Heat transfer characteristics of a gas-particle mixture under direct radiant heating

In this paper, a new model is first developed for calculating the rate of heat transfer from a particle to a surrounding gas. The model, which assumes no relative motion between the particle and the gas, is based on kinetic theory and is applicable at all Knudsen numbers. The result is then used in a sample application in which a gas-particle suspension is radiantly heated. Both the temperature difference between the particles and the gas and the rate of gas temperature increase are shown to have theoretical maximums. Using the optical and thermal properties of carbon, some numerical results for a carbon particle/air mixture are presented.