblies are conveniently augmented by the use of mastic or other sealing compositions in the manner described above with reference to the connection together of adjacent side wall units. Where the tank is one having tall side walls, it will normally require some supplementary support to prevent the top edges of the walls from being distorted by the pressure exerted by the contents of the tank. Such support can be, for example, one or more cross braces extending across the tank, or angle irons extending across the tank, or angle irons extending along the top edges of the walls and connected together at the corners of the tank. However, such supplementary support is not to be confused with the internal or external reinforcement required for the lower portions of the tanks of the prior art. The former can be so positioned that it is out of contact with the contents of the tank, even when the latter is full. Normally it is above the level of the contents. This is important in obviating corrosion of the supplementary support which would otherwise occur if the supports were immersed in contents having a corrosive effect on it, for example galvanised steel stays in contact with water. The supplementary support can take the form of a cover for the tank provided that it is so positioned with respect to the walls of the tank that it provides the necessary support. The cover, for example, can be constructed from units of this invention or it can be of conventional construction. The panels can be in the shape of triangles or other polygons. Depending on the shape, it may be necessary to use 'filler' units to provide a straight edge where side and end walls are connected together. WHAT WE CLAIM IS:

1. A storage tank whose walls comprise a single row of upstanding constructional units each of said units comprising a panel of fibrous reinforced hardenable material having flanges extending outwardly with respect to the tank from at least two opposed respective edge regions thereof, said flanges providing means by which adjacent units are connected together, and the units being arranged relative to one another so that said two flanges of each unit are vertically aligned with respect to the tank.

6. A storage tank according to Claim 5.

outwardly with respect to the tank from each edge thereof, the side edge egions of the panels of the two units at the end of each of said end walls each having formed therein a row of apertures parallel to the adjacent panel side edge by means of which said units are connected to the adjacent flanges of the units constituting the ends of the side walls.

13. A storage tank according to Claim 1. substantially as described herein with reference to the accompanying drawings.

14. A storage tank substantially as described herein and substantially as shown in Figure 3 of the accompanying drawings.

15. A constructional unit substantially as described herein and substantiailly as shown in Figure 1 and 2 of the accompanying drawings.