An apparatus for detecting ground faults in a multifurnace installation with at least two induction furnaces and a multifurnace installation are described. A ground-fault sensor is associated with each induction furnace and is connected to the electrical supply line to the induction furnace coil. Furthermore, the apparatus has a ground-leak sensor. Moreover, the apparatus includes an additional ground-fault sensor that measures at the same location as the ground-leak sensor. In this manner an improvement of security during the operation of the system is obtained.

An apparatus for detecting ground faults in a multifurnace installation with at least two induction furnaces and a multifurnace installation are described. A ground-fault sensor is associated with each induction furnace and is connected to the electrical supply line to the induction furnace coil. Furthermore, the apparatus has a ground-leak sensor. Moreover, the apparatus includes an additional ground-fault sensor that measures at the same location as the ground-leak sensor. In this manner an improvement of security during the operation of the system is obtained.

A method of cooling an electric induction furnace for melting and holding a reactive metal or alloy is provided where the electric induction furnace has an upper furnace vessel and an induction coil in a modular inductor furnace is positioned below the upper furnace vessel with a melt-containing vessel positioned inside the induction coil with a gap between the outside surface of the melt-containing vessel and the inside surface of the induction coil that is used to circulate a cooling fluid for cooling the melt-containing vessel to inhibit leakage of the reactive metal or alloy melt from the melt-containing vessel. The melt-containing vessel can be integrated with a cooling system for cooling the melt-containing vessel. Modularity of the melt-containing vessel, induction coil and cooling system facilitates servicing of the modular inductor furnace without disassembly of the entire electric induction furnace.

A method of cooling an electric induction furnace for melting and holding a reactive metal or alloy is provided where the electric induction furnace has an upper furnace vessel and an induction coil in a modular inductor furnace is positioned below the upper furnace vessel with a melt-containing vessel positioned inside the induction coil with a gap between the outside surface of the melt-containing vessel and the inside surface of the induction coil that is used to circulate a cooling fluid for cooling the melt-containing vessel to inhibit leakage of the reactive metal or alloy melt from the melt-containing vessel. The melt-containing vessel can be integrated with a cooling system for cooling the melt-containing vessel. Modularity of the melt-containing vessel, induction coil and cooling system facilitates servicing of the modular inductor furnace without disassembly of the entire electric induction furnace.

A metal oxide barrier and a connecting method for solving the problems in which sectors of an existing cold crucible are connected by means of a mica plate and the mica plate is damaged due to arcing and the like and in which the sectors are strongly connected by means of the mica plate and thus are difficult to replace and maintain. A cold crucible, comprising a metal oxide barrier, according to the present invention can prevent arcing, enables reduction of damage on the edge part of a water cooling sector due to a molten material and thus enhances durability. Moreover, the metal oxide barrier can easily be replaced compared to an existing mica plate and thus enables easy maintenance and repair.

A metal oxide barrier and a connecting method for solving the problems in which sectors of an existing cold crucible are connected by means of a mica plate and the mica plate is damaged due to arcing and the like and in which the sectors are strongly connected by means of the mica plate and thus are difficult to replace and maintain. A cold crucible, comprising a metal oxide barrier, according to the present invention can prevent arcing, enables reduction of damage on the edge part of a water cooling sector due to a molten material and thus enhances durability. Moreover, the metal oxide barrier can easily be replaced compared to an existing mica plate and thus enables easy maintenance and repair.

An electric induction furnace for melting and holding a reactive metal or alloy is provided with an upper furnace vessel, an induction coil positioned below the upper furnace vessel, and a melt-containing vessel positioned inside the induction coil with a gap between the outside surface of the melt-containing vessel and the inside surface of the induction coil that can be used to circulate a cooling fluid for cooling the wall of the melt-containing vessel to inhibit leakage of the reactive metal or alloy melt from the vessel. The melt-containing vessel can be integrated with a cooling system for cooling the melt-containing vessel. The melt-containing vessel, induction coil and cooling system can be provided as modular components to facilitate servicing of the melt-containing vessel, the induction coil and the cooling system.

An electric induction furnace for melting and holding a reactive metal or alloy is provided with an upper furnace vessel, an induction coil positioned below the upper furnace vessel, and a melt-containing vessel positioned inside the induction coil with a gap between the outside surface of the melt-containing vessel and the inside surface of the induction coil that can be used to circulate a cooling fluid for cooling the wall of the melt-containing vessel to inhibit leakage of the reactive metal or alloy melt from the vessel. The melt-containing vessel can be integrated with a cooling system for cooling the melt-containing vessel. The melt-containing vessel, induction coil and cooling system can be provided as modular components to facilitate servicing of the melt-containing vessel, the induction coil and the cooling system.

An induction furnace comprising a upper furnace vessel; an induction coil positioned below the upper furnace vessel; and a melt-containing vessel positioned inside the induction coil and communicably connected to the upper furnace vessel, wherein the positioning of the melt-containing vessel inside the induction coil defines a gap between an outside surface of the melt-containing vessel and an inside surface of the induction coil. A system for direct-chill casting comprising at least one an induction furnace; at least one in-line filter operable to remove impurities in molten metal; at least one gas source coupled to a feed port associated with the gas; and at least one device for solidifying metal by casting. A method of cooling an induction furnace comprising introducing a gas into a gap between an induction coil and a melt-containing vessel positioned inside the induction coil; and circulating the gas through the gap.

An induction furnace comprising a upper furnace vessel; an induction coil positioned below the upper furnace vessel; and a melt-containing vessel positioned inside the induction coil and communicably connected to the upper furnace vessel, wherein the positioning of the melt-containing vessel inside the induction coil defines a gap between an outside surface of the melt-containing vessel and an inside surface of the induction coil. A system for direct-chill casting comprising at least one an induction furnace; at least one in-line filter operable to remove impurities in molten metal; at least one gas source coupled to a feed port associated with the gas; and at least one device for solidifying metal by casting. A method of cooling an induction furnace comprising introducing a gas into a gap between an induction coil and a melt-containing vessel positioned inside the induction coil; and circulating the gas through the gap.