Using the explosion hazard criteria of program CHETAH to predict the flammability limits of vapour fuels in air
Abstract
The energy hazard criteria of ASTM program CHETAH have been tested as flammability criteria, for gaseous mixtures containing an organic vapour and air as oxidiser, at lean concentrations. A predictive method of calculating the lower flammability limits in air, at atmospheric pressure and ambient temperature, is proposed as a result of a statistical study which involved 216 combustible compounds of the elements carbon, hydrogen, oxygen and nitrogen. CHETAH’s fourth energy hazard criterion was found to be the most reliable flammability criterion. The standard deviation of the predicted lower flammability limits is 0.28 mole percent. The majority of the predictions have a « pessimistic bias », most of the lower limits being slightly under evaluated, which is preferable for safety purpose.