Über die Zerlegung definiter Funktionen in Quadrate

A continuous casting system provides with a foreign matter receiving gutter between two adjacent rolls to receive foreign matters dropping during the drawing operation of castings, and a foreign matter removing nozzle to wash away the foreign matter dropped on the gutter. An electromagnetic agitator of the continuous casting system is provided with a proximity switch at least at its inlet side to sense a magnetic substance approaching the agitator thereby to control the operation of the agitator, thus eliminating troubles caused by the vibration of the magnetic substance.