Contactless Aluminum Degassing System—GaInSn Model Experiments and Numerical Study

Abstract: Hydrogen dissolves in molten aluminum and it is essential to reduce hydrogen concentration before making aluminum product. We propose a novel contactless degassing method that uses electromagnetic forces to drive the melt flow and split the injected inert gas bubbles. A numerical and experimental model of the proposed system were studied with a focus on characterizing permanent magnet-driven flows. For solving the multiphysics problem numerically, we coupled OpenFoam for hydrodynamic calculations and Elmer for electromagnetic calculations. The velocity field and developed pressure in a laboratory-scale physical model built using GaInSn in different operating regimes were examined and compared with the numerical model predictions. To characterize the conditions for bubble collapse, velocity pulsations were measured, and turbulence generation rate was computed. The results verify the feasibility of scaling the proposed degassing system. By implementing this gas purging method, the need of a rotating impeller and its associated problems would be eliminated. Graphical Abstract: [Figure not available: see fulltext.]