Flame Propagation and Combustion in Methane-Coal-Air Mixture

Combustion and explosion experiments are carried out in an explosion tank of 10 m3 for the mixture of 8% methane 75 g/m3 coal dust-air. Optical method and pressure method are adopted to obtain the laminar burning velocity, flame speed, flame thickness, Markstein length as well as the explosibility index of the mixture when the flame spread. The results show that the burning velocity of the mixture of methane-coal dust-air is 0.437 m/s, while the value is 0.459 m/s according to the relationship between pressure and time, and the results from the two methods are coincide. The flames trends determined by flame thickness and Markstein length are the same, and both tend towards stability. The maximum of explosibility index occurs at 0.5 m, and the explosibility index at the wall of explosion chamber is a bit small.