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Inhibition of Premixed Methane-Air Flames by Halon Alternatives.


pdf icon Inhibition of Premixed Methane-Air Flames by Halon Alternatives. (475 K)
Linteris, G. T.; Truett, L.

National Institute of Standards and Technology (NIST) and Society of Fire Protection Engineers (SFPE). International Conference on Fire Research and Engineering (ICFRE). Proceedings. September 10-15, 1995, Orlando, FL, SFPE, Boston, MA, Lund, D. P.; Angell, E. A., Editor(s)(s), 153-158 pp, 1995.

Sponsor:

Air Force, Washington, DC

Keywords:

fire research; halon alternatives; chemical inhibition; flame chemistry; flame models; flame retardants; flame speed

Abstract:

Halogenated hydrocarbons are effective and widely used as fire suppressants. Because of their suspected destruction of stratospheric ozone, however, the production of these agents, the most popular being halon 1301 (CF3Br), has been discontinued. There exists a need to develop alternatives to the halons, to establish the relative effectiveness of alternative inhibitors, and to understand the mechanism of inhibition of the new agents. The agents which are currently being considered are most fluorinated alkanes. This article describes the first measurements of the reduction in burning rate of premixed methane-air flames inhibited by the two-carbon fluorinated species C2F6, C2HF5, C2H2F4 and the three-carbon species C3F8 and C3HF7, all of which are being considered as replacements to CF3Br. The burning rate of premixed methane-air flames stabilized on a Mache-Hebra nozzle burner is determined using the total area method from a schlieren image of the flame. The inhibitors are tested over a range of concentration and fuel-air equivalence ratio, theta. The measured burning rate reduction caused by addition of the inhibitor is compared (for the two-carbon species) with that predicted by numerical solution of the mass, species, and energy conservation equations employing a detailed chemical kinetic mechanism recently developed at the National Institute of Standards and Technology (NIST).