Multi compartment collapsible tank

Abstract

A collapsible tank comprises a flexible unitary container having an inner surface and an outer surface and a flexible partial container having an inner surface and an outer surface. The inner surface of the unitary container defines a first compartment for storing a first fluid. The partial container is mounted to the unitary container to divide the unitary container into a first portion and a second portion and to form a second compartment between the inner surface of the partial container and the outer surface of the second portion of the unitary container to store a second fluid. The second portion of the unitary container is flexible and movable relative to the first portion of the unitary container and the partial container to reciprocally change the relative volumes of the first and the second compartments.

1 . A collapsible tank comprising: 
 a unitary container formed of a first contiguous wall having an inner surface and an outer surface, the inner surface of the first contiguous wall defining a first compartment for storing a first fluid; and    a flexible partial container formed of a second contiguous wall having an inner surface, an outer surface and an open end;    wherein the open end of the second contiguous wall is mounted to the first contiguous wall to divide the first contiguous wall into a first portion and a second portion and to form a second compartment between the inner surface of the second contiguous wall and the outer surface of the second portion of the first contiguous wall for storing a second fluid.    
   
   
       2 . The collapsible tank according to  claim 1 , wherein the second contiguous wall is about half of the size of the first contiguous wall.  
   
   
       3 . The collapsible tank according to  claim 1 , wherein the second portion of the first contiguous wall is flexible and movable relative to the first portion of the first contiguous wall and the second contiguous wall to change the relative volumes of the first and the second compartments.  
   
   
       4 . The collapsible tank according to  claim 3 , wherein an increase in the maximum volume of one of the first and the second compartments corresponds to a decrease in the maximum volume of the other of the first and the second compartments.  
   
   
       5 . The collapsible tank according to  claim 4 , wherein the maximum volumetric increase and decrease of the first and the second compartments are of substantially equal magnitude.  
   
   
       6 . The collapsible tank according to  claim 1 , wherein the first and the second compartments have comparable maximum capacities.  
   
   
       7 . The collapsible tank according to  claim 1  and further comprising a fill/discharge assembly, a vent, and a drain mounted to each of the first contiguous wall and the second contiguous wall.  
   
   
       8 . The collapsible tank according to  claim 1 , wherein the first contiguous wall comprises a fluid barrier.  
   
   
       9 . The collapsible tank according to  claim 8 , wherein the fluid barrier comprises an inner surface fluid barrier on the inner surface of the first contiguous wall and an outer surface fluid barrier on the outer surface of the fluid barrier.  
   
   
       10 . The collapsible tank according to  claim 9 , wherein the inner surface fluid barrier and the outer surface fluid barrier comprise a polymer coating.  
   
   
       11 . The collapsible tank according to  claim 10 , wherein one of the inner surface fluid barrier and the outer surface fluid barrier comprises a polyester coating and the other of the inner surface fluid barrier and the outer surface fluid barrier comprises a polyether coating.  
   
   
       12 . The collapsible tank according to  claim 9 , wherein the second contiguous wall comprises an inner surface fluid barrier on the inner surface thereof.  
   
   
       13 . The collapsible tank according to  claim 12 , wherein the inner surface fluid barrier of the second contiguous wall comprises the same material as the outer surface fluid barrier of the first contiguous wall.  
   
   
       14 . The collapsible tank according to  claim 13 , wherein the inner surface fluid barrier of the second contiguous wall and the outer surface fluid barrier of the first contiguous wall comprises one of a polyester and a polyether coating.  
   
   
       15 . The collapsible tank according to  claim 1  and further comprising a lap joint at a junction between the first contiguous wall and the second contiguous wall.  
   
   
       16 . The collapsible tank according to  claim 15 , wherein the lap joint is thermowelded.  
   
   
       17 . The collapsible tank according to  claim 1 , wherein the first fluid and the second fluid are different fluids.  
   
   
       18 . The collapsible tank according to  claim 17 , wherein the first fluid is one of a fuel and water, and the second fluid is the other of the fuel and the water.  
   
   
       19 . A collapsible tank comprising: 
 a flexible container having an interior surface defining a maximum volumetric capacity; and    a flexible partition mounted to the interior surface of the container to divide the container into a first compartment with a first volume for storing a first fluid and a second compartment with a second volume for storing a second fluid;    wherein the partition has sufficient size and pliability so that it is movable within the container to reciprocally change the first and second volumes.    
   
   
       20 . The collapsible tank according to  claim 19 , wherein the partition is sized so that first and second compartments each have a maximum capacity comparable to the maximum volumetric capacity of the container.