CFD-based process modelling of a rotary furnace for aluminium scrap melting

A Computational Fluid Dynamics (CFD)-based process model of a rotary furnace for aluminium scrap melting was developed and integrated with user-developed sub-models. The model consists of a gas region with turbulent flow and combustion, radiative heat transfer in the upper part of the furnace, a solid region of the furnace lining, and a solid-liquid region of salt and metal in the lower part of the furnace. Scrap melting and scrap burn-off in the solid-liquid region were simulated by the user-developed sub-models. A discritised population balance model for aluminium scrap was established to represent the distributed nature of the scrap feed. Industrial data measurements were carried out to support and validate the model. Based on the developed process model, the influence of the distributed scrap properties, burn-off rate, the pre-treatment of the feed, and the natural gas firing strategy on scrap melting time and natural gas consumption was studied.