Numerical Simulation of the Combustion of a Coal Char Particle Spherically Shrinking in a Drop Tube Furnace

Modeling the combustion of a coal char particle in a drop tube furnace is still a challenge, although different models are available in the literature. A simple model is proposed here which considers the combustion of a single coal char particle in a drop tube furnace, assuming that the shrinking particle remains spherical during its combustion, among other hypotheses. This model is much simpler than most available ones, as it is based on two differential equations respectively describing the evolution with respect to the time of the particle temperature and that with respect to the particle radius of the oxygen concentration inside the particle. This model further gives access to local quantities which allow characterizing the combustion process. The simulations performed with this model are validated mainly through comparisons between the experimental and simulated particle temperatures under three constant regulation temperatures of the drop tube furnace.