Ultrasonic Measurements in a Model Experiment for Continuous Casting of Round Blooms with Magnetic Stirring in the Submerged Entry Nozzle

We present an experimental study about the influence of magnetic stirring in the submerged entry nozzle (SEN) for continuous casting of round blooms performed at the mini-LIMMCAST facility at Helmholtz-Zentrum Dresden-Rossendorf (HZDR).
The experimental setup consists of a round mould with an inner diameter of 80 mm made of acrylic glass (PMMA), representing a mould used in industry. A magnetic field, employed by permanent magnets, rotates around the SEN with variable rotation frequencies. In our experiment we use a near eutectic alloy GaInSn under isothermal conditions as a model fluid, which is liquid at room temperature.
Measurements are carried out using ultrasonic velocity sensors by means of Ultrasound Doppler Velocimetry (UDV). The sensors are mounted directly at the SEN as well as on several positions along the mould, allowing us to have an insight into the effects by the magnetic stirring in the mould and in the SEN itself. We show a comparison of our results with measurements obtained at the same setup where the magnetic stirring in the SEN is replaced by electromagnetic stirring in the mould by means of a rotating magnetic field (RMF).