Method for reducing the severity of vapor cloud explosions

Abstract

It has been found that high porosity, high surface area protective materials such as expanded metal foil can be used in places such as the semi-confined, congested operating areas of chemical process plants to reduce or eliminate the hazard caused by the sudden accidental release and ignition of large quantities of potentially flammable vapors into the area.

We claim:  
     
         1 . A method of reducing the severity of vapor cloud explosions in partially confined areas, comprising placing porous, high surface area to volume ratio protective material in the area in sufficient amount to reduce the pressure effects caused by ignition of the flammable vapor clouds.  
     
     
         2 . The method of  claim 1  wherein the protective material is a metal mesh or foil material.  
     
     
         3 . The method of  claim 1  wherein the protective material is an expanded aluminum alloy foil.  
     
     
         4 . The method of  claim 1  wherein the volume of protective material used in the operating area is equal to or greater than 5% of the total available volume of the operating area.  
     
     
         5 . The method of  claim 1  wherein the density of the protective material is between 10 and 100 kg/m 3  and the surface area to volume ratio of the protective material is greater than 100 m 2 /m 3 .  
     
     
         6 . The method of  claim 1  wherein the surface area to volume ratio of the protective material is greater than 500 m 2 /m 3 .