Liquified Natural Gas Sump For a Gravity Based Structure
A liquefied natural gas (LNG) sump is provided for a gravity based structure (GBS). The sump includes a sump containment structure having a predetermined volume and floor surface area. The volume and floor surface area are selected in order to allow spilled LNG contained within the sump containment structure to vaporize at a predetermined, safe rate. A trough is provided for collecting spilled LNG on the GBS, such as at the processing area and on a jetty, and delivering the spilled LNG to the sump containment structure.
1 . A liquefied natural gas (LNG) sump for a gravity based structure (GBS), said sump comprising:
a sump containment structure having a predetermined volume and bottom surface area, said volume and bottom surface area being selected in order to allow spilled LNG contained within said sump containment structure to vaporize at a predetermined rate; and
a trough for collecting spilled LNG on said GBS and delivering said spilled LNG to said sump containment structure.
2 . The LNG sump as recited in claim 1 , wherein said sump containment structure comprises a cylinder having a diameter that is substantially smaller than a height of the cylinder.
3 . The LNG sump as recited in claim 1 , wherein said sump containment structure is disposed inside a concrete compartment within said GBS.
4 . The LNG sump as recited in claim 1 , wherein said sump containment structure is insulated.
5 . The LNG sump as recited in claim 1 , wherein heat tracing is provided on said sump containment structure for controlling the vaporization rate of spilled LNG.
6 . The LNG sump as recited in claim 1 , further comprising a cryogenic sump pump disposed on a bottom surface of said sump for removing water from said sump.
7 . The LNG sump as recited in claim 2 , wherein the height of said sump containment structure is at least 10 times greater than the diameter of said sump containment structure.
8 . The LNG sump as recited in claim 1 , wherein said sump containment structure comprises aluminum.
9 . The LNG sump as recited in claim 1 , wherein said sump containment structure comprises concrete.
10 . The LNG sump as recited in claim 1 , wherein said sump containment structure comprises a material resistant to cryogenic temperatures.
11 . A liquefied natural gas (LNG) sump for a gravity based structure (GBS), said sump comprising:
containment means for collecting spilled LNG and for allowing the spilled LNG contained to vaporize at a predetermined rate; and
collecting means for collecting spilled LNG on said GBS and delivering said spilled LNG to said containment means.
12 . The LNG sump as recited in claim 11 , wherein said containment means comprises a cylinder having a diameter that is substantially smaller than a height of the cylinder.
13 . The LNG sump as recited in claim 11 , wherein said containment means is disposed inside a concrete compartment within said GBS.
14 . The LNG sump as recited in claim 11 , wherein said containment means is insulated.
15 . The LNG sump as recited in claim 11 , further comprising means for adjusting the vaporization rate of spilled LNG within said containment means.
16 . The LNG sump as recited in claim 11 , further comprising means for removing water from said sump.
17 . The LNG sump as recited in claim 12 , wherein the height of said containment means is at least 10 times greater than the diameter of said sump containment structure.
18 . The LNG sump as recited in claim 11 , wherein said containment means comprises aluminum outer walls.
19 . The LNG sump as recited in claim 11 , wherein said containment means comprises concrete outer walls.
20 . The LNG sump as recited in claim 11 , wherein said containment means is constructed from a material resistant to cryogenic temperatures.
21 . A method for handling liquefied natural gas (LNG) spills on a gravity based structure (GBS), said method comprising:
a step of collecting spilled LNG and delivering said spilled LNG to a containment means; and
a step of allowing the spilled LNG contained to vaporize at a predetermined rate.
22 . The method as recited in claim 21 , wherein said containment means comprises a cylinder having a diameter that is substantially smaller than a height of the cylinder.
23 . The method as recited in claim 21 , wherein said s containment means is disposed inside a concrete compartment within said GBS.
24 . The method as recited in claim 21 , wherein said containment means is insulated.
25 . The method as recited in claim 21 , further comprising a step of adjusting the vaporization rate of spilled LNG within said containment means by proving at least one of insulation and heat tracing on said containment means.
26 . The method as recited in claim 21 , further comprising a step of removing water from said containment means.
27 . The method as recited in claim 22 , wherein the height of said containment means is at least 10 times greater than the diameter of said sump containment structure.
28 . The method as recited in claim 21 , wherein said containment means comprises aluminum outer walls.
29 . The method as recited in claim 21 , wherein said containment means comprises concrete outer walls.
30 . The method as recited in claim 21 , wherein said containment means is constructed from a material resistant to cryogenic temperatures.