MULTIFREQUENCY ELECTROMAGNETIC STIRRING OF LIQUID-METALS

In some applications of electromagnetic stirring of metals a character istic flow pattern is requested in the melt which requires a certain v olume force distribution. The possibilities to achieve such a volume f orce distribution by a suitable geometry and position of the stirrer a re limited. More flexibility is obtained when the stirring is performe d with two or more magnetic fields traveling with different velocities in different directions. It is shown in the present paper that such a stirring can be realized with a conventional stirrer by feeding its t hree-phase winding with a current made up by superposition of two or m ore currents with different frequencies and traveling directions.