US3537416A - Shipping container and method for transporting hydrocarbon fluids and the like - Google Patents

Description

United States Patent Walter C. Cowles Stamford, Connecticut Jan. 2, 1969 Nov. 3, 1970 Esso Research and Engineering Company a corporation of Delaware Inventor Appl. No. Filed Patented Assignee SHIPPING CONTAINER AND METHOD FOR TRANSPORTING HYDROCARBON FLUIDS AND THE LIKE 5 Claims, 3 Drawing Figs.

220/15, 220/97 Int. Cl 1363b 25/16, B65d 25/00, B65d 21/02 Field of Search 1 14/74,

[56] References Cited UNITED STATES PATENTS 3,103,278 9/1963 Kuzma et al. 220/97X 2,810,265 10/1957 Beckwith 114/74(A)UX 2,954,003 9/1960 Farrell et al. 1l4/74(A)UX 2,968,161 1/1961 Bliss 220/9(Al)UX 3,050,951 8/1962 Gebien ll4/74(A)UX Primary Examiner-Trygve M. Blix Attorneys-Manahan and Wright and Donald F. Wohlers ABSTRACT: Means for the transportation of liquefied gases and the like which comprises a plurality of nested cargo cylinders each fitted with hexagonal support collars and so arranged that the collars bear against each other when the individual cargo cylinders are nested. Each plurality of such nested cargo cylinders are in turn enclosed in a boxlike enclo sure, which serves as a secondary barrier in the event that one or more ofthe individual cargo cylinders fails. The boxlike enclosure may in turn be nested to provide as much cargo-handling capacity as desired.

[III

SHIPPING CONTAINER AND METHOD FOR TRANSPORTING IIYDROCARBON FLUIDS AND THE LIKE BACKGROUND OF THE INVENTION This invention relates generally to containers for hydrocarbon fluids and especially to a container for transporting natural gas.

The considerable distances that separate sources of natural gas at points of utilization have led to extensive wastes of that material. For example, vast amounts of natural gas from oil well operations in Venezuela and the Middle East are presently flared each year.

The fact that liquefied natural gas possesses only one/sixhundredth of the volume that is displayed by the material in its gaseous state has spurred interest in means for transporting natural gases as liquid, particularly at very low temperatures; and to this end, oceangoing vessels have been especially fitted to carry cargoes of the liquefied gas.

Prior art schemes are often accompanied with important drawbacks. The tanks fitted in these especially designed ships usually consist of an outer steel shell, which is secured about a balsa wood or other insulating material liner. An all-welded aluminum inner shell is then fastened inside the balsa wood insulation. These tanks are supported on foundation beams which must be carefully designed and properly placed in order to provide uniform support for the tanks and in order to protect the transporting vessel as well as the tanks from high stress concentrations and low temperatures. Additionally, for the purposes of increased reliability and safety and in accordance with accepted regulatory codes, it has been a well established practice in the prior art to provide a primary and secondary liquid type barrier system for the transportation and storage of natural gas at low temperatures, each of these barriers being independently capable of withstanding thermal and hydrostatic stresses imposed by the liquefied cargoes. The primary barrier in the prior art schemes, as hereinabove indicated, has usually taken the form of an inner tank which is expensively constructed of aluminum or nickel alloy steel. Since the tanks are often-quite large in size, their construction involves a considerable amount of welding and this may make these tanks susceptible to failure upon the repeated stressing that is encountered during loading and unloading of the natural gas as well as during its transportation-Of course, any discontinuities which might develop in the inner tank from these stresses or from the failure of a weldment, obviously can lead to a loss of the cargo or the incurrence of a substantial safety hazard.

A further disadvantage of the tanks of the prior art is that, due to their size, the tanks must necessarily be constructed in the shipyard as an integral part of the transporting vessel. Such construction has proved to be expensive, inefficient, and Y wasteful of valuable shipyard space and time.

It is, therefore, an important object of the present invention to provide an improved method and apparatus for the bulk transportation of normally gaseous materials such as natural gas and the like.

Another object of the present invention is to provide improved means for conveying natural gas and the like, which means are simple and economical to use.

A still further object of the invention is to provide a container means for transporting natural gas which is susceptible of construction independent from its transportation means and which is readily inserted in and removed from various transporting devices.

A still further object of the invention is to provide a container for transporting liquefied gases which does not require construction to close dimensional tolerances.

Yet another object of the invention is to provide a container for transporting natural gas, which container is adaptable for either transporting the gas in liquid form at substantially atmospheric pressures or at pressures substantially above atmospheric.

SUMMARY OF THE INVENTION The transportation means of the instant invention is comprised of a plurality of individual cargo containers incorporating a double barrier and insulation and which are suitable for installation in ships, barges, on trucks, or railroad flat cars. The instant containers are also particularly useful as local transport, delivery and storage containers. The basic cargo units comprise a nest of pipes with dished ends, each fitted with hexagonal support collars and so arranged that the collars bear against each other when the individual pipes are nested. Each plurality of such nested pipes are in turn enclosed in a boxlike enclosure forming a secondary barrier, which in the preferred embodiment is approximately 8feet X 8feet X 40 feet long, which is a standard container size. A suitable insulation media is provided on the exterior of the boxlike enclosure and suitable means are also provided for stacking the individual cargo units in an interlocking manner. A manifold compartment is provided at one end of each basic unit so that the plurality of tanks may be interconnected for easy cargo handling. Where the primary cargo is to be carried at above atmospheric pressures and hence at temperatures which are not in the cryogenic range, an additional fluid cargo may be accommodated in the intertube spaces of each basic cargo container.

The invention both as to its structure and mode of operation will be better understood by reference to the following DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings and specifically to FIG. 1, reference numeral 3 denotes in general the basic cargo unit of the instant invention. Cargo unit 3 is comprised of a plurality of primary cargo cylinders 4 housed within a boxlike enclosure 2. Cylinders 4 may be fabricated of any material suitable to withstand low temperatures and of sufficient strength to withstand pressures in the range of from about 15 p.s.i. to about 200 psi. Such materials include, by way of example, aluminum, 9 percent nickel steel, and certain fiberglass-reinforced thermosetting resins. In the case of fiberglass-reinforced plastics, the cylinders may be filament wound as is the current practice with rocket casings and the like. Each of the cylinders 4 is provided with bearing collars 6, which, as may be clearly seen in FIG. 2, are hexagonal in shape. As may also be seen, collars 6 are designed to bear against each other so as to position and support tubes 4 within the boxlike enclosure 2. To further stabilize tubes 4, a suitable bulkhead 8 is provided, which bulkhead is supported within the interior of boxlike enclosureZ. The individual tubes 4 may be firmly affixed to bulkhead 8 by use of a suitable locking collar (not shown) or a suitable weldment. Each of the tubes 4 is provided with a feed inlet and exit line 15, which lines are in communication with a container feed manifold 14. Manifold 14 projects through the boxlike enclosure 2 and is provided with coupling means 17 for coupling it either directly to a fuel supply or to the manifold of an adjacent container (again not shown in FIG. 1).

Boxlike enclosure 2, which in the preferred embodiment is of frame and plate construction, is provided with a suitable insulation layer 10. The plating 5 forming the skins of the enclosure is designed to serve as a secondary barrier in the event that a leak or failure occurs in one of the cargo cylinders 4. Additionally, box 2 is provided with a pair of keys 12, which bear on the framework 7 of the enclosure 2. Additionally, enclosure 2 is provided with keyways 13 designed to accommodate the keys of another container 3 to be placed thereon, as will be further discussed.

As shown in FIG, 2, a plurality of triangular support chocks 16 are provided on the bottom of enclosure 2 to support the first tier of hexagonal collars 6 and, in turn, the cargo cylinders 4. In a similar manner, a plurality of trapezoidally shaped chocks 19 are welded to the lateral framework of the container 2 to further stabilize the cargo cylinders.

In FIG. 3 a schematic illustration is presented indicating how the basic cargo units of the instant invention may be utilized in a marine tanker, indicated by the reference numeral 18. Thus, as shown, a plurality of the cargo units would be positioned within the hold 20 of the tanker 18. Each of the units would be maintained in proper spaced relationship by means of the keys l2 and keyways l3 hereinbefore discussed. Additionally, piping connections 24 would be provided interconnecting each of the basic cargo units in a particular tier. These, in turn, would be fed by a main feed manifold 26 through which cargo could be introduced or withdrawn. It is to be appreciated that FIG. 3 is schematic only and that obviously various piping layouts along with suitable valving arrangements may be provided.

From the foregoing discussion it is readily apparent that the system herein disclosed provides several advantages in the transportation of natural gas. Thus, the basic cargo units may be shop-fabricated and in effect mass-produced to achieve substantial economies in overall construction. Furthermore, any number of these units can be provided to achieve any particular capacity desired. In addition, nonexotic insulation may be utilized, since a secondary barrier is provided in the form of the skins of the individual boxlike enclosures.

As a still additional advantage, the individual units are, in themselves, suitable for, not only marine transportation, but transportation by rail, truck, barge or the like and can if desired be adapted to'serve as units which may be used to transport, deliver and store the cargo. Furthermore, the units may be designed so that they are capable of handling either a pressurized noncryogenic cargo or a liquefied cargo under cryogenic conditions. In the former case, two cargoes could be carried in each unit, a primary cargo contained within the individual cylinders and a secondary cargo carried in the intercylinder spaces within the boxlike enclosures of each basic unit. In the case of the transportation of cryogenic cargoes, cool-down of the units can be readily achieved by circulating a cold gas such as nitrogen or the like through the containers around the individual cylinders prior to the loading of the main cargo. This would, of course, minimize boil-off of the cargo.

While the instant invention has been described in considerable detail by way of the drawings and the previous discussion, it is to be appreciated that obviously certain changes and modifications may be made without departing from the spirit of the invention. Thus, in determining the full scope of the invention, reference should .be had to the following appended claims.

lclaim:

l. in a ship having a cargo hold for transporting cargoes of natural gas and the like, an improved cargo-carrying system which comprises, in combination, a plurality of boxlike enclosures each of which has key and keyway means respectively disposed on opposing surfaces thereof, said boxlike enclosures being positioned within said cargo hold such that the key means of one of said enclosures is disposed in operable relationship with the keyway means of a second of said enclosures located adjacent said one enclosure, a multiplicity of individual primary cargo cylinders disposed in spaced relation ship in each of said boxlike enclosures and adapted to receive cargoes, collar means operably associated with each of said primary cargo cylinders for properly positioning adjacent ones ofsaid cylinders within said boxlike enclosure, said enclosures serving as secondary barriers in the event of a failure in one or more of said primary cargo cylinders, and insulation means disposed on the walls of said boxlike enclosures.

2. The system of claim 1 wherein each of said primary cargo cylinders is provided with hexagonally shaped sup ort collars, which collars bear against the support collars of a acent ones of said cylinders, whereby said cylinders are supported in spaced relationship within individual ones of said boxlike enclosures.

3. The system of claim 2 wherein said cylinders are fabricated from a material selected from the group consisting of aluminum, 9 percent nickel steel and fiberglass-reinforced thermosetting resins.

4. A transportation unit for transporting natural gas and the like which comprises, in combination, a boxlike, fluidtight en closure, said enclosure having internal framing and a sheathing ofplates which form said fluidtight enclosure, a plurality of cylinders disposed within said enclosure, each of said cylinders being provided with hexagonally shaped support collars, which collars bear against the support collars of adjacent ones of said cylinders whereby said cylinders are supported in an array with the individual cylinders being held in spaced relationship to each other within said enclosure, a plurality of cylinder chocks affixed to said internal framing to support said array, means for introducing natural gas or the like into each of said cylinders within saidenclosures and insulation means disposed on said sheathing of plates.

5. The unit of claim 4 wherein said sheathing defines a pair of keys and a pair of keyways.

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