Tanker for liquified and/or compressed gas

Abstract

In a marine vessel having a hull structure for transporting or storing a cargo tank adapted to contain liquefied and/or compressed gas, the tank is supported by an annular skirt having opposed edges integrally secured respectively to the hull structure and to a peripheral portion of the tank; the skirt minimizes the stresses transferred between the tank and the hull structure and is adapted to accommodate changes in the dimensional characteristics of the tank, due to temperature changes therein, independently of the hull structure.

What is claimed is: 
     
       1. Apparatus for storing liquified gas in combination with a cargo tank on board a marine vessel having a hull structure, said tank being generally curvilinear in cross section, and said apparatus comprising skirt means operably interconnecting said tank and said hull structure for supporting said tank on said structure, said skirt extending tangentially to said tank and having one end thereof integrally connected to said hull structure and the other end thereof integrally connected to said tank along a peripheral portion thereof, and separate means for maintaining a low temperature condition within said tank to maintain said gas in its liquid phase. 
     
     
       2. Apparatus as in claim 1 wherein said skirt is tangentially secured to said peripheral portion throughout the full curvilinear dimension thereof. 
     
     
       3. Apparatus as in claim 1 wherein said curvilinear peripheral portion is circular and said skirt comprises a generally cylindrical member. 
     
     
       4. Apparatus as in claim 2 wherein said skirt comprises a generally frusto-conical member. 
     
     
       5. Apparatus as in claim 2 wherein said skirt is formed of plate construction. 
     
     
       6. Apparatus as in claim 2 including thermal insulation surrounding said skirt and extending from the point of juncture of said skirt with said tank towards said hull structure, said insulation having a decreasing thickness at points remote from said point of juncture whereby the temperature gradients in said skirt are predetermined. 
     
     
       7. Apparatus as in claim 2 wherein said skirt edges are welded to said tank and said hull structure. 
     
     
       8. Apparatus as in claim 7 wherein the edge of said skirt secured to said tank has a generally sinusoidal configuration whereby a relatively large weld area is provided between said skirt and said tank. 
     
     
       9. Apparatus as in claim 8 wherein said skirt has a plurality of apertures at predetermined locations to distribute stress concentrations therein. 
     
     
       10. Apparatus as in claim 2 including an annular ring of heat conductive material mounted between said tank and said skirt adjacent the point of juncture therebetween, whereby the temperature of said skirt adjacent said point of juncture is substantially the same as that of said tank. 
     
     
       11. Apparatus as in claim 2 wherein said skirt means comprises a first skirt portion secured at one edge to said tank and having an opposed edge remote from the point of juncture of said one edge with said tank, and a second skirt portion having one edge integrally secured to said hull structure and an opposed edge remote from the point of juncture of its first edge with said hull structure, said opposed edges of said first and second skirt portions being positioned adjacent each other and having mutually opposed flange portions operably connected with each other to form said skirt means. 
     
     
       12. Apparatus as in claim 11 wherein said flanges are operably connected by means for .[.accomodating.]. .Iadd.accommodating .Iaddend.changes in the peripheral dimension of said first skirt portion with respect to said second skirt portion due to temperature variations in said cargo tank. 
     
     
       13. Apparatus as in claim 12 wherein said accommodating means prevents rotational movement and lateral movement of said flanges with respect to each other. 
     
     
       14. Apparatus as in claim 12 wherein said accommodating means comprises means for defining radial and circumferential tracks at predetermined locations on one of said flanges and a plurality of radial and circumferential extensions on the other of said flanges adapted to be inserted in said tracks, said radial extensions having substantially the same width as said radial tracks to prevent rotational and lateral movement between said flanges, and said circumferential extensions having a width substantially less than the width of said circumferential tracks, thereby to accommodate changes in the radial dimensions of said first skirt portion with respect to said second skirt portion. 
     
     
       15. Apparatus as in claim 14 including a plurality of resilient pads secured to one of said flanges to provide resilient support between said first and second skirt portions. 
     
     
       16. Apparatus as in claim 3 wherein said tank is spherical and said skirt is tangentially connected thereto at the equatorial plane of the tank. 
     
     
       17. Apparatus for storing liquified gas in combination with a transport carrier, said apparatus comprising a cargo tank being generally curvilinear in cross section and adapted to contain liquified gas, said tank being a pressure vessel for containing said gas under at least atmospheric pressure, and means for supporting said tank on said carrier, said supporting .[.meanS.]. .Iadd.means .Iaddend.being integrally connected at one end to said carrier and integrally connected in tangential relation at its other end along a peripheral portion of said tank, to thermally isolate said tank from said carrier, and separate means for maintaining a low temperature condition within said tank to maintain said gas in its liquid phase, whereby changes in the dimensional characteristics of said tank due to temperature changes in .[.sand.]. .Iadd.said .Iaddend.tank are permitted independently of said carrier. 
     
     
       18. Apparatus as in claim 17 wherein said cargo tank has a generally circular cross section and said supporting means comprises a skirt integrally secured at one end to said tank in tangential relation and integrally secured at its opposed end to the structural members of said carrier. 
     
     
       19. Apparatus as in claim 18 wherein said tank includes an integral peripheral interface structure and said one edge of said skirt is integrally secured to said structure. 
     
     
       20. Apparatus as in claim 19 wherein said interface structure comprises an annular ring having an integral extension extending tangentially to said tank and defining a free end positioned a predetermined distance from said tank, said free end of said extension being integrally secured in abutting relation to said one end of said skirt. 
     
     
       21. Apparatus as in claim 20 wherein said interface structure has an annular groove formed therein between said ring and said extension, said groove having .Iadd.a .Iaddend.predetermined configuration whereby the stresses transmitted through said skirt to said tank are minimized. 
     
     
       22. Apparatus as in claim 19 wherein said interface structure comprises a pair of vertically spaced parallel structural members secured to the exterior periphery of said .[.tanks.]. .Iadd.tank.Iaddend., a plurality of generally vertically extending plates secured between said structural members, a pair of vertically spaced parallel structural members secured to the interior of said tank in positions opposite said exterior structural members and a plurality of vertically extending plates secured between said interior structural members to support said tank on said carrier. 
     
     
       23. Apparatus as in claim 19 including means for maintaining a low temperature condition within said cargo tank to maintain said gas in its liquid phase. 
     
     
       24. Apparatus as in claim 18 wherein said skirt member is welded to said cargo tank and the structural members of said carrier. 
     
     
       25. Apparatus as in claim 24 wherein said skirt is of plate construction. .Iadd. 26. Apparatus for storing liquified gas in combination with a tank on board a marine vessel having a hull structure, said tank being generally curvilinear in cross-section, said apparatus comprising skirt means operably interconnecting said tank and said hull structure for supporting said tank on said structure, said skirt extending tangentially to said tank and having one end thereof integrally connected to said hull structure and the other end thereof integrally connected to said tank along a peripheral portion thereof, separate means for maintaining a low temperature condition within said tank to maintain said gas in its liquid phase, and thermal insulation at least on the outer side of said skirt with respect to said tank extending at least from the point of juncture of said skirt with said tank to a predetermined distance below the point of juncture of said skirt with the tank thereby to control the temperature gradient and thermal stresses produced in said skirt. .Iaddend..Iadd. 27. The apparatus as defined in claim 26 wherein said insulation is located on both the inner and outer sides of said skirt. .Iaddend..Iadd. 28. The apparatus as defined in claim 27 wherein said tank is covered on its outer surface with insulating material. .Iaddend. .Iadd. 29. Apparatus for storing liquified gas in combination with a marine vessel, said apparatus comprising a tank being generally curvilinear in cross-section and adapted to contain liquified gas, said tank being a pressure vessel for containing said gas under at least atmospheric pressure, and means for supporting said tank on said vessel, said supporting means including an annular skirt for thermally isolating said tank from said vessel, said skirt having upper and lower ends, with said lower end being integrally connected to said vessel and said upper end being integrally connected in tangential relation along a peripheral portion of said tank, separate means for maintaining a low temperature condition within said tank to maintain said gas in its liquid phase, and thermal insulation surrounding said skirt on at least the outer side thereof with respect to said tank and extending from the point of juncture of said skirt with said tank to a predetermined distance below the point of juncture of said skirt with the tank thereby to control the temperature gradient and thermal stresses produced in said skirt, whereby changes in the dimensional characteristics of said tank due to temperature changes in said tank are permitted independently of said vessel. .Iaddend..Iadd. 30. The apparatus as defined in claim 29 wherein said insulation is located on both the inner and outer sides of said skirt. .Iaddend..Iadd. 31. The apparatus as defined in claim 30 wherein said tank is covered on its outer surface with insulating material. .Iaddend.