WATERPROOF AND THERMALLY INSULATING TANK COMPRISING A GAS DOME STRUCTURE

摘要

The invention relates to a sealed and thermally insulating tank for storing a liquefied gas, said tank having an upper wall having a multilayer structure; the vessel further comprising a gas dome structure (1) comprising: - a vapor collecting duct (15); a sheath (19) which is arranged around the vapor collecting duct (15) and is sealingly connected to the secondary sealing membrane (6); said sheath (19) being sealingly connected to the vapor collecting pipe (15) by means of an upper annular plate (20) extending transversely between the sheath (19) and the vapor collecting pipe (15) so as to provide a sealed primary space (22) which communicates with the primary thermally insulating barrier (7); the sheath (19) having, between the upper annular plate (20) and the secondary sealing membrane (6), a frustoconical portion (43) tapering towards the secondary sealing membrane (6); and - a primary exhaust device for discharging a fluid from the primary thermally insulating barrier (7); the primary exhaust device comprising a conduit (27) sealingly connected to the upper annular plate (20).