Modelling of a rotary kiln for the pyrol

This paper deals with the mathematical modelling of a rotary kiln which is used for the recycling of aluminium waste. The objective is to develop a model that captures the various physical and chemical processes occurring when particles of aluminium, coated with organic materials, are introduced into the kiln. The methodology involves coupling a bed model to describe the processes within the aluminium waste bed, a kiln model for heat transfer in the kiln, and a gas model for processes in the gaseous phase. Mass and energy balances are utilized in the bed model to predict the fraction of organic material and temperature of the aluminium particles. The kiln model includes equations for heat conduction and heat exchange with both solid and gaseous materials, while the gas model is grounded in fluid mechanics equations factoring in turbulence, radiation, and combustion. The software FluentTM is employed to solve the gas model equations. Numerical results are presented and compared to experimental data obtained from the pilot-scale rotary kiln at Alcan research centre, providing insights into the coupling procedure of the various models.