The explosion overpressure field and flame propagation of methane/air and methane/coal dust/air mixtures

摘要: The explosion of the methane/air mixture and methane/coal dust/air under 40 J center spark ignition condition was experimentally studied in a large-scale system 10 m3 vessel. Five pressure sensors were arranged space with different distances from point. A high-speed camera used to record growth flame. maximum overpressure appeared at 0.75 m away point; thickness flame about mm propagation speed fluctuated around 2.5 m/s methane concentration 9.5%. 0.5 m. had structure three concentric zones outside red zone, yellow illuminating zone bright white respectively; increased gradually, reached 3.5 cm 1 cm, 9.2 28 ms.