Magnetic field stabilized transferred arc furnace

摘要

A DC electric arc furnace utilizing a magnetic field stabilized electric arc. A DC magnetic field is employed to cause rotation and angular deflection of the electric arc about the surface of the melt. In one embodiment the DC magnetic field is induced by a field coil. In an alternate embodiment a specially shaped electrical insulating member can be positioned in the melt so that the flow of arc current through the melt creates a magnetic field which is used to cause arc rotation. In a further embodiment a plurality of coil sets are located about the periphery of the furnace are used in conjunction with current reversing and current sequencing means to create a rotating DC magnetic field which is used to rotate the arc. A ceramic electric insulator can also be supplied in the chamber of the furnace to prevent arc fixation in the region wherein the DC magnetic field is substantially parallel to the flow of arc current. Another embodiment utilizes a center insulator having an arm radially extending arm to the sidewall. Current flow through the melt to an electrode therein creates a magnetic field for precession of the arc. The arm prevents reversal of current flow in the melt to assure unidirectional arc precession. A split-ring electrode having an insulating ceramic insert can also be used in place of the center insulator and arm to produce precession.