Multi-wire induction heating
First Claim
1. In an apparatus for inductively heating simultaneously a plurality of elongate workpieces to a generally similar temperature over the length thereof, said workpieces having a substantially uniform cross-section over their respective lengths, and wherein said workpieces are individually conveyed at the same predetermined uniform rate of speed longitudinally along a plurality of similar work paths;
- the improvement comprising, inductor heating means having at least one elongated heating zone, said heating zone comprising multi-channel inductor coils, each coil having an entrance and an exit end and having electrical windings which completely envelop said plurality of work paths over the length of said coil, each coil also beig divided into at least two adjacent coil lengths, wherein the direction of the current flow and the direction of the coil winding are reversed simultaneously between at least two adjacent coil lengths, said multi-channel inductor coils being longitudinally disposed about said plurality of work paths to form a stack of separate, closely spaced guide channels defining a linear heating path of prescribed length; and
means for activating said inductor heating means to a prescribed adjustable energization level.
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Accused Products
Abstract
In the induction heating of thin (e.g. 0.5 to 3 mm diameter) steel wires (W) in continuous heating processes, relatively low field strengths of e.g. up to 20,000 Am-1 are employed but are chosen so as to set the relative magnetic permeability μr at 40 or more. The wire are passed through coil blocks (1), which are wound flat around a row of ceramic tubes (3) to guide and insulate the wires. The coil blocks are energized at frequencies typically up to 30 kHz. The direction of winding and/or the phase of the current is changed between adjacent coil blocks (1), or groups of blocks, to reduce voltage build-up along the wires.
50 Citations
57 Claims
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1. In an apparatus for inductively heating simultaneously a plurality of elongate workpieces to a generally similar temperature over the length thereof, said workpieces having a substantially uniform cross-section over their respective lengths, and wherein said workpieces are individually conveyed at the same predetermined uniform rate of speed longitudinally along a plurality of similar work paths;
- the improvement comprising, inductor heating means having at least one elongated heating zone, said heating zone comprising multi-channel inductor coils, each coil having an entrance and an exit end and having electrical windings which completely envelop said plurality of work paths over the length of said coil, each coil also beig divided into at least two adjacent coil lengths, wherein the direction of the current flow and the direction of the coil winding are reversed simultaneously between at least two adjacent coil lengths, said multi-channel inductor coils being longitudinally disposed about said plurality of work paths to form a stack of separate, closely spaced guide channels defining a linear heating path of prescribed length; and
means for activating said inductor heating means to a prescribed adjustable energization level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
- the improvement comprising, inductor heating means having at least one elongated heating zone, said heating zone comprising multi-channel inductor coils, each coil having an entrance and an exit end and having electrical windings which completely envelop said plurality of work paths over the length of said coil, each coil also beig divided into at least two adjacent coil lengths, wherein the direction of the current flow and the direction of the coil winding are reversed simultaneously between at least two adjacent coil lengths, said multi-channel inductor coils being longitudinally disposed about said plurality of work paths to form a stack of separate, closely spaced guide channels defining a linear heating path of prescribed length; and
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18. An induction heating apparatus for heating a plurality of elongate elements, said induction heating apparatus comprising a coil having windings and a generally flat cross section;
- said coil being divided into at least two adjacent coil lengths, wherein the direction of the curent flow and the direction of the coil winding are reversed simultaneously between at least two adjacent coil lengths.
- View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. An induction heating apparatus which is divided into distinct coil sections each having a coil winding direction and a current flow direction, the coil winding direction and the current flow direction being reversed simultaneously between two adjacent coil sections, so as to reduce longitudinal potential differences to substantially harmless levels and at the same time to maintain the magnetic field in an identical direction over the total heating length.
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36. A method of induction heating a plurality of elongate elements comprising:
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providing an induction coil with a plurality of windings having a generally flat cross section; dividing said induction coil into at least two adjacent coil lengths; simultaneously reversing current flow and direction of the coil winding between at least two adjacent coil lengths; and moving said elongate elements through said induction coil. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57)
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Specification