Abstract:

In order to study influence of coal dust's mass concentration on propagation and injury distance of methane and coal dust coupled explosion, a self-made 15m explosion pipeline system was used for an experiment where 7% methane and coal dust at different mass concentration(0, 50, 100 and 200 g/m³) had coupled explosion. Then, maximum over-pressure calculation model was derived from conservation laws of mass, momentum and energy. The results show that in coupled explosion, the maximum over-pressure decreases at first and increases and then decreases gradually along with the increase of distance from explosion source. As mass concentration of coal dust increases, the maximum over-pressure in explosion cavity first increases and then decreases, while that in propagation pipeline increases with it, and is inversely proportional to the square root of distance from explosion source. Moreover, distances of death, serious injury and minor injury all increase with the increase of dust concentration whose change has the greatest impact on distance of minor injuries and the least on that of death.

Key words: methane and coal dust, coupled explosion, maximum over-pressure, propagation characteristic, injury distance