Some Observations on Near-limit Flames.
Furno-AL; Cook-EB; Kuchta-JM; Burgess-DS
13th Int'l Symp on Comb 8/23-29/70 Univ of Utah Salt Lake City Utah PP 593-599 :593-599
Lean mixtures of hydrogen-air and rich mixtures of n-butane-air were spark ignited within a 12-ft-diam sphere. At hydrogen concentrations below 8.0 percent, and at butane concentrations above 6.1 percent, the pressure rises were very small since little of the combustible mixture was consumed by upward flame propagation. With the onset of downward propagation of 8.5 percent hydrogen or 6.0 percent butane, combustion was complete. The limits of downward flame propagation are compared with available data on the detonable limits of gas mixtures when initiated by solid explosives. The interpretation follows spalding's treatment of the optimum gas concentrations for spark ignition, using the concept of preferential diffusion.
13th Int'l. Symp. on Comb., 8/23-29/70, Univ. of Utah, Salt Lake City, Utah, PP. 593-599