ABSTRACT
This chapter argues that although changes in chemical kinetics may influence limit phenomena, heat losses to the surroundings of the flame practically always are important. It focuses on results explained by energy-conservation requirements and heat losses. The chapter describes the consideration of special effects associated with finer details of chemical kinetics, such as radical diffusion or surface reactions. It suggests that the greater the degree of heterogeneity of the system, the more complicated the analyses tend to become. The chapter explains to premixed-flame extinction, to quenching distances and deals with some rough physical ideas and observations that serve to define terms and to relate various ignition and extinction phenomena. Although ignition, extinction, and flammability limits appear to be highly diverse phenomena, they share many common elements. Extinction phenomena are of interest in problems of safety and of fire suppression as well as in various aspects of control of combustion processes in industry and propulsion.
