Rim seal flammable liquid storage tank

Abstract

A rim seal for a flammable liquid storage tank is provided. The rim seal forms a vapor impermeable barrier with passive fire-suppressing capabilities provided by layers of buoyant members that suppress flammable vapors to prevent fires. The buoyant and fire-retardant members are contained within a closed flexible membrane. The closed flexible membrane contains one or more layers of the buoyant members. The closed flexible membrane and the buoyant members therein extend across the gap formed between an outer circumferential edge of a floating roof and the inner wall of the liquid storage tank. The buoyant members form the layers under the influence of gravity. The buoyant members are formed from a material which is resistant to hydrocarbon degradation, and which is flame retardant and vapor suppressing. The layers of the buoyant members form a passive fire protective barrier between the flammable liquid in the storage tank and the atmosphere.

1 . A rim seal for a flammable liquid storage tank, comprising:
 a plurality of round, buoyant members adapted to float on a liquid received within a liquid storage tank, the round, buoyant members being formed from a material which is resistant to hydrocarbon degradation; and   a closed flexible membrane, the plurality of round, buoyant members being received therein, wherein the closed flexible membrane is formed from a material that does not dissolve in the liquid,   wherein the closed flexible membrane and the plurality of round, buoyant members received therein are adapted to be received within, and extend across, a gap formed between an outer circumferential edge of a floating roof and an inner surface of a sidewall of the liquid storage tank.   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . The rim seal for a flammable liquid storage tank as recited in  claim 1 , wherein a shape of each of the round, buoyant members is selected from the group consisting of spherical, ovoidal, ellipsoidal and oblate spheroidal. 
     
     
         5 . The rim seal for a flammable liquid storage tank as recited in  claim 1 , further comprising a layer of resilient foam received within the closed flexible membrane. 
     
     
         6 . The rim seal for a flammable liquid storage tank as recited in  claim 5 , wherein the layer of resilient foam comprises reticulated foam. 
     
     
         7 . The rim seal for a flammable liquid storage tank as recited in  claim 1 , wherein each of the round, buoyant members comprises a core and an outer layer formed on an outer surface of the core, the outer layer comprising a heat-reactive intumescent material. 
     
     
         8 . The rim seal for a flammable liquid storage tank as recited in  claim 1 , wherein each of the round, buoyant members is formed from a material selected from the group consisting of glass, ceramic, plastic, resin and a composite material. 
     
     
         9 . The rim seal for a flammable liquid storage tank as recited in  claim 1 , wherein each of the round, buoyant members has a diameter in the range of about 0.01 inches to about 4.0 inches. 
     
     
         10 . The rim seal for a flammable liquid storage tank as recited in  claim 1 , wherein each of the round, buoyant members has a specific gravity in the range of about 0.01 to about 0.5. 
     
     
         11 . A liquid storage tank with a rim seal, comprising:
 a hollow cylindrical tank having a closed lower end, an open upper end, and a cylindrical sidewall;   a floating roof received within the hollow cylindrical tank, the floating roof having a circular contour and being adapted to float on a liquid received within the hollow cylindrical tank; and   a rim seal, comprising:   a plurality of round, buoyant members adapted to float on the liquid received within the hollow cylindrical tank, the round, buoyant members being formed from a material which is resistant to hydrocarbon degradation; and   a closed flexible membrane, the plurality of round, buoyant members being received therein, wherein the closed flexible membrane is formed from a material that does not dissolve in the liquid,   wherein the rim seal is positioned within, and extends across, a gap formed between an outer circumferential edge of the floating roof and an inner surface of the cylindrical sidewall of the hollow cylindrical tank.   
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . The liquid storage tank with a rim seal as recited in  claim 11 , wherein a shape of each of the round, buoyant members is selected from the group consisting of spherical, ovoidal, ellipsoidal and oblate spheroidal. 
     
     
         15 . The liquid storage tank with a rim seal as recited in  claim 11 , further comprising a layer of resilient foam received within the closed flexible membrane. 
     
     
         16 . The liquid storage tank with a rim seal as recited in  claim 15 , wherein the layer of resilient foam comprises reticulated foam. 
     
     
         17 . The liquid storage tank with a rim seal as recited in  claim 11 , wherein each of the round, buoyant members comprises a core and an outer layer formed on an outer surface of the core, the outer layer comprising a heat-reactive intumescent material. 
     
     
         18 . The liquid storage tank with a rim seal as recited in  claim 11 , wherein each of the round, buoyant members is formed from a material selected from the group consisting of glass, ceramic, plastic, resin and a composite material. 
     
     
         19 . The liquid storage tank with a rim seal as recited in  claim 11 , wherein each of the round, buoyant members has a diameter in the range of about 0.01 inches to about 4.0 inches, and wherein each of the buoyant members has a specific gravity in the range of about 0.01 to about 0.5. 
     
     
         20 . The liquid storage tank with a rim seal as recited in  claim 11 , further comprising a bumper mounted on the floating roof and projecting outwardly therefrom.