Flammability limits of five selected compounds each mixed with HFC-125

Flammability limits of five selected combustible gases each mixed with 1,1,1,2,2-pentafluoroethane (HFC-125) were investigated. Actually, the investigation was made for methane, propane, propylene, methyl formate, and 1,1-difluoroethane (HFC-152a). The observed data were analyzed using the extended Le Chatelier's formula. As a result, the HFC-125 mixing effect on the flammability limits of individual gases was found to be adequately interpreted using the extended Le Chatelier's formula. However, contrary to the cases of nitrogen and carbon dioxide dilutions, it was not possible to appropriately interpret the HFC-125 mixing effects on all five gases simultaneously using a common set of parameter values. This fact suggests that the reaction of HFC-125 in flame is different if the coexisting fuel is different. (C) 2008 Elsevier Ltd. All rights reserved.