Methane-Air Detonation Experiments At NIOSH Lake Lynn Laboratory
The methane-air detonation experiments are performed to characterize high pressure explosion processes that may occur in sealed areas of underground coal mines. The detonation tube used for these studies is 73 m long, 105 cm internal diameter, and closed at one end. The test gas is 97.5% methane with about 1.5% ethane, and the methane-air test mixtures varied between 4% and 19% methane by volume. Detonations were successfully initiated for mixtures containing between 5.3% and 15.5% methane. The detonations propagated with an average velocity between 1512 and 1863 m/s. Average overpressures recorded behind the first shock pressure peak varied between 1.2 and 1.7 MPa. The measured detonation velocities and pressures are close to their corresponding theoretical Chapman-Jouguet (CJ) detonation velocity (DCJ) and detonation pressure (PCJ). Outside of these detonability limits, failed detonations produced decaying detached shocks and flames propagating with velocities of approximately 1/2 DCJ. Cell patterns on smokefoils during detonations were very irregular and showed secondary cell structures inside primary cells. The measured width of primary cells varied between 20 cm near the stoichiometry and 105 cm (tube diameter) near the limits. The largest detonation cell (105 cm wide and 170 cm long) was recorded for the mixture containing 15.3% methane. © 2011 .
R. K. Zipf and V. N. Gamezo and M. J. Sapko and W. P. Marchewka and K. M. Mohamed and E. S. Oran and D. A. Kessler and E. S. Weiss and J. D. Addis and F. A. Karnack and D. D. Sellers, "Methane-Air Detonation Experiments At NIOSH Lake Lynn Laboratory," Journal of Loss Prevention in the Process Industries, Elsevier, Jan 2013.
The definitive version is available at http://dx.doi.org/10.1016/j.jlp.2011.05.003
Mining and Nuclear Engineering
Keywords and Phrases
Detonation; Experiments; Limits; Methane
Article - Journal
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