Abstract: Method and apparatus for providing harmonic inductive power, and more particularly for delivering current pulses providing a desired amount of pulse energy in high frequency harmonics to a load circuit for inductive heating of an article. By controlling the shape and/or frequency of such current pulses, the apparatus and method can be used to enhance the rate, intensity and/or power of inductive heating delivered by the heater coil and/or to enhance the lifetime or reduce the cost and complexity of an inductive heating power supply. Of particular significance, the apparatus and method may be used to significantly increase the power inductively delivered to a ferromagnetic or other inductively heated load, without requiring an increase of current in the heater coil. This enables new heating applications, and in some known applications, decreases the energy consumption or cooling requirements and/or increase the lifetime of the heater coil.

Abstract: Apparatus and method for inductive heating of a material located in a channel, to modify the state of the material between flowable and nonflowable states. An internal inductive heating assembly is disposed in the material in the channel, and a signal is supplied to the assembly to generate a magnetic flux in at least one of the assembly and the material, the magnetic flux generating inductive heating of the assembly and/or the material. The signal is adjusted to produce a desired rate of temperature cycling of the material in the channel which includes modifying the state of the material between flowable and nonflowable states. In one embodiment, the heating assembly includes an interior coil, an exterior sheath inductively coupled to the coil, a dielectric material disposed between the coil and sheath, a flux concentrator, and a conductor for supplying a signal to the coil to generate the magnetic flux.

Abstract: Apparatus and method for inductive heating of a material located in a channel. In one embodiment, the heating assembly comprises an interior coil, an exterior sheath inductively coupled to the coil, a dielectric material disposed between the coil and sheath, and a conductor for supplying a signal to the coil to generate the magnetic flux for inductive heating of the sheath. The heating assembly is disposed in the material in the channel, and the magnetic flux generated by the coil may also inductively couple to the material in the channel. The material may be heated from a nonflowable to a flowable state, such as heating a metal or polymer plug formed in a melt channel of a molding apparatus.

Abstract: Method and apparatus for providing harmonic inductive power, and more particularly for delivering current pulses providing a desired amount of pulse energy in high frequency harmonics to a load circuit for inductive heating of an article. By controlling the shape and/or frequency of such current pulses, the apparatus and method can be used to enhance the rate, intensity and/or power of inductive heating delivered by the heater coil and/or to enhance the lifetime or reduce the cost and complexity of an inductive heating power supply. Of particular significance, the apparatus and method may be used to significantly increase the power inductively delivered to a ferromagnetic or other inductively heated load, without requiring an increase of current in the heater coil. This enables new heating applications, and in some known applications, decreases the energy consumption or cooling requirements and/or increase the lifetime of the heater coil.

Abstract: Method and apparatus for providing harmonic inductive power, and more particularly for delivering current pulses providing a desired amount of pulse energy in high frequency harmonics to a load circuit for inductive heating of an article. By controlling the shape and/or frequency of such current pulses, the apparatus and method can be used to enhance the rate, intensity and/or power of inductive heating delivered by the heater coil and/or to enhance the lifetime or reduce the cost and complexity of an inductive heating power supply. Of particular significance, the apparatus and method may be used to significantly increase the power inductively delivered to a ferromagnetic or other inductively heated load, without requiring an increase of current in the heater coil. This enables new heating applications, and in some known applications, decreases the energy consumption or cooling requirements and/or increase the lifetime of the heater coil.

Abstract: Apparatus and method for inductive heating of a material located in a channel. In one embodiment, the heating assembly comprises an interior coil, an exterior sheath inductively coupled to the coil, a dielectric material disposed between the coil and sheath, and a conductor for supplying a signal to the coil to generate the magnetic flux for inductive heating of the sheath. The heating assembly is disposed in the material in the channel, and the magnetic flux generated by the coil may also inductively couple to the material in the channel. The material may be heated from a nonflowable to a flowable state, such as heating a metal or polymer plug formed in a melt channel of a molding apparatus.

Abstract: Apparatus and method for inductive heating of a transfer pipe having a bore for transporting a flowable material. A heating coil assembly is disposed along an exterior length of the pipe for generating a magnetic flux for inductively heating the pipe and/or a material flowing in the bore. The coil configuration comprises a continuous coil having spaced-apart coil groups along the pipe length, with adjacent coil turns in each group. In various applications, such as for transporting molten metals from a furnace to a casting assembly, this coil configuration can provide one or more benefits including: reduced energy consumption by reducing thermal losses in the pipe and thus reducing the required temperature at which the molten material is delivered to the pipe; tighter temperature control; improved consistency of the molten material; increased heating efficiency, and/or greater thermal uniformity of the pipe and/or the molten material in the pipe.

Abstract: Method and apparatus for providing harmonic inductive power, and more particularly for delivering current pulses providing a desired amount of pulse energy in high frequency harmonics to a load circuit for inductive heating of an article. By controlling the shape and/or frequency of such current pulses, the apparatus and method can be used to enhance the rate, intensity and/or power of inductive heating delivered by the heater coil and/or to enhance the lifetime or reduce the cost and complexity of an inductive heating power supply. Of particular significance, the apparatus and method may be used to significantly increase the power inductively delivered to a ferromagnetic or other inductively heated load, without requiring an increase of current in the heater coil. This enables new heating applications, and in some known applications, decreases the energy consumption or cooling requirements and/or increase the lifetime of the heater coil.

Abstract: Heating systems and methods for inductive heating or a combination of resistive and inductive heating. A heater coil is inductively coupled to an article and a current signal is supplied to the heater coil. The heater coil generates a magnetic flux, based on the applied current signal, for inductively heating the article. Current pulses of a certain profile are used to enhance the rate, intensity and/or power of inductive heating delivered by the heating element or coil and/or to enhance the lifetime or reduce the cost of the inductive heating system.

Abstract: A system and method for inductive heating, in which a power source provides current pulses with high-frequency harmonics to a heater coil, the coil generating a magnetic flux for inductive heating of an article. The high-frequency harmonics enhance a relative proportion of inductive heating, compared to resistive heating of the heater coil. Providing these high-frequency harmonics, occurring above the border frequency of the heating system, enables the system to deliver an increased proportion of inductive heating, compared to resistive heating, without requiring an increase in the Root Means Square (RMS) current in the coil. Providing better coupling between the coil and the core, such as by embedding the coil wholly or at least partially in the core, and providing a magnetic yoke to close the loop with the core, can provide a significantly decreased border frequency.

Abstract: Heating systems and methods for inductive heating or a combination of resistive and inductive heating. A heater coil is inductively coupled to an article and a current signal is supplied to the heater coil. The heater coil generates a magnetic flux, based on the applied current signal, for inductively heating the article. Current pulses of a certain profile are used to enhance the rate, intensity and/or power of inductive heating delivered by the heating element or coil and/or to enhance the lifetime or reduce the cost of the inductive heating system.