TANK AND SILO SYSTEM

Abstract

A tank or silo storage system comprising a plurality of curved tessellating panels, the tessellating panels being arranged in use to form a plurality of cylindrical rings, the plurality of cylindrical rings being arranged in use to be adjacent to one another to form an elongate cylindrical tank or silo body, the panels are provided with protuberances and continuity couplings for the protuberances or the tank or silo is provided with a radially alternating stiffening arrangement.

Description

TECHNICAL FIELD

The present invention is concerned with the storage of liquids and materials in tanks and silos. An invention described herein is particularly, but not exclusively, applicable to large modular bolted coated and stainless-steel industrial tanks and silos of the type used in municipal, industrial, agricultural, mining, renewable energy, biofuels and other diversified markets sectors including but not limited in aquaculture, stormwater/firewater and desalination applications.

Conventional tanks generally comprise a series of panels bolted together in combination with some form of sealant to contain the contents of the tank.

For large tanks in certain environmental locations it can in many instances be challenging to design, manufacture and construct a large tank that can be built efficiently and still withstand the environmental conditions. This is particularly the case when tanks are partially full for wind effects where wind pressure can be significant and necessitate thicker gauge steel panels, particularly in the upper portion of the shell.

The inventors have devised a tank and silo arrangement with sub-components that allow tanks to be engineered and efficiently constructed that are capable of withstanding appropriate and in some cases extreme environmental conditions.

The system the inventors have developed allows for modular bolted coated tanks and silos to be designed and built according to a specific loading that is expected. Especially for larger tanks the difference in internal pressure on the tank between being filled and unfilled can be substantial. Specific engineered components allow, in part, these opposing operating conditions to be resolved.

An apparatus and method described herein provides a highly versatile arrangement.

SUMMARY OF THE INVENTION

Aspects of the invention are set out in the accompanying claims.

Viewed from a first aspect of the disclosure there is provided a tank storage system comprising a plurality of curved tessellating panels, the tessellating panels being arranged in use to form a plurality of cylindrical rings, the plurality of cylindrical rings being arranged in use to be adjacent to one another to form an elongate cylindrical tank body, wherein some or all of the plurality of curved tessellating panels comprise one or more protuberance(s) extending circumferentially along and radially from the outer surface of the panel(s), the system further comprising protuberance bridging links, each bridging link aligning at a first end with a contour of a protuberance on a first panel and at a second end with a contour of a protuberance of an adjacent panel.

Thus, according to such an arrangement a highly rigid structure can be formed wherein the rigidity and hoop strength of the tank storage system can be both optimised and maintained around and throughout the height of the structure. It can also be conveniently transported and constructed. Still further it can be adapted to a range of structural, strength and size requirements.

The protuberances may be in the form of elongate generally convex ribs extending along and around each panel and further comprising a smooth intersecting perimeter intersecting with the surface of the panel surrounding the protuberance. As such the second moment of area of a panel can be modified and the structural rigidity provided.

Such a protuberance may be conveniently manufactured or formed into a panel.

An edge region of each panel, which in use is aligned with an adjacent panel, may be substantially smooth. This conveniently allows adjacent panels to be both brought into close alignment and abutment but also for sealants to be used between panels to prevent liquid ingress or egress from the storage system.

A panel described herein may conveniently comprise either (A) a single protuberance(s) extending circumferentially along and radially from the outer surface of the panel; or (B) more than one parallel protuberance(s) extending circumferentially along and radially from the outer surface of the panel. Thus, the structural rigidity of each panel and the overall structure can be modified. This also allows for different structural strength at different positions, for example heights, around and up the structure.

A perimeter of each panel may be provided with a plurality of holes allowing adjacent panels to be coupled together through said holes. This may, for example, be my means of a nut and bolt arrangement. Alternative coupling or fasteners may equally be used such as rivets or adhesives securing adjacent panels together.

The end portions of the bridging links may have a profile generally complementary to the outer surface of the protuberance to allow alignment and connection to a protuberance. Thus, an un-interrupted ridge or rib protuberance is provided not just across each panel but also across each of the joints at which panels are connected together. This in turn maintains a continuous structural performance around each ring of the structure maintaining strength.

The central portion of each bridging link between the opposing end portions may be spaced radially inwards from the radial position of the two opposing end portions so as to abut with the surfaces of two adjacent panels. Such a profile or contoured shape allows the bridging link to maintain continuous contact with the panels against which it contacts. This maintains strength across the connection and link between adjacent panels.

The central portion of each bridging link between the opposing end portions may also comprise a plurality of holes for alignment with the perimeter holes of adjacent panels. Such an arrangement allows for the secure coupling of the bridging links at multiple positions across the connection between adjacent panels. A highly secure coupling with high rigidity can thereby be provided.

The bridging link may further comprise a radially outer link arranged in use to extend in a line between the first end portion and the second end portion of a bridging link. By providing an additional link or bridge extending at a radius corresponding to the outer radial extend of the protuberance a continuous rigid surface may be provided. This also provides a continuous smooth outer surface to the tank outer structure.

The bridging link and outer link may be arranged in use to be coupled to adjacent protuberances of adjacent panels at either end thereof and the central portion of the bridging link is arranged in use to be couplable to adjacent panels. As described above multiple connection points can then be provided through a variety of coupling mechanisms such as but not limited to bolts, fasteners, rivets, and adhesives.

Viewed from another aspect of the disclosure of an invention described herein, there is provided a protuberance bridging link, for aligning in use at a first end with a contour of a protuberance on a first panel and at a second end with a contour of a protuberance of an adjacent panel of a tank storage system as claimed in any preceding claim.

Viewed from yet another aspect of the disclosure of an invention described herein there is provided a tank storage system comprising a plurality of curved tessellating panels, the tessellating panels being arranged in use to form a plurality of cylindrical rings, the plurality of cylindrical rings being arranged in use to be adjacent to one another to form an elongate cylindrical tank body, wherein the tessellating panels each comprise a plurality of holes allowing adjacent panels to be coupled together;

• • the system further comprising one or more stiffening arrangements, the stiffening arrangement comprising:
  • an outer ring arrangement coaxial with and extending around the tank body; and
  • an intermediate ring arrangement coaxial with and extending around the tank body and located in use between the outer ring arrangement and an outer surface of the tank body,
  • wherein the intermediate ring arrangement is radially alternating in profile having circumferential regions in contact with the outer ring arrangement and circumferential regions in contact with the outer surface of the tank.

In such an arrangement the circumferential regions in contact with the outer surface of the tank may be positioned between circumferential regions in contact with the outer ring arrangement. Thus a rigid structure can be created using such modular components to surround a tank body.

The outer ring arrangement and intermediate ring arrangement may be formed of a plurality of discrete elements which, when coupled together, define the outer ring and intermediate ring circumferences. Alternative coupling mechanisms may equally be used such as but not limited to bolts, fasteners, rivets, and adhesives.

The plurality of discrete elements forming the intermediate ring may comprise opposing end portions radially spaced from a central region there-between, wherein the end portions comprise a coupling for connection to adjacent intermediate ring elements and the central region comprises coupling for connection to the outer surface of the tank body. Such a modular arrangement allows for flexibility is design whilst maintaining structural strength of the silo system.

Adjacent end portions of the discrete elements forming the intermediate ring may be arranged to align with a vertical line along which adjacent tessellating panels are coupled together. Thus, a further connection to adjacent panel joints may be provided thereby further enhancing structural strength.

The outer ring arrangement and the intermediate ring arrangement may be coupled together at positions where the two are in abutment with each other. This still further enhances strength. Optionally each cylindrical ring may comprise a pair of stiffening arrangements.

Viewed from a still further aspect of the disclosure of an invention described herein there is provided a tank stiffening arrangement, the stiffening arrangement comprising:

• • an outer ring arrangement coaxial with and extending around a tank body; and
  • an intermediate ring arrangement coaxial with and extending around the tank body and located in use between the outer ring arrangement and an outer surface of the tank body,
  • wherein the intermediate ring arrangement is radially alternating in profile having circumferential regions in contact with the outer ring arrangement and circumferential regions in contact with the outer surface of the tank.

In the arrangements described above the stiffening ring bridging or continuous stiffening components may be formed of a material selected from any suitable composite material, including but not limited to, carbon fibre reinforced plastic, aluminium or alloys thereof, steel or alloys thereof.

Adjacent tessellating panels may optionally be arranged to be coupled together by a plurality of holes and bolts and wherein the linear density of bolt holes is higher at a lower height of the tank body than at a higher height of the tank body. Alternative coupling mechanisms may equally be used on the stiffening ring bridging or continuous stiffening components such as but not limited to bolts, fasteners, rivets, and adhesives.

It will be recognised that the arrangements described above may be conveniently used in any suitable combination.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, and with reference to the following figures in which:

FIG. 1 shows a contoured protuberance or ribbed stiffener and the bridging link component interconnecting system in a single and double/twin row configuration;

FIG. 2 shows a continuous ring stiffening interconnecting arrangement, again in a single and double/twin configuration;

FIG. 3 shows a hybrid arrangement comprising both arrangements shown in FIGS. 1 and 2, and both in single and double/twin configurations

FIG. 4 again shows a panel from FIG. 1 and illustrates further the radially extending protuberance or rib 4;

FIG. 5 illustrates the abutment of two adjacent panels shown in FIG. 4;

FIG. 6A illustrates the intermediate element of a ring stiffening component bridging link 7 or bridging connector which couples adjacent tessellating panels together;

FIG. 6B shows the arrangement in FIG. 6A inverted and in cross-section;

FIG. 7 shows an exploded view of the components forming one full stiffening ring bridging link 7 connection between adjacent tessellating panels;

FIG. 8 illustrates the resulting connection where panels, bridging link and outer links are in position;

FIG. 9 shows an alternative arrangement of a continuous ring tank stiffener;

FIG. 10 shows a closer image of the coupling between adjacent tessellating panels;

FIG. 11 shows the intermediate ring in isolation;

FIG. 12 illustrates alternative arrangements of intermediate sub-sections 22.

FIGS. 13A and 13B show a tank comprising the arrangement shown in FIGS. 9 to 12; and

FIG. 14 illustrates an enlarged portion of the cross-section shown in FIG. 13B.

While the invention is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are herein described in detail. It should be understood however that the drawings and detailed description attached hereto are not intended to limit the invention to the particular form disclosed but rather the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claimed invention.

Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field. As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to”. The invention is further described with reference to the following examples. It will be appreciated that the invention as claimed is not intended to be limited in any way by these examples. It will also be recognised that the invention covers not only individual embodiments but also combination of the embodiments described herein.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the spirit and scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

It will be recognised that the features of the aspects of the invention(s) described herein can conveniently and interchangeably be used in any suitable combination.

DETAILED DESCRIPTION

FIGS. 1, 2 and 3 show three different configurations of tank and silo stiffening arrangement according to inventions described herein.

FIG. 1 shows a ribbed stiffener and the bridging link component interconnecting system in a single and double/twin row configuration. FIG. 2 shows a continuous ring stiffening interconnecting arrangement, again in a single and double/twin configuration. FIG. 3 shows a hybrid arrangement comprising both arrangements shown in FIGS. 1 and 2, and both in single and double/twin configurations

Turning to FIG. 1, this shows a first embodiment of an invention described herein.

A cylindrical tank 1 is shown which is made up of a plurality of individual panels 2. The panels 2 tessellate together, as shown, to define a series of cylindrical rings A to F. As a whole, the cylindrical rings which are arranged on top of each other, define the elongate cylindrical body of the tank body 1.

As also illustrated, each tessellating panel is joined to adjacent panels by means of a series of couplings 3. In the example shown this is by means of a plurality of holes arranged around the perimeter of each panel and then by means of a nut and bolt or similar coupling holding the panels in position. Other couplings or connections may equally be used to connect adjacent panels together such as rivets or adhesives.

FIG. 1 also illustrates the first stiffening ring arrangement which utilised a modification to each of the panels and a novel ring stiffening component bridging arrangement cooperating with each modification to the panels. This is illustrated with reference to FIG. 4.

FIG. 4 again shows a panel from FIG. 1 but illustrates further the radially extending protuberance or rib 4. The protuberance or rib 4 is integral with the panel i.e. it is formed by deformation of the panel into the desired protuberance or rib shape, for example through pressing or it can be fabricated. The protuberance or rib extends radially out of the panel away from the central axis of the cylindrical tank body i.e. away from the centre of the tank (also referred to herein as a silo).

The right-hand portion of FIG. 4 illustrates the contours of the rib as ghost lines against the panel surface showing one possible geometry. In the example shown the ribs are in the form of generally dome or hemispherical ribs when viewed in cross-section although it will be appreciated that other shapes may be utilised. A curved contour as shown in FIG. 4 minimises stress raisers in the panel material as the material transitions in geometry from the profile that follows the normal cylindrical surface 5 of each panel (and therefore tank) and the curved rib profile 4.

In FIG. 4 the rib is shown to extend substantially from one end of the panel to the other i.e. extending almost all of the way around the curved panel. However, the rib may extend around a smaller percentage of the width of the panel and the bridging portions (described herein) may be correspondingly longer. In either arrangement the profile of the protuberance which is created by the rib and the corresponding bridging portions provides a continuous rib profile thereby enhancing the structural rigidity (with by short ribs and long bridging portions or conversely with a long rib and shorter bridging portions).

In the example shown, each rib 4 terminates at each end before the edge of the panel and in another smooth curved geometry 6. Again this removes any stress raiser and allows for convenient pressing or fabrication manufacture. The dotted ghost lines of the rib 4 and end geometry 6 show the contours of the rib extending radially from the panel surface 5.

As also illustrated each panel is curved, with a curvature calculated based on the number of panels needed to extend around the circumference of the tank or silo. The curvature of each rib corresponds to that predetermined panel curvature.

The panel coupling holes 3 are also illustrated in FIG. 4.

FIG. 4 also shows a twin rib arrangement for a single panel. One, two or a plurality of ribs many be applied to each panel depending on the desired mechanical strength property requirements for the application. A pair of ribs provides for convenient manufacture whilst achieving high rigidity. The rigidity is increased by virtue of increasing the second moment of area of the panel by means of the one or two ribs or protuberances, applying a change to the cross-section shape, width, height or length of the protuberances.

FIG. 5 illustrates the abutment of two adjacent panels shown in FIG. 4. Here the coupling holes 3 are overlapped with each-other so as to be in alignment to receive a coupling such as a bolt.

As shown, as the two panels are brought together the two opposing protuberances or ribs 4, 4′ are also brought into alignment.

The curved portion 6 which forms the end of each rib intersects with the smooth surface of the panel with a space between the end of the curved portion 6 and the couple holes 3. This region between each opposing rib has a smooth surface corresponding to the geometry of the base surface of the panel from which the protuberances extend. This forms part of the panel coupling or bridging surfaces which will now be described.

FIG. 6A illustrates the intermediate element of a ring stiffening component bridging link 7 or bridging connector which couples adjacent tessellating panels together.

As shown the bridging link 7 comprises two opposing raised ends 8, 8′ and a central region 9 extending between the two raised ends 8, 8′.

The height h of the raised portions 8, 8′ measured from the central base portion 9 corresponds to the radial height of the protuberances 4, 4′ shown in FIGS. 4 and 5.

As also illustrated in FIG. 6A the bridging links comprises two smoothed curved portions 2, 2′ which extend between the central base portion 9 and the two opposing raised end portions 8, 8′. In effect the bridging link 7 is provided with a geometry that is shape or profile complementary to the outer surface of the protuberances 4.

The adjacent panels 2′ also illustrate the curved radius R at the end of each raised end portions which cooperates with corresponding curvature of each end of a respective rib. This thereby prevents lateral movement of the bridge relative to the rib enhancing the connection between the ribs and the bridging links.

FIG. 6A also shows central region coupling holes 10 and raised end portion coupling holes 11, 11′. FIG. 6 illustrates 3 central region coupling holes 10 and 2 raised end portion coupling holes 11 but it will be recognised that the number of coupling holes will depend on the width of the bridging link and the desired coupling strength. FIG. 6B shows the arrangement in FIG. 6A inverted and in cross-section. The bridging link may also be manufactured with/without holes dependent upon the fixing methods, including but not limited to bolts, fasteners, rivets, and adhesive.

The connection of adjacent tessellating panels will now be described with reference to FIGS. 7 and 8.

FIG. 7 shows an exploded view of the components forming one full stiffening ring bridging link 7 connection between adjacent tessellating panels. Referring back to FIGS. 1 and 3 each adjacent rib 4 is connected to an associated adjacent rib of an adjacent panel using such a bridging link 7.

The connection between adjacent ribs 4 is made by lowering the bridging link 7 down onto the rib 4 such that the raised end portions 8 are brought into contact with the upper surface of the rib. A bolt (or other suitable fastener) 12 then passes through the coupling hole 13 formed in the rib and through the raised portion coupling hole 14. A washer, 23, nut 24 and nut cap 25 may then be tightened to secure the assembly together. This is then repeated for each of the coupling holes shown to secure the bridging link to the rib. An additional radially outer link 15 may additionally be coupled to cross the bridging link as shown (via the same nuts and bolts). This further enhances the strength of the connection and provides a continuous strengthening ring path between adjacent ribs, as shown. The outer surface of the ribs around the circumference of the tank is thereby in essence continuous.

The centrally located coupling holes 16 can be coupled to the panel coupling holes 17 to join the panel surfaces together at their perimeters.

Thus, a rigid connection between two adjacent panels can be formed.

Adhesives may be used instead of fixing holes and fasteners.

Where the tank or silo is made liquid retaining through the use of sealant the process of coupling of the bridging link 7 to the panel will follow the same principles of sealant application as the bolts 12 which connect the lapped adjacent tessellating panels.

FIG. 8 illustrates the resulting connection where panels, bridging link and outer links are in position. It will be recognised that this provides an extremely rigid connection between adjacent rigid panels. Continuity of rigidity is preserved by virtue of the bridging link and outer link assembly connecting adjacent ribs according to this embodiment.

FIG. 9 shows an alternative arrangement of tank stiffener. In FIG. 9 the arrangements is shown in two configurations. The upper part of the tank illustrates a pair of adjacent stiffeners and the lower part a single stiffener. The selection of a pair, single or other multiple of stiffeners is dependent on the desired mechanical strength of the stiffening arrangements which is itself dictated by the expected wind and/or internal pressure loading on the tank/silo panels.

In effect, the arrangement shown in FIG. 9 creates a ring structure around the tank as will now be described.

FIG. 10 shows a closer image of the coupling between adjacent tessellating panels. The arrangement comprises an outer ring arrangement 18 located at a radial separation from the outer surface of the tank panels/surface and an intermediate ring 19.

As illustrated in FIG. 10, the intermediate ring arrangement is radially alternating in profile having circumferential regions 20 in contact with the outer ring arrangement and circumferential regions 21 in contact with the outer surface of the tank.

The radially alternating profile of the intermediate ring provides rigidity to the structure when the outer ring and intermediate ring are coupled to the tank panels (for example via the coupling bolt arrangement shown in FIG. 10). The radially inwardly and outwardly alternating profile of the intermediate ring increases the second moment of area of the stiffener ring increasing its rigidity.

The intermediate ring is shown in isolation in FIG. 11.

In this embodiment the intermediate ring is formed of a plurality of sub-sections 22 of intermediate ring. The circumference of the entire tank body is divided by the desired number of sub-sections to determine each sub-section length. It will be recognised that the longer the sub-section the greater the degree of curvature around the tank the sub-section must conform to. In the example shown in FIG. 11 the sub-section has length L and is in the form of 8 portions 23A-23H that connect to the outer ring and 7 portions 24A-24G that connect to the tessellating panel.

The end portions 25, 25′ are provided with coupling holes to allow for connection to the next adjacent sub-section in the circumferentially extending intermediate ring. Thus, a continuous intermediate ring around the tank body can be provided as illustrated in FIG. 9.

FIG. 12 illustrates alternative arrangements of intermediate sub-sections 22.

Example 26A shows a single radially alternating arrangement with a central portion which is arranged to abut with the panel surface and two opposing radially spaced portions at either end which are coupled to both an adjacent portion 26A and to the outer ring. Component 26A is, in effect, multi-use and has the same general geometry as the bridging link as described with reference to FIG. 7. These may be used interchangeably.

Example 26B shows an elongated radially alternating arrangement in a single width configuration i.e. a single row of coupling holes to receive coupling bolts to secure the intermediate arrangement to the panel surface.

Example 26C corresponds to the arrangement 26B but instead is greater in width and comprises a pair of coupling holes to receive a pair of rows of coupling bolts to provide greater rigidity to the panel surface.

In the same way that the intermediate ring may be sub-divided into a plurality of sub-sections, similarly the outer ring may also be sub-divided into sub-sections and coupled together in same manner.

FIGS. 13A and 13B show a tank comprising the arrangement shown in FIGS. 9 to 12.

In FIG. 13A the tank 27 comprises two arrangements extending around the upper two cylindrical rings of the tank. The upper most ring comprises a pair of stiffeners shown in FIGS. 9 to 12 and the second ring comprises a single stiffener as shown in FIGS. 9 to 12.

As a result of the naturally increasing head of pressure from the internal contents of the tank or silo the panels towards the lower portion of the tank are generally thicker which gives them more rigidity to external pressure when the tank or silo is empty (not internally loaded). This is not the case for the higher portion of the tank or silo which dictates that additional stiffness or rigidity is more likely to be required in the higher portion of the tank or silo. Each specific tank or silo configuration will consider the individual environmental and operating conditions which will dictate the exact configuration of specification and placement of stiffening rings.

FIG. 13 B shows the stiffener of FIGS. 9 to 12 in cross-section when fully assembled. As illustrated in FIG. 13B the sub-section has an arc of curvature such that when all sub-sections are brought together the circumferential ring around the tank 27 is provided.

FIG. 14 illustrates an enlarged portion of the cross-section shown in FIG. 13B.

The tank or silo wall 28 is formed of the plurality of tessellating panels as described above. As also described above the panels are each provided with a plurality of coupling holes arranged to receive a plurality of bolts to secure the panels to adjacent panels and also to secure the panels and stiffening arrangement together.

The stiffening arrangement comprises the intermediate ring 29 which has an undulating or radially alternating profile i.e. it alternates in contact between the surface of the panel at portion A and the outer ring 30 at portion B.

An important development over existing technologies provided by the inventions described herein is that the new combined system provides enhanced stiffening through its more complex convex/concave shapes of the ribs and connecting elements that are novel in designed.

In the example shown the outer ring is formed of a plurality of sub-sections which are coupled together by overlapping the end of one sub-section 31 with the opposing end of the next subsection 32. The assembly is then coupled together by a plurality of nut and bolt couplings 33, passing through coupling holes in the panels, the intermediate ring sub-sections and the outer ring sub-section.

Thus, the stiffening ring can be created that encircles the tank as shown in FIG. 13A.

A variety of different materials may be selected for the components described herein including steel, aluminium and composite materials. The choice of this material(s) will determine the resulting strength and rigidity of the components in each combination which will then determine the offset/distance that the intermediate ring will extend from the tank.

It will be recognised that in examples described herein bolting fasteners are described. However, it will be recognised that a variety of fasteners, either releasable or fixed may be used including rivets, adhesives or other fastening arrangements.

Claims

1. A tank storage system comprising a plurality of curved tessellating panels, the tessellating panels being arranged in use to form a plurality of cylindrical rings, the plurality of cylindrical rings being arranged in use to be adjacent to one another to form an elongate cylindrical tank body, wherein some or all of the plurality of curved tessellating panels comprise one or more protuberance(s) extending circumferentially along and radially from the outer surface of the panel(s), the system further comprising protuberance bridging links, each bridging link aligning at a first end with a contour of a protuberance on a first panel and at a second end with a contour of a protuberance of an adjacent panel.

2. A tank storage system as claimed in claim 1, wherein the protuberances are in the form of elongate generally convex ribs extending along and around each panel and further comprising a smooth intersecting perimeter intersecting with the surface of the panel surrounding the protuberance.

3. A tank storage system as claimed in claim 1 or 2, wherein an edge region of each panel which in use is aligned with an adjacent panel is substantially smooth.

4. A tank storage system as claimed in any preceding claim wherein a panel comprises either (A) a single protuberance(s) extending circumferentially along and radially from the outer surface of the panel; or (B) a pair of parallel protuberance(s) extending circumferentially along and radially from the outer surface of the panel.

5. A tank storage system as claimed in any preceding claim wherein the perimeter of each panel in provided with a plurality of holes allowing adjacent panels to be coupled together through said holes.

6. A tank storage system as claimed in any preceding claim wherein, the end portions of the bridging links have a profile generally complementary to the outer surface of the protuberance to allow alignment and connection to a protuberance.

7. A tank storage system as claimed in claim 6, wherein the central portion of each bridging link between the opposing end portions is spaced radially inwards from the radial position of the two opposing end portions so as to abut with the surfaces of two adjacent panels.

8. A tank storage system as claimed in any preceding claim where the central portion of each bridging link between the opposing end portions comprises a plurality of holes for alignment with the perimeter holes of adjacent panels.

9. A tank storage system as claimed in any preceding claim wherein the bridging link further comprises a radially outer link arranged in use to extend in a line between the first end portion and the second end portion of a bridging link.

10. A tank storage system as claimed in claim 9, wherein the bridging link and outer link are arranged in use to be coupled to adjacent protuberances of adjacent panels at either end thereof and the central portion of the bridging link is arranged in use to be couplable to adjacent panels.

11. A protuberance bridging link, for aligning in use at a first end with a contour of a protuberance on a first panel and at a second end with a contour of a protuberance of an adjacent panel of a tank storage system as claimed in any preceding claim.

12. A tank storage system comprising a plurality of curved tessellating panels, the tessellating panels being arranged in use to form a plurality of cylindrical rings, the plurality of cylindrical rings being arranged in use to be adjacent to one another to form an elongate cylindrical tank body, wherein the tessellating panels each comprise a plurality of holes allowing adjacent panels to be coupled together; the system further comprising one or more stiffening arrangements, the stiffening arrangement comprising:an outer ring arrangement coaxial with and extending around the tank body; andan intermediate ring arrangement coaxial with and extending around the tank body and located in use between the outer ring arrangement and an outer surface of the tank body,wherein the intermediate ring arrangement is radially alternating in profile having circumferential regions in contact with the outer ring arrangement and circumferential regions in contact with the outer surface of the tank.

13. A tank storage system as claimed in claim 12, wherein the circumferential regions in contact with the outer surface of the tank are positioned between circumferential regions in contact with the outer ring arrangement.

14. A tank storage system as claimed in claim 12 or 13, wherein the outer ring arrangement and intermediate ring arrangement are formed of a plurality of discrete elements which, when coupled together, define the outer ring and intermediate ring circumferences.

15. A tank storage system as claimed in claim 14, wherein the plurality of discrete elements forming the intermediate ring comprise opposing end portions radially spaced from a central region there-between, wherein the end portions comprise a coupling for connection to adjacent intermediate ring elements and the central region comprises coupling for connection to the outer surface of the tank body.

16. A tank storage system as claimed in claim 15, wherein adjacent end portions of the discrete elements forming the intermediate ring are arranged to align with a vertical line along which adjacent tessellating panels are coupled together.

17. A tank storage system as claimed in any of claims 12 to 16, wherein the outer ring arrangement and the intermediate ring arrangement are coupled together at positions where the two are in abutment with each other.

18. A tank storage system as claimed in any of claims 12 to 17, wherein each cylindrical ring comprises a pair of stiffening arrangements.

19. A tank stiffening arrangement, the stiffening arrangement comprising: an outer ring arrangement coaxial with and extending around a tank body; andan intermediate ring arrangement coaxial with and extending around the tank body and located in use between the outer ring arrangement and an outer surface of the tank body,wherein the intermediate ring arrangement is radially alternating in profile having circumferential regions in contact with the outer ring arrangement and circumferential regions in contact with the outer surface of the tank.

20. A tank storage system as claimed in any preceding claim wherein the stiffening ring bridging or continuous stiffening components are formed of a material selected from carbon fibre reinforced plastic, aluminium or alloys thereof, steel or alloys thereof.

21. A tank storage system as claimed in any preceding claim, wherein adjacent tessellating panels are arranged to be coupled together by a plurality of holes and bolts and wherein the linear density of bolt holes is higher at a lower height of the tank body than at a higher height of the tank body.

22. A cylindrical tank for storing material comprising a combination of tank storage system as claimed in any of claims 1 to 11 in combination with a tank storage system as claimed in any of claims 12 to 18.