Suppression characteristics and mechanisms of ABC powder on methane/coal dust compound deflagration

Abstract ABC powder was widely used at the places of fire extinguishing and explosion suppression due to its excellent suppression performance. In order to investigate the suppression characteristics and mechanism of ABC powder on methane/coal dust compound deflagration flame. A vertical combustion pipe was built to conduct the deflagration experiment of methane/coal dust/ABC powder. The thermal decomposition of coal dust/ABC powder was studied by simultaneous thermal analyzer. The chemical bonds and surface functional groups of the deflagration residue were characterized, and the suppression mechanism of ABC powder was summarized. The experimental results show that the addition of ABC powder increased the initial temperature of coal dust thermal decomposition, which reduced significantly the thermal decomposition rate, heat release and maximum heat flow. The existence of ABC powder weakened significantly the deflagration characteristics of methane/coal dust. The methane/coal dust deflagration was suppressed effectively under 30% ABC powder. The deflagration reaction can be destroyed by physical effects such as heat absorption, heat insulation, dilution of combustible and oxygen concentration, as well as the chemical action of the intermediate which produced by the thermal decomposition of ABC powder on the adsorption of free radicals which maintain the chain reaction.