Stationary Thermal Ignition of Particle Suspensions

A calculational method is presented for the stationary thermal ignition of pulverized coal suspensions based on radiative energy transport in a heat generating medium. A diffusion-limited, Arrhenius model for heat generation is used in the description of the heterogeneous ignition and combustion of particles with the gases in which they are dispersed. The discrete ordinates method, which is used to solve numerically the radiative transfer equation, is combined with an iterative procedure to obtain both the temperature and radiation intensity distributions throughout the reacting system. Numerical examples are presented to show the variation in the critical behavior of a system in plane geometry with wall temperature and reflectivity, optical thickness of the system, particle size, optical parameters, anisotropy of the scattering, and the parameters of the heat generation model.