Some Critical Discussions On Flash And Fire Points Of Liquid Fuels

The liquid fuel temperatures of the flash and fire points were discussed for their accurate measurement according to their definitions from the view point of spilled fuel fire hazard prevention. The flash and fire points for some hydrocarbon and alcohol fuels were measured at the open cup system with an electric spark ignition source, avoiding the external air blow. Measured results were compared with those by the usual methods of Tag Closed Cup and Pensky-Martens , and some influencing factors in the measurement were discussed. In the present study, pre-flash phenomenon, namely "Pre-flash point", was found at a 11ttle lower liquid temperature than the flash point. It suggests that the specification of the scale of flame appearance at flash phenomenon above the fuel pool surface should be introduced in the usual methods of flash point measurement. Presented consideration on flash point covers the theoretical prediction of flash point of the binary hydrocarbon fuel mixture. RECENT PHASES OF THE STUDIES Many studies on the fire hazard prevention for liquid fuel have concentrated their serious interests to the flash point of the fuel for more than forty years. The flash point is defined as the fuel temperature at which the equilibrium fuel vapor concentration of its lower flammability limit is attained. It has been measured and investigated concerning such parameters as the latent heat of vaporization, the boiling temperature and the fuel vapor concentration of lower flammability limit for the purpose of theoretical prediction of the accurate fuel temperature when the flash phenomenon occurs (1-8). Many previous reports, however, have presented divergent measured values one another, which are due to complex parametric factors in their measuring apparatuses and methods for flash point such as the position and dimension of ignition source, mixing or no-mixing in vapor phase above pool, and fuel container condition (open or closed)(1-14). Then, not all investigations in this field are, of course, necessarily complete, as discussed in detail by Glassman et al.(16). It seems that some unsolved problems remain still in the usual methods of flash point measurement for the purpose of obtaining the accurate flash point (9,13-17). Although the fire point is defined as the lowest fuel temperature at which the diffusion flame is sustained above the fuel pool without any external heat supply (7,19,20), generally reliable data have not been published. We can see the considerable The present address for Hiroki Ishida is Dept. of Mechanical Eng., Nagaoka Technical Colleae 888, Nishikatakai, Nagoaka, Niigata-pref., 940, Japan. FIRE SAFETY SCIENCE-PROCEEDINGS OF THE FIRST INTERNATIONAL SYMPOSIUM 217 Copyright © International Association for Fire Safety Science divergence among the fire point data in some previous papers, and the divergence seems due to more complex parametric factors in the measuring methods which have significant effects on the measured result than in flash point measurement(15-20). FAVORABLE MEASUREMENT OF FLASH AND FIRE POINTS