| 摘要 |
<p>The invention relates to an improvement in partial secondary barriers for self-supporting, axi-symmetrical cargo tanks having a layer of thermal insulation thereon, the cargo tanks mounted on board marine vessels having a double-bottom construction with an inner shell by means of an annular support supporting the cargo tank of the vessel. The improvement in the partial secondary barrier comprises a secondary barrier tank, preferably cylindrical in shape. The secondary barrier tank is installed under each cargo tank wherein the cross-section of the secondary barrier tank is substantially less than the maximum horizontal cross-section of the cargo tank. The barrier tank, in one embodiment, is structurally joined to the inner shell of the double bottom of the vessel. The tank comprises a stiff external wall, and internal thermal insulation, and an inner impermeable layer for withstanding the low temperatures of the liquid being collected in the secondary barrier tank. Leak drainage pipes originating from the interface of the thermal-insulation with the cargo tank extend into the tank for draining off any leak that may occur in the cargo tank. Collected leaking liquid can be discharged from the secondary barrier tank.</p> |
