Fire Safety Science Digital Archive

Multiplier effect of mixed agents of trifluorobromomethane (halon 1301) and inert gases on flame extinction has been investigated, for the purpose of minimizing the use of halons. The inert gases examined are argon, nitrogen and carbon dioxide. The fire-extinguishing efficiency was determined by flame-extinguishing concentrations for n-heptane measured with a cup burner. An additive-property equation was derived by thermodynamic considerations to predict the fire-extinguishing efficiency of mixed agents and used as a measure of multiplier-effect test. The mixed agents of halon 1301 and inert gases showed multiplier effect. There were the optimized mixing ratios of the most effective agents. Flame-extinction temperatures were calculated for the n-heptane flames with the flame extinguishing concentrations of agents. The temperatures suggested that the chemical effect of halon 1301 was enhanced with decreasing the flame temperature by the addition of inert gases. The flame temperature and the concentration of halon 1301 determined strength of the multiplier effect of halon 1301 and inert gas.