Suspended deck for liquid natural gas tank

Abstract

A non-welded deck used to support insulation from the roof of a low temperature or cryogenic storage tank is disclosed. The deck may be comprised of a plurality of spaced apart bars with metal sheets covering the spaces between the bars. The edge of the metal sheets may be clamped to the bars to form the deck. The edges of adjacent metal sheets may overlap and be clamped together in such a way as to deform the sheets creating a metal-to-metal vapor and dust proof seal. The plurality of clamping bars and support bars may secure the metal sheets with sufficient strength to allow the entire deck to support loadings as a stressed membrane. The tank may be constructed with hardware that remains secure even after being subjected to repeated thermal cycling of over 200° Celsius (360° Fahrenheit).

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to an insulation deck suspended from the roof of a low temperature tank, such as a liquid natural gas tank for example. [0003] 2. Description of the Related Art [0004] Every year more and more natural gas reserves are discovered. Unfortunately, much of it is found far from the major consumer countries making economical transportation and distribution vital. Presently far more natural gas is removed from discovered natural gas reserves than is consumed globally. The excess amount of natural gas requires the rapid construction of storage facilities to hold the extracted natural gas. The size of the needed storage facilities and vessels can be decreased if the natural gas is stored at cryogenic temperatures, which liquifies the natural gas. Liquifying natural gas decreases the volume of the natural gas by more than 600 percent. Thus, liquid natural gas (“LNG”) requires less stora...

AI Technical Summary

Benefits of technology

[0013] The apparatus of one embodiment of the present disclosure is an insulation deck that is constructed by assembling aluminum components without welding and prevents the contamination of material, such as LNG, stored in a low temperature tank from the insulation supported by the insulation deck. As used herein, a low temperature tank is a tank in which temperatures within the tank reach cryogenic temperatures and the term low temperature tank may be utilized interchangeably with LNG tank, cryogenic tank, and the like, and each term (low temperature tank, LNG tank, cryogenic tank) is to be given its ordinary meaning.

[0015] One embodiment of the present disclosure is an insulation deck for use in a low temperature tank comprising a plurality of beams, a plurality of support bars connected to the plurality of beams, a plurality of metal sheets wherein an external portion of each of the metal sheets rests on one of the support bars and covers openings between the support bars, a plurality of clamping bars that engage a top surface of at least one the metal sheets, and a plurality of fasteners that secure the clamping bars to the support bars. The plurality of clamping bars and support bars may secure the metal sheets with sufficient strength to allow the entire deck to support loadings as a stressed membrane. Additionally, one embodiment of the insulation deck may include a termination member extending around the edge of the insulation deck. The plurality of fasteners may be lock bolts. Alternatively, the plurality of fasteners may be mechanically locked in place. Insulation may be placed on the plurality of metal sheets. In one embodiment, the insulation may be a fine powder, such as perlite, or may contain significant dust components.

Problems solved by technology

However, the components could all be comprised of the same material, but not necessarily be aluminum alloy, so that the expansion and contraction rates of the deck components are uniform.

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