Numerical Approach for the Implementation of the Interaction of Pyrolysis Gases and Combustion Products in an Aluminium Melting Furnace

Within the scope of the project P5 of the AMAP (Advanced Metals And Processes) research cluster in Aachen a virtual remelting furnace is set up as a CFD (Computational Fluid Dynamics) simulation to investigate the resource and energy efficiency of the aluminium recycling process in melting furnaces. During the melting process of aluminium scrap (e.g. used beverage cans) a reactive flow has got a major impact on the heat transfer to the load. Thereby it is mostly dominated by gas combustion due to the heating burners in the furnace and pyrolysis/thermolysis reaction caused by organic contamination of the charge. Obtaining more understanding of the underlying mechanisms is imperative for improving the performance of the melting and combustion process and in preservation of the equipment. In the present work, numerical simulations were carried out using the commercial software FLUENT for generating a helpful tool in evaluating operational conditions. The main perspective is to analyse the relevant operational conditions inside an aluminium melting furnace employing methane oxygen burner which is capable to run in the flameless combustion mode. To overcome the obstacle of simulating highly diluted combustion occurrence proved detailed chemistry model is involved. Another important aspect is to evaluate additional in house written codes for the evaporation and gas release due to contaminated input material. The subject of the investigation is the numerical simulation of the heating and holding process sequence as a steady state process.