| 摘要 |
PROBLEM TO BE SOLVED: To enable the application of electromagnetic stirring to the continuous casting of a narrow width slab and to improve the stirring efficiency by arranging two sets of annular linear motors winding electric coils to annular magnetic yokes having plural downward projecting poles at both sides of an immersion nozzle and the center in the short side direction of a mold and rotating molten steel just below the linear motor in the horizontal direction. SOLUTION: The annular linear motors are arranged on the molten steel surface MF in the mold and at both sides interposing the immersion nozzle 2. The linear motor has the total six pieces of the downward projecting poles at four corners of a rectangular ferromagnetic yoke 6YK and at two points of long side centers and winds the water cooling copper pipe in almost horizontal to each projecting pole to constitute the electric coils 6CL. The currents having different phase by 60 deg. in the order of the adjacent projecting pole, are supplied to these electric coils 6CL to form the rotating magnetic field into the molten steel below the coils. Then, the frequency (f) of AC current at that time is to satisfy such condition as 0.3×fc <=f<=3.0×fc . Wherein, fc in the inequality is a critical frequency.
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