The suppression of methane–air ignitions by fine powders

Abstract The effect of the particle size of some inorganic materials on their efficiency as ignition suppressors has been studied. It has been found that there is a direct relationship between this efficiency and the surface area of the powder exposed to the advancing flame. Flame inhibitors have been placed in an order of efficiency on this basis. The alkali halides have been shown to have an efficiency which cannot be fully accounted for by the thermal characteristics of the powders, and an explanation is suggested.