Fluid pressurization device

Abstract

A fluid pressurization device 10 comprises a pressure container 12 and a first bladder 14 , a second bladder 16 and a sheet 18 , that are located in the pressure container 12 . The bladders 14 and 16 have pipe connectors 32 and 40 , respectively, for filling/discharging fluid from the bladders. The bladders 14 and 16 are located in the container 12 adjacent one another, with the bladder 16 being folded in concertina fashion and the sheet 18 being wrapped around the bladder 16 to form a roll surrounding the folded bladder 16 . In use, the bladder 14 is filled with a combustible fluid such as oxygen and the bladder 16 is filled with compressed air to a relatively higher pressure than the oxygen in the bladder 14 for pressurizing the oxygen contained therein. As oxygen is delivered from bladder 14 , the sheet 18 unravels gradually, allowing the bladder 16 to continue to exert a force on the bladder 14.

1 . A fluid pressurization device including: 
 a pressure container defining a fixed volume, in use;    a first resiliently deformable inflatable bladder for containing a fluid under pressure, that is located within the pressure container;    a second resiliently deformable inflatable bladder for containing a fluid under a relatively higher pressure than the pressure of the fluid in the first bladder and that is located within the pressure container adjacent the first bladder; and    releasable holding means for initially holding the second bladder at a fixed volume when inflated to thereby hold the fluid contained therein under pressure, and for releasing the second bladder thereby permitting the second bladder to expand and exert a force on the first bladder for pressurizing the fluid contained therein.    
   
   
       2 . A fluid pressurization device as claimed in  claim 1 , wherein the first bladder contains a volatile fluid under pressure and the second bladder contains a non-volatile fluid at a relatively higher pressure than the pressure of the fluid in the first bladder.  
   
   
       3 . A fluid pressurization device as claimed in  claim 1 , wherein the first bladder has an opening in which a valve is located, through which fluid can be introduced into and discharged from the first bladder.  
   
   
       4 . A fluid pressurization device as claimed in  claim 1 , wherein the second bladder has an opening including a valve through which the second bladder can be inflated with fluid.  
   
   
       5 . A fluid pressurization device as claimed in  claim 1 , wherein the releasable holding means comprises a flexible sheet element that is wrapped around the second bladder to form a roll surrounding the second bladder wherein portions of the sheet element overlap and contact one another, the rolled-up sheet element being in contact with the second bladder, an inner side of the pressure container and the first bladder in an arrangement wherein frictional forces acting between said overlapping portions of the sheet element and the second bladder in a hoop direction and frictional forces acting between said sheet element and the pressure container and the first bladder, respectively, resist unrolling of the sheet element, in use.  
   
   
       6 . A fluid pressurization device as claimed in  claim 5 , wherein the sheet element is configured and the first and second bladders are located in the pressure container, in an arrangement permitting gradual unrolling of the sheet element when fluid is discharged from the first bladder, causing a reduction in size of the first bladder and a consequent reduction in the frictional forces acting between said overlapping portions of the sheet element and the second bladder and the pressure container.  
   
   
       7 . A fluid pressurization device as claimed in  claim 6 , wherein the pressure container has a frusto-conical shape in said in-use configuration thereof.  
   
   
       8 . A fluid pressurization device as claimed in  claim 7 , wherein the first bladder has a frusto-conical shape when inflated.  
   
   
       9 . A fluid pressurization device as claimed in  claim 8 , wherein the second bladder has a frusto-conical shape when inflated.  
   
   
       10 . A fluid pressurization device as claimed in  claim 9 , wherein the sheet material is tapered towards one end thereof when viewed in plan view, thereby permitting the sheet element to form a roll around the second bladder which has a frusto-conical shape conforming substantially to the shape of the second bladder when inflated.  
   
   
       11 . A fluid pressurization device as claimed in  claim 10 , wherein a relatively narrower end of the sheet element is wrapped around a relatively narrower end of the second bladder, thereby resulting in the frictional forces acting between the overlapping portions of the sheet element in a hoop direction at said narrower ends, being relatively less than the frictional forces acting in a hoop direction between the overlapping portions of the sheet element at a relatively wider end of the sheet element.  
   
   
       12 . A fluid pressurization device as claimed in  claim 5 , wherein the sheet element is of fabric material.  
   
   
       13 . A fluid pressurization device as claimed in  claim 1 , wherein the pressure container is in the form of a flexible bag of a fabric material.  
   
   
       14 . An ordnance deflagration device including 
 a fluid pressurization device including:    a) a pressure container defining a fixed volume, in use;    b) a first resiliently deformable inflatable bladder containing a combustible fluid under pressure, that is located within the pressure container, the first bladder having an opening in which a valve is located, through which fluid can be discharged from the first bladder having an opening in which a valve is located, through which fluid can be discharged from the first bladder;    c) a second resiliently deformable inflatable bladder containing a non-volatile fluid under a relatively higher pressure than the pressure of the combustible fluid in the first bladder and that is located within the pressure container adjacent the first bladder; and    d) releasable holding means for initially holding the second bladder at a fixed volume when inflated to thereby hold the fluid contained therein under pressure, and for releasing the second bladder thereby permitting the second bladder to expand and exert a force on the first bladder for pressurizing the fluid contained therein; and    a torch that is connected in flow communication with the combustible fluid contained in the first bladder thereby to ignite the fluid to produce a flame that can be used to burn through the casing of unexploded ordnance and into explosive material contained therein, to cause the destruction of said ordnance.    
   
   
       15 . An ordnance deflagration device as claimed in  claim 14 , wherein the fluid pressurization device is equivalent to the fluid pressurization device as claimed in  claim 3.