LOW-PRESSURE FLAME STUDIES OF HALON REPLACEMENT COMBUSTION - CHARACTERIZATION OF BY-PRODUCTS AND FORMATION MECHANISMS

This work seeks to characterize halon replacement combustion byproduct formation mechanisms and chemical kinetics. Experimental studies of i nhibited, premixed, one-dimensional flames are described. Microprobe s ampling mass spectrometer, thermocouple, and laser induced fluorescenc e diagnostics are used to measure temperature and chemical species con centration profiles. The effects of 0.33% iodotrifluoromethane and 0.2 4% perfluoropropane on a 40.0 torr stoichiometric methane/air flame ar e investigated. Experimental results are compared to a premixed, one-d imensional, laminar flame model. The chemical kinetics model was devel oped independently of the experimental data and combines the GRI metha ne oxidation mechanism with a halogen reaction mechanism developed fro m previous work on CF3Br flame suppression by Westbrook (1983) and Bab ushok et al. (1994). The model predicts essentially complete combustio n of the iodotrifluoromethane and perfluoropropane with hydrofluoric a cid as the primary halogenated product. In,addition, iodotrifluorometh ane is predicted to generate iodine atoms early in the flame zone. The experimental stable chemical species concentrations profiles show qua litative agreement with the calculated values.