Separation of nonmetallic inclusions from liquid metal by pinch force

S. Taniguchi¹ - J. K. Brimacombe²

¹ Department of Metalurgy, Faculty of Engineering, Tohoku University, Sendai, Japan
² The Center of Metalurgical Process Engineering, The University of British Columbia, Vancuver, B.C., Canada

Abstract
In the pinch force field, electrically nonconducting particles suspended in a liquid metal experience a force in the opposite direction to the pinch force, and are squeezed out from the liquid metal. In the present study, the force acting on a polystyrene sphere was measured in a KCl aqueous solution in which an AC magnetic field and AC current were simultaneously imposed. Measured value of root-mean-squared force agreed well with the calculated value by the DC-force theory. The application of pinch-force separation of nonmetallic inclusions from a circular pipe flow of liquid metal was then investigated theoretically. The separation efficiency of inclusions, h, was calculated under laminar flow conditions. The value of h could be correlated with three dimensionless parameters, VR, CIDR2Re-1Z and r1/d. The results obtained were applied to the estimation of h for a continuous casting tundish equipped with a channel-induction furnace. Figs. 6, refs. 10.