Drip pan lng tank

Claim 2

A container for liquefied gases at cryogenic temperatures for use in a tanker which comprises, in combination: a primary tank of sufficient structural strength to contain the liquefied gas, said primary tank containing internal structural means fixed to the interior walls thereof; a larger liquid-tight secondary enclosure substantially similar in shape to said primary tank and completely surrounding said primary tank, said secondary enclosure containing a lower portion of predetermined thickness less than the thickness of the primary tank but sufficient to retain small quantities of the liquefied gases that may leak through said primary tank; thermally conductive structural means for maintaining said lower portion in spaced relationship and structurally integral with said primary tank, said structural means having sufficient depth to prevent failures in the primary tank from propagating to said lower portion; said secondary enclosure also containing a liquid-tight upper portion for deflecting seepage through upper portions of the primary tank into said lower portion; means for mechanically fastening said upper portion of said secondary enclosure to said lower portion and said primary tank solely for support and to permit relatively quick assembly and disassembly while maintaining said upper portion structurally independent of said primary tank and said lower portion; said lower portion being spaced at a first distance from the sides of said primary tank, and said upper portion being spaced at a second distance which is less than said first distance from said primary tank.

Claim 3

A container in accordance with claim 1 wherein thermal insulation means is secured externally to the entire surface of the upper and lower portions of said secondary enclosure.

Claim 4

A container in accordance with claim 1 wherein keying means are attached to said container for operable cooperation with the structure of said tanker for permitting relative movement therebetween, said keying means including at least a top and bottom longitudinally extending key-keyway.

Claim 5

A container in accordAnce with claim 3 wherein a plurality of transversely extending wooden bearing members are located between the bottom portion of said lower portion of said secondary enclosure and the hull of said tanker on either side of the bottom key-keyway, whereby the entire normal static load of said container and liquefied gas cargo is transmitted to the bottom hull of said tanker.

Claim 6

A container in accordance with claim 2 wherein the thermal insulation means applied to said upper portion of said secondary enclosure comprises a double layer of foam insulation sandwiching a thermally nonconductive member, said member acting to support the foam insulation, and an outer metallic covering over the outer layer of foam insulation which covering shields the foam insulation from leaks in the hull of said tanker.

Claim 7

The container in accordance with claim 1 wherein the secondary enclosure only substantially surrounds the primary tank.

Claim 8

A container in accordance with claim 1 wherein the mechanical fastening means includes a connector operably secured with said lower portion and said upper portion of said secondary enclosure and constructed and arranged for deflecting leaks in the upper portion of said primary tank downward into said lower portion.

Claim 9

A container in accordance with claim 5 wherein said outer metallic covering comprises a shingle-type arrangement with a downward overlap.

Claim 10

A container for liquefied gases at cryogenic temperatures for use in a tanker which comprises, in combination: a primary tank of sufficient structural strength to contain the liquefied gas, said primary tank containing internal structural means fixed to the interior walls thereof; a larger liquid-tight secondary enclosure substantially similar in shape to said primary tank and completely surrounding said primary tank, said secondary enclosure containing a lower portion of predetermined thickness less than the thickness of the primary tank but sufficient to retain small quantities of the liquefied gases that may leak through said primary tank; thermally conductive structural means for maintaining said lower portion in spaced relationship and structurally integral with said primary tank, said structural means having sufficient depth to prevent failures in the primary tank from propagating to said lower portion; said secondary enclosure also containing a liquid-tight upper portion for deflecting seepage through upper portions of the primary tank into said lower portion; means for mechanically fastening said upper portion of said secondary enclosure to said lower portion and said primary tank solely for support and to permit relatively quick assembly and disassembly while keeping said upper portion structurally independent of said primary tank and said lower portion; top and bottom keying means operably disposed between said container and the adjacent structure of said tanker for restraining said container from undesirable shifting while permitting relative movement therebetween, each of said top and bottom keying means including a key-keyway extending longitudinally along the centerline of the container and a pair of transverse key-keyways located on either side of the longitudinal key-keyway substantially at the midpoint thereof.

Claim 11

A container for liquefied gases at cryogenic temperatures for use in a tanker which comprises, in combination: a primary tank of sufficient structural strength to contain the liquefied gas, said primary tank containing internal structural means fixed to the interior walls thereof; a larger liquid-tight secondary enclosure substantially similar in shape to said primary tank and completely surrounding said primary tank, said secondary enclosure containing a lower portion of predetermined thickness less than the thickness of the primary tank but sufficient to retain small quantities of the liquefied gases that may leak through said primary tank; thermally conductive structural means for maintaining said lower portion in spaced relationship and structurally integral with said primary tank, said structural means having sufficient depth to prevent failures in the primary tank from propagating to said lower portion; said secondary enclosure also containing a liquid-tight upper portion for deflecting seepage through upper portions of the primary tank into said lower portion; means for mechanically fastening said upper portion of said secondary enclosure to said lower portion and said primary tank solely for support and to permit relatively quick assembly and disassembly while keeping said upper portion structurally independent of said primary tank and said lower portion; top and bottom keying means operably disposed between said container and the adjacent structure of said tanker for restraining said container from undesirable shifting while permitting relative movement therebetween, each of said top and bottom keying means including a key-keyway extending longitudinally along the centerline of the container and a pair of transverse key-keyways located on either side of the longitudinal key-keyway substantially at the midpoint thereof.

Claim 12

A container in accordance with claim 9 wherein a plurality of transversely extending load bearing insulation members are spaced longitudinally along the bottom of said container on either side of the longitudinally extending bottom key-keyway.