US 5,208,433 A · Inductive heating coil

Abstract

A cooling tube (T) is incorporated into each conductor (C1) of the coil. The current carried by this conductor is divided between the strands which are maintained in thermal contact with the tube even in transposition or twist areas in which the conductor undergoes particularly marked deformations. The conductor features at least one half-turn twist between the electrical terminals of the coil.

Drawings

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Drawings

Claims11

Dependent claims

In an inductive heating coil comprising a plurality of electrical connectors forming a group and being connected in parallel between tow electrical terminals of said coil, each of said conductors comprising:

a cooling tube for carrying a cooling fluid, and
strands for carrying electrical current, said strands being connected in parallel between said terminals of said coil and being in thermal contact with walls of said tube,
said conductors including deformations along a length of said conductors, with said conductors being transposed in said coil, and said strands being transposed in each conductor to reduce a formation of unwanted current loops;
the improvement wherein positions of said strands relative to the walls of said tube and relative to each other in a cross-section of said each conductor are substantially unchanged over a complete length of each said conductor, and said transposition between said strands being locally effected by a twist of at least one half-turn of each said conductor about a conductor axis in at least one marked deformation section of limited length of each said conductor.

1 more element

Dependencies are inferred from the claim text.

Description2,964 words

Summary852 words

#The present invention is generally concerned with electromagnetic induction heating. It applies in particular, although not exclusively, to heating the moving edges of flat metallurgical products to be deformed at raised temperature. This includes products of the iron and steel industry that have to be heated or reheated before they are flattened and/or widened by passing them between the rolls of a rolling mill.

#This heating is typically provided by a device comprising:

#a magnetic circuit including an airgap,

Brief description of the drawings7 figures

#How the present invention may be put into effect will now be described by way of non-limiting example only with reference to the appended diagrammatic drawings in which the same component is identified by the same reference number if it appears in more than one figure.

#FIG. 1 shows an edge heating device in accordance with the invention incorporating two coils.

#FIG. 2 is an electrical circuit diagram of the device.

Detailed description1,971 words

#Referring to FIG. 1, an edge heating device is used in an iron and steelworks on the entry side of a rolling mill. A flat product in the form of a thick steel plate 1 runs on transport rollers 2 in a direction perpendicular to the plane of the drawing as shown by the end view of an arrow V.

#It passes at high speed through the air gap of a magnetic circuit 4 whose two ends constitute the ferromagnetic cores 5 and 6 of two identical heating coils 7 and 8.

#The coils are protected from the heat by insulative layers 8A, etc.

Facts

Application

07/715,192Filed 14 Jun 1991

Priority

FR 90 0750715 Jun 1990

Granted

4 May 1993

Term ended

14 Jun 2011

Estimated · how

Pre-1995 term; greater of 17 years from grant or 20 years from filing when eligible. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification5 codes

H05B 6/104
Multiple metal pieces successively being moved close to the inductor: metal pieces being elongated like wires or bands
H05B 6/42
Coil arrangements: cooling of coils
H01F 2038/003
Adaptations of transformers or inductances for specific applications or functions: high frequency transformer for microwave oven
H05B
Electric heating

Inductive heating coil

Life of this patent

Inductive heating coil

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims11

Description2,964 words

Drawings

Classification5 codes

Life of this patent

Description2,964 words