Sunken tank with floating cover for liquid gas storage

摘要

The central portion of a heat insulated impervious roof 22, Fig. 2 (not shown), covering a ground storage reservoir 10 holding liquid methane floats on the surface of the liquid and is connected to the rim 18 of the reservoir by a flexible sealing joint 26. The central roof portion is formed of aluminium plates 33, 34 faced inwardly with textile fabric, outwardly with plastic sheeting and separated by concentric metal tubes 38 and by perlite. The joint 26 comprises panels 46, 48, Fig. 3 (not shown) of metal foil lined with textile and plastic material and are spaced by concentric tubes 44 similar to tubes 38 and by perlite. The peripheral panels of the joint are juxtaposed to form a skirt 50 which dips into an icefilled gutter 52 protected from ambient heat by insulation 56. The external side wall 16 of the reservoir is coated with fibre glass 20. In a modification the central portion of the roof is provided with concentric corrugations and the joint is sealingly covered by a flexible sheet through which compressed nitrogen is passed.