Numerical Modeling of an Industrial Aluminum Melting Furnace

Abstract

For the present work, a numerical simulation of the 100% oxy-firing combustion process inside an industrial aluminum remelting reverb furnace is presented. Three different configurations were analyzed: (i) a staged combustion process with parallel injection jets for oxygen and natural gas, (ii) a staged combustion process with a divergent jet for the oxygen, and (iii) a non-staged combustion process, with parallel jets. In all the cases, the injections were directed towards the aluminum bath, which was maintained at constant temperature. The numerical procedure was based on the finite volume formulation. The κ-ε model of turbulence was selected for simulating the turbulent flow field. The combustion process was calculated based on the finite rate models of Arrhenius and Magnussen, and the Discrete Transfer Radiation model was employed for predicting the radiation heat transfer. The numerical predictions allowed the determination of the flame patterns, species concentration distribution, temperature and velocity fields. This kind of analysis can be a powerful tool for evaluating design options such as the type, number and positioning of the burners. The present work illustrates a preliminary comparison of three types of burners. From the results obtained, the staged combustion process with a divergent jet presented the best configuration, since the flame length was not too long as to damage the refractory wall. Further it presented the largest region with low water vapor concentration close to the aluminum surface.