Ignition of dispersed coal in local conductive heating conditions

Present work studies the ignition of a brown coal by a hot metal particle. The experiments establish the limits of the gas-phase ignition and ignition delay times in conditions whee the metal particle situated on the surface of dispersed coal layer. The coal particle size was different in different series of experiments, and it was ranged from 0.1 to 1 mm; the shapes of the metal particles were sphere, disk, and cube; their initial temperature varied between 1000 and 1400 K. Three modes of gas-phase ignition of coal were established with the ignition zone of volatiles located in the vicinity of the hot particle. The practical application of obtained results is the development of fire prevention guidelines for tightening fire safety management at productions dealing with coal mining, transportation, storage, processing, and combustion.