A method of vacuum arc remelting an ingot provided in a crucible assembly having an electrode includes generating a rotating magnetic field normal to a longitudinal axis of the ingot and localized to an arc region during remelting. The rotating magnetic field interacts with a melting current to produce a rotating arc directed radially outward.

An electric power apparatus for an electric arc furnace comprises at least one electrode and is connectable to a power network to supply to the electrode the electric energy to generate an electric arc to melt a metal mass. The apparatus comprises an electric regulation unit interposed and connected to the power network and to the electrode and configured to regulate at least one electric quantity for powering the electrode. The apparatus comprises at least one detection device to detect the electric quantity, interposed between the electrode and the electric regulation unit, a positioning device to move the at least one electrode nearer to/away from the metal mass to be melted and a control and command unit.

An electric power apparatus for an electric arc furnace comprises at least one electrode and is connectable to a power network to supply to the electrode the electric energy to generate an electric arc to melt a metal mass. The apparatus comprises an electric regulation unit interposed and connected to the power network and to the electrode and configured to regulate at least one electric quantity for powering the electrode. The apparatus comprises at least one detection device to detect the electric quantity, interposed between the electrode and the electric regulation unit, a positioning device to move the at least one electrode nearer to/away from the metal mass to be melted and a control and command unit.

A vacuum arc remelting system for forming an ingot from an electrode is provided that includes a crucible assembly configured to accommodate the electrode and the ingot, an electromagnetic energy source arranged about the crucible assembly, and a lift mechanism operable to move the electromagnetic energy source along a longitudinal axis of the crucible assembly. A magnetic field generated by the electromagnetic energy source is localized to an arc region during remelting, and in one form, the electromagnetic energy source is a coil assembly having a magnetic core and a plurality of coil pairs wrapped around the core, wherein the coil assembly is operable to generate a magnetic field from the coil based on electric current flowing in the plurality of coil pairs.

Provided is an AC-DC-AC converter for delivering power to a load from a power source that includes a front-end converter, a load-end converter, and a DC link. The front-end converter being a hybrid modular multilevel rectifier, and the load-end converter being either a modular multilevel converter or a hybrid modular multilevel converter.

An apparatus is disclosed for a split spray-cooled roof for a tilting metallurgical furnace. The split spray-cooled roof has a center, a first hollow metal roof section and a second hollow metal roof section. The first and second hollow roof sections are attached together along a prescription split line. The prescription split line having a first split line and a second split line, wherein the first split line is not aligned with the second split line and wherein the first and second split line are not aligned with the center.

An apparatus is disclosed for a split spray-cooled roof for a tilting metallurgical furnace. The split spray-cooled roof has a center, a first hollow metal roof section and a second hollow metal roof section. The first and second hollow roof sections are attached together along a prescription split line. The prescription split line having a first split line and a second split line, wherein the first split line is not aligned with the second split line and wherein the first and second split line are not aligned with the center.

An electric power apparatus for an electric arc furnace comprises at least one electrode and is connectable to a power network to supply to the electrode the electric energy to generate an electric arc to melt a metal mass. The apparatus comprises an electric regulation unit interposed and connected to the power network and to the electrode and configured to regulate at least one electric quantity for powering the electrode. The apparatus comprises at least one detection device to detect the electric quantity, interposed between the electrode and the electric regulation unit, a positioning device to move the at least one electrode nearer to/away from the metal mass to be melted and a control and command unit.

An electric power apparatus for an electric arc furnace comprises at least one electrode and is connectable to a power network to supply to the electrode the electric energy to generate an electric arc to melt a metal mass. The apparatus comprises an electric regulation unit interposed and connected to the power network and to the electrode and configured to regulate at least one electric quantity for powering the electrode. The apparatus comprises at least one detection device to detect the electric quantity, interposed between the electrode and the electric regulation unit, a positioning device to move the at least one electrode nearer to/away from the metal mass to be melted and a control and command unit.

The method for adjusting the impedance of one or more phases of a secondary circuit of an electric furnace, in order to limit the unbalance between the phases themselves comprises the transformer (31), a variable impedance secondary circuit for one or more phases (F1, F2, F3), the rigid and fixed interconnection (32) for each phase (F1, F2, F3) connected to the transformer, the flexible cables (33) connected by means of the proximal end to the fixed interconnection (32), the electrode holding arms (34) connected to the distal end of the flexible cables (33), the conductive electrodes (35) fixed to the respective electrode holding arms (34). The rigid and fixed interconnection (32) of a phase (F1, F2, F3) comprises at least one turn (11), wherein the impedance is either continuously or discreetly variable in order to obtain the desired impedance value.