Device to minimize the explosive effects of a metal casing in the event of accidental internal overpressure

Abstract

To prevent the violent bursting of the casing of a thruster containing propergol during an accidental fire in its vicinity, a pyrotechnic composition ( 5, 6 ) is attached to this casing. This pyrotechnic composition locally heats the casing during this fire, and therefore embrittles this casing which opens at this place before the internal pressure becomes excessive. This prevents the fragmentation of the casing and the bursting out of the fragments.

What is claimed is:  
     
         1 . A device for minimizing the explosive effects of a metal casing subjected to internal overpressure, comprising a pyrotechnic system attached to the casing that is activated immediately upon detection of a phenomenon that causes a rise in overpressure in the casing, the ignition of this pyrotechnic system causing a limited local degradation, through heating, of the mechanical characteristics of the casing.  
     
     
         2 . A device according to  claim 1 , wherein the pyrotechnic system is attached to the exterior of the casing, in contact with it.  
     
     
         3 . A device according to  claim 1 , wherein the pyrotechnic system is attached to the interior of the casing, in contact with it.  
     
     
         4 . A device according to  claim 1 ,  2  or  3 , wherein the ignition of the pyrotechnic system is prompted by heating.  
     
     
         5 . A device according to one of the  claims 1  to  3 , wherein the ignition of the pyrotechnic system is activated by a sensor of physical or chemical conditions.  
     
     
         6 . A device according to one of the above claims, wherein the casing is lined with a layer of heat-insulating material.  
     
     
         7 . A device according to one of the above claims, wherein the casing is that of a missile thruster.