Impact of the Electromagnetic Brake Position on the Flow Structure in a Slab Continuous Casting Mold: An Experimental Parameter Study

Flow measurements are performed in a slab model for continuous casting of steel under the influence of a ruler type Electromagnetic Brake (EMBr). The Mini-LIMMCAST facility utilizes the low melting GaInSn alloy for flow modeling. Two-dimensional velocity distributions in the center plane of the rectangular mold with a cross-section of 300 x 35 mm² are determined by means of the Ultrasound Doppler Velocimetry (UDV). This study especially focuses on the influence of the vertical position of the EMBr and its magnetic flux density as well as the effect of different immersion depths of the Submerged Entry Nozzle (SEN).

The horizontal flow velocity just below the free surface can effectively be reduced by choosing an optimal position of the EMBr while an improper positioning even increases the near-surface velocity compared to the case without activated brake. A general braking effect of the EMBr on the submerged jet is not observed. The decisive mechanism for controlling the near-surface flow results from a modification of the jet geometry and a reorganization of the flow field. In terms of an effective flow control an appropriate positioning of the EMBr has at least the same significance as the regulation of the magnetic field strength.