| 摘要 |
<p>This invention relates to a double wall underground tank of a composite material, characterized in that it comprises an inner tank frame structure having the function of a rotating metal mandrel, and two separated concentric cylindrical non-metallic pressure resisting containers enclosing the tank frame structure and each having two hemispherical end portions and wavy wall surfaces. The metal tank frame structure provides the tank with a buckling resistance and a pressure resisting strength against a load of earth when the tank is buried under the ground. The pressure resisting containers are made of the same material, and comprise a first container positioned on the inner side and a second container positioned on the outer side so as to enclose the first container, both of which containers have equal tensile strength and corrosion resistance. The double wall tank of composite material according to the present invention is made by greatly improving a conventional steel and reinforced plastic tank, and it prevents the leakage of a dangerous liquid stored in the tank, whereby a method of preserving the environment with higher reliability is provided. Each of the two pressure resisting containers is formed out of a multilayer composite laminated material formed by uniquely arranging fiber-reinforced material-containing cloths impregnated with a thermosetting polymeric matrix. Each hemispherical end member is provided with a sealable rotary shaft fitting hole. At a discharge port portion in a top region of the tank, the inner and outer walls are combined with each other at non-wavy parts of the cylindrical double wall structure, and sandwiched between two bolt-connected metal plates. These metal plates are joined structurally to the tank frame, and sealed by putting a laminated structure on the surfaces thereof.</p> |
