TITLE:
Nitrogen Injection in Molten Aluminum in a Tank Degasser
AUTHORS:
Luis A. Maldonado, Miguel A. Barron, Dulce Y. Miranda
KEYWORDS:
Aluminum Degassing, Bubble Diameter, CFD Simulations, Molten Aluminum, Nitrogen Injection, Residence Time, Tank Degasser
JOURNAL NAME:
World Journal of Engineering and Technology,
Vol.6 No.4,
September
13,
2018
ABSTRACT: The injection of nitrogen in molten aluminum through a static impeller in a tank degassing unit is studied. Using basic principles of fluid mechanics, it is analyzed the influence of the nozzle diameter on the bubble diameter and the mean residence time of the bubbles in the molten aluminum. By means of transient isothermal 2D Computational Fluid Dynamics (CFD) simulations, the influence of the nitrogen volumetric flow rate on the phase distributions and the tank degasser dynamics is studied. Finally, an adiabatic CFD simulation is carried out in order to elucidate the changes in the molten aluminum temperature due to the injection of nitrogen at ambient temperature. This simulation shows that molten aluminum does not suffer drastic temperature reductions given that, in spitethatthe nitrogen is fed at ambient temperature, the mass of nitrogen is relatively small compared with the mass of aluminum.