Fire Safety Science Digital Archive

Tests were made of the extinction of fires with the J.F.R.O. inert gas and foam generator in the Models Laboratory, a 250000 ft3 barn-like building. Inert gas containing 7 per cent oxygen and delivered at 45000 ft3 per min. at 100 - 120C extinguished oil fires and reduced wood fires to smouldering in 8-10 min. High level ventilation of up to 200 ft2 did not impair extinction; small distributed leaks allowed air to enter and descend to floor level, where fires could continue to burn; large openings at floor level increased the amount of air that entered the building. The atmosphere within the building became transparent after 2 min of gas injection, except in places where air entered the building. Firemen wearing breathing apparatus and service clothing could work for about 15 min in the atmosphere produced by the inert gas in the building, if the temperature of the atmosphere was not more than about 60C. Gas at such a temperature can be supplied by a prototype appliance at present under construction, which incorporates devices to reduce the temperature of the inert gases produced. The appliance will produce gases of a wide-range of compositions at temperatures of 40 - 70C.