Numerical Assessment of In-line Rotor-Stator Mixers in High-Shear Melt Conditioning (HSMC) Technology

Abstract

© 2020 The Author(s). High shear melt conditioning technology refines the as-cast structure of light alloy melts, thereby improving the mechanical properties of the casting and reducing the occurrence of defects, without requiring chemical grain refiners. To upscale the technology and apply it to processes involving larger melt volumes, a computational fluid dynamics study is conducted with three rotor–stator mixers operating in both batch and continuous modes. Analysis of the results show that rotor–stator mixers with smaller stator holes outperform those with larger ones because of larger shear rates—increasing the deagglomeration rate—and larger volume flow rates—increasing the dispersion of the intensively sheared melt in the bulk liquid. Compared with batch mode, continuous operation results in lower mass flow rate through the mixer and reduced mixing, although the mixer design has a larger impact on both measures.