Gassy, Tempered, Hybrid Division

“Tempered: A term used in the analysis of runaway reactions where the risein total pressure is due to the increase in vapor pressure of the components present as they self-heat.If the pressure is above ambient then pressure relief will result in flash evaporation and evaporative cooling of the reaction mass. This will reduce the rate of the runaway reaction, i.e. it will “temper”.

 “Gassy: A term used in the analysis of runaway reactions where the rise in total pressure is due to the generation of non-condensible gas. If the pressure is above ambient then pressure relief will result pressure reduction but essentially no cooling of the reaction mass. For this reason the rate of the runaway reaction will continue to accelerate.

 “Tempered: A tempered reaction system contains a volatile fluid that vaporizes or flashes during the relieving process. This vaporization removes energy via the heat of vaporization and reduces the rate of temperature rise due to the exothermic reaction.”

 “Hybrid: A term used in the analysis on runaway reaction systems in which the rise in pressure is due to both the vapor pressure of the components present and the generation of non-condensible gases. Testing will be required to confirm whether the hybrid system has sufficient vapor pressure present for it to “temper” on pressure relief.