Cong BH, Qi F, Liao GX, Kuang KQ, Zhou XM (2005) Experimental study on inhibition of low pressure premixed flat methane-oxygen flames by trifluoromethane. Chinese Science Bulletin 50(14), 1429-1434. [In English]

Web link:http://dx.doi.org/10.1360/982005-402

Keywords:

flame inhibition, trifluoromethane, molecular beam mass spectrometry, synchrotron radiation photoionization, intermediate species profiles, air flames, fluoromethanes,

Abstract: This paper presents measurements of combustion species of low pressure laminar premixed flat methane-oxygen flames inhibited by trifluoromethane (CF3H) using synchrotron radiation-molecular beam mass spectrometry (SR-MBMS). Fire suppression chemistry of CF3H is investigated by selective detection of combustion radicals and intermediates. Results show that SR-MBMS offers a powerful tool for studying fire suppression chemistry of halon replacements, which may extensively detect combustion species in the inhibited flames, especially radicals and intermediates. The suppressant CF3H is completely consumed in the preheat zone of premixed flames and produces fluorinated radicals such as CF3 and CF2. CF3 is the main radical participating in flame inhibition cycles in the reactive zone. Unlike HBr, HF produced by CF3H is very stable and will not act as a radical scavenger because the bond energy of H-F is much higher than that of H-Br, which is responsible for less effectiveness than conventional bromine-based suppressants.