PRESSURE LIMITS OF FLAME PROPAGATION OF PUREnHYDROCARBON-AIR MIXTURES AT REDUCED PRESSURE

摘要

The flammability limits of 18 high-boiling hydrocarbons at reduced pressures were studied in a closed flame tube with hot-wire ignition. Characteristic two-lobe flammability-limit curves were exhibited by all the hydrocarbons studied. The minimum pressure limit was not affected by the molecular weight.nThe rich limit, the lean limit, and the flammability range, when expressed as volume percent fuel, decreased as the number of carbon atoms increased. However, if the concentration of fuel is expressed as percent stoichiometric, the lean limit of the n-alkanes and n-alkenes attains a maximum value near a molecular weight of 75. Likewise the rich limit of the same two series attains a maximum near a molecular weight of 100. The flammability range, when expressed as volume percent fuel in the mixture, correlated with the molecular weight raised to the -0.70 power. The rich limit correlated with the lean limit raised to the 0.56 power.