Investigation of the suppression effect of inert dust on the pressure characteristics of gas coal dust explosion

Abstract

The suppression effect of inert powder on gas-induced suspension coal dust explosions was investigated using a semi-closed pipeline experimental platform. The shock wave overpressure propagation characteristics of gas explosions with different concentrations of mixed dust (calcium carbonate and coal dust) were measured and analyzed. The suppression mechanism of inert powder on the explosion process was also discussed. The results indicate that when the coal dust concentration is 200g/m?, the peak overpressure of the explosion decreases gradually with increasing inert powder concentration, and the peak overpressure ratio in the pipeline shows a decreasing-increasing trend; the acceleration of the explosion pressure reduces with increasing mixed dust concentration, and when high concentration of mixed dust is involved in the explosion, the acceleration of the explosion pressure is lower than that when only coal dust is involved; The inhibitory effect of calcium carbonate on dust explosion increased linearly with its concentration when the ratio of inert dust to coal dust was 1:2.; Inert powder mainly suppresses the explosive power by physical heat absorption and reducing heat exchange efficiency. The experimental results established the theoretical basis for inert dust suppressing coal dust participation in explosions, and have reference significance for formulating mine explosion suppression measures.