Induction pump for high-temperature molten metals using rotating twisted magnetic field: molten gallium experiment

We report a study of an electromagnetic pump, applicable to processing high-temperature molten metal such as molten steel at over 1500°C. A rotating twisted magnetic field is generated by a stator with three pairs of helical windings. Axial thrust, as well as rotational torque, acts on the molten metal in cylindrical ducts. We carried out a molten metal circulation experiment using molten gallium at 50°C and confirmed that the conventional slip-thrust relation is satisfied in the experiment. Here, we identify the slip for each experimental condition and discuss the motion of molten gallium in the rotating twisted magnetic field. The normalized stalling pressure is obtained at the frequency at which δ/a₂≈0.6, where δ is the skin depth and a₂ is the radius of molten metal.