Citation

Parks DJ, Alvares NJ, Beason DG. Fire Safety J. 1980; 2(4): 237-242.

Copyright

(Copyright © 1980, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

We have been using an acoustically tuned flame tube to measure fundamental flame speed and flammability envelopes of premixed propane/air and methane/air that contain minute amounts of CF3Br. The flat propagation boundaries produced by this tube allow one to measure fundamental flame speed directly without having to make complicated velocity adjustments because of irregular flame shape. Measurement data show that flame speed decreases exponentially with the concentration of CF3Br regardless of the equivalence ratio, and more CF3Br is needed to make fuel-rich mixtures inert than to make fuel-lean mixtures inert. Consequently, one can attain significantly lower flame speed on the fuel-rich side of the flammability envelope. The implications of these data for gross extinguishment mechanisms indicate that CF3Br combines with free hydrogen radicals in competition with oxygen to interfere with chain-branching propagation.