Experimental research on methane and coal dust explosion characteristics in tube

The explosion overpressure and speed of methane-air mixtures and methane-coal dust-air mixtures was studied in a 199 mm inner diameter and 32.4 m long horizontal tube under the condition of strong ignition. The experiments results show that the maximum overpressure and speed of methane-air mixtures is 4 MPa and 1 766 m/s with strong ignition. Detonation happened when the methane concentration is 2.5%, 4.1%, 15.2% which is out of the limit concentration. The explosion overpressure and speed of methane-coal dust-air mixtures is greater than the methane-air mixtures and dust-air mixtures under the same concentration. The methane-coal dust-air mixtures explosion overpressure and speed descend as the methane decrease and coal dust increase while at explosion equivalent concentration.