Fundamental characteristics of molten metal flow control by linear induction motor

Abstract

Molten metal flow control using linear induction motor is expected much t o be a new revolutionary basic technology t o realize high quality and low cost processes. We report an experiment with fused metal(me1ting point : 45 " C ) and lOOkg molten steel. According t o the fused metal experiment, t h e linear induction motor has a good ability for stopping and acceleration as well as braking of metal flow. However, the electromagnetic force to be able t o stop the metal flow in vertical arrangement is several times larger than the one in horizontal arrangement because of the liquid metal effect. A resonance condenser is useful t o reduce the required power source capacity. Therefore, t o control the molten metal flow, voltage(current) regulation is superior t o frequency regulation. Though the large air gap also makes the electromagnetic force reduced, a conductive shorting bar( Z,B, ), installed inside the non-conductive firebrick, increases the electromagnetic force.

Design trends of linear induction motor (LIM) and design issues of a single sided LIM

“…In steel making plant, molten metal flow control using LIM is a great application in the field of basic technology to get high quality & low cost process. K. Fujisaki, J. Nakagawa, and H. Misumi (1994) [17] have done an experiment with 100kg molten steel having melting point 450c. According to that experiment, LIM had a good ability for stopping, acceleration as well as braking of metal flow.…”

Three-Dimensional Design and Performance Assessments of a Linear Induction-Type Electromagnetic Stirrer

“…For driving the molten metal with predefined stirring forces in its continuous casting process, efforts on appropriately design and operate the electromagnetic stirrer have been investigated [1]- [4]. Conceptually such equipment can be easily realized by implementing sets of current-carrying windings around the mold, in which the molten metal will be injected, to produce a strong magnetic field that can interact with the metal to supply the desired mechanical driven forces.…”

Performance Improvements of an In-Mold Electromagnetic Stirrer with Minimum Hardware Adjustments

“…1, by injecting adequate but opposite sequence multiphase currents into the windings on these stators, driving forces along the positive and negative y directions can be respectively generated. Hence, the desired equivalent stirring force, which is composited by these two opposite ydirectional forces, can be established to drive the molten metal inside the mold [1].…”