Fire Safety Science Digital Archive

The effects of additive type and concentration on the extinguishment of liquid fuel fires are examined in the paper. Tests were conducted using gasoline, diesel and ethanol pool fires, while included NaHCO3, AFFF, and a multi-component agent named MC additives. Results show that water mist suppression effectiveness varies greatly depending on fuel type, additive type and concentration. The benefit of adding a small quantity of AFFF to water mist is observed in the suppression of gasoline and diesel pool fires, forming a thin film on the fuel surface by active surfactants. But, too much AFFF additive may decrease the marginal effectiveness due to the saturation effect of surface tension. The AFFF has none effect on ethanol fires because of the fuel erosion. Addition of NaHCO3 may increase the performance of water mist gradually both for ethanol and hydrocarbon fires, although less effective than the film-forming agent. And there exists upper agent limit for the metallic additive because of the associated limiting vapor pressure of the active metal compound. The multi-component additive shows the combined suppression effect of film-forming agent and metal chemicals. It may effectively extinguish both ethanol and hydrocarbon fires though coupling the physical and chemical fire suppression mechanisms.