EFFECTS OF OBSTACLE ON METHANE-COAL DUST HYBRID EXPLOSION AND ITS MITIGATION WITH ULTRA-FINE WATER MIST*

Abstract

The experimental investigation on mitigation of methane-coal dust hybrid explosion contain obstacles with ultra-fine water mist is presented in this article. Different diameters of coal dust and volume fluxes of ultra-fine water mist were considered. The parameters of explosion overpressure, the maximum rate of overpressure rise, the critical volume flux of ultra-fine water mist, and the deflagration index were determined and analyzed. The results show that the hybrid explosion is mainly influenced by coal dust diameter and the obstacle. The maximum explosion pressure (gauge pressure), the maximum rate of overpressure rise, and the critical volume flux of the ultra-fine water mist decreased with the increase of coal dust diameter; only when the volume flux of water mist increased to a certain range, the hybrid explosion would be completely mitigated.