US2256673A - Support for double-walled containers - Google Patents

Description

Scemh Reem il'ross Reference Sept. 23, 1941.

o. A. HANSEN SUPPORT FOR DOUBLEWALLED CONTAINERS Filed Aug. 19, 1939 INVENTOR Patented Sept. 23, 1941 SUPPORT FOR DOUBLE-WALLED CONTAINERS Odd A. Hansen, Kenmore, N. Y., assignor to The Linde Air Products Company, New York, N. Y., a corporation of Ohio Application August 19, 1939, Serial No. 290,969

8 Claims.

This invention relates to supports for doublewalled containers for liquefied gases, and particularly to supporting frames for double-walled containers having an intervening space that may be evacuated, whereby the containers are adapted for storing and/or transporting liquefied gases which have relatively low boiling points at atmospheric pressure, such as liquid air and liquid oxygen.

The invention has for its object generally the 1 provision of an improved construction for supporting frames of the character indicated, which avoids the concentration of stresses in the wall of the outer vessel and employs an arrangement of structural elements'for" supporting separately the inner and outer vessels. 7

More particularly, an object of the invention is to provide a double-walled container for liquefied gases of the kind indicated with supporting structure and which avoids stresses tending to collapse the wall of outer vessels, particularly cylindrical vessels or tending to reduce the insulating efficiency of the space between the walls of double-walled containers when evacuated.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts, which will be exemplL fied in the construction hereinafter set forth and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing, in which:

Fig. 1 is a view, partly in elevation and partly in vertical section, showing a double-walled container for a liquefied gas, such as liquid oxygen, constructed in accordance with the invention and adapted to have the insulating space evacuated;

Fig. 2 is an enlarged vertical sectional view showing the construction of a safety relief device was,

that may be employed when an evacuated insulating space is employed in the invention;

Fig. 3 is another view partly in section and partly in elevation, similar to Fig. 1, showing a modified form of the invention; and

Fig. 4 is an enlarged fragmentary sectional view showing a detail in the construction for supporting the inner vessel in the modification shown in Fig. 3.

Referring now to the drawing, and particularly to Fig. 1, l0 denotes generally an exterior frame composed of uprights, or leg members, and relatively stiif connecting or cross-members like, from which a wall H of an inner vessel of the containefis suspended, such vessel being adapted to hold a liquefied gas that is to be placed or stored in the container either with or Without the aid of a lining or basket (not shown). Outside of the vessel I l and. disposed in rigid spaced relation with respect thereto is a second or outer vessel l2 which is also supported from the frame Hi, the manner of support being described below. The space intervening between the vessels thus provided is a closed space adapted for insulating purposes and preferably has a filling of a powdered insulating material. There being no communication with the outside except that which may be provided through a special connection in the Wall of the outer vessel, the intervening space may readily be evacuated when desired.

A valve controlled filling connection [3 is provided leading from a suitable point without the outer vessel through the intervening space to a point within the inner vessel. Similarly, a valve controlled withdrawal connection 14 is provided leading from a point near the bottom of the vessel Ii through the intervening space to a suitable external point'andhas a-suitable coupling means I5 by which it may be connected to a suitable discharge receiving device at a place of use. Each pipe connection here employed is provided, at the point where it passes through the wallof the vessel It, with sealing means that transmits relatively little heat to the connection. Such means is here depicted, by way of example, in detail on the connection [4, and consists of a conical wall l6 of a material having a relatively low thermal conductivity and shaped to interpose a relatively large amount of thermal resistance to the passage of heat from the vessel I2 to the connection It; the cone being welded or otherwise integrally attached both to the wall of vessel 12' and to the connection I4. Such connection is preferably so shaped and disposed that expansion, contraction, and otherstresses are accom- 4 a... F u-" modated without liability of incurring a break in what is intended to be a hermetically sealed Wall. There may be also connected, in association with the connection I l, or otherwise, one or more trycocks, such as shown at I4. Other standard accessories, such as a liquid-level gauge, may also be connected to the inner vessel.

The inner vessel I I is here provided with a conventional blowdown or evaporation connection II which is valve controlled and when closed is adapted to afford relief for any excess of pressure that may accumulate, through a safety valve I8 that is connected thereto; there being also preferably attached a bursting diaphragm device IQ, of any known construction. By such means quick relief is afforded in the event of any rise in pressure in the vessel II.

In order that the space between the Walls of the vessels II and I2 may be evacuated after assembly, or while in service, a valved connection 20 is attached to the outer vessel I2 and arranged to communicate with the space within. The outer end of connection 20 has a coupling 2I adapted for attachment to a suitable vacuum pulling means, indicated diagrammatically in the drawing as a pump. A suitable vacuum pulling means of this character may be, for example, a mechanical vacuum pump. To the connection 20 there is preferably attached a vacuum space relief device 22 that has a diaphragm adapted to be burst should any undesired pressure occur in the space between the walls of the vessels H and I2. Any suitable device of this latter character may be employed, for example, that shown in Fig. 2.

In the construction here shown, the'inner vessel II is so supported that the load is carried directly by the frame I!) and not from the inner surface of the walls of vessel I2. To this end, the inner vessel II has suspending means attached to cross-member I: comprising a girth member 23 having a bracket or lug, as shown at 23', at each end, such means being made fast to the outer surface of vessel I I if desired. Attached to the lugs are suspending rods or cables 24, each of which extends generally upwardly and outwardly and is secured in suitable-means, such as a collar 25, made fast to cross member Illa: closely adjacent a leg member. The rods 24 are preferably also of relatively low thermal conductivity and may be constructed of a material having such property, as well as a high tensile strength, for example, of stainless steel. Each such rod 24 is passed through the collar and is threaded at its upper end for engagement with one or more nuts 25 which are screwed on the end of the-rod. The collar is preferably secured to the frame by brazing or welding and has a reduced lower end for the reception of a sleeve 21 which houses the rod 24 and is brazed or welded at its lower end onto the wall of vessel I2 and may be similarly attached to the collar itself.

In order that this structure may be hermetically sealed against the passage of gas into or out of the space between vessels II and I2, a housing or cap 28 is disposed over the nuts 26 and soldered onto the collar 25; the joint between collar and cap being shown as made by reducing the top of the collar sufficiently to fit snugly into the cap, the joint being preferably closed by soldering or brazing.

To provide a rigid support for the vessel II in the above-described manner at least three rods or cables are required, the support thus provided being advantageous for spherical vessels. Four or more cables, however, may be employed, es-

pecially where the frame I0 is square or rectangular in plan. Still more, for example, six or eight, may be employed when the nested vessels have the form of elongated vessels with spherical ends, or have the shape of oblate ellipsoids.

To support the outer vessel I2 in place, additional supporting means are provided between the frame I0 and the outer Wall of vessel I2, such means being structurally independent of the support for vessel II. Such means as here shown comprises not only sleeves 21 but web members 29, interposed as shown, each having one edge bolted or welded to a leg member of frame I0 and an opposite edge in rigid contact with or madefast to the outer wall of vessel I2. The web members thus complete atriangular structure with the frame that holds the outer vessel rigidly. In cases where the collars are substantially over the leg members, the webs may be dispensed with. In such case it may be convenient or desirable to braze or weld the wall of the outer vessel directly to the leg members.

Heretofore, in low temperature apparatus, such as double-walled receptacles for a liquefied gas where insulation was provided by the evacuation of the space between the inner and outer walls, the evacuated space has nevertheless had an undesirably high heat transfer capacity. The transfer or passage of heat across the space between inner and outer walls of such vessels or receptacles when at different temperatures takes place in three Ways, namely, by convection, conduction, and radiation. Where a highly evacuated insulating space is employed for insulating double-walled vessels or receptacles'thetransfer of heat is chiefly by radiation. To reduce this transfer, it has heretofore been necessary to make the inner surfaces of the two walls highly reflecting. In metal walled receptacles, this has been accomplished by polishing. For large commercial vessels for storing or transporting a liquefied gas, such as liquid oxygen, polishing is a relatively expensive item'in manufacture. Also the maintenance of a relatively high vacuum is inconvenient in ordinary commercial practice.

In order to convert the insulating space between the walls of containers II and I2 into one in which the heat transfer occurs substantially entirely by conduction, the space is first filled with a finely divided or comminuted substantially dry insulating material, such as asbestos fiber, magnesium carbonate, or the like, and thereafter evacuated.

When such material has been properly disposed in the space between. the walls of vessels II and I2, and distributed so as to avoid uneven packing or the formation of pockets, a vacuum of sufiiciently low value is pulled by suitable vacuum pulling means attached through the connection 20 until the thermal conductivity of the insulating space is of a desired low value, for example, the conductivity provided when a vacuum of an order of 0.1 mm. of mercury is pulled; the employment of vacuum of this order for the purpose of increasing the efficiency of powder filled insulating spaces being taught and claimed in copending application, Serial No. 307,945, filed on December 7, 1939 in the name of L. I. Dana.

To permit ready access to the space between the Vessels II and I2 for the purpose of filling and disposing desired comminuted or powdered insulating material therein, as here proposed, one or more openings are provided in the wall of vessel I2 which preferably have flanges to which a cover may be brazed or welded when it is de- Ink-v llhUL-l nnup u b "-I sired to close or hermetically seal the same. Two IN and I02. These rings are preferably parallel such openings are shown for the vessel I2 in the drawing, one at 30 for the top and one at 3| for the bottom.

The container of the present invention when thus equipped is not only capable of operating at high efliciencies for long periods of time but also meets all the safety requirements for devices of this character and avoids substantially all possibility of damage arising from possible sudden rises in pressure in either the inner or the outer vessel.

The vacuum space relief device shown generally at 22 may be of any suitable form but is preferably that disclosed in copending application, Serial No. 307,564, filed December 5, 1939 in the name of H. C. Kornemann and shown in detail in Fig. 2, where it is seen to consist of a chamber 40 which also has an open side surrounded by a flange M on which a diaphragm 42 rests, the diaphragm being held in place by means of a retaining member 43 adapted to clamp the edge of the diaphragm and fit over the flange 4|. This chamber has openings 44 and 44 through which it is attached or inserted in the conduit 20. Thus the space within the chamber 40 is subject to a vacuum of the same degree that obtains in the space between the walls of vessels II and I2. A cutting member 45 is associated with the device in such a manner that it is adapted to cut or pierce the diaphragm 42 in the event that it springs upward by reason of pressure accumulating in the space between the walls of vessels II and I 2. Any convenient form of cutting or piercing member' 45 .may be here employed, for example, a cutting edge on an arm that is attached to the ring 43 over the diaphragm 42. In operation, the container is filled by con- "necting the connection I3 to a source of supply gasometer, in the event that it is desired to conserve the gas thus displaced. Liquid may be withdrawn from the container in the usual manner by opening the withdrawal connection I4. In the interim it may be desired to maintain the vessel II closed to the atmosphere. This, of course, is accomplished by closing the valve in the evaporation connection IT.

A modified form of the invention is shown in Fig. 3, with certain details in Fig. 4. In this form, a supporting arrangement is shown, which is advantageous in connection with double-walled con-' tainers of relatively large capacity, especially with cylindrically shaped containers. I-Iere, stiffening means for the wall of the outer vessel, such as interiorly disposed rings, are employed, and are arranged to act as load or thrust transmitting members for the exterior frame that supports the inner vessel. In this modification, the wall of the inner vessel is shown at I I, while that of the outer vessel is shown at I2. The supporting frame comprises a plurality of relatively short leg members I30 disposed respectively somewhat under and on opposite sides of the outer vessel, the legs being made fast to the outer vessel by welding or brazing. Within the vessel I2 and embracing the portion of the wall supporting the leg members I are disposed a pair of stiffening rings and have their central portions cut away so as to clear the vessel I I by aconsiderable distance, the inner edge being indicated at I03. This arrangement provides strength without unduly adding to the exterior construction and at the same time avoids unduly reducing the insulating value of the intervening space.

To support the inner vessel in position, a girth member I 23 is provided, which has lugs I23 at its ends to which are attached suspending rods or cables I24, the latter passing upwardly and out through openings in the wall of the outer vessel. These rods or cables are anchored in suitable external terminal structures which also cooperate with the stifiening rings and are shown generally at I05 in the drawing. An opening in the wall of the outer vessel for passing a rod or cable into the terminal structure is shown at I21: in Fig. 4, together with further details ofthe terminal structures.

In Fig. 4, the terminal structure is seen to consist of an annular member or bushing I06, brazed or welded over the opening In, its wall at diametrically opposite points being preferably arranged to be in line with, and serve as a continuation of the interior stiffening rings IOI and I02. The latter are seen to fit snugly against the wall of the vessel I2 and are adapted to transmit the weight and other stresses to the leg members I00. The bushing I06 has a flange I01 to which is affixed a top plate I03 which is perforated in order to receive a supporting collar I 2'5, brazed in place and provided with an opening through which the rod 'or'cable I24 passes. The upper end of the rod or cable is threaded and provided with suitable holding means, such as a plurality of nuts I26 that are disposed thereon and bear on the collar I25. In order that this structure,

may be gas-tight, a cap I28 is disposed thereover and soft soldered in place.

Where the container of the present invention is intended for transport service, the external frame is, of course, constructed to be mounted on a portable device, such constructions being well known in the art.

Since certain changes may be made inthe above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire tosecure by Letters Patent is: r 1. In a double-walled container for liquefied gases, the combination comprising an inner vessel for holding the liquefied gas, an .outer vessel surrounding and spaced from said inner vessel thereby providing an intervening space for insulating purposes, a supporting frame comprising external compression members attached to said outer vessel, wall supporting rings within said outer vessel at points associated with said compression members, supporting sleeves disposed in the wall of said outer vessel over said supporting rings, supporting brackets associated with the wall of said inner vessel, and supporting connections extending from said brackets through said sleeves and made fast and sealed in said sleeves.

2. In a double-walled container for liquefied gases, the combination comprising an inner vessel for holding the liquefied gas, an outer vessel surrounding and spaced from said inner vessel IUJUIII thereby providing an intervening space for insulating purposes, a supporting frame comprising external compression members attached to said outer vessel, wall supporting rings within said outer vessel disposed at points associated with said compression members, supporting sleeves sealed in the wall of said outer vessel at points adapted to transmit compression stresses directly to said supporting rings, brackets disposed in supporting relation to the wall of said inner vessel, supporting connections extending from said brackets through said sleeves and anchored therein, and means for hermetically sealing said connections in said sleeves.

3. In a double-walled container for liquefied gases, the combination comprising an inner ves sel for holding the liquefied gas, an outer vessel surrounding and spaced from said inner vessel thereby providing an intervening space for insulating purposes, a frame at least having a part externally associated with said outer vessel, means on said frame extending into engagement with the wall of said outer vessel for supporting the same, other means including rods provided with anchoring means on said frame and extending therefrom into supporting engagement with said inner vessel through openings provided in the wall of said outer vessel, rigid sleeve-like members additionally supporting said outer vessel and disposed about said other means and extendin continuously from said anchoring means to and welded in said openings, and means for hermetically sealing the outer ends of said sleeve-like members.

4. In a double-walled container for liquefied gases, the combination comprising an inner vessel forholding the liquefied gas, an outer vessel surrounding and spaced from said inner vessel thereby providing an intervening space for insulating purposes, a frame at least having a part externally associated with said outer vessel, means on said frame extending into engagement with the wall of said outer vessel for supporting the same, other means including rods of a material having a relatively low thermal conductivity and coefficient of expansion having their lower ends extending into supporting engagement with said inner vessel through openings provided in the wall of said outer vessel, anchoring means on said frame for the upper ends of said rods, rigid sleeve-like members additionally supporting said outer vessel and disposed about said other means including said rods and extending continuously from said anchoring means to and welded in said openings, and means for hermetically sealing the outer ends of said sleeve-like members. 7

5. In a double-walled container for liquefied gases, the combination comprising an inner vessel for holding the liquefied gas, an outer vessel surrounding and spaced from said inner vessel thereby providing an intervening space for insulating purposes, a frame at least having a part externally associated with said outer vessel, means on said frame extending into engagement with the wall of said outer vessel for supporting the same, other means including a plurality of rods each provided with an anchoring means on said frame and arranged to depend therefrom through openings respectively provided in the wall of said outer vessel, a corresponding number of brackets disposed in supporting engagement with the outer wall of said inner vessel attached to the'lower ends of said rod means, rigid cylindrical sleeves additionally supporting said outer vessel and disposed about each of said rod means extending continuously from said anchoring means to said openings and secured therein by welding, and means for hermetically sealing the outer ends of said sleeves.

6. In a double-walled container for liquefied gases, the combination comprising an inner vessel for holding the liquefied gas, an outer vessel surrounding and spaced from said inner vessel thereby providing an intervening space for insulating purposes, a frame at least having a part externally associated with said outer vessel, means on said frame extending into engagement with the wall of said outer vessel for supporting the same, other means including a plurality of rods each provided with an anchoring means on said frame and arranged to depend therefrom through openings respectively provided in the wall of said outer vessel, a corresponding number of brackets disposed in supporting engagement with the outer wall of said inner vessel attached to the lower ends of said rod means, rigid cylindrical sleeves additionally supporting said outer vessel each surrounding a rod of said other means and extending continuously from said anchoring means to said openings and secured therein by welding, means for hermetically sealing said sleeves, and filling and Withdrawal. connections for said inner vessel passed hermetically through the wall of said outer vessel. I

'Z. In a double-walled container for liquefied gases, the combination comprising an inner vessel for holding the liquefied gas, an outer vessel surrounding and spaced from said inner vessel providing an intervening space for insulating purposes, wall supporting rings on the interior of said outer vessel, supporting compression members attached to said outer vessel in the region of and associated with said rings, supporting sleeves secured to said outer vessel over said supporting rings and extending outwardly from said outer vessel, and supporting connections for said inner vessel extending between spaced ones of said rings and out through the corresponding said sleeve and made fast and sealed in said sleeve.

8. In a double-walled ,container for liquefied gases, the combination comprising an inner vessel for holding the liquefied gas, an outer vessel surrounding and spaced from said inner vesselproviding an intervening space for insulating purposes, a pair of wall supporting rings on the interior of said outer vessel, supporting compression chambers attached to said outer vessel underneath it in the region of said rings, supporting sleeves secured to said outer vessel, supporting connections for said inner vessel extending upwardly between said ..rings and out through the sleeve members and secured therein, said sleeve members being positioned to transmitthelsupporting stresses from said connections to" said rings.

ODD A. HANSEN.

' CERTIFICATE OF CORRECTION. Patent-"no; 2; 256,675. September 25, mm.

" om) A.' HANSEN.

It is hereby certified that error appears in the printed specification of the above nnmbered patent requiring correction as follows: Page 1, first column, line 214., for the word "sever" read --severe-; page 1;, second column, line 60, claim 8, for "chambers" read -members--; and that the sold Letters Patent should be read with this correction therein that the same may conform to therecord. of the case in the Patent Office.

Signed and sealed this 28th day of October, A. D. 19141.

Henry Van Arsdale, kSeal) Acting Commissioner of Patents.

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