Storage tank with inventory reduction

Abstract

The disclosed floating-roof storage tank has an articulated floor with an annular outer portion, an intermediate transition portion, and a raised inner portion. Pipe elements or equipment that may hang from an outer, annular section on the roof or extend from the tank wall fit around the outside of the transition portion. Liquid-tight seams connect the transition portion of the floor to the outer portion and to the raised inner portion of the floor, sealing off an inventory-reduction compartment beneath the raised portion of the floor. The inventory-reduction compartment is supported by a solid or liquid fill or by a metal support structure. The raised inner portion of the floor may support the floating roof in a low position, and may support columns or the like that are used to support a fixed roof above the floating roof.

1 . A storage tank for liquid resources such as crude oil, gasoline, or the like that has a cylindrical outer wall and a floor that has:
 an annular outer portion;   a raised inner portion;   an intermediate transition portion that is narrower in width than the raised inner portion and connects the outer portion of the floor and the inner portion of the floor; and   liquid-tight seams that connect the transition portion to the outer portion of the floor and to the inner portion of the floor.   
   
   
       2 . A storage tank as recited in  claim 1 , in which the tank also has a floating roof. 
   
   
       3 . A storage tank as recited in  claim 2 , in which the roof has a peripheral, annular section that has a bottom surface that fits around the transition portion. 
   
   
       4 . A storage tank as recited in  claim 2 , in which the tank has pipe elements or equipment that extends inwardly from the outer wall toward the intermediate portion of the floor. 
   
   
       5 . A storage tank as recited in  claim 2 , in which the roof has pipe elements that extend beneath a peripheral, annular section of the roof that has a bottom surface that fits around the transition portion of the floor. 
   
   
       6 . A storage tank as recited in  claim 2 , in which the raised inner portion of the floor supports the roof in a low position. 
   
   
       7 . A storage tank as recited in  claim 1 , in which structural granular fill or concrete is provided beneath the raised inner portion of the floor. 
   
   
       8 . A storage tank as recited in  claim 1 , in which a metal support structure is provided beneath the raised inner portion of the floor. 
   
   
       9 . A storage tank as recited in  claim 1 , in which the outer portion of the floor is part of a continuous floor that extends beneath the raised inner portion of the floor. 
   
   
       10 . A storage tank as recited in  claim 1 , in which the outer portion of the floor is part of a continuous floor that extends beneath the raised inner portion of the floor, and the tank includes a sealed, liquid-filled inventory-reduction compartment beneath the raised inner portion. 
   
   
       11 . A storage tank as recited in  claim 1 , in which the raised inner portion of the floor is made primarily of steel that is at least ⅛ of an inch thick and no more than ¾ of an inch thick. 
   
   
       12 . A storage tank as recited in  claim 1 , in which the transition portion is welded to the outer portion of the floor. 
   
   
       13 . A storage tank as recited in  claim 1 , in which the raised inner portion of the floor is at least 6″ and no more than 60″ above the outer portion of the floor. 
   
   
       14 . A storage tank as recited in  claim 1 , in which the raised inner portion of the floor is sloped toward the transition portion of the floor. 
   
   
       15 . A storage tank as recited in  claim 1 , in which the intermediate transition portion is approximately vertical. 
   
   
       16 . A storage tank as recited in  claim 1 , in which the storage tank has a diameter of at least 60 feet and the intermediate transition portion of the floor begins to rise upwardly within 20 feet of the cylindrical outer wall of the tank. 
   
   
       17 . A storage tank as recited in  claim 1 , in which the storage tank has a diameter of at least 60 feet and the intermediate transition portion of the floor is approximately vertical and is positioned within 20 feet of the cylindrical outer wall of the tank. 
   
   
       18 . A storage tank for liquid resources such as crude oil, gasoline, or the like that has a cylindrical wall, the tank comprising a floor that has:
 an annular outer portion;   a raised inner portion;   an approximately vertical intermediate transition portion that connects the outer portion of the floor and the inner portion of the floor;   liquid-tight seams connecting the transition portion to the outer portion and to the inner portion.   
   
   
       19 . A storage tank for liquid resources such as crude oil, gasoline, or the like that has a cylindrical outer wall and a floor that has:
 an annular outer portion that is adjacent a reduced storage volume;   a raised inner portion;   an intermediate transition portion that connects the outer portion of the floor and the inner portion of the floor;   an inventory-reduction compartment beneath the raised inner portion of the floor, the volume of the inventory-reduction compartment being at least double a reduced heel volume; and   liquid-tight seams that connect the transition portion to the outer portion of the floor and to the inner portion of the floor.   
   
   
       20 . A storage tank as recited in  claim 19 , in which the intermediate transition portion is narrower in width than the raised inner portion.