Extinction limit of a pool fire with a water mist

This work describes an experimental investigation of fire extinction limit and enhancement for a gasoline pool fire interacting with a water mist. A downward-directed nozzle produces a fine water spray over a small-scale opposed pool fire. The fire extinction limit is obtained from minimum nozzle injection pressure measured when the fire extinguish takes place. The burning rate of the fuel is also measured using a verified technique. For the conditions tested, it is shown that there are two distinct regions in the relationship between the distance from the nozzle to the fuel pan and the injection pressure, i.e. a fire extinction region and a fire enhanced region. The effective water flux is shown to be a more useful parameter than the injection pressure for the fire extinction limit. It is also revealed that the larger the spray thrust the larger the burning rate is in the fire enhanced region.