US 2911125 A
Abstract available in
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Description (OCR text may contain errors)
Nov. 3, 1959 c. D. DOSKER STORAGE TANK 30R cow LIQUIDS 2 Sheets-Sheet 1 Filed July 9, 1958 FIG. 1
INVENTOR. orfleizus D Das/zer Nov, 3, 1959 2 Sheets-Sheet 2 Filed July 9, 1958 I r T 0 m w h. w ww d 8 n n fl g m; 8 6 5 5 L a b N a w age and transportation problems arise. rectly contacted by the cold liquid must be of special construction to withstand the extremely cold temperasronaon TANK FOR corn mourns Cornelius D. Dosker, Iiouisville, Ky., assign'or to Constock International Methane Limited, Nassau, Bahamas, a corporation of Bahamas Application July 9, 1958, Serial No. 747,413
14 Claims. (Cl. 220-11) This invention relates, as indicated, to improvements in tanks used for storing cold liquids, and more particularly, but not by way of limitation, to an improved land-based storage tank for storing liquefied natural gas.
Many occasions arise whenit is desirable to store natural gas in a liquefied state for variable periods of time. For example, in those areas having a natural-gas shortage and being supplied with natural gas from a reform at equivalent'pressure, it is most desirable to store the'natural gas in a liquefied state at the point of use.
In addition to the above, an industry is now in the stageof development for the primary purpose of shippingnatural gas to localities which cannot be economically reached by pipeline'from the source of natural gas supply. The naturalgas could be transported to the remoteloc alities in a gaseous form by use of ships and the like. However, and as noted above, natural gas in gaseous form-occupies so much volume as to'make transportation thereof in this form impractical. Therefore,.
the'natural gas is liquefied at or near the source of supply 'and transported in a liquefied state to the remote locality for revaporization and use as a fuel. It is highly desirable to maintain a supply of the gas in a liquefied state both at or near the source of supply and at or near I the point of use. Such storage involves unusual problems, principally due-t the fact that liquefied natural gas has atemperature of from 240 to 258 F. at,,or slightly above, atmospheric pressure, the pressure at which the -liquefied natural gas-is normally transported as well as stored at the source of supply and the point of use.
When storing a cold liquid such as liquefied natural gas in the conventional manner by use of a metal tank simply surrounded with an insulating material, 'bothstor- The metal ditures, with the metal usually" being stainless steel or aluminum; Such metals are, of course, expensive when compared with more conventional plate steel tanks. Also, I such a metal tank must of necessity have suflicient strength.
to befs'elf-supporting and contain the volume of liquid desired to be stored, thereby requiring not only an ex pensive installation,- but also ,a serious transportation problem in transporting the tank to the point of use. It may also be noted that such a tank will be subjected to substantial expansion and contraction by the substantial temperature changes in the tank, which variations .'-in the dimensions of the tank soon render most popular United States Patent 0" 2,911,125 Patented Nov. 3, 1959 insulating materials, such as the fibrous insulating materials, inoperable.
invention contemplates the: construction of such a tankprincipally out of wood to provide a light-weight structure which may be easily assembled at the point of useand easily transported to the point of use. The side walls of the tank are preferably formed out of insulating wood panels sealed in side-by-side relation around the periphery of the tank to provide a self-supporting and efiective insulation barrier. The bottom of thetank is also preferably formed out of the same material. A relatively thin lining extends around the inner periphery of the tank and over the bottom of the tank to provide a storage chamber for receivingthe liquefied natural gas. The
. lining is not bonded to the inner surface of the insulating panels and is usually not self-supporting. I therefore contemplate the use of a novel supporting structure positioned within the lining to retain the lining in the desired position in the tank, without interfering wth expansion and contraction of the lining resulting from the temperature changes when the tank is emptied and filled with the cold liquefied natural gas.
An important object of this invention is to provide a light-weight and economical tank for storing cold liquids.
Another object of this invention is to provide a tank for storing cold liquids which may be transported to the point of use disassembled, and then easily assembled in the field at the point of use. i
A further object of this invention is to provide a novel tank for storing cold liquids having a separate and relatively thinlining for receiving the cold liquid, without the use of an outer supporting metal shell or a cumbersome framework. I
A stillfurther object of this invention is to provide a novel non-self-supporting lining in a storage tank used for storing cold liquids, and a novel'supporting structure fora-retaining the lining in the desired position in the tank.
Other objects and advantages ofthe invention will be evident from the following detailed description, when read in conjunction with the accompanying drawings which schematically illustrate my invention.
In the drawings:
Figure 1 is a vertical sectional View through a tank constructed in accordance with this invention;
Figure 2 is a detailed horizontal sectional View through a typical portion of the side walls of the tank illustrated in Fig. 1; 1
Figure 3 is a vertical sectional view through a portion of the bottom of the tank shown in Fig. l illustrating the connection of the bottom of the lining to the bottom of the tank;
Fig. 4 is an enlarged sectional view througha portion of the lining illustrating the construction of the lining and the support for the lining; and 1 Figure 5 is a view similar to Fig. 4 illustrating a modified construction.
Referring to the drawings in detail, and particularly Fig. 1, reference character 10 generally designates the entire tank structure which includes a base ring 12 supported on suitable footings 14' spaced circumferentially around; the base ring to support the major portion of the weight of the tank structure 10 and the contents of the near the outer periphery of the ring to provide an upwardly facingshoulder 16." Normally, the ring .12 will be of substantially circular configuration, although it will be understood that the ring 12' may have any desired configuration, such as an oval shape or a polydiagonal shape, such as an octagon. The bottom ,18 of the tank rests on the top of the ring 12 and preferably comprises a plurality of insulating wood panels extending diagonally across the ring 12 and sealed in side-by-side relation to provide a continuous bottom wall for the tank. Each of the insulating panels comprising the bottom 18 is preferably constructed with an insulating wood layer 20 of substantial thickness, with sheets of hardwood 22 on the upper and lower faces of the insulating wood 20. The insulating wood layer 20 may be, for example, balsa or quippo wood and the sheets 22 may be formed out of a hard plywood. The bottom 18 is additionally supported by a suflicient number of footings 24 and wood pads 26 providing cushions between the bottoms of the panels comprising the bottom 18 and the footings 24.
The vertical side Walls of the tank 10 are formed by use of a plurality of vertically extending insulating panels 28 extending upwardly from around the periphery of the bottom 18 and sealed in side-by-side relation to provide a continuous insulating barrier around the periphery of the tank. The lower end of each panel 28 is notched at 30 to mate with the upwardly facing shoulder 16 extending around the base ring 12 and support the panels 28 directly on the base ring 12. Also, the lower end portions of the panels 28 are secured to the outer periphery of the bottom 18 by suitable splines or keys 32 extending into mating grooves in the panels 28 and theends 'of the panels comprising the bottom 18. A sealing compound (not shown) may be provided between the contacting surfaces of the vertical panels 28 and the bottom 18 to provide an uninterrupted insulation around the sides and bottom of the tank 10.
The panels 28 are suitably constructed to be selfsupporting, that is, the panels 28 are of suflicient strength to support at least their own weight without collapsing and without appreciably bending. I prefer to construct the panels 28 in the same manner as the panels comprising the bottom 18, that is (see Fig. 2), with a relatively strong layer 34 of an insulating wood, such as balsa or quippo wood, and hardwod sheets 36 bonded over the inner and outer faces of the layer 34. When the tank 10 is formed with a generally circular horizontal cross section, the panels 28 are curved transversely, as indicated in Fig. 2, with the panels in side-by-side abutting relation. I also prefer to insert a strip of hardwood 38 in each side edge of each panel 28 throughout the length of the respective panel, with the outer face of each strip 38 being tapered at 40 from the inner surface of the respective panel. The tapers 40 of adjacent strips 38 are extended in opposite directions to form a tapered groove for receiving a tapered strip 42 of relatively soft wood, such as balsa wood. Each strip 42 extends throughout the length of the panels 28 and is wedged against the respective mating tapers 40 to provide an effective seal between adjacent panels 28 and to provide an expansion joint between adjacent panels 28. When cold liquid is stored in the tank, as will be hereinafter described, the inner portions of the panels 28 will become substantially colder than the outer portions of the panels, thereby causing the inner portions, particularly, of the panels to contract and expand. The strips 42 accommodate this relative movement between adjacent panels to provide an expansion joint and maintain an effective seal between the adjacent panels. I also prefer to extend a sealing strip 44 formed out of rubber or the like through mating grooves in the mating faces of each pair of strips 38 outwardly of the strips 42 to further assure that a seal will be main- 4 tained between adjacent panels when the tank is filled with a cold liquid.
The vertical panels 28 are retained in assembly and provided with additional radial strength by use of a plurality of vertically spaced retaining bands 46 encircling the panels 28, as illustrated in Fig. 1. The bands 46 may be formed out of any desired metal, such as steel, since they will not be exposed to any substantial temperature changes. The bands 46 are suitably secured around the tank in relatively tight engagement with the outer surfaces of the panels 28. To assure that the panels 28 will withstand the force imposed thereon by the bands 46, I prefer to provide a hardwood, such as Douglas fir, inserts 48 in each panel 28 opposite each of the bands 46. The inserts 48 may be of any desired configuration as long as they are suitably bonded to the insulating wood 34 in the respective panels and provide additional compressive strength in the panels at the points ,of contact with the retaining bands 46. I also prefer to provide a hardwood insert 50 in the upper'and lower ends of each panel 28 to engage the base ring 12 and the cover 52, which will be hereinafter described. The hardwood inserts 50 at the lower ends of the panels 28 assure that the panels 28 will not be damaged by being supported on their ends, and the hardwoodinserts St) at boththe upper and lower ends of the panels provide protection for the insulating wood in the panels from adverse weather.
The cover 52 may be of any desired construction, such as of the bow-string truss type using a suitable base portion 54 and a suitable number of trusses 56 extending upwardly in the form of bow strings from the opposite edges of the base portion 54. The base portion 54 and the trusses 56 may be easily formed out of wood to provide a light-weight and economical construction. I also prefer to secure a metal shield 58 over the top of the cover 52 to protect the cover from rain, snow, and the like. The shield 58 is preferably formed out of aluminum. The cover 52 is preferably insulated by suitably securing a plurality of insulating panels 60Qacross the bottom of the base portion 54 in side-by-side sealing engagement to provide a continuous insulation over the lower faceof the cover. The panels 60 are shaped tofit closely against the inner surfaces of the upper ends of the vertically extending panels 28, with the base portion 54 of the cover 52 being of a larger diameter to rest on the tops of the panels 28. It is also desirable to apply a sealing compound between the contacting surface of the base portion 54 of the cover and the upper ends of the panels 28 to assure that no appreciable amount of vapor will leak from the tank around the cover.
A relatively thin lining, generally designated by reference character 62, and formed out of a gas and liquidimpervious material, extends around the inner surfaces of the vertical panels 28 and over the upper face of .the bottom 18 to form the storage chamber for receiving cold liquid fed to the tank. The lining 62 extends loosely over the inner surfaces of the vertical panels 28 and the bottom 18 for expansion and contraction independently of the panels 28 and the bottom 18, and comprises a base plate 64 with a plurality of vertically superimposedan- 'nular panels or rings 66 extending vertically from around the outer periphery of the plate 64. Both the plate 64 and the panels 66 are preferably formed out of a thin metal which will withstand the substantial temperature changes incurred by handling liquefied natural gas, such as stainless steel or aluminum. However, the lining 62 may be formed out of any other material, such as a plastic, which will withstand the temperatures involved.
The base plate 64 hasthe same configuration as the bottom 18 of the tank and is provided with at least one circumferentially extending corrugation 68 to accommodate expansion and contraction of the plate. The base plate 64 is also keyed to the bottom 18 to prevent the plate 64 from creeping on the bottom 18 and to retain the plate 64 centered with respect to the bottom 18.
Any desired shape of key may be used, such as a square configuration in the center of the plate 64. However, I prefer to utilize the corrugation 68 or a similar corrugation for keying the plate 64 to the bottom 18, as illustrated in Fig. 3. Thecorrugation68 is turned downwardly and loosely fits in a circumferential groove 70 formed in the upper'face of a ring 72 of, for example, balsa wood. The ring 72 is in turn disposed in a circumferential groove 74fo'rmed in the upper face of the bottom 18. It will thusbeapparent that at least a portion of the corrugation 68 will remain in the mating groove 70 upon expansion and contraction of the base plate 64 to retain the base plate centered with respect to the bottom 18 of the tank.
As illustrated in Fig. 1, the lower edge of the lowermost panel 66 is suitably welded or brazed around the outer periphery of the base plate 64 to provide a gas and liquid-impervious connection of the lower panel 66 to the base plate, This lower panel extends upwardly along the inner surfaces ofthe vertical panels 28 and is welded or brazed at its upper end to aring 76 (Fig. 4) which is preferably formed out of stainless steel andis T-shaped in cross section. The upperedge of the lower panel 66 is welded to the downwardly extending flange of the ring j 76 and the lower edge of the next upper panel 66 is T-shaped rings 76 in the same manner to complete the lining 62. It may also be noted that a ring 76 (Fig. 1) is secured to the upper edge of the uppermost panel 66, and this uppermost panel 66 terminates a short distance below the upper ends of the vertical panels 28.- Furthermore, each panel 66 is provided with an inwardly extending circumferential corrugation 78 in the medial portion thereofto accommodate vertical expansion and contraction of the panels 66 without appreciably'moving the rings 76 vertically, as will be described.
The lining 62 is prevented from collapsing by a supporting structure, generally designated by reference character 80, and comprising a plurality of vertically spaced wood rings 82 supported by vertically extending wood columns 84. Each ring 82 is preferably formed out of laminated wood and is provided with a circumferential vided for each of the rings 76, and the rings 76 are of a size to fit loosely within the lining 62 when the lining 62 is contracted to its smallest diameter. The horizontal vflange portion of each ring 76 and each groove 86 is of a length such that the ring 76 will remain extended into the respective groove 86 as the diameter of the lining 62 is increased and decreased by expansion and contraction, whereby the rings 76 will be retained in substantially fixed vertical positions by the support rings 82, yet the rings 76 may slide freely in and out of the grooves 86. If desired, a soft insert 87 of balsa wood or the like may be placed in the inner end of each groove 86, as shown in Fig. 5, to cushion the force imposed on the rings 76 in the event the rings 76 contract an excessive amount. It should also be noted (see Fig. 1) that each pair of the rings 76 and 82 are positioned opposite the retaining bands 46 encircling the panels 28, and therein the event of excessive expansion of the rings 76.
'is positioned in the lower end of the lining 62 to provide a base for the supporting structure 80 and prevent buckline of the lower portion of the lining 62.
Referring back to Fig. 1, it will be observed that the insulating panels 60 secured on the bottom of the cover 56 extend outwardly over the uppermost support ring 82 and may be supported-on this ring 82 through the medium of a suitable insulatingpad 92 formed out of any desired insulating material. T
From the foregoing, it will be apparent that the presentinvention provides a novel tank for storing cold liquids, which will be light-weight and may be economicallyconstructed. The various components of the tank may be shipped to the point of use disassembled and then easily assembled in the field. In the assembly operation, the bottom 18 of the tank will be assembled and the vertical panels 28 assembled around the outer periphery of the bottom in the manner illustrated in Figs. 1 and 2. The lowermost panel 66 of the lining 62 may be welded onto the base plate 64 and the lower supporting ring 82 assembled in the lower portion of the lining. The remaining portions of the lining 62 may then be welded in the field while the supporting structure 80 is being simultaneously assembled in the lining. The entire lining 62 and supporting structure 80 may then be inserted in the vertical panels 28 onto the bottom 18 of the tank,
or, the lining 62 may be assembled in the tanks after the vertical panels 28 have; been assembled on the bottom 18 and the base ring 12. It will be further apparent that the supporting structure 80 will adequately support the lining 62 in the tank and prevent collapse of the lining without placing any undue stresses on the lining. Finally, it will be apparent that the lining 62 may contract and expand relative to the panels 28 and the bottom 18 without placing any undue strains in the remaining tank structure and without damageto the insulation surrounding the lining 62.
Changes may be made in the combination and arrangement of parts or elements as heretofore set forth in the specification and shown in the drawings, it being understood that changes may be made in the precise embed ments disclosedwithout departing from the spirit and scope of the invention as defined in the following claims.
I claim: 1. In a tank for storing cold liquids, a bottom member, a plurality of elongated insulation panels extending upwardly from the outer periphery of the bottom and sealed in s-ide-by-side relation to form the vertical side walls of the tank, said panels being of sufficient strength to be self-supporting,'vertically spaced retaining bands the bottom and upwardly around the inner periphery of The supporting columns 84 are also preferably formed out of laminated wood and are provided with vertically spaced notches 88, as shown in Figs. 4 and 5, for receivthe side walls of" the tank to form a storage chamber for receiving liquid fed to the tank, and support means positioned in the storage chamberto prevent collapse of the lining.
2. A tank as defined-in claim 1 characterized further in that each panel comprises a layer of insulating wood and sheets of hardwood bonded to the inner and outer faces of the insulating wood layer.
3. Atank as defined in claim 2 characterized further to include hardwood inserts embedded in the panels opposite the retaining bands.
4. A tank as defined in claim 2 characterized further to include a hardwood strip embedded in each side edge of each panel, and a relatively soft and tapered wood strip wedged between the mating edges of the panels adjacent panels.
5. A tank as defined-in claim 1 characterized further in that said means for preventing collapse of the lining includes a plurality of wood rings extending around the inner periphery of the lining, and vertical wood columns supporting the rings in vertically spaced relation in the lining.
6. In a tank for storing cold liquids, a wood base ring, a plurality of self-supporting insulation panels extending diagonally across and supported on the base ring to form the bottom of the tank, a plurality of selfsupporting insulation panels extending upwardly from the base ring in side-by-side relation to form the side 'walls of the tank, the lower end portions of said vertical insulation panels being secured around the outer periphery of said tank bottom, an expansion joint between each pair of vertical insulation panels, a plurality of vertically spaced retaining bands encircling the vertical insulation panels and holding said panels in assembly, an insulated cover for the tank, and a gas and liquid-impervious lining extending loosely over the tank bottom and around the inner periphery of the tank walls to form a chamber and receive cold liquid stored in the tank.
7. A tank as defined in claim 6 characterized further in that each insulation panel comprises a layer of insulating wood, and hardwood sheets bonded to the inner end outer faces of the insulating wood layer.
8. A tank as defined in claim 6 wherein said lining is non-self-supporting, and characterized further to include means positioned in the chamber formed by the lining to prevent collapse of the lining.
9. A tank as defined in claim 8 characterized further to include a plurality of vertically spaced rings interposed in the vertical portion of the lining, each of said rings in the lining having an inwardly extending flange thereon, corrugations extending circumferentially around the vlining between the rings in the lining, and characterized further in that said means to prevent collapse of the lining comprises a plurality of wood support rings in the chamber formed by the lining, each of said support rings having a circumferential groove in the outer periphery thereof, and a plurality of circumferentially spaced wood support columns holding each support ring concentricv with a ring in the lining and'withthe inwardly extending 'flange of each ring in the lining slidingly extending into the groove in the respective support ring;
10. A tank as defined in claim 6 characterized further in that the central portion of the bottom of the lining is keyed to the bottom of the tank to prevent creeping of the lining with contraction and expansion of the lining -in the tank. v
11. In a tank for storing coldliquids, a non-self-supporting lining forming a chamber for receiving the cold liquid, said lining having vertical side Walls and a bottom wall, a plurality of horizontally extending rings secured to the side walls of the lining in vertically spaced relation, each of said rings having an inwardly extending circumferential flange thereon, a plurality of Wood support rings rigidly supported in vertically spaced relation in the in that said support rings are supported by circumferentiab 1y spaced wood columns.
13. A tank as defined in claim 11 characterized further to include a circumferential corrugation in the side walls of the lining between each pair of the flanged rings, and a circumferential corrugation in the bottom of the lining.
l 1 4. A tank as defined in claim 11 characterized further in that said lining comprises a base plate forming the bottom wall of the lining, and a plurality of annular panels extending upwardly-in superimposed relation above the base plate to form the side Walls of the lining, the lower edge of the lowermost annular panel being sealed to the outer periphery of the base plate and the adjacent edges of each pair of said annular panels being sealed to one of said flanged rings to provide a gas and liquid-impervious lining.
No references cited.