Three dimensional model of transport and chemical late phenomena on a MSW incinerator

A mathematical model was developed of the drying, volatilization, and combustion phenomena on the packed bed of solid wastes on a moving grate. Gas-solid flow and the heterogeneous chemical reactions were considered. Since experimental work in this area of study is very difficult and costly, the development of such a model is very important. The gas phase turbulence was modeled using k-epsilon turbulent model and the particle phase was modeled using kinetic theory of granular flow. The reaction rates of heterogeneous reaction were determined by Arrhenius-eddy dissipation reaction rates and the Arrhenius-diffusion reaction rate. Flow patterns, gas velocities, particle velocities, composition profiles of gas product and distributions of reaction rates were obtained. Predicted values using the present code were compared with experimental data for validation. The results showed that the predicted exit gas compositions were in good agreement with the experiments. This indicates that the numerical model presented is valid and provides a promising way to simulate the combustion of solid waste on a moving grate, which is the dominant technology for waste incineration. (C) 2013 Elsevier Masson SAS. All rights reserved.