Experimental data revealing explosion characteristics of methane, air, and coal mixtures

Whenever air and gases mix with pulverised coal, explosions are possible. Such explosions constitute a primary category of safety concerns during coal bed methane mining. This study investigated the explosion parameters and characteristics of methane-air-coal dust mixtures by using an XKWB-1 sealed explosion system. Maximum explosion pressure (P-max), maximum explosion pressure rise rate (dP/dt)(max), and explosion index (K) were recorded and calculated. Findings showed that relative to the maximum explosion pressure of an air-methane gas mix Pmax-G, that of a gas-dust mixture Pmax-GD was elevated when a 7.0 vol% methane-air mixture coexisted with 500.0 g m(-3) of coal dust in the explosion. Pmax-GD decreased as C-G increased and increased as V-ad increased for a methane-air-coal dust mixture. Both Pmax-GD and (dP/dt)(max-GD) increased first, but were diminished with an increase in C-D. The C-opt values of five coal samples of HC, KZD, DFS, TC, and YMZ were 400.0, 500.0, 500.0, 500.0, and 600.0 g m(-3), respectively. Based on the coal dust explosion pathways, the effects of coal dust volatility on the explosion characteristics were analysed. Finally, with respect to 7.0 vol% methane, the data showed that the explosion index of a gas K-g was consistently lower than the explosion index of a gas-dust mixture K-m; that is, K-g < K-m.