In order to evaluate and control the hazards of coal dust explosion in coal mines and power plants, the explosion characteristics of bituminous coal dusts were tested in a Siwek 20 litre spherical vessel. The effects of particle size of coal dust, coal dust concentration and ignition energy on maximum explosion pressures，maximum rates of pressure rise, explosion indices and minimum explosible concentrations were discussed. The finer sizes have lower minimum explosible concentrations and higher explosion intensity. When particle sizes of coal dust are less than 75 μm，minimum explosible concentrations and explosion intensity approach a limiting value. In the concentration range measured ( less than 700 g/m3), maximum explosion pressures, maximum rates of pressure rise and explosion indices increase along with the increase of coal dust concentrations. Explosion intensity rapidly enhances along with ignition energy augmenting. Explosion reaction is weak while ignition energy is less than 1 kJ. The results will provide important reference for understanding the explosion hazard of coal dust, controlling coal dust explosion and making inherent safety design.
