PURPOSE: To prevent DC arcs in a furnace from being made nonuniform by affecting them with the magnetic field generated around feed cables to furnace bottom electrodes of the DC electric furnace.
CONSTITUTION: A furnace bottom electrode unit 1 with many small-diameter furnace bottom electrodes 30 is buried at the furnace bottom of a DC electric furnace. Three feed cables 5a, 5b, 5c are uniformly dispersed and arranged at the angle 120° on a conducting, air-cooled pipe 34 provided at the center section of the furnace bottom electrode unit 1, and the current and voltage are independently fed to the cables 5a, 5b, 5c under control. DC arcs in the furnace are unified in polarity by the magnetic field generated around the feed cables 5a, 5b, 5c. The occurrence of cold spots on the furnace wall is reduced, and the fusing of scrap is accelerated.
TAKASHIBA NOBUMOTO
MIYAZAKI YOJI
IWAMURA TADAAKI
