Influence of difference in surface tension on indirect fire suppression on fire extinguishing ability

Abstract

The influence of surface tension of extinguishant on the flame blowout probability of indirect fire extinguising method which the fire extinguishant droplet was impinged on heated solid surface was investigated experimentally. The surface tension was controlled by mixing a small amount of a surfactant in pure water. The droplet collision behavior onto the heated plate was captured with high-speed camera. We especially focused on the spreading behavior, liquid film evaporation behavior, and secondary atomization of the droplet. It was found that the fire extinguishing ability was reduced by increasing the surfactant concentration in pure water. It was also found that the indirect fire extinguishing ability depends on the amount of vapor generated after the collision of droplet.