CN108349576B

CN108349576B - Storage tank containment system

Info

Publication number: CN108349576B
Application number: CN201580084156.5A
Authority: CN
Inventors: R·拉莫; T·兰布
Original assignee: Altair Engineering Inc
Current assignee: Altair Engineering Inc
Priority date: 2015-10-26
Filing date: 2015-10-27
Publication date: 2020-02-07
Anticipated expiration: 2035-10-27
Also published as: JP6661762B2; CN108349576A; KR102354360B1; MY187593A; WO2017074313A1; JP2018532962A; KR20180073651A

Abstract

A large volume natural gas storage tank includes a plurality of rigid tubular walls having a middle section extending along a longitudinal axis and having a closed cross-section and opposing ends. Each wall is interconnected at each end with respective ends of two other walls such that the interconnected interiors define an interior fluid storage chamber. The outer surfaces of the flat continuously interconnected walls define the sides of the tank. The tank also includes outer support structures that each extend between the outer surfaces of the walls forming each side of the storage tank and reinforce the storage tank against dynamic loads from the fluid in the inner fluid storage chamber. The tank is characterized by closure panels each extending at least partially across an outer surface of the outer support structure. The inner surface of the closure plate, the inner surface of the outer support structure, and the outer surface of the wall at least partially define an auxiliary fluid storage chamber.

Description

Storage tank containment system

Technical Field

Embodiments disclosed herein relate generally to storage tanks, and more particularly to storage tanks for fluids (including liquids and gases).

Background

Industrial tanks for containing fluids such as liquids or compressed gases are common and of critical importance to industry. Tanks may be used to temporarily or permanently store fluids at an onsite location, or may be used to transport fluids on land or at sea. Many inventions have been made over the years relating to the structural construction of fluid storage tanks. One example of an unconventional fluid storage tank having a cubic-shaped configuration can be found in US3944106 to thomas lamb.

The need for efficient storage and long distance transport of fluids such as Liquefied Natural Gas (LNG), particularly overseas, by large ocean-going tankers or carriers, continues to grow. In order to more economically transport fluids such as LNG, the holding or storage capacity of such LNG carriers has increased significantly from about 26,000 cubic meters in 1965 to over 200,000 cubic meters in 2005. Naturally, the length, beam width and draft of these super carriers will also increase to accommodate greater cargo capacity. However, the ability to further increase the size of these super carriers has practical limitations.

Marine vessels can encounter difficulties in storing and transporting fluids, particularly in liquid form. The trend in large LNG carriers is to use large side membrane tanks and insulation can supported tanks. As the volume of the tank transporting the fluid increases, the hydrostatic and dynamic loads on the tank containment walls increase significantly. These membrane and insulated tanks suffer from the disadvantage of managing the "sloshing" movement of the liquid in the tank due to the natural movement of the carrier through the ocean. Thus, the effective holding capacity of these types of tanks has been limited to above 80% full load or below 10% full load to avoid damaging the tank's liner and insulation. As the size of the transport vessels increases, an increase in the disadvantages and limitations of these tanks can be expected.

The tank of the prior US patent US3944106 was evaluated against a geometrical cubic tank of similar dimensions for containing LNG in large volumes, for example in large LNG marine transport ships. It has been determined that the' 106 can is more rigid using one third of the wall thickness of a geometric cube. The' 106 tank further significantly reduces the velocity of the fluid, reduces the energy transferred to the tank, and reduces the forces transferred by the fluid to the tank, compared to a geometric cubic tank, which results in significantly reduced deformation of the tank. However, it was further determined that cans of the' 106 configuration could be improved.

Cubic tank designs for LNG and Compressed Natural Gas (CNG) have also been developed. Details of these tanks can be found in U.S. patent application publications US2008/0099489 and US 2010/0258571.

Therefore, it would be advantageous to design and manufacture storage tanks for efficient storage and transport of large quantities of fluids (e.g., LNG) on land or at sea. It is further desirable to provide a storage tank that can be manufactured in a dock for large LNG carriers. It would further be advantageous to provide a modular tank design that is convenient to design, manufacture and use on site.

Disclosure of Invention

Embodiments of a large volume natural gas storage tank are disclosed herein.

In one aspect, a large volume natural gas storage tank comprises: a plurality of rigid tubular walls, wherein each rigid tubular wall comprises a mid-section extending along a longitudinal axis and having a closed tubular cross-section and opposing ends, wherein each rigid tubular wall is interconnected at each end with a respective end of two other rigid tubular walls of the plurality of rigid tubular walls such that an interconnected interior of the plurality of rigid tubular walls defines an interior fluid storage chamber, wherein an outer surface of the flat continuously interconnected rigid tubular walls defines a side of the storage tank; a plurality of outer support structures, wherein each outer support structure extends between the outer surfaces of the rigid tubular walls forming each side of the storage tank, wherein each outer support structure reinforces the storage tank against dynamic loading from fluid in the inner fluid storage chamber; and characterized by comprising a plurality of closure plates, wherein each closure plate extends at least partially across an outer surface of one of the plurality of outer support structures, wherein an inner surface of the closure plate, an inner surface of the outer support structure, and an outer surface of the plurality of rigid tubular walls at least partially define an auxiliary fluid storage chamber.

These and other aspects will be described in more detail below. Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for carrying out the present invention is read in conjunction with the accompanying drawings.

Drawings

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

FIG. 1 is a perspective view of a first example of a tank containment system having a tank and a tank support structure;

FIG. 2 is a perspective view of the bottom side of the tank containment system of FIG. 1 as viewed from direction A in FIG. 1;

3A-3C are perspective views of the tank containment system of FIG. 1 showing possible variations in the configuration of the support structure;

FIG. 4 is a rear partial perspective view of an example of a corner of the tank as viewed from the interior space of the tank;

FIG. 5A is a rear partial perspective view of the exemplary corner of FIG. 4 as viewed from the interior space of the tank;

FIGS. 5B and 5C are rear partial perspective views of an alternative example of a corner as viewed from the interior space of the tank;

FIGS. 6A and 6B are cross-sectional views taken along lines 6A-6A in FIG. 5A and 6B-6B in FIG. 5B, respectively, illustrating an exemplary method for completing a joint between components of a corner;

FIG. 7 is a perspective view of the storage tank container of FIG. 1 with the storage tank depicted in phantom to show an example of a gusset positioned within the interior space of the storage tank and a dividing wall in the horizontal cylindrical wall of the storage tank;

FIG. 8 is a perspective view of the reservoir container of FIG. 1 similar to FIG. 7, without the reservoir and the divider wall shown;

FIG. 9 is a cross-sectional perspective view of the storage tank of FIG. 1 taken along line 9-9 showing the interior space formed between the cylindrical walls;

FIGS. 10A-10C are perspective views of examples of closure panels shown in the various figures for closing the interior space shown in FIG. 9;

FIG. 11 is a perspective view of a second example of a tank containment system having a tank and an optional tank support structure;

FIG. 12 is a perspective view of the bottom side of the tank containment system of FIG. 11 as viewed from direction B in FIG. 11;

FIG. 13 is a cut-away perspective view of the storage tank system of FIG. 5, showing an alternative example of a divider wall positioned in the horizontal cylindrical wall of the storage tank;

FIG. 14 is an alternative cut-away perspective view of the storage tank containment system of FIG. 11 showing the divider walls positioned in the horizontal cylindrical wall of the storage tank;

FIG. 15 is a cut-away perspective view of the storage tank containment system of FIG. 11 showing an example of corner reinforcements positioned in the bottom corners of the storage tank;

FIG. 16 is an alternative cut-away perspective view of the storage tank containment system of FIG. 11 showing an example of corner reinforcements positioned in the bottom corners of the storage tank;

FIG. 17 is an alternative cut-away perspective view of the tank containment system of FIG. 11;

FIG. 18 is an alternative perspective view, partially in section, of the tank system of FIG. 11 showing an additional example of a gusset within the interior space of the tank;

FIG. 19 is an alternative perspective view, partially in section, of the tank containment system of FIG. 11 showing an alternative example of corner reinforcements and gussets;

FIG. 20 is a perspective view of a third example of a tank containment system showing the structure of the tank and optional tank supports and closure plates;

FIG. 21 is a perspective view of the bottom side of the tank containment system of FIG. 20 as viewed from direction C in FIG. 20;

FIG. 22 is a side view of the tank containment system of FIG. 20; and

FIG. 23 is a cross-sectional view of the tank containment system of FIG. 20 shown in an installed position within the cargo compartment of the carrier.

Detailed Description

An example of a tank containment system 10 is shown in fig. 1-23. A first example of a tank containment system 10 is shown in fig. 1-10. Referring to fig. 1-3, a first example of a tank containment system 10 includes a tank 12 having a generally cubic configuration with six geometrically square sides oriented substantially at right angles with respect to one another. The tank 12 is preferably constructed of twelve interconnected hollow or tubular walls (a single exemplary cylindrical wall 14 shown in fig. 1). Although in the examples below the interconnected tubular walls are cylindrical and have a closed, generally circular cross-section, other hollow or tubular shapes are possible.

The exemplary storage tank 12 includes four vertically oriented cylindrical walls 16 positioned approximately 90 degrees apart from each other and eight horizontally oriented cylindrical walls 18 disposed between and rigidly connected to the ends of the vertical walls 16 at corners 20 a. As shown, the eight horizontal cylindrical walls 18 include four lower cylindrical walls 18a disposed at the bottom of the storage tank 12 and four upper cylindrical walls 18b disposed at the top of the storage tank 12. In a preferred example, each of the vertical and

horizontal walls

16,18 may have the same length, have substantially the same cross-section, and curvature.

The interconnected hollow cylindrical walls 14 define an internal fluid storage chamber 22, the internal fluid storage chamber 22 being adapted to contain a material comprising a fluid, such as Liquefied Natural Gas (LNG), maintained at or above atmospheric pressure. Other fluids (e.g., gases) known to those skilled in the art may also be stored or contained by the tank 12. Although depicted and shown as a cube having all six sides of the same size, it should be understood that the tank 12 may take on different geometric configurations, such as a rectangle having a longer horizontal dimension and a smaller vertical dimension. Other shapes and configurations known to those skilled in the art may be used.

Fig. 4 shows an exemplary corner 20a as viewed from an interior space 295 (best seen in fig. 9) of the tank 12, and fig. 5A shows the corner 20a as viewed from outside the tank 12. In this example, corner 20a is disposed adjacent each opposing end of the four vertical cylinder walls 16 for a total of eight corners 20a forming eight corners of the exemplary cubic storage tank 12. In this example, the vertical cylinder wall 16 is connected to two lower horizontal cylinder walls 18 a. The vertical cylinder wall 16 extends along a substantially vertical longitudinal axis 24, and the two horizontal cylinder walls 18a each extend substantially at right angles to the axis 24 along

axes

26 and 28, respectively. The

axes

26 and 28 extend at substantially right angles relative to each other in a plane orthogonal to the axis 24 such that the horizontal cylindrical wall 18a is positioned in a substantially horizontal orientation.

Axes

24, 26 and 28 intersect at a point (not shown) inside corner 20 a. As generally illustrated, the vertical cylindrical wall 16 and the two horizontal cylindrical walls 18a extend along their respective axes and their respective distal ends 30, 32 and 34 are connected substantially at a joint 40 between the respective cylindrical walls, thereby enclosing the internal fluid storage chamber 22. The joint 40 includes a closure member 60 positioned to close the space or gap between the respective distal ends 30, 32 and 34 of the vertical and two

horizontal cylinder walls

16 and 18a, as described below, although other configurations for the joint 40 are possible.

In an alternative example of the corner 20B shown in fig. 5B, the vertical cylinder wall 16 and the two horizontal cylinder walls 18a similarly have their respective distal ends 30, 32, and 34 connected at a joint 42. It can be seen that the joint 42 in this example does not include a closure member 60. In yet another alternative example of the corner 20C shown in fig. 5C, rather than all of the respective distal ends 30, 32 and 34 of the vertical cylinder wall 16 and the two horizontal cylinder walls 18a meeting at the joint 42, the end cap 50 abuts portions of the respective distal ends 30, 32 and 34 at the joint 44 (as generally shown). In this example, the end cap 50 is spherical in shape, but other shapes, configurations, and joints known to those skilled in the art that will close and form fluid tight corners may be used.

In an alternative example not shown, the corners 20 may be rounded or spherical to more closely match the profile of the cylinder wall for manufacturing and/or assembly purposes.

The basic structure of the tank 12 is preferably constructed of aluminum, but other materials may be used, such as nickel steel, high strength pressure grade steel, and other materials known to those skilled in the art. It is also to be understood that different components from those described and illustrated above, as well as different shapes and orientations, known to those skilled in the art, may be used. In a preferred example, during manufacture, the component parts of the tank 12 are rigidly and permanently joined together using a seam welding process in a manner that forms the fluid-tight internal fluid storage chamber 22. For example, the

joints

40, 42, and/or 44 may be completed and sealed to form fluid tight corners between the vertical cylinder wall 16 and the horizontal cylinder wall 18. The configuration of the finished joint, as well as the processes used to complete the joint, may vary depending on one or more design, strength, manufacturing, and/or other considerations. Examples of various joints between components of the storage tank 12 are described with reference to fig. 6A and 6B.

Fig. 6A is a cross-section of the joint 40 in fig. 5A between the vertical wall 16 and the horizontal wall 18 a. According to this example, the storage tank 12 is assembled prior to completion of the joint 40 such that a space or gap exists between the distal ends 30 and 32 of the vertical wall 16 and the horizontal wall 18a, respectively, prior to completion of the joint 40. As shown, the closure member 60 is sized and configured to substantially close the gap between the respective distal ends 30 and 32. The closure member 60 extends along the joint 40, and as can be appreciated with reference to fig. 4 and 5A, the closure member 60 has three generally annular, open-ended annular portions in the exemplary corner 20 a. However, the closure member 60 may have other shapes that may vary depending on the application of the closure member in the joint between the optional corners and/or other components of the storage tank 12. The closure member 60 may be advantageously used in situations where it is not feasible, cost effective, or otherwise undesirable to manufacture and/or assemble the components of the storage tank 12 to tolerances that allow for direct welding. Additionally or alternatively, a closure member 60 may be included to perform a reinforcing or stiffening function in the joint 40.

The respective distal ends 30 and 32 of the vertical wall 16 and the horizontal wall 18a are chamfered from both the inside (facing the internal fluid reservoir 22) and the outside of the walls such that a sharp apex is formed at each

distal end

30 and 32, although the apex may alternatively be rounded, for example. The illustrated closure member 60 is shaped to have a rectangular cross-section and is oriented such that a sharp apex is opposite each point of the apexes 56 and 58. In this configuration, four inwardly tapered grooves are formed.

Specifically, two grooves are formed for receiving solder to join the vertical wall 16 to the closing member 60, and two grooves are formed for receiving solder to join the closing member 60 to the horizontal wall 18 a. For example, the cross-section of the closure member 60 may have a different size or shape depending on the size of the gap to be closed. It should be understood that one or more of the distal ends 30 and 32 and the closure member 60 may have a shape and configuration other than that specifically illustrated. For example, the distal ends 30 and 32 and the opposing portions of the closure member 60 can alternatively be, for example, circular, and the distal ends 30 and 32 and the closure member 60 can be formed such that only a groove is formed that opens to one of the outside or inside of the

walls

16 and 18 a.

Fig. 6B is a cross-section of the joint 42 in fig. 5B between the vertical wall 16 and the horizontal wall 18 a. According to the exemplary joint 42 shown in fig. 6B, the storage tank 12 is assembled prior to completing the joint 42 such that the respective distal ends 30 and 32 of the vertical and

horizontal walls

16 and 18a to be joined are substantially adjacent and may be continuously seam welded or otherwise mechanically joined together to complete the joint 42. In the example shown, the respective distal ends 30 and 32 of the vertical wall 16 and the horizontal wall 18a are chamfered from both the inside and outside of the walls, such that a sharp apex is formed at each

distal end

30 and 32. An inwardly tapered recess is formed by opposing points of the distal ends 30 and 32, which are sized and shaped for receiving solder to join the vertical wall 16 and the horizontal wall 18 a. It should be understood that distal ends 30 and 32 can alternatively be, for example, rounded, or can be formed such that a single groove is formed that opens to only one of the outside or inside of

walls

16 and 18 a.

Other configurations and orientations of the joint formed by the intersection of the vertical and

horizontal cylinder walls

16,18 a at the corners known to those skilled in the art may be used. Additionally, it should be understood that the joints shown are described with reference to corners for illustration only, and the examples described can in principle be applied to any other joint or seam between components of the storage tank 12.

The disclosed tank retention system 10 includes additional external and/or internal structures configured to effectively and efficiently handle and manage static and dynamic loads from the fluid contained within the storage tank 12, as well as loads from the storage tank 12, as further described below.

Referring to fig. 1-3, 7 and 8 in a first example, a representative external support structure 100 is shown attached to an exterior surface of the storage tank 12. The support structure 100 is positioned generally about the exterior of the wall 14 to provide radial support and/or reinforcement to one or more portions of the tank 12 in order to strengthen the tank containment system 10 against stresses caused by movement of fluid within the internal fluid storage chamber 22, and overall stresses from the bulk of the tank containment system 10. The first example support structure 100 includes a plurality of first supports 102 (i.e., 102a, 102b, 102c, etc.), a plurality of second supports 104 (i.e., 104a, 104b, 104c, etc.), and a plurality of third supports 106 (i.e., 106a, 106b, 106c, etc.). A base 150, described further below, is also used. It should be understood that certain components of the support structure 100 and the base 150 that are described and/or illustrated as discrete connected components may be integral, for example, and vice versa.

In a first example, each of the

supports

102, 104, and 106 is a generally planar member that extends outwardly from the storage tank 12 and has an opening 108 (a representative opening 108 for the support 102a is shown) sized and shaped to closely surround a selected outer portion of the storage tank 12. In a first example, the

supports

102 and 104 are vertically oriented and horizontally spaced apart and aligned at right angles to each other and parallel to respective edges of the sides of the storage tank 12. The supports 106 are horizontally oriented and vertically spaced apart and are similarly aligned parallel to respective edges of the sides of the storage tank 12. The

supports

102, 104 and 106 are generally positioned and oriented to reinforce and provide radial support to selected outer portions of the adjacent horizontal and

vertical cylinder walls

16 and 18, respectively, forming the six sides of the storage tank 12.

For example, in the first example, the

supports

102, 104, and 106 are interconnected to form a portion 120 of the support structure 100 that surrounds the storage tank 12 along an outward facing portion of the lower cylindrical wall 18a that forms an upright side of the storage tank 12. It can be seen that the illustrated components of the portion 120 of the support structure 100 can be further shaped and positioned to abut the

closure plate

300b or 300c, which will be described in further detail below, as well as additional portions of the storage tank 12.

Each portion 120 of the support structure 100 includes a vertically oriented brace 102 that abuts an outwardly facing portion of two parallel lower cylinder walls 18a, thereby generally enclosing portions of two opposing upright sides of the storage tank 12. In the example shown, the support 102 also surrounds the bottom side of the storage tank 12. The support 102 extends vertically to a position approximately midway between two opposite upright sides of the storage tank 12. The supports 102 are horizontally spaced apart such that an outer support 102c of the supports 102 is positioned to extend upwardly from the vertical cylinder wall 16 in a radial direction along the vertical cylinder wall 16 and to abut a circumferential portion of the connected horizontal cylinder wall 18 a.

The portion 120 similarly includes vertically oriented supports 104 abutting the outwardly facing portions of the other two parallel lower cylinder walls 18a, thereby generally enclosing the bottom side of the storage tank 12, as well as portions of the other two opposing upright sides of the storage tank 12 other than the supports 102. The support 104 also extends vertically to a position approximately midway between the two opposite upright sides of the storage tank 12. The supports 104 are horizontally spaced apart such that an outer one 104c of the supports 104 is positioned to extend upward from the vertical cylinder wall 16 in a radial direction along the vertical cylinder wall 16 and to abut a circumferential portion of the connected horizontal cylinder wall 18 a.

In this example, the horizontal support 106 can, optionally, rigidly interconnect the support 102 including the portion 120 and the support 104 at each respective upright side of the storage tank 12. It should be understood that any of the

supports

102, 104, and 106 can be provided in alternative numbers and/or configurations. For example, as shown in fig. 3A, the support 106d can optionally be configured to substantially surround the storage tank 12. The support 106d is positioned to extend from the horizontal cylinder walls 18a in the radial direction along the four horizontal cylinder walls 18a, and abuts with the circumferential portion of the connected vertical cylinder wall 16. In addition, it can be seen that certain portions of the support 106 interconnecting the support 102 and the support 104 are not included in this variation.

In addition, the

central supports

102a and 104b of the

supports

102 and 104 are configured to substantially surround the storage tank 12. As shown, the center supports 102a and 104b are positioned to abut outwardly facing portions of four of the eight

cylindrical walls

18a and 18b that extend in parallel, thereby generally enclosing a bottom side of the storage tank 12, two opposing upright sides of the storage tank 12, and a top side of the storage tank 12. It can be seen that the

central supports

102a and 104b intersect at the bottom and top sides of the storage tank 12 and interconnect the four portions 120 of the support structure 100 that surround the outer portions of the four lower cylindrical walls 18a, as described above.

The concentration of the

supports

102, 104, and 106 toward the lower half of the storage tank 12 is used to reinforce the lower portion of the storage tank 12 and its capacity for hydrostatic and other forces. In a second example, a T-plate 103 is selectively connected to and perpendicular to

supports

102 and 104 to form a T-shaped cross-section in order to increase the strength of the supports to prevent buckling and other deformation. As best shown in fig. 2, it is also contemplated that the concentration of supports may be selectively integrated into the base 150, such as at the center of the bottom side of the storage tank 12.

Fig. 3B and 3C illustrate an alternative variation of the construction of the support structure 100, wherein the support structure 100 is further designed to provide controlled lateral and vertical support of the storage tank 12 by adapting to the shape of a storage area, such as a cargo hold 160 (shown in fig. 3B but not shown in fig. 3C for clarity) of a marine transport vessel 162, in which the storage tank 12 is disposed. For example, the outer surfaces or perimeters 110 of the

braces

102, 104, and 106 (a representative perimeter 110 for brace 104a is shown) opposite respective portions of the opening 108 surrounding the side of the storage tank 12 may be configured to abut and/or engage an upright wall 164 and/or a top wall 166 defining the cargo space 160.

Additionally, or alternatively, means for securing the containment system 10 and tanks 12 to the cargo hold 160 may be positioned between the walls 164 of the cargo hold 160 and portions of the containment system 10 to inhibit movement of the containment system 10 relative to the cargo hold 160, such as in the case of roll or pitch movement of the carrier 162. For example, as shown, the spacer block 170 is positioned between the upright wall 164 and the upright portion of the support structure 100 of the containment system 10. Further, in the example shown, the spacer block 172 is positioned between the top wall 166 and an upper portion of the support structure 100. In the case of flooding, for example, of the cargo hold 160, the spacer 172 may be advantageously used to inhibit the containment system 10 from floating. Although the

spacers

170 and 172 are shown and described, other means known to those skilled in the art may be used.

In a preferred example, the first, second, and

third supports

102, 104, 106 are made of aluminum sheet, and the respective openings 108 are sized to coincide with portions of the exterior of the storage tank 12 where the supports are selectively positioned. It should be understood that other materials described above for the wall 14 may be used, as well as other materials known to those skilled in the art.

The tank containment system 10 includes a base 150 for supporting the tank 12 on a rigid support surface, such as the floor 168 of the cargo hold 160. In one example, the base 150 is formed by the

vertical supports

102 and 104, as best seen in FIG. 2. In this example, the perimeters 110 of the

vertical supports

102 and 104 opposite the respective portions of the opening 108 surrounding the bottom of the storage tank 12 may form a substantially flat platform or surface to form a base 150, as shown in fig. 2, providing a flat landing area for the storage tank 12 to abut a flat floor 168 of the cargo compartment 160.

As described above, the base 150 may be formed partially or entirely from the

supports

102 and 104, or may be formed from alternative structures, either alone or in combination with the

supports

102 and 104. The illustrated base 150 is reinforced by an angularly oriented reinforcing skirt 152 adjacent the bottom side of the storage tank 12. As shown in fig. 3A, a plurality of rigidly connected reinforcing webs 154 may also be used.

The base 150, skirt 152 and/or web 154 may be shaped similarly to the support structure 100 described above with reference to fig. 3B and 3C to accommodate the shape of the cargo compartment 160. For example, the perimeter 110 of the

vertical supports

102 and 104 forming the base 150 is chamfered in the variation of fig. 3B and 3C to approximate the cross-section of the cargo compartment 160 between the upright walls 164 and the floor 168.

Further, the means for supporting the containment system 10 and the tank 12 within the cargo bay 160 may be positioned between the floor 168 and the base 150 of the cargo bay 160. For example, as shown, the spacer 174 is positioned between the floor 168 and the base 150 of the containment system 10. Although spacers 174 are shown and described, other means known to those skilled in the art may be used to support containment system 10 within cargo bay 160. The above-described variations are provided as non-limiting examples, and it should be understood that many other variations of the components of the support structure 100 and/or the base 150 are possible depending on the particular configuration of the cargo hold 160.

The base 150 is secured to the structure of the adjacent storage tank 12 in the manner described for the wall 14 and supports 102, 104 and 106. The structure forming the base 150 may be made of the same materials as the supports described above, or may be made of other materials and configurations known to those skilled in the art.

Fig. 7 illustrates features of the tank containment system 10 in a first example, incorporating some of the above-described inventive external, internal, and other structures for the tank 12. The tank containment system 10 of fig. 7 includes a tank 12 having the corner 20a described above formed in combination with the closure member 60, as shown in fig. 4, 5A and 6A. The support structure 100 and base 150 are constructed in accordance with the discussion of fig. 1-3, 7 and 8. As shown, this example also includes internal structures configured to store and manage fluid within the internal fluid storage chamber 22 and elsewhere.

For example, as shown in fig. 7, the tank containment system 10 includes a partition wall structure 200a in which the planar panel 204 is comprised of a reinforced outer perimeter 204a and an in-film portion 204b configured to partially block the flow of liquid by defining oval-shaped holes 206. The interior space 295 is defined in part by the closure plate 300b and

houses intersecting gussets

502, 504, and 506 positioned between and rigidly connected to the walls 14.

Exemplary storage tank 12 has dimensions of 150 feet (f) or 50 meters (m) on each geometric side. In applications for storing LNG, the thickness of the aluminum plate forming the bottom horizontal cylindrical wall 18 may vary between about 2-5 inches, the thickness of the aluminum plate forming the top horizontal cylindrical wall 18 may vary between about 0.5-3 inches, the thickness of the aluminum plate forming the vertical horizontal cylindrical wall 16 may vary between about 2-4 inches, the thickness of the aluminum plate forming the bottom corner 20 may vary between about 3-6 inches, and the thickness of the aluminum plate forming the top corner 20 may vary between about 1-3 inches. The thickness of the aluminum forming the closure plate 300b may vary between about 2-4 inches. The thickness of the aluminum forming the closure member 60 may vary between about 4-6 inches at the bottom corner 20 and 3-4 inches at the top corner 20.

The thickness of the aluminum plates forming the support structure 100 and the components of the internal structure and stiffeners described above may generally vary between about 1-3 inches. Portions of support structure 100, such as reinforcing outer perimeter 204a of T-plates 103 and flat panels 204, may be formed from aluminum plates that vary in thickness between about 3-6 inches.

The composition and configuration of the components of representative external support structure 100 may vary according to one or more design, strength, manufacturing, and/or other criteria. For example, it is contemplated that the external support structure 100 described above may be modified or differently designed based on actual, predicted, and/or simulated static and dynamic loads from the fluid contained within the storage tank 12 as well as loads from the storage tank 12 itself. It will be appreciated, therefore, that the number, arrangement and orientation of the

supports

102, 104 and 106 may vary. Similar variations in the construction and materials of the base 150 known to those skilled in the art may be used. One example of a possible variation of the representative external support structure 100 is used in the second example of the tank containment system 10 shown in fig. 11-19.

Referring to fig. 11 and 12, the support structure 100 in the second example mainly includes a first support 102 (identified by 102m, 102n, and 102o in the second example), a second support 104 (identified by 104m, 104n, and 104 o), and a third support 106 (identified by 106m, 106n, and 106 o). A base 150 substantially as described above is also used. In the second example, each of the

supports

102, 104, and 106 is a generally planar member that defines an interior opening 108 sized to closely surround a selected outer portion of the storage tank 12.

In a second example, the

supports

102 and 104 are vertically oriented and horizontally spaced apart and aligned at right angles to each other and parallel to respective edges of the sides of the storage tank 12. The supports 106 are horizontally oriented and vertically spaced apart and are similarly aligned parallel to respective edges of the sides of the storage tank 12. As with the first example, the

supports

vertical cylinder walls

16 and 18, respectively, forming the six sides of the storage tank 12.

In the second example, each of the

supports

102, 104, and 106 is configured to substantially surround the storage tank 12. Two of the outer supports 102m and 102o, with respect to a single side of the storage tank 12, are each positioned to extend in a radial direction upwardly from the vertical cylinder wall 16 along the vertical cylinder wall 16, and to abut a circumferential portion of the connected

horizontal cylinder walls

18a and 18 b. Similarly, two of the outer supports 104m and 104o are each positioned to extend upward from the vertical cylinder wall 16 in the radial direction along the vertical cylinder wall 16, and to abut with the circumferential portions of the connected

horizontal cylinder walls

18a and 18 b. Finally, two of the outer supports 106m and 106o of the supports 106 are each positioned to extend horizontally in a radial direction from the horizontal cylinder wall 18 along the horizontal cylinder wall 18 and to abut a circumferential portion of the connected vertical cylinder wall 16.

Although the outer ones of the

supports

102, 104, and 106 are described with respect to a single side of the tank 12 for clarity, it can be appreciated from the figures that the outer ones of the

supports

102, 104, and 106 can be configured to surround multiple sides of the tank 12. For example, it can be seen that the outer of the

supports

102, 104 and 106 may surround four sides of the storage tank 12 to generally form a ring around the storage tank 12, with the positioning and orientation of the four components being in principle similar to that described above with respect to a single side.

The center supports 102n and 104n are positioned to abut the outwardly facing portions of four of the eight

cylinder walls

18a and 18b that extend in parallel, thereby substantially enclosing the bottom side of the storage tank 12, the two opposing upright sides of the storage tank 12, and the top side of the storage tank 12. The central support 106n is positioned to abut the outwardly facing portions of the four vertical cylinder walls 16, thereby substantially enclosing all four upright sides of the storage tank 12. The central supports 102n, 104n, and 106n may span a space 290 on the side of the storage tank 12 formed between the spaced apart cylindrical walls 14. However, the intermediate support may be further shaped and positioned to abut the closing plate 300c, described in further detail below.

It can be seen that the

supports

102, 104 and 106, positioned as described and illustrated above, may be rigidly interconnected at their respective intersections to form a reinforced lattice structure around the storage tank 12. In one variation of the second example of the representative outer support structure 100, not shown, it is contemplated that one or more of the upper supports 106 may be reduced in load bearing capacity due to a gradual reduction in the hydrostatic forces exerted on the storage tank 12 by its contents. For example, because the hydrostatic load on the interior of the wall 14 is greater closer to the base 150, a support structure 100 including a plurality of horizontally-oriented supports 106 may include a first support 106 and a second support 106 positioned farther from the base 150 than the first support 106, the first support being relatively stronger than the second support. However, it is further contemplated that depending on the application, this gradual reduction in hydrostatic force may be offset by expected dynamic loads in some applications.

Similar to the first example, the first, second, and

third supports

102, 104, 106 of the second example are made of aluminum plates, and the respective openings 108 are sized to coincide with portions of the exterior of the storage tank 12 where the supports are selectively positioned. It should be understood that other materials described above for the wall 14 and other materials known to those skilled in the art may be used.

As described below, the tank containment system 10 disclosed in the first and second examples also includes internal structures configured to store and manage fluid within the internal fluid storage chamber 22 or elsewhere, as well as to further strengthen the tank 12. It should be understood that the various internal structures and other features described below with reference to one or both of the first and second examples of the tank containment system 10 may also be used in any combination with each other, as well as in further combination with one or more features of the above-described examples of the support structure 100.

In a preferred example of a containment system 10 for storing liquids such as LNG, the tank 10 may include a dividing

wall structure

200a, 200b, 200c and/or 200d positioned within and secured to the internal fluid storage chamber 22, as shown in fig. 7, 13, 17 and 18, respectively. As generally shown in the figures, a dividing wall structure 200 is located in each horizontal cylindrical wall 18 for preventing or mitigating wobble or dynamic movement of the fluid contained in the internal fluid storage chamber 22.

In one example, each partition wall 200 is positioned and secured to an adjacent horizontal cylindrical wall 18 at a substantially midstream location. As mentioned above, the shaking motion of the liquid contained in the wall 14 generates a corresponding dynamic load on the interior of the wall 14. The partition wall structure 200 provides an internal structure to partially block the flow of liquid contained in the horizontal cylindrical wall 18, thus reducing the degree of wobble and reducing the magnitude of dynamic loads received by the ends of the horizontal cylindrical wall 18. Additionally, it should be understood that all or part of the dividing wall structure 200 may be configured to perform the stiffening function of the cylindrical cross-section of the wall 14.

As shown in fig. 7, the example partition wall structure 200a includes a generally planar plate 204 configured to span a cross-section of the horizontal cylindrical wall 18 defining a portion of the internal fluid storage chamber 22. In this example, the planar plate 204 defines a plurality of oval-shaped apertures 206 arranged in an "x" pattern around the plate 204 to allow fluid communication on either side of the plate 204.

The material of outer perimeter 204a of planar plate 204 may be relatively more rigid than the material of inner portion 204b of planar plate 204. In this arrangement, the outer periphery 204a of the planar plate 204 performs a stiffening function to the cylindrical cross-section of the wall 14, while the inner portion 204b acts as a membrane to partially block the flow of liquid contained in the horizontal wall 18 by, for example, defining an aperture 206 as shown. In the application of the tank system 10 in the above-described dimensional example for containing LNG, the thickness of the aluminum material forming the plate 204 may be about 4-5 inches at the outer perimeter 204a, while the inner portion 204b may be about 1-2 inches thick, although it should be understood that a variety of materials of different thicknesses may be used. In this example, a plurality of cross-members 208 may further be provided to reinforce the inner portion 204b against dynamic loads perpendicular to the planar plate 204 due to the flow of liquid contained in the horizontal wall 18.

It should be understood that alternative configurations for the planar plate 204 may be used, more or fewer apertures may be used, and the aperture 206 may have any suitable polygonal or circular profile to suit a particular content or application, as known to those skilled in the art. For example, the planar plate 204 may be configured to have a substantially uniform thickness. In addition, in the exemplary partition wall structure 200b shown in FIG. 13, each plate 204 defines six rectangular holes 206 arranged in two rows of three holes 206 each. In another example of the partition wall structure 200c shown in fig. 18, a plurality of polygonal holes 206 are arranged around the periphery of the planar plate 204. In the example of the partition wall structure 200d shown in fig. 19, a plurality of polygonal holes 206 are uniformly arranged around the flat plate 204.

Fig. 15 and 16 show an example of a horizontally cut section of the containment system 10, showing an example of a corner reinforcement 250 provided for reinforcing the interior of the corner 20. Referring to fig. 15, a corner stiffener 250 positioned in the bottom corner 20 of the storage tank 12 includes a first plate 252, a second plate 254, and a third plate 256 (positioned angularly below and extending downwardly from the first and second plates). First plate 252, second plate 254, and third plate 256 span respective portions of corners 20 and are connected to respective interior walls of corners 20 within interior fluid reservoir 22, as best seen in fig. 16 (all four lower corners 20 having corner stiffeners 250 are shown). It should be understood that some or all of the corners 20 may include corner stiffeners 250, and one or more of the corner stiffeners 250 may not be required depending on the application.

In one example, the first plate first edge 258, the second plate first edge 260, and the third plate first edge 262 are each connected to the corner 20 along an adjacent joint 30 formed by the vertical cylinder wall 16 and the horizontal cylinder wall 18. First plate 252, second plate 254, and third plate 256 are connected at joint 264. In one example, the first plate 252, the second plate 254, and the third plate 256 are spaced 120 degrees apart. It should be understood that the corner stiffeners 250 may take the form of other configurations, plates or webs to suit a particular application, as known to those skilled in the art.

In the example partition wall structure 250, each of the first, second, and third plates 252, 254, and 256 define respective through-holes 270, 272, and 274 to allow fluid communication on either side of the plate so that portions of the otherwise partitioned internal fluid storage chamber 22 are not blocked. As shown in fig. 15, a partition wall structure 250 may be positioned in each top corner 20 of the storage tank 12. It will be appreciated by those skilled in the art that other configurations and orientations for the divider wall structure 250 may be used and that other stiffeners may be positioned in the corners 20.

Referring to fig. 19, an alternative example of a corner reinforcement 440 is shown. In this example, the reinforcement 440 of the can corner 20 is in the form of a plate 445 (only half of the plate is shown in the cross-sectional view of fig. 19) defining an interior aperture 450 (surrounded by the plate 445). In this example, the plate 445 is angled at about 45 degrees and is seam welded on its ends, or alternatively completely around its periphery, to the adjacent walls of the corner 20 and to the adjacent vertical 16 and horizontal 18 cylinder walls. The apertures 450 serve to reduce weight and provide resistance to the stored fluid from shaking, as described above.

Other forms, configurations, orientations, and locations of corner stiffeners known to those skilled in the art to suit a particular application may be used. The materials used to construct the storage tank 12 as described above may be used to construct the

partition walls

200, 250, and 440. In one example, the illustrated

divider walls

200, 250, and 440 are rigidly and continuously seam welded to the tank 12.

It should be understood that the illustrated

corner reinforcements

250 and 440 may not be necessary or desirable in certain applications. As can be seen with reference to fig. 7-9, certain disclosed embodiments, such as the embodiment of fig. 1-10 with the first example of the external support structure 100, may not include corner reinforcements. In this and other examples, the reinforcing function of the illustrated

corner reinforcements

250 and 440 may be performed by other aspects of the storage tank 12 and/or the outer support structure 100, if desired.

In the example of the storage tank 12 described and illustrated above, the twelve

cylindrical walls

16 and 18 are closed-section, forming an internal fluid reservoir 22. In this example, an opening 290 is formed on each of the six sides of the canister 12, opening into the interior space 295 between the facing interior walls of the cylinder. In the illustrated example of the tank containment system 10, the opening 290 is sealed closed and the interior space 295 is disposed in fluid communication with the interior fluid storage chamber 22 inside the cylinder to utilize the interior space 295 as an additional reservoir of fluid, as described below.

Referring representatively to fig. 9, it can be seen that the closure plate 300a and the inward facing portions of the outer

cylindrical walls

16 and 18a (e.g., inner portion 310 of the vertical cylindrical wall 16 and inner portion 312 of the horizontal cylindrical wall 18a are labeled) can be used to seal and define the secondary storage chamber 302 defined by the closure plate 300a and the

inner wall portions

310 and 312 forming the

cylindrical walls

16 and 18a of the storage tank 12.

Various configurations of the closure plate 300 are shown in the various figures, which are explained with additional reference to FIGS. 10A-C. In the example shown in fig. 10A, the closeout plate 300A is planar and is configured to extend normally between adjacent walls 14. In an alternative example shown in fig. 10B, the closing plate 300B is spherical or rounded and extends substantially between adjacent walls 14, but at a position further outside of an imaginary line connecting the longitudinal axes of the adjacent walls 14. In an alternative example shown in fig. 10C, the closeout plate 300C is also spherical or rounded, but extends between adjacent walls 14 at an outer portion of the walls 14, such that the closeout plate 300C extends generally tangentially between adjacent walls 14.

Increased storage capacity is achieved by using the

closure panels

300a, 300b, or 300c and, correspondingly, the interior space 295 for storage. In one example of a tank 12 having the above dimensions, the volumetric storage efficiency of the tank system 10 is increased from about 0.81 to 0.88, which is far superior to existing designs, compared to a cube of similar dimensions. Further, when the closing

plates

300b, 300c connected at positions incrementally outside the center of the can 12 are used, heat loss is reduced, i.e., the outer surface of the can 12 includes less bends and corners that are easy to serve as a heat sink.

For example, the tank containment system 10 may be configured to include only one type of

closure panel

300a, 300b, and 300c, or may be configured to include a combination of

closure panels

300a, 300b, and 300c and other closure panels (e.g., triangular or l-shaped closure panels) not specifically shown. The

closure plates

300a, 300b, and 300c may be made of the material used for the

walls

16,18 a, as described above. Those skilled in the art will appreciate that other configurations and orientations of the

closure plates

300a, 300b, and 300c may be used for sealing and defining the auxiliary storage compartment 302.

As best seen in fig. 9, in the one example described above, where the cylindrical wall 14 is of closed cross-section and the internal fluid reservoir 22 serves as the sole storage area, the

cylindrical walls

16 and 18a have

outer portions

320 and 322, respectively (e.g., the outer half or circumference of the circular cross-section facing the exterior of the tank), and corresponding

inner portions

310 and 312. As shown in fig. 9, the respective first and second wall portions may be defined by or positioned adjacent to the closure plate 300 a.

As further shown in fig. 9, the liquid contained in the internal fluid reservoir 22 exerts a radial hydrostatic force F1 against the interior 310 of the vertical cylindrical wall 16. The load-bearing capacity of the vertical

cylindrical walls

310, 320 must be sufficient to handle the force F1. Without the use of the closure panel 300a and without the use of the auxiliary storage compartment 302 (or space 295) for storage, the inner wall portion 310 must bear similar loads and require a substantially similar construction as the outer wall portion 320. In the application of the tank system 10 in the dimensional example described above for containing LNG, the thickness of the

walls

16 and 18 is estimated to be 1 to 6 inches thick for aluminum. For steel, a thickness of 0.5-4 inches may be used. Other thicknesses known to those skilled in the art may be used depending on the materials and applications used.

However, in the case where the closing plate 300a (or the

closing plate

300b or 300c) is used and the auxiliary storage chamber 302 is used, containing the liquid in the auxiliary storage chamber 302 generates an opposite radial static force F2 to the opposite side portions of the vertical cylindrical wall portion 310 that partially defines the auxiliary storage chamber 302. Since the hydrostatic force F2 counteracts and balances the hydrostatic force F1, the load bearing capacity and corresponding thickness of the vertical and

horizontal cylinder walls

16 and 18a may be reduced in the

respective wall portions

310 and 312, which reduces the mass and material costs of the storage tank 12.

In the example of a storage tank 12 that utilizes only an internal fluid storage chamber 22 within the cylindrical wall 14, one or more ports in the exterior of the wall (not shown) in communication with the internal chamber 22 may be used to fill or withdraw fluid from the internal fluid storage chamber 22. Where the auxiliary reservoir chamber 302 is used with an internal fluid reservoir chamber 22, one or more ports (not shown) on, for example, the wall portions 310 and/or 312 may be provided in the appropriate wall 14 to provide fluid communication between the internal fluid reservoir chamber 22 and the auxiliary reservoir chamber 302.

Referring to fig. 18, an example of a first gusset 400 (two shown) is shown. In this example, each gusset 400 is positioned between and rigidly connected to vertically adjacent horizontal tubular walls 18 in auxiliary storage compartment 302. Each gusset 400 may include one or more apertures 410 (two shown) to allow fluid flow through the gusset 400 to prevent wobble of fluid in the auxiliary storage chamber 302, substantially as described above with respect to the partition wall 200. In one example, the gusset is a rigid planar plate, but may take other forms and configurations known to those skilled in the art to suit the application.

As also seen in fig. 18, one or more second gussets 420 are positioned substantially as shown between and rigidly connected to the first gusset 400 and the horizontal cylinder 18. In this example, the second gusset 420 preferably has a plurality of similar apertures 425 to allow restricted flow of fluid to prevent fluid from dangling inside the auxiliary storage chamber 302. The first and second gussets 400, 420 provide structural reinforcement and prevent fluid from dangling inside the auxiliary storage chamber 302. Other gussets, stiffeners and anti-roll structures known to those skilled in the art may be used. For example, as shown in fig. 19, the second gusset 420 is used without the first gusset 400. In this example, the second gusset 420 is rigidly connected to four adjacent horizontal cylinder walls 18, and further includes a third gusset 430, which is shown substantially at a horizontal position between the generally vertically oriented second gussets 420.

As further seen in fig. 7 and 8,

gussets

502 and 504 may be positioned between and rigidly connected to vertically adjacent parallel horizontal cylinder walls 18 in auxiliary storage compartment 302, while gusset 506 is positioned between and rigidly connected to horizontally adjacent parallel vertical cylinder walls 16. In addition,

gussets

502, 504, and 506 are connected at their respective intersections. Each of the

gussets

502, 504, and 506 extends in a plane passing through the center of the storage tank 12. The

gussets

502 and 504 extend vertically parallel to respective opposite sides of the storage tank 12 and are interrupted at the intersection with the wall 14 and at the intersection with the respective adjacent gusset. The gussets 506 extend horizontally parallel to the opposing top and bottom surfaces of the storage tank 12, and are also interrupted at the intersection with the wall 14 and at the intersection with the respective adjacent gussets. For clarity, only three

gussets

502, 504, and 506 of the total eight gussets are illustrated and described. It can be seen and understood that other gussets are similarly positioned and configured as

gussets

502, 504, and 506.

As shown,

gussets

502, 504, and 506 may be rigidly interconnected at their intersections and with support structure 100. As shown, vertically disposed

gussets

502 and 504 are connected to central

vertical supports

104a and 102a, respectively, while horizontally disposed gusset 506 is connected to horizontal support 106 a.

Gussets

502, 504, and 506 may fluidly separate auxiliary reservoir chamber 302, or, as described above, may include one or more apertures (not shown in this example) to allow fluid flow.

Referring to fig. 13, 14 and 15, one example of a means for filling and extracting fluid from tank 12 is in the form of a packed tower 350. In this example, the packed tower 350 includes a substantially horizontal hollow tube 352 connected to a substantially vertical hollow tube 354. The vertical tube 354 includes an intake 356 located near or extending from the top of the storage tank 12. The intake 356 is configured to be connected to a remote fluid source such as a transfer pump (not shown) or other device known to those skilled in the art. Vertical tube 354 also includes an output port 357 located near the bottom of storage tank 12. Horizontal hollow tube 352 may be connected to vertical tube 354 at the location of output port 357, and as shown in fig. 15, to and through one or more of cylindrical horizontal walls 18 to provide fluid communication between intake port 356 and internal fluid storage chamber 22.

As best shown in fig. 13, the vertical hollow tubes 354 are supported by a plurality of support brackets or structures 358, which preferably allow fluid communication on either side of the support structures 358. The vertical tubes 354 and the support structures 358 are positioned along channels formed in the central portion of the partition wall structure 200b in the spaces between the planar plates 204. The vertical tube 354 may include one or more additional ports (not shown) to provide fluid communication between the intake 356 and the auxiliary storage chamber 302. Optionally, a through port (not shown) may pass through an inner portion of cylindrical wall 16b and/or 18b to facilitate fluid flow into and out of tank 12.

The packed tower 350 may also be used to draw fluid from the internal fluid storage chamber 22 and the auxiliary storage chamber 302. To optimize extraction, the output port 357 may be positioned proximate to the inner surface of the bottommost closure plate 300b when the canister 12 is in the installed position. The closing plate 300b may be shaped to utilize gravity when extracting fluid from the auxiliary storage chamber 302. As shown in fig. 13, the location of the output port 357 at the lowest point of the auxiliary storage chamber 302, just above the inflection point on the surface of the curved closure plate 300b, allows all of the fluid within the tank 12 to be extracted from the auxiliary storage chamber 302, and correspondingly from the interconnected internal fluid storage chambers 22. It should be understood that other lines, pipes, or ports may be used to allow rapid, substantial flow of fluid into and out of the tank 12 to facilitate filling and extraction of the fluid.

Referring to fig. 20-23, a third example of the tank containment system 10 is shown. Fig. 20 is a perspective view showing the storage tank 12 and a pair of external support structures 100 on either side of the storage tank 12. The outer support structure 100 extends between the outer surfaces of the rigid

cylindrical walls

16,18 and reinforces the storage tank 12 against dynamic loading from the fluid in the inner fluid storage chamber 22. One of the outer support structures 100 in fig. 20 is shown to include a plurality of

interconnected supports

102, 106 that form a reinforcing grid structure.

The other outer support structure 100 in fig. 20 is shown covered by a generally planar closure plate 300a that extends at least partially across an outer surface of one of the outer support structures 100. It should be understood that both outer support structures 100 in fig. 20 may comprise a grid structure of

interconnected supports

102, 106 and may be covered by a closing plate 300a extending at least partially over the outer surface of each outer support structure 100.

The inner surface of the closure plate 300a, the inner surface of the outer support structure 100, and the outer surfaces of the plurality of rigid

cylindrical walls

16,18 may be used to define an auxiliary storage compartment 302 similar to that described with reference to fig. 1-19. By positioning the closure plate 300a outside the outer support structure 100 and outside the outer surfaces of the

rigid cylinder walls

16,18, the volume of the auxiliary storage compartment 302 can be greatly increased. The design of the packed column 350 can also be simplified, as described with reference to fig. 23.

The outer support structure 100 in fig. 20 also includes a plurality of blocks 600. Some of the blocks 600 are arranged within openings 602, each opening 602 being defined by the intersection of four of the rigid interconnecting supports 102, 106 in each grid structure. The blocks 600 disposed within the openings 602 are configured to retain the storage tanks 12 in an installed position when abutting a bracket extending from a cargo hold of a carrier, as further described with reference to fig. 23. The block 600 may be formed of marine grade, laminated, dense wood and bonded to the

supports

102, 106 using, for example, epoxy. Other high strength materials may also be used for the block 600.

Some of the blocks 600 are also disposed on a support surface 604 of the outer support structure 100, the support surface 604 extending from an outer surface of one of the bottommost rigid cylinder walls 18 to a respective closure plate 300a overlying the respective outer support structure 100 when the storage tank 12 is in an installed position within the cargo compartment of the carrier. The support surface 604 and the coupling block 600 are configured to abut a ledge extending from a cargo hold in the transport vessel to hold the tank in an installed position, as further described with reference to fig. 23.

Fig. 21 is a perspective view of the bottom side of the tank containment system 10 of fig. 20 as viewed from direction C in fig. 20. Here, both outer support structures 100 are substantially covered by a closure panel 300a extending across the outer surface of the outer support structure 100, as depicted in fig. 20. The tank 12 further includes a closure plate 300a extending between an outer surface of the bottommost rigid cylindrical wall 18 and a plurality of partition walls 200, wherein each partition wall 200 extends through an opposing horizontal rigid cylindrical wall 18 and across the internal fluid chamber 22 in an orientation transverse to a longitudinal axis of the opposing horizontal rigid cylindrical wall 18.

Furthermore, each partition wall 200 extends outwardly from the outer surface of the opposing horizontal rigid cylindrical wall 18 between the cross-sections of the bottommost closure plate 300a to form a base 150 for the storage tank. The base 150 of the storage tank 12 is configured to support the storage tank 12 in an installed position within the cargo compartment of the carrier. In the example of fig. 21, two divider walls 200 extend centrally through the opposing horizontal rigid cylindrical walls 18 and intersect at the center of the bottommost side of the storage tank 12, forming a cross shape for the base 150, although other shapes, intersections, and numbers of divider walls 200 are possible. A plurality of blocks 600 may also be arranged along the base 150 to position the tanks 12 within the cargo hold of the carrier and to keep the tanks 12 warm.

Fig. 22 is a side view of the tank containment system 10 of fig. 20. Two support surfaces 604 are shown extending from the outer surface of the opposite bottommost rigid cylinder wall 18 to the respective closure plate 300 a. By including support surfaces 604 extending from the opposing rigid cylinder walls 18, the storage tank 12 may be restrained against pitch or roll of the carrier when in the installed position. The support surface 604 is shown extending angularly at an angle between 15 and 60 degrees above a horizontal plane extending through the longitudinal axis of the horizontal rigid cylindrical wall 18 forming the bottommost side of the storage tank 12 when the storage tank 12 is in the installed position.

In one non-limiting example, the support surface 604 may be angled between 25 and 40 degrees above horizontal to optimize support of the storage tank 12. For example, the angled support surface 604 may rest on a ledge extending from the cargo compartment, as shown in fig. 23, and at the same time may allow for expansion and contraction of the cargo compartment. By angling the support surfaces 604, any variations in the build tolerances or wall positions of both the storage tank 12 and the cargo compartment will not adversely affect the ability to hold the storage tank 12 in the installed position.

Figure 23 is a cut-away perspective view of the tank containment system 10 of figure 20 shown in an installed position within the cargo hold 160 of a marine carrier 162. The blocks 600 within the openings 602 formed by the

interconnected supports

102, 106 of the side external support structure 100 are engaged by supports 606 extending from the upright walls 164 defining the sides of the cargo hold 160. The support 606 may be configured to clamp the blocks 600 within adjacent openings 602 to inhibit movement of the tank 12 relative to the cargo hold 160, for example, in the event of roll or pitch motion of the carrier 162.

The additional blocks 600 may extend from the base 150 and from a support surface 604 on the underside of the opposing outer support structure 100 to rest on the bottom surface and a skirt or ledge 608 extending from the upright wall 164 of the cargo hold 160, respectively. Ledge 608 may be configured to support the weight of tanks 12 in carrier 162 when tanks 12 are in the installed position. By angling the support surface 604 and, optionally, angling the blocks 600 extending from the support surface 604, any variation in the size of the cargo hold 160 may be accommodated in the design of the tank 12. This is important in view of the temperature difference between the tank 12 and the carrier 162 and the large size of the tank 12 and the cargo hold 160.

The single divider wall 200 is also shown in fig. 23 as comprising a plurality of generally planar panels 204 configured to span the cross-section of the horizontal wall 18 defining a portion of the internal fluid storage chamber 22. Each planar plate 204 defines a plurality of oval-shaped apertures 206 arranged in an "x" pattern around the plate 204 to allow fluid communication on either side of the plate 204. The channel 610 is also present in the central portion of the partition wall 200 in the space between the planar plates 204. The passageway 610 is sized sufficiently to allow the packed column 350 to extend through the tank 12.

In the third example of fig. 23, the closure plate 300a is shown extending between and below the bottommost horizontal rigid cylindrical wall 18. A plurality of vanes 612 extend along the inner surface of the closure plate 300a to facilitate mitigating wobble or dynamic movement of the fluid within the auxiliary storage chamber 302. Considering the position of the closing plate 300a under the bottommost horizontal rigid cylindrical wall 18, it is only necessary to use the vertical hollow tube 354 described in fig. 13-15 for the filling tower 350 instead of the combination of the vertical hollow tube 354 and the horizontal hollow tube 352, since the horizontal rigid cylindrical wall 18 may be designed with holes to allow fluid to enter the auxiliary storage chamber 302.

It should be understood that the above-described embodiments, features, and examples of the structure and features of the tank containment system 10 may be modified and/or combined in various different ways depending on one or more design, strength, manufacturing, cost, and/or other criteria. These dimensions are described based on some contemplated design scenarios and are given as non-limiting examples. It should be understood that other thicknesses may be used depending on the materials used and the application.

In some examples, a large volume natural gas storage tank is disclosed, comprising: a plurality of rigid tubular walls, each rigid tubular wall comprising a mid-section having a closed tubular cross-section and opposing ends, each rigid tubular wall of the plurality of rigid tubular walls being interconnected at each end with a respective end of two other rigid tubular walls of the plurality of rigid tubular walls such that an interconnected interior of the plurality of rigid tubular walls defines an internal fluid storage chamber; and a plurality of closure plates, each closure plate connected between outer surfaces of the successively interconnected rigid tubular walls to define a side of the storage tank, wherein an inner surface of the closure plate and an outer surface of the plurality of rigid tubular walls at least partially define an auxiliary fluid storage chamber.

The closure plates on opposite sides of the tank can be connected to the exterior of the continuously interconnected rigid tubular walls at a location that maximizes the distance between the opposing closure plates. Each closure plate can extend tangentially between the exterior of the continuously interconnected rigid tubular walls on each side of the tank. Each closure plate can extend tangentially between the exterior of the continuously interconnected rigid tubular walls on each side of the tank. Each closure plate may include one of a spherical outer surface, a rounded outer surface, a triangular outer surface, an l-shaped outer surface, or a flat outer surface.

In some examples, the bulk natural gas storage tank includes a packed tower including an outlet disposed proximate an inner surface of a closure panel forming a bottommost side of the storage tank. The packed tower may include a substantially vertical hollow tube extending across the auxiliary fluid storage chamber between two opposing sides of the storage tank from an intake at the first end to an output at the second end. The vertical hollow tube can define a plurality of ports spaced along an exterior of the vertical hollow tube and providing fluid communication with the secondary fluid storage chamber. The vertical hollow tube can be supported by a plurality of support structures, each connected on opposite sides of the storage tank between the outer surfaces of the rigid tubular walls. The fill tower may include a generally horizontal tube in fluid communication with the output port and extending across the auxiliary fluid storage chamber between two opposing sides of the storage tank along an inner surface of the closure panel forming a bottommost side of the storage tank.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.

Claims

1. A natural gas storage tank (12), comprising:

a plurality of rigid tubular walls (16, 18),

wherein each rigid tubular wall (16, 18) comprises a middle section extending along a longitudinal axis and having a closed tubular cross-section and opposite ends,

wherein each rigid tubular wall (16, 18) is interconnected at each end with a respective end of two other rigid tubular walls of the plurality of rigid tubular walls (16, 18) such that the interconnected interiors of the plurality of rigid tubular walls (16, 18) define an internal fluid storage chamber (22),

wherein the outer surfaces of the flat continuously interconnected rigid tubular walls (16, 18) define the sides of the tank (12);

a plurality of external support structures (100),

wherein each outer support structure (100) extends between the outer surfaces of the rigid tubular walls (16, 18) forming each side of the tank (12),

wherein each outer support structure (100) reinforces the tank (12) against dynamic loads from the fluid in the inner fluid storage chamber (22); and is

Characterized in that it comprises a plurality of closing plates (300),

wherein each closure plate (300) extends at least partially across an outer surface of one of the plurality of outer support structures (100),

wherein an inner surface of the closure plate (300), an inner surface of the outer support structure (100), and an outer surface of the plurality of rigid tubular walls (16, 18) at least partially define an auxiliary fluid storage chamber (302), and

wherein at least one external support structure (100) comprises a support surface (604) extending from an outer surface of one of the bottommost rigid tubular walls (16, 18) to the respective closure plate (300) when the tank (12) is in an installed position within a cargo hold (160) of a transport vessel (162), the support surface (604) being configured to abut a ledge (608) extending from the cargo hold (160) and to allow expansion and contraction of the cargo hold (160) when the tank (12) is held in the installed position.

2. The natural gas storage tank (12) of claim 1, wherein each outer support structure (100) comprises a plurality of lattice structures formed of rigidly interconnected supports (102, 104, 106).

3. The natural gas storage tank (12) of claim 2, further comprising:

a plurality of blocks (600), each block (600) disposed within an opening (602) defined in one of the grid structures by four rigidly interconnected supports (102, 104, 106) and configured to retain the tank (12) in an installed position when abutting a bracket (606) extending from a cargo hold (160) of a carrier (162).

4. The natural gas storage tank (12) of claim 1, wherein the two outer support structures (100) on opposite sides of the storage tank (12) include support surfaces (604) configured to restrain the storage tank (12) against pitch or roll when in an installed position.

5. The natural gas storage tank (12) of claim 1, wherein the support surface (604) extends at an angle of between 15 and 60 degrees above a horizontal plane extending through the longitudinal axes of all rigid tubular walls (16, 18) forming the bottommost side of the storage tank (12) when the storage tank (12) is in the installed position.

6. The natural gas storage tank (12) of claim 5, wherein the angle of the support surface (604) is between 25 degrees and 40 degrees.

7. The natural gas storage tank (12) of claim 1, further comprising:

a plurality of partition walls (200), wherein each partition wall (200) extends through at least one rigid tubular wall (16, 18) and across the internal fluid storage chamber (22) in an orientation transverse to a longitudinal axis of the at least one rigid tubular wall (16, 18).

8. The natural gas storage tank (12) of claim 7, wherein each dividing wall (200) defines at least one aperture (206) to allow a restricted flow of fluid through the dividing wall (200).

9. The natural gas storage tank (12) of claim 7, wherein each partition wall (200) extending through the bottommost rigid tubular wall (16, 18) of the storage tank (12) extends outwardly from an outer surface of the rigid tubular wall (16, 18) to form a base (150) for the storage tank (12).

10. The natural gas storage tank (12) of claim 9, wherein the base (150) of the storage tank (12) is configured to support the storage tank (12) in an installed position within a cargo hold of a transport vessel.

11. The natural gas storage tank (12) of claim 9, wherein the base (150) of the storage tank (12) includes a partition wall (200) extending outwardly from an outer surface of each rigid tubular wall (16, 18) at a bottommost side of the storage tank (12).

12. The natural gas storage tank (12) of claim 9, wherein the partition wall (200) on the base (150) of the storage tank (12) extends centrally through the rigid tubular walls (16, 18) and intersects at a center of a bottommost side of the storage tank (12).

13. The natural gas storage tank (12) of claim 1, further comprising:

a fill tower (350) disposed in fluid communication with the auxiliary fluid storage chamber (302), the fill tower (350) including an output port (357) disposed proximate an inner surface of a closure plate (300) forming a bottommost side of a storage tank (12).