Experimental Investigations of Rotary Electromagnetic Mould Stirring in Continuous Casting Using a Cold Liquid Metal Model

Abstract

This paper presents the experimental study of an electromagnetically stirred mould flow using a 1:3 scale acrylic glass model of the round bloom caster from voestalpine Stahl Donawitz GmbH. An electromagnetic stirrer was installed at the strand producing a rotating magnetic field (RMF). Flow measurements were performed in the eutectic alloy GaInSn at room temperature by means of the ultrasound Doppler velocimetry (UDV). Up to 10 ultrasonic transducers were employed simultaneously in order to obtain a two-dimensional reconstruction of the flow structure. The experiments contribute to a better understanding of electromagnetically stirred mould flows and provide an extensive and valuable data base for the validation of numerical methods. The flow measurements reveal a distinct influence of the secondary flow on the distribution of the angular velocity in various regions of the mould. The submerged jet intensifies this secondary motion in the upper part of the mould and thus causes a strong deformation of the free surface of the melt. The jet is deflected, bent and rotates around the strand axis.