A heat and mass transfer analysis of the ignition and extinction of solid char particles

We present work studies the ignition and extinction of a spherical solid fu el particle exposed to a quiescent, hot, oxygen-containing environment. Usi ng particle sizes and ambient temperature and oxygen concentration as param eters, the ignition, burning, and extinction of particles were parametrical ly analyzed by studying the relative heat production and heat-loss rates. F ar a given ambient condition, the results show ed that it is possible that bath large and small particles might not ignite at ail, When a particle bur ns, its size decreases with time and its combustion characteristics are alt ered The extinction condition may be reached due solely to the diminishing size of the particle. The particle extinction diameter was calculated. It s trongly depends on the ambient condition and the reaction rate, bur nor on the initial particle size.