Citation

Bai C, Gong G, Liu Q, Chen Y, Niu G. Safety Sci. 2011; 49(10): 1349-1354.

Copyright

(Copyright © 2011, Elsevier Publishing)

DOI

10.1016/j.ssci.2011.05.005

PMID

unavailable

Abstract

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