Buoyant cover

Abstract

A buoyant cover has a planar body, the body having a first buoyant insulating layer, a second tensile layer overlaying the first buoyant insulating layer, the planar body having a periphery configured based on the tank perimeter to provide a limited gap with the tank perimeter, and the body defining a plurality of peripheral holes positioned about the periphery and proximate the periphery. The second tensile layer may be wrapped about an edge of the first buoyant insulating layer. There may be an underlying portion of the second tensile layer near the periphery. A peripheral seam may be sewn through the underlying portion and the first buoyant insulating layer. The peripheral holes may penetrate the underlying portion. There may be grommets defining the peripheral holes. The planar body may have a circular periphery.

I claim: 
     
         1 . A buoyant cover for an open top outdoor fluid storage tank having a tank perimeter comprising:
 a planar body;   the planar body having a first buoyant insulating layer;   a second tensile layer overlaying the first buoyant insulating layer;   the body having a periphery configured based on the tank perimeter to provide a limited gap with the tank perimeter; and   the planar body defining a plurality of peripheral holes positioned about the periphery and proximate the periphery.   
     
     
         2 . The buoyant cover of  claim 1  wherein the second tensile layer is wrapped about an edge of the first buoyant insulating layer. 
     
     
         3 . The buoyant cover of  claim 2  including an underlying portion of the second tensile layer near the periphery. 
     
     
         4 . The buoyant cover of  claim 3  wherein a peripheral seam is sewn through the underlying portion and the first buoyant insulating layer. 
     
     
         5 . The buoyant cover of  claim 3  wherein the peripheral holes penetrate the underlying portion. 
     
     
         6 . The buoyant cover of  claim 1  including grommets defining the peripheral holes. 
     
     
         7 . The buoyant cover of  claim 1  wherein the planar body has a circular periphery. 
     
     
         8 . The buoyant cover of  claim 1  wherein the planar body is formed in multiple parts, each having holes about their peripheries and joined at a seam with peripheral holes aligned with respective peripheral holes in an adjacent part, and fasteners connected to each peripheral hole of a corresponding pair of peripheral holes. 
     
     
         9 . The buoyant cover of  claim 1  wherein the first buoyant insulating layer is a closed-cell foam sheet between laminated upper and lower sheets. 
     
     
         10 . The buoyant cover of  claim 9  wherein the laminated sheets are polyethylene. 
     
     
         11 . The buoyant cover of  claim 1  wherein the second tensile layer is a woven mesh. 
     
     
         12 . The buoyant cover of  claim 1  including a plurality of vertical lines each having an upper end configured to connect to an upper portion of the tank, and an intermediate portion passing through a respective one of the peripheral holes. 
     
     
         13 . The buoyant cover of  claim 12  including a weight connected to a lower end of each line. 
     
     
         14 . The buoyant cover of  claim 12  wherein the length of each line is based on the height of the tank.