Inductotherm Corp.

Mike Maochang Cao

Oleg S Fishman

Satyen N Prabhu

John H Mortimer

Joseph T Belsh

Vitaly A Peysakhovich

Jean Lovens

Vladimir V Nadot

Nier Wu

Large steel ingot casting is accomplished with a top suspended induction heating device supplied with variable power and variable frequency from a power source. By the induction heating and stirring provided by the top suspended induction heating device, metal solidification advances progressively upwards from bottom to top, and the upper molten metal in a riser part compensates for shrinkage of the lower solidified metal in the main part. Inclusions are selectively moved out of the molten metal by a variable electromagnetic stirring force and the formation of casting defects is suppressed.

Controlled casting of in-mold large steel ingot with induced variable power and variable frequency applied to the top surface of molten metal in-mold

A fluid latent heat absorption electric induction heater is provided for raising the temperature of a fluid supplied to a fluid-driven turbine in a turbine-driven electric power generation system. The fluid latent heat absorption electric induction heater alternatively transfers heat to the fluid by induced susceptor heating, or a combination of inductor Joule heating and induced susceptor heating. The fluid may be water-steam for powering a steam-driven turbine or another fluid used in a phase change system for driving a fluid-driven turbine in a turbine-driven electric power generation system.

Electric induction fluid heaters for fluids utilized in turbine-driven electric generator systems

An apparatus and process are provided for controlling the heating and melting of a material that is non-electrically conductive in the solid state and is electrically conductive in the non-solid state. Power is selectively directed between coil sections surrounding different zones of the material in a susceptor vessel by changing the output frequency of the power supply to the coil sections. Coil sections are at least one active coil section, which is connected to the output of the power supply, and at least one passive coil section, which is not connected to the power supply, but is connected in parallel with a tuning capacitor so that the at least one passive coil section can be selectively operated at, or near, resonant frequency when the transition material in the vessel is molten. Depending upon the state of the transition material in the susceptor vessel, the frequency of the power applied to the active coil section can be changed to generate a magnetic field that selectively couples with the susceptor vessel, transition material in the vessel, and/or the passive coil section.

Electric induction heating, melting and stirring of materials non-electrically conductive in the solid state

Apparatus and process for heating and melting a material in a susceptor vessel are provided wherein phase synchronized ac voltage is supplied from a separate power source to each one of at least two induction coils in separate zones around the vessel. Power magnitude from each source to an induction coil is controlled by pulse width control of the source's output voltage. Output frequency from each source is either fixed or variable based upon the electrically conductive state of the material. Optional electromagnetic stirring is achieved by establishing a phase shift between the voltage outputs of the power supplies after the material in the susceptor vessel has melted.

Electric power system for electric induction heating and melting of materials in a susceptor vessel

Apparatus for, and method of, containing, transferring and electromagnetically stirring an electrically conductive fluid is provided. A vessel is formed from spaced-apart annular structural elements, or hoops, that are bound together by a high-temperature electrical insulating material, which also forms the interior surface of the vessel. Reinforcing members are embedded in the high-temperature electrical insulating material and passed through the hoops. The vessel is disposed within an electrical stator having multiple electrical poles. Each pole is wound with a separate coil. Current can be supplied to each coil winding, with a suitable phase shift between currents to all coil windings, to achieve an electromagnetically induced stirring and heating of the electrically conductive fluid. The vessel may be removably disposed in the electrical stator so that the vessel can be transported to and from the electrical stator for induced stirring.

Combination holding furnace and electromagnetic stirring vessel for high temperature and electrically conductive fluid materials

A current fed inverter with duty cycle regulation of dc current to the input of the inverter is provided to increase the magnitude of inverter output power while operating a resonant load at resonant frequency. The regulator duty cycle period is synchronized to the period of the output current of the inverter so that there are two regulator periods for each single output current period of the inverter. Duty cycle regulation may be provided by a single pulse in the regulator period, or a series of pulses in the regulator period. Output power magnitude greater than that available at full duty cycle can be provided by operating the inverter at off resonance. Multiple current fed inverters may be connected to individual coil sections around a crucible and selectively interconnected for a heating or melting mode, or a stir mode.

Current fed inverter with pulse regulator for electric induction heating, melting and stirring

An apparatus and process are provided for inductively heating a workpiece to a desired cross sectional temperature. At least one pair of coils form a transverse flux inductor. The workpiece is located between the pair of opposing coils, which are oriented across the cross section of the workpiece. Each coil comprises a plurality of coil sections. The distance between one or more opposing coil sections is adapted to achieve the desired cross sectional induction heating temperature profile in the workpiece. Alternatively the distance between all opposing coil sections are equidistant from each other, and one or more flux concentrators, moveable at least in a direction perpendicular to the surface of the workpiece, can be used to achieve the desired cross sectional induction heating temperature profile in the workpiece.

Transverse flux electric inductors

An apparatus and process are provided for inductively heating a workpiece by transverse flux induction. The apparatus comprises a pair of identical coils, each of which includes a reversed head section bent to the opposite side of the workpiece. The assembled pair of coils is configured to effectively form a generally O-shaped coil arrangement on opposing sides of the workpiece. Combination electrically conductive and magnetic compensators, passive or active/passive, are also provided for use with transverse flux inductors.

Transverse flux induction heating apparatus and compensators

An apparatus and process are provided for controlling the heating or melting of an electrically conductive material. Power is selectively directed between coil sections surrounding different zones of the material by changing the output frequency of the power supply to the coil sections. Coil sections include at least one active coil section, which is connected to the output of the power supply, and at least one passive coil section, which is not connected to the power supply, but is connected in parallel with a tuning capacitor so that the at least one passive coil section operates at a resonant frequency and the output frequency of the power supply is changed so that the induced power in the at least one passive coil section changes as the frequency is changed.

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Westampton, NJ, United States of America

Mike Maochang Cao