Optimization of the Circular Channel Size and the A.C. Magnetic Field Parameters for Application in a Channel-Type Induction-Heating Tundish

Abstract

In this paper, the appropriate channel design and operating conditions for the simultaneous operation of the inclusion removal and the induction heating of the molten steel by imposing the A.C. magnetic field around the circular channel have been studied. (1) The effect of the lift force and the turbulence force on the inclusion in the transition zone of the channel has been computed; the results show that when the diameter of the inclusion is not less than 0.1 mm, both forces can be neglected because they are less than the electromagnetic pinch force, especially when the shielding parameter is not less than 5.0. (2) The minimal channel length to remove the inclusions out of the dead zone was computed without the lift force and the turbulence force; the shielding parameter of 10.0~15.9 is optimal to obtain the shortest channel length. Furthermore, the slow velocity of the molten steel is desirable. (3) The molten steel temperature increase per unit channel length by the induction heating can be controlled by the A.C. magnetic field frequency; a high frequency condition is better for the efficient thermal supply in this calculation condition. (4) When the flow velocity of the molten steel in the channel with a length of 1 m and a radius of 0.075 m is 0.1 m/s, the shielding parameter of 15.9 is the optimal parameter to simultaneously remove the inclusions and heat up the molten steel in the circular channel. And when the non-dimensional magnetic field intensity of the A.C. magnetic field is 31.7, the removal rate of the 0.1 mm inclusion in the channel can reach more than 95% and the molten steel temperature can be heated over 10 K.