US3196622A

US3196622A - Cryogenic storage tank

Info

Publication number: US3196622A
Application number: US256491A
Authority: US
Inventors: Ernest L Smith; Arthur R Duffy
Original assignee: Texas Eastern Transmission Corp
Current assignee: Texas Eastern Transmission Corp
Priority date: 1963-02-04
Filing date: 1963-02-04
Publication date: 1965-07-27
Anticipated expiration: 1982-07-27

Description

July 27, 1965 E. L. sMn'H ETAL cRYoGENIC 'sToRAGE TANK Original Filed Dec. 24, 1962 J V 1 ww f a Q w M ,fm m 5. W f a JMF A e W f I I I I I I I I I I. 17./ Z l l l l I I I I I I I I MM .I I I I ,I I. I I l I I I i I I I I lllllllllllllllllllllllllllll' July 27, 1965 E. L. sMl'rH ETAL 3,196622 CRYOGENIC STORAGE TANK original Filed Dec. 24, 1982 5 sneets-sheet 2 Aff//ur f. u/fy INVENTORJ July 27, 1965 E. L. sMn'H ETAL 3,1%.622

CRYOGENIC STORAGE TANK Original Filed Dec. 24, 1962 5 Sheets-Sheet 3 Ar ur fi. Duffy INVENToRs /UTOR/VEVJ July 27, 1965 E.L.sM|1'H ETAL 3,196,622

'CRfx'OGENIC STORAGE TANK Original Filed Dec. 24, 1962 5 Sheets-Sheet 5 United States Patent O This invention relates to storage tanks, and particui larly to cryogenic storage tanks for storing such materials as liquefied natural gas and is a continuation of application No. 246,816, filed December 24, 1962, now abandoned. The particular designs of tanks embodying this invention illustrated in the drawings were made for the storage of liquefied natural gas and, while the tanks might be used for storing other cryogenic iluids, the description will be directed to a tank specifically designed for the storage of liquefied natural gas.

Recent years have seen the ever increasing transmission of natural gas from remote .gas fields to areas of dense population. This gas is being used in commercial establishments as well as in homes for power and heating. As the gas is transported over tremendous distances, the amount of gas available for a given period of time is determined by the size of the pipeline and the pressure at which it is operated.

During peak demand conditions, such as occur on very cold days, the customer demand for gas is much greater than normal. Means have been sought to provide this peak demand without the construction of pipelines capable of supplying this demand on a year-round basis, because the cost of such lines would be uneconomical. For instance, in some areas of the country underground storage of gas near the point of ultimate usel hasprovided a solution. In these instances natural gas is injected into underground earth formations in the gaseous phase during the summer months to provide a ready source of gas for peak demand during the Winter.

Another' solution to this problem is the storage of natural gas in tanks. Oflcourse, to be practical the gas must be liquefied and maintained in storage in liquid form at about -258 F., as the tremendous volumes necessary for peak demand would make the cost of storage in gaseous form prohibitive.

It is an object of this invention to provide a practical tank construction capable of being positioned all or partially below ground level, which tank is within the realm of economic storage of liquefied natural gas.

For economical reasons a tank for storing liquefied natural gas for pe'ak demand purposes 'must be o-f considerable size. For instance, it may have a diameter in excess of 'one hundred feet, and a height in ex-cess of fifty feet. To place the tank underground requires, as a practical matter, that the insulation be carried within the tank. Due to vapors which are constantly formed within the tank, a liner serving as a liquid and vapor barrier must also be provided. These provisions for insulation and liner must be compatible with the very large dimensional changes of the tank due to a change in temperature in the tank from ambient conditions when empty down to a temperature lower than -250 F. It will be appreciated that each hole Vwhich is made throughthe liner and insulation material is a potential source of leak, and every structural member `which eXtends through the insulation and liner is a potential source of heat loss. For these reasons, it is preferred to provide a means of maintaining the insulation and liner within the tank which requires as few direct supports from the shell of the tank as possible.

3,1%,622 Patentecl July 27, 1965 ice It is accordingly an object of this invention to provide a cryogenic tank with insulation material and a liner which are capable of functioning in the temperatures expected, and in which a minimum number of direct supports from the shell of the tank are required.

A more specific object is to provide a cryogenic tank with means for supporting a lining of insulation material and a lining of impervious material to act as a liquid and vapor barrier in which there are no direct supports from the side wall or floor of the tank which require that holes be made in either the insulation material or the liner.

Notwithstanding every etfort to prevent leaks from the tank, some may occur, and these should be detected as quickly as possible to minimize fire hazard.

Another vobject =of this invention is to provide a system for detecting any leak which may occur in the underground cryogenic vessel, and to provide for removal of small amounts of vapors which might penetrate the liner before they reach the exterior of the tank.

In time, the earth `surrou'ndng the wall of the tank and the earth beneath the tank Will become very cold. During excavation a substantial4 area around the tank will be removed, and in back-filling a material may be chosen in which frost heave is not a problem. It may, however, be necessary to support the tank on or adjacent to earth which will present a frost heave problem, and it is desirable to provide a means for preventing damage to the tank due to frost heave.

Another object is to control the temperature of the earth surrounding the buried tank in which frost heave might occur at a temperature above freezing to prevent frost heave without undue heat input to the tank.

Other objects, features and advantages of the invention Will be apparent from the drawings, the specification and the claims. i

In the drawings, wherein like reference numerals indicate like parts and wherein illustrative embodiments of the invention are shown:

FIGURE 1 is a cross-sectional view through a tank embodying this invention;

FIGURES 2A and 2B are cross-sectional views on an enlarged scale of the upper and lower corners of the tank of FIGURE 1, with FIGURE 2B being a continuation of FIGURE 2A but with a substantial portion of the intermediate section of the tank between the top and bottom omitted;

FIGURE 3 is a horizontal cross-section through the side wall of the tank taken along the line 3-3 of FIG- URE 2B; i

FIGURE 4 is an elevational view of a fragment of the side wall of the tank taken from the inside of the tank;

FIGURE 5 is a view in Vertical cross-section through a modifiedform of this invention;

FIGURE 6 is a view along the line 6-6 of FIGURE 5 on an enlarged scale; and

FIGURE 7 is a view in cross-section of the lower corner of a` further modified form of tank,

Referring first to FIGURES l through 4, there is shown the preferred form of this invention embodied in an underground cryogenic tank. It will be appreciated that theprinciples of this invention are also applicable to 'an above-ground tank, but their greatest value lies in their use in a sub-surface tank.

As shown in FIGURE 1, the location for the tank is first excavated as represented by the surface 10, and a backfill of a selected material 11 spread `over the bottom of the excavation to prevent frost heave. Before backfilling, suitable coils as shown at 12 may be placed in the backfill to control temperature in a frost heave susceptible soil, as will be described hereinafter.

The tank, which is built in the excavation and on the backfill 11, has an outer supporting shell of concrete.

This supporting shell includes the fioor 13, the side wall 14 and the top or roof 15. As shown, the preferred side wall configuration is cylindrical.

The contraction and expansion of the fioor 13 and wall 14- with differing temperature conditions will not be alike', and the temperature of the wall 14 will not only vary progressively along the wall vertically, but will be different in magnitude from the temperature of the fioor. Forthis reason, a vessel of the type shown in FlGURE 1 should havethe side wall 14 separated from the fioor 13, and provision should be made to perrnitthe side wall to slide over the base vor fioor.

Referring to FIGURE 2B, there is shown a preferredV form of sliding wall and base. After the fioor 13 has been poured and allowed to cool, the plate 16, is set in concrete ma on top of the fioor. Suitvable ties 17 are preferably embedded in the fioor 13, and nuts 13 on these ties are used to assist in tying the plate 16 in place. A suitable angle` iron y19 may be providedat spaced intervals, or continuously if desired, about the outer periphery of plate to act as a stop orretainer.

A suitable jsliding means 21 rest's upon the plate 15. This means 21 may be aV thin layer of any suitable material which will perrnit relative slidingimovement between the wall 14 andthe fioor 13. Preferably, Teflon is employed for thisv purpose. In order to protect the joint against foreignl materials during construction, a Sheet metal Shield 22 may be formed over ,the joint in the manner shown in FIGURE 2B tov excludelforeign material from the V`area of the Tefion sheet.

After the slid'ing joint is completed, the sidel wall 14 maybe constructed by a cast-in-place methodpor erected from precastsections. p i

Preferably, the side wall 14 is pre-stressed with. a wrapping of vWire 23 in 'a continuous hor-izontally extending loop to. provide additional strength for the side wall. Also, it might be noted that a backfilll adjacent the side wall 14 may also serve to supply a portion, of the poststress to the wall 14 and the design ofI the wall' may advantageously take into account the post-stressing value of the backfill indicated generally at 24. v The tank is completed by .the topr15 which lis preferably an arched concrete dome. Other types of roof obviously might be utilied and the roof might be fabricated from othermaterials, but an arched dome is preferred.V

Insulation means indicated generally at 25 completely lines the tank. .The insulation means 25 is provided by a plurality of 'blocks of insulating material, such as solid block 26.* Preferably as shown a plurality of layers of insulating jmaterial such as shown

atv

27, 28 and 29 is provided. The several blocks of insulation material are shiplapped as 'shown at 31, for instan'ce, `and the joints in adjacent` layers of insulation are staggered, as will be readily apparent from a consideration of FIGURES 2, 3 and 4. This construction will give Superior results in reducing heat loss across, the insulation. i

Preferably, one of the cellular expanded plastics provides the insulation material. For instance, the insulation material might be constructed from urethane,

-Sty1ofoam,'or other cellular expanded plastics or other types ofmaterial having similar Vinsulation and strength properties at low temperatures. Investigation has pnoved urethane to be a Superior material. While the insulation material is not relied upon to provide a liquid and vapor barrier, it must be recognized that failure of the vapor barrier is possible, and an insulating material which would retard loss of the stored 'fluid would be preferred.

to as a liner, completely lines the tank and provides a liquid and vapor barrier.

The liner may be provided from any suitable material which lis impervious to and chemically compatible with the liquid 'being stored, andwhich has suitable mechanical properties vat very low temperatures. Obviously, it must be a material which is non-brittle, as it must be continuous and preferably 'it should be susceptible of being easily fabricated in place. For instance, it is preferred that the insulation material =be factory prefabricated in as large Sections as can be handled, and that final fabrication take place within the tank. A suitable liner may be provided by a polyester film obtainable from the E.I. du Pont de Nemours Company, known as Mylar. It is preferred that this film `be laminated to each side of an aluminum foil. To this assernbly a fabric is also preferably -laminated to provide tear resistance.

It is very important that this liner have as few holes as possible therethroug'h. It is -also preferred to have as few paths of heat transmission as possiblel through the insulation material. For these reasons, it is preferred to maintain the fioor and side wall insulation material and liner in place by a system totally within the interior of the tank, i.e., a system which 'is not attached to either the fioor or the side walls. By erecting suitable columns within the vessel, the liner and insulation material lining the roof of the tank could also be so supported. In the illustrated embodiment, however, this is not necessary due to the provision of the space 33 between the insulatron and root which additionally assists in insulating the top of the tank.

'The liner is preferably sandwi-ched between the innermost layer 29 and the intermediate layer 28 of insulation material providing protection for theliner. It has been found that urethane has sufiicient strength to permit a limited amount of construction activity over the urethane if adequate precautions are taken against imposing too great a force on the urethane.

In laying the insulation material and liner, the sandwich of liner and insulation .material is first laid on the fioor in the manner illustrated in FIGURE 2B. As the material is laid, a layer of plywood 34 is put down over the insulation-liner to protect it. After the insulationliner Sandwich has been laid on the floor and completely covered with plywood, a slab-'of concrete 35 is preferably cast in place over plywood 34. This slabserves to hold the insulation-liner Sandwich in. place, and particularly to prevent, the inner layer 29 of the insulating material from fioating on the body of liquid. Also, the slab 35 serves as a protection for the insulating material-liner Sandwich during construction of the remainder of the insulation.

The means for holding the Sandwich of insulation material-liner in place against the side wall is provided by a grid work of structural members indicated at 3d and best shown'in FIGURE 4. This grid work includes a plurality of shoes 37 which engage the innermost layer of insulation material and hold it in place. The shoes 37 are held in spaced VerticalV relationship in the tank by a plurality of risers 38 which extend vertically along the side walls of the tank.

In order to firmly hold the Sandwich of insulation and liner' materials against the shell of the tank, means is provided for urging the shoes'radially outwardly. Such means may be provided by a plurality of circumferentially spaced Springs 39 between adjacent shoes 37 to urge adjacent shoes away from each other and give a resultant i outward component of force. As best shown in 'FIG-

URES

3 and 4, the shoes 37 are provided with abutments 41 at their ends between whichthe Springs 39 are compressed. A suitable bolt 42 extends through the abutments 41 and the spring 39 to insure that the spring remains in place. As each sectionof the wall is put in place, the nuts 43 on bolts 42 may be run up to compress the Springs topthe extent shownnin FIGURE 4.`V Then, after the shoes are all in place so that each shoe forms a part of a complete circle of shoes, the nuts 43 may be backed off so that the springs 39 will be effective to urge the shoes away from each other, and thus hold the insulation material-liner Sandwich firmly in place. It will be appreciated that with the construction outlined above, there is no need for any bolts, keys, or the like, extending radially inwardly from the side wall 14 on which the insulation material-liner might be hung. This avoids holes through the insulation material and the liner and permits these elements to function at maximum efficiency. It might be noted that it is, of course, possible for the stored liquid to find its way to the liner, at least adjacent the joints between adjacent blocks which make up the inner layer of insulation material. It is believed, however, that this inner layer of insulation material will still function and will be beneficial as compared to the use of a more protective layer for the vapor barrier 32. In any event, the inner layer functions as insulation material above the liquid level aiid, as this level will change from time to time, the inner protective layer is preferably of a good insulation material. Obviously material having poor insulation properties might be used as an inner layer to provide a protective layer for the liner.

It is also pointed out that the cellular plastic Sandwich with an interior liner provides a support for the liner which will give and not tear the liner. Thus, if the insulation materal of the floor is not exactly smooth, the insulation material will give and not tear the liner as would be the case with a stiff protective material against the liner.

By reference to FIGURE 2A, the preferred form of lining the top of the tank will be observed. In this instance a thin sheet of aluminum 44 suitably reinforced by structural components or members 45 is suspended from the roof by Suspension rods 46; These rods support the aluminum Sheet 44 by means of a suitable washer 47 of larger size than the hole through the aluminurn sheet and a suitable nut 48 thereon. If desired, the vapor barrier 44 may be sealed to the hanger but this is not necessary as any vapors which may escape into the static vapor space 33 may be recovei'ed along with the vapors below the top insulation for venting or reliquefaction. It will be appreciated that during storage the cold liquid is subject to vapor boil-ofl, and these vapors are removed from the tank and either vented, flai'ed, or reliquefied, and re-introduced to the tank. Thus, any vapors which escape into the dead space 33 may be treated in the same manner as vapors in the tank, if desired.

To provide for removal of relatively small `amounts of .vapor due to permeation through the liner, there is provided about the entire tank a series of purge spaces. In the floor of the tank and cast into the concrete 13 are a plurality of conduits or grooves 49 which extend across the entire floor. Preferably, these spaces extend radially outward from the center of the iioor and each conduit 49 communicates with a like purge space or conduit 51 extending vertically up the inside of the concrete wall 14. These purge spaces 51 are also narrow grooves cast in the side wall and each extends upwardly and communicates with a pipe such as shown at 52.

.Suitable-connection is made between the purge spaces 49 in the fioor and the purge spaces 51. in 'the side wall in any desired manner such as through a small pipe 53 extending through the insulation material from a purge space 49 to a purge space 51. The dead space 33 m the roof may be purged by introducing purge gas through `inlet conduits 54 and withdrawing gas through the Outlet conduit 55. With this construction it will be apparent that by sweeping the purge system with a suitable gas any vapors which may have permeated through the vapor barrier may be collected and reliquefied.

As previously mentioned, frost heave can be Controlled by selecting backfill material. However, if backfill is not 6 sufficent to control frost heave in the virgin soil adjacent to the selected backfill, this problem may be overcome by burying conduits 12 beneath the floor of the vessel. While a single continuous conduit 12 is indicated, it will be understood that this single conduit could be provided by a number of bundles of conduit.

During filling of the tank, gas froin the source pipeline may be passed through conduit 12 and thence to the liquefaction equipment indicated schematically at 56. The liquefied natural gas is injected into the tank from liquefaction equipment 56 through the conduit 57. It will be appreciated that heat exchange will occur in the coil 12 between the cold surrounding earth and the relatively warmer gas. In this Way the temperature immediately below the tank may be kept above freezing to prevent frost heavel During the time that the tank is not being .filled, natural gas from the source ppeline may be passed `through conduit 12 and thence returned to the pipeline through the line 58. If it is not desired to pass gas through coil 12 when the tank is not being filled, then other heating means may be provided beneath the tank for maintaining the temperature above the freezing point. i

During peak needs, the liquefied natural gas may be removed from the tank by the pump indicated generally at 59.

Reference is now made to FIGURE 5` which is identical with the tank previously explained except that a different means of supporting the insulation-vapor barrier against the side wall is shown. This means has the ad- Vantage of counterbalancing or absorbing some of the stresses in the roof 15.

In the FIGURE 5 form of the invention a plurality of vertically extending structural members 61 are spaced circumferentially about the tank adjacent the side wall 14. These structural members are suitably anchored at their base against movement away from the side wall. Conveniently they may have a member 62 which engages the periphery of the concrete slab 35 to hold each structural member against radial inward movement.

Each structural member 61 has its upper end tied to the roof 15 by a suitable tie member 63. As shown, the member 63 is cast in the roof and supports the structural member 61 in the Vertical position and will, of course, resist radial inward movement of the structural member.

A plurality of shoes 64 extend circumferentially about the interior of the tank and bear against the insulationvapor barrier 25, Suitable Springs 65 are held in compressionbetween the several shoes 64 and the several structural members 61 to thus urge the shoes away from the structural members and hold the insulation-vapor barrier firmly in place against the side wall.

It will be appreciated from the above explanation that the force exerted by the several Springs 65 is effective as an inwardly directed force on the tie means 63 at the top of the structural member. As this force is transmitted to the roof 15, and preferably at the outer periphery of the roof 15, there results a radially inward pull on the roof 15. As the roof 15 is an arched dome, there are present in the roof stresses resulting in a radially outward force being present in the outer periphery of the roof. This radiallyV outward force in the roof due to the dome construction is offset or counterbalanced in part by the force on the ties 63 to thus reduce the stresses in the roof to a point nearer equilibrium. i

In FIGURE 7 there is shown an alternative embodiment of the tank of FIGURE 1. This embodiment of the tank will be identical with that of FIGURE 1 except that the side wall 68 will be cast integrally with the floor and footer. The footer 67 is annular and underlies the side wall 68 about the entire periphery of the tank. As noted hereinabove, very large expansion and contraction of the tank will occur. The effect of this is shown by the dashed lines 69 which indicate a torsional movement of the annular footer 67 and a flexing of the fioor 66 as also indicatedvin dashed lines. The action illustrated and above explainedrequires torsional and linear freedom to alleviate the high stresses in the side wall which would occur if the base were held rigid. It will be appreciated that the limitation of torsional resistance inj the annular footer coupled with the fiexibility of the floor permits the required freedom ofmovement. This construction will eliminate the need for the sliding side wall as portrayed in FIGURES 1 through 6. The tank of the form shown in FIGURE 7, after being Vcast in place, would then be equipped with the insulation material-vapor barrier, and with either of the previously described forms for holding the insulation material-liner in place.

While the tank has been illustrated and discussed with regard to liquefied natural gas, it is apparent that the tank would be equally useful for storing any other liquid where either eXtreme temperature conditions or factors of 'safety are material. While the tank has been illustrated as being underground, it will Vbe appreciated that the tank might be positioned partially underground,ror it might be at or above ground level. Underground storage is preferred, as the earth itself will assist in insulating the liquid, and, in the event of a leak, there results only little fire hazard. i

The use of the internal insulation and liner supported in the `manner taught herein'eliminates the necessity for a double-wall construction which has been practiced in the past in above-ground storage. There results a tank which is less costly per gallon of liquid stored, requires less maintenance, and enjoys a' much higher Safety factor than the above-ground tanks which have previously been used for storing liquefied gases. i

The term *'cryogenic as used herein includes temperatures between zero degrees centigrade and absolute zero and is specifically intended Vto include tanks in which substances which are normally gases at temperatures above C. are liquefied and stored at any` temperature less than 0 C. Other liquids which may advantageouslybe stored in the tanks ofthis invention include liquefied propane or butane.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, Shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What we claim is: g

1. A cryogenic storage tank comprising,

lan outer supportingV shell having a substantia'lly vertical side wall and floor and top providing a complete continuous enclosure, said side wall and floor being made of concrete,

insulation means completely lining said tank including -a plurality of blocks of insulation material,

a sheet of'continuous impervious :material completely lining the floor and vside wall of said tank. and providing a Liquid and Vvapor barrier,

said insulation means lining said side Wall Varranged in a plurality of layers with one layer on each side of the portion of the Sheet of impervious material lining said side wall,

and means supported on said floor' engaging the inner layerV of said insulation means lining said side Wall and holding the insulation means and sheet of impervious material lining said side wallrin place.

2. A cryogenic storage tank comprising,

an'outer supporting shell having a substantially Vertical side wall, floor and top providing'a complete continuous enclosure, said fioor and side wall being of concrete, i i J insulation means completely lining said tank including a plurality of .blocks of insulation material, said insulation material lining said'side wall arranged in at i vleast twolayers,

a sheet of continuous impervious material completely lining said iloorand side wall of said tank and providing a liner, said impervious material positioned between said layers of insulation material lining the side wall and fioor of said tank,

and means including means supported on said floor engaging the innermost layer of insulation material lining said side wall and floor and holding said insulation material and vapor barrier in place.

3. The underground cryogenic storage tank of claim Z wherein purge grooves are provided in one of the internal surfaces of said side wall and floor of said supporting shell of concrete and the confronting surface of said insulation means to provide pathways for purge gas to be carried about the concrete shell and purge therefrom any gas evoived from the fiuid stored in the tank which may be present in the purge pathways.

4. A cryogenic storage tank comprising,

an outer supporting shell having a substantially Vertical side wall, floor and top providing a complete continuous enclosure, said side wall and floor being of concrete,

insulation means completely lining said tank including va plurality of blocks of insulation material arranged in at least two layers with the edges of the blocks staggered and shiplapped to minimize the tendency for fluids to flow through the'juncture between two blocks,

a sheet of continuous impervious material completely lining the floor and side wall of said tank and positioned between said layers of insulation material which line said side wall and said floor,

i and means supported on said floor holding said insulation material and sheet of impervious material in place including means engaging the innermost layer of insulation material lining said `side wall and floor.

5. A cryogenic storage tank comprising', i

an outer supporting shell having a substantially vertical side wall, fioor and top providing a complete continuous enclosure, said side wall and floor being of concrete,

insulation means completely lining said tank including a plurality of blocks of insulation material arranged in at least two layers with the edges of the blocks staggered and shiplapped to minimize the tendency for fluids to ilow through the juncture between two blocks,

a Sheet of continuousimpervious material completely lining the vside wall and floor of said tank and positioned 'between said layers of insulation material which line said side 'wa'll and said floor,

and means holding said insulation material and sheet of impervious material in place including,

a plurality of shoes engaging the innermost layer of insulation on the side wall of said tank,

means supported on said floor holding said shoes in spaced relationship about the side wall of the tank,

and means urging said shoes radially outward to hold said insulation material and sheet of impervious material in place` 6. A cryogenic storage tank comprising,

an outer supporting shell having a side wall and floor and top providing a complete continuous enclosure, said side wall and floor being of concrete,

insulation means completely lining said tank including a plurality of blocks of cellular plastic insulation material arranged in at least two layers with the edges of the blocks staggered and shiplapped to minimize the tendency for fiuid to flow through the juncture between two blocks,

a sheet of continuous impervious material lining said tank and providing a vapor barrier, said sheet of material positioned between said layers of insulation lining said side wall and floor,

a slab of concrete poured on the insulation material on the floor of said tank,

`and means suspending the top insulation and sheet of material section from the roof of the tank.

7. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation and liner means completely lining said tank including a plurality of blocks of insulation material and a continuous sheet of impervious liner material arranged in layers,

a plurality of vertically extending structural members spaced along the inside of said side wall and having their lower extremities anchored against movement away from said side wall,

means securing the upper extremity of each structural member to said roof,

a plurality of shoes engaging said insulation and liner means lining said side wall,

and resilient means between said shoes and said structural members urging said shoes and structural members apart and counterbalancing some of the stresses present in said arched roof.

8. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation means completely lining said tank including a plurality of blocks of cellular plastic insulation material arranged in at least two layers with the edges of the blocks staggered and shiplapped to minimize the tendency for fluid to flow through the juncture between two blocks,

a sheet of continuous impervious material arranged in layers with said insulation material and providing a liner, said liner sandwiched between the layers of insulation material lining said side wall,

a plurality of Vertically extending structural members spaced along the inside of said tank wall and having their lower extremities anchored against movement away from said wall,

means securing the upper extremities of each structural member to said roof,

a plurality of shoes engaging the innermost layer of insulation lining the side wall of said tank,

and resilient means between said shoes and said structural members urging said structural members and shoes apart and counterbalancing some of the stresses present in said arched roof.

9. A cryogenic storage tank comprising,

an outer supporting shell having a substantially Vertical side wall and fioor and top providing a complete continuous enclosure,

insulation means completely lining said tank,

a sheet of continuous impervious material completely lining the side wall and fioor of said tank and providin g a liquid and vapor barrier,

a layer of non-rigid protective material lining said side wall inwardly of and holding said sheet of continuous impervious material against said side wall,

and means supported on said floor engaging the protective material lining said side wall and holding the insulation means and sheet of continuous impervious and protective material lining said side wall in place.

10. A cryogenic storage tank comprising,

an outer supporting shell having a substantially Vertical side wall and floor and top providing a complete continuous enclosure,

insulation means completely lining said tank,

a sheet of continuous impervious material completely lining the side wall and floor of said tank and providing a liquid and vapor barrier,

a layer of non-rigid protective material lining said side wall and fioor inwardly of and holding said sheet of continuous impervious material against said fioor and side Wall,

i and means supported on said fioor engaging the protective material lining said side wall and holding the insulation means and sheet of continuous irnpervious and protective material lining said side wall in place.

11. A cryogenic storage tank comprising,

an outer supporting shell having a side wall and fioor and top providing a complete continuous enclosure, said side wall and floor being of concrete,

a sheet of continuous impervious material lining the floor and side wall of said tank and providing a vapor barrier, said sheet of material positioned between said layers of insulation lining said side wall and fioor,

a slab of concrete poured on the insulation material on the floor of said tank,

a plurality of shoes engaging the innermost layers of insulation on the side walls of said tank,

means supporting said shoes in spaced relationship about the side wall of the tank,

means urging said shoes radially outwardly to hold said insulation material and sheet of material in place in said tank,

and means suspending the top insulation section from` the roof of the tank.

12. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation and liner means lining said tank including a plurality of blocks of insulation material completely lining said tank and a continuous sheet ofimpervious liner extending over the floor and side wall, said blocks of insulation material and impervious liner arranged in layers over said fioor and side wall,

means securing the upper extremity of each structural member to said roof,

a plurality of shoes engaging said insulation and liner means lining said side wall,,

13. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation means completely lining said tank including a plurality of blocks of cellular plastic insulation material arranged in at least two layers with the edges of the blocks staggered and shiplapped to minimize -the tendency for fluid lto flow through the juncture -between two blocks,

a sheet of continuous impervious material arranged in layers with said insulation material and providing a liner, said liner extending over said fioor and side walls and sandwiched between the layers of insulation material lining said side wall,

a plurality of vertically extending structural members spaced along the inside of saidtank wall and having References Cited by the Examiner UNITED STATES PATENTS Kerr 62-54 Jackson 62-54 Klingberg 62-45 Cooper 62-45 Kornernann 62-54 Cooper 62-54 Dosl-:er 62-45 Wiedemann et al 62-45 Van Bergen et al. 220-9 Dosker 220-9 ROBERT A. OLEARY, Prmaly Examiner.

Claims

1. A CRYOGENIC STORAGE TANK COMPRISING, AN OUTER SUPPORTING SHELL HAVING A SUBSTANTIALLY VERTICAL SIDE WALL AND FLOOR AND TOP PROVIDING A COMPLATE CONTINUOUS ENCLOSURE, SAID SIDE WALL AND FLOOR BEING MADE OF CONCRETE, INSULATION MEANS COMPLETELY LINING SAID TANK INCLUDING A PLURALITY OF BLOCKS OF INSULATION MATERIAL, A SHEET OF CONTINUOUS IMPERVIOUS MATERIAL COMPLETELY LINING THE FLOOR AND SIDE WALL OF SAID TANK AND PROVIDING A LIQUID AND VAPOR BARRIER, SAID INSULATION MEANS LINING SAID SIDE WALL ARRANGED IN A PLURALITY OF LAYERS WITH ONE LAYER ON EACH SIDE OF THE PORTION OF THE SHEET OF IMPERVIOUS MATERIAL LINING SAID SIDE WALL, AND MEANS SUPPORTED ON SAID FLOOR ENGAGING THE INNER LAYER OF SAID INSULATION MEANS LINING SAID SIDE WALL AND HOLDING THE INSULATION MEANS AND SHEET OF IMPERVIOUS MATERIAL LINING SAID SIDE WALL IN PLACE.