Influence of particle size on the explosion parameters in two-phase vapor–liquid n-hexane/air mixtures

Abstract

A number of explosions believed to be two-phase in nature have occurred within process industries, which emphasizes the need for investigations regarding the underlying mechanisms that contribute to mist explosions. This study provides new experimental data regarding the influences of the particle size of liquid-phase n-hexane on the explosion parameters in two-phase vapor–liquid n-hexane/air mixtures. A series of experiments was conducted as follows. First, a set of two-phase vapor–liquid n-hexane/air mixtures of various concentrations was obtained with a Sauter mean diameter SMD of 18.51μm. In this case, the ignition energy (CU2/2) was constant at 28J. The concentration was varied and the explosion pressure and explosion temperature were measured in order to determine the influence of the concentration on the explosion pressure and temperature, and the lower flammability limits were analyzed. Finally, a series of experiments was conducted on n-hexane/air mixtures with various concentrations and at various ignition energies. The minimum ignition energies of the heterogeneous n-hexane/air mixtures were determined and are discussed here. Particularly, we clarify a comparison with our previous experimental analyses. The maximum rate of pressure rise [dP/dt]max of the two-phase vapor–liquid n-hexane/air mixtures indirectly proved that a range of particle size at which a significant burning velocity enhancement occurs (i.e., transition range).