Inert effects on flammability limits and flame propagation of LPG by CO₂

In this study, the inert effects of CO₂ on the flammability limit and flame propagation of LPG has been investigated experimentally. The observation was done using cubic combustion bomb with the dimension of 500 mm x 200 mm x 10 mm. The results showed that the lower flammability limit (LFL) of LPG-Air mixtures is found to be 2.7% (by volume) and upper flammability limit (UFL) is 8.6% (by volume) with upward propagation of flame. The CO2 dilution effects on the flammability limits have been explored, the limits of flammability was narrowed by adding CO2 and propagation flame was reduced accordingly. The results indicated that to formulate an inflammable refrigerant mixture, using CO2, with substantial hydrocarbon content is not possible.