The Relationship Between Particulate Aerosol Cooling Process and Its Effectiveness As A Fire Extinguishing Agent

The powdered aerosol technology has gained a lot of interest as a viable alternative to Halon fire protection. In the past years we have seen several approaches to producing the powdered aerosols either chemically (by combustion methods) or physically (by evaporation methods). The solid dry powder particles entering the fire zone act chemically and physically in the combustion process to slow it down and eventually stop it by extinguishing the open flames. We have observed that the temperature of the powdered aerosol as it enters the fire area is an important factor in the extinguishing process. According to recent studies, the "hot" aerosol particles are more active, fill the protected volume for longer time periods, extinguish the flames faster at lower concentrations in air. Cooling the aerosol particles to the environment temperature, requires more material for some extinguishing fire scenarios, longer extinguishing time periods, in addition to obvious obscuration and clean-up problems. The present paper presents recent test data and some interesting conclusions regarding this fire extinguishing technology.