WO1996026296A1 - Variable-width induction heater - Google Patents

Variable-width induction heater Download PDF

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Publication number
WO1996026296A1
WO1996026296A1 PCT/GB1996/000387 GB9600387W WO9626296A1 WO 1996026296 A1 WO1996026296 A1 WO 1996026296A1 GB 9600387 W GB9600387 W GB 9600387W WO 9626296 A1 WO9626296 A1 WO 9626296A1
Authority
WO
WIPO (PCT)
Prior art keywords
carrier
strip
pole piece
path
induction heating
Prior art date
Application number
PCT/GB1996/000387
Other languages
French (fr)
Inventor
Michael Petch
Original Assignee
Davy Mckee (Poole) Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Davy Mckee (Poole) Limited filed Critical Davy Mckee (Poole) Limited
Priority to EP96903117A priority Critical patent/EP0812366A1/en
Priority to GB9717645A priority patent/GB2314246A/en
Priority to JP8525489A priority patent/JPH11500262A/en
Publication of WO1996026296A1 publication Critical patent/WO1996026296A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
    • C21D9/56—Continuous furnaces for strip or wire
    • C21D9/60—Continuous furnaces for strip or wire with induction heating
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • This invention relates to induction heaters for metal strip.
  • the objective of the present invention is to obtain uniform heating in any width of strip using a single inductor with variable-width capability.
  • Such an inductor should preferably be capable of adjusting its width whilst under power; also it is preferred that width adjustment should be stepless and should not entail movement of major parts of the main inductor core or windings, since this may lead to premature failure under the severe conditions of vibration and heat which are encountered in this application.
  • a first feature of the present invention provides a transverse flux induction heating system for metal strip, comprising at least one inductor having a fixed pole assembly, and a pair of adjustably positioned auxiliary pole pieces of magnetically permeable material each of which is positioned towards one side of the path of the strip to modify the distribution of the induction field.
  • a second aspect of the invention provides a transverse flux induction heating system for metal strip, comprising at least one inductor having a fixed pole assembly and a pair of adjustably positioned shading plates each of which is positioned towards one side of the path of the strip.
  • an adjustable transverse flux induction heating system for metal strip comprising a fixed pole assembly, and at least one movable assembly including an auxiliary pole piece and/or a shading plate, at each side of the strip path.
  • the carrier assembly includes both an auxiliary pole piece, and a shading plate, and also includes means for adjusting their relative positions on the carrier.
  • a preferred embodiment of the invention comprises a transverse flux induction heating system for metal strip including a fixed pole assembly and at least one transversely movable carrier at each side of the path of the strip, which is slidably mounted for movement across the strip path, and carries a shading plate; first actuator means for controlling the position of the carrier; an auxiliary pole piece mounted in the carrier, and second actuator means for moving the pole piece in the carrier.
  • Figures la and lb are schematic cross-sectional views of an induction heating system showing adjustments for different width strip
  • Figure 2 is a view as seen looking at the face of the strip of an induction heating system according to the invention.
  • Figure 3 is a perspective view of a part of the apparatus of Figure 2.
  • each shading plate (2) and flux modifier pole piece (4) is provided with an individual positioner (6, 8).
  • the design takes into account the conditions experienced in an inductor of substantial power rating, where the shading plates and flux modifiers are subject to complex electro-magnetic forces of considerable magnitude and are also subject to constant vibration and to heat. This necessitates a form of construction which is both rugged and vibration resistant and at the same time suitably compact so that it can be accommodated in the restricted space available between the two halves of the inductor.
  • the runways are arranged so that a shading plate (2) mounted in a sliding carrier (12) is positioned above each end of each pole face (14) .
  • the actuator can be a manually operated adjuster or, where remote control is required, it may be an electric positioner, or similar hydraulic or pneumatic device, of suitably long stroke.
  • the associated flux modifier (4) Housed within the shading plate carrier (12) is the associated flux modifier (4) ; this itself is mounted on a sliding or rolling member which can move within the carrier to adjust the flux modifier position relative to the shading plate.
  • the positioning of the flux modifier is controlled by an actuator (8) attached to the carrier and this again may be a manually operated adjuster or a remotely controlled positioner similar to that used for shading plate adjustment; however, since the flux modifier movements are relatively small, its actuator need only be of short stroke.
  • the long stroke positioner (6) can move the shading plate to whatever position is required, carrying with it the flux modifier (4) and its short stroke positioner (8) ; this movement constitutes the primary width adjustment of the inductor relative to a specific strip width as illustrated in Figures la and lb. If necessary the flux modifier can then be adjusted over a short distance as required to trim the inductor performance to suit the particular type of strip material.
  • all the actuators should be of the remote control type. This makes it possible rapidly to set up the pattern of shading plate and flux modifier positions which result in the desired distribution of heating for a strip of given width and characteristics, either by selection from a previously gathered database or by direct control from devices such as scanning pyrometers which monitor the temperature profile across the strip.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Induction Heating (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)

Abstract

A transverse flux induction heating system for metal strip including a fixed pole assembly and at least one transversely movable carrier at each side of the path of the strip, which is slidably mounted for movement across the strip path, and carries a shading plate; first actuator means for controlling the position of the carrier; an auxiliary pole piece mounted in the carrier, and second actuator means for moving the pole piece in the carrier.

Description

"Variable-Width Induction Heater"
This invention relates to induction heaters for metal strip.
In process lines for thermal treatment of continuously moving metal strip by transverse flux induction heating it is usual for successive coils of strip to vary in nominal width, one from another, over a range of 2:1 or more. Moreover it is common for the width of strip to vary gradually by small amounts within the length of any given coil.
The requirement to obtain uniform heating in strips of different widths can be addressed by providing interchangeable inductors, each designed for a specific width. In a production line of typical width spread this may entail the provision of as many as eight or more inductors, which is clearly uneconomic in utilisation of equipment.
The objective of the present invention is to obtain uniform heating in any width of strip using a single inductor with variable-width capability. Such an inductor should preferably be capable of adjusting its width whilst under power; also it is preferred that width adjustment should be stepless and should not entail movement of major parts of the main inductor core or windings, since this may lead to premature failure under the severe conditions of vibration and heat which are encountered in this application.
It is known that in an inductor for the heating of metal strip by transverse flux induction a desired distribution of heating effect across the width of the strip can be obtained by the addition to the inductor poles of auxiliary pole pieces of magnetically permeable material (flux modifiers) which serve to enhance the magnetic flux in the vicinity of the edges of the strip, and also by the provision of electrically conductive shields (shading plates) which are positioned generally outboard of the edges of the strip so as to screen the outlying portions of the inductor.
Accordingly a first feature of the present invention provides a transverse flux induction heating system for metal strip, comprising at least one inductor having a fixed pole assembly, and a pair of adjustably positioned auxiliary pole pieces of magnetically permeable material each of which is positioned towards one side of the path of the strip to modify the distribution of the induction field.
A second aspect of the invention provides a transverse flux induction heating system for metal strip, comprising at least one inductor having a fixed pole assembly and a pair of adjustably positioned shading plates each of which is positioned towards one side of the path of the strip.
According to a further aspect of the invention there is provided an adjustable transverse flux induction heating system for metal strip, comprising a fixed pole assembly, and at least one movable assembly including an auxiliary pole piece and/or a shading plate, at each side of the strip path.
Preferably, the carrier assembly includes both an auxiliary pole piece, and a shading plate, and also includes means for adjusting their relative positions on the carrier.
Accordingly, a preferred embodiment of the invention comprises a transverse flux induction heating system for metal strip including a fixed pole assembly and at least one transversely movable carrier at each side of the path of the strip, which is slidably mounted for movement across the strip path, and carries a shading plate; first actuator means for controlling the position of the carrier; an auxiliary pole piece mounted in the carrier, and second actuator means for moving the pole piece in the carrier. A preferred embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:
Figures la and lb are schematic cross-sectional views of an induction heating system showing adjustments for different width strip;
Figure 2 is a view as seen looking at the face of the strip of an induction heating system according to the invention; and
Figure 3 is a perspective view of a part of the apparatus of Figure 2.
Referring to the drawings each shading plate (2) and flux modifier pole piece (4) is provided with an individual positioner (6, 8). The design takes into account the conditions experienced in an inductor of substantial power rating, where the shading plates and flux modifiers are subject to complex electro-magnetic forces of considerable magnitude and are also subject to constant vibration and to heat. This necessitates a form of construction which is both rugged and vibration resistant and at the same time suitably compact so that it can be accommodated in the restricted space available between the two halves of the inductor.
A system of runways of substantial construction shown in the illustration as slideway channels (10) fabricated from insulating materials having suitable strength and heat resistant properties, is attached to the inner face of each half of the inductor. The runways are arranged so that a shading plate (2) mounted in a sliding carrier (12) is positioned above each end of each pole face (14) . An actuating device (6) . the outer end (16) of which is anchored to the main frame (18) of the inductor, can traverse the shading plate from its outermost position to its innermost position. In the preferred arrangement shown, this range of movement being at least half the difference between the maximum and minimum widths of the strip widths under consideration. The actuator can be a manually operated adjuster or, where remote control is required, it may be an electric positioner, or similar hydraulic or pneumatic device, of suitably long stroke.
Housed within the shading plate carrier (12) is the associated flux modifier (4) ; this itself is mounted on a sliding or rolling member which can move within the carrier to adjust the flux modifier position relative to the shading plate. The positioning of the flux modifier is controlled by an actuator (8) attached to the carrier and this again may be a manually operated adjuster or a remotely controlled positioner similar to that used for shading plate adjustment; however, since the flux modifier movements are relatively small, its actuator need only be of short stroke.
It will be seen that the long stroke positioner (6) can move the shading plate to whatever position is required, carrying with it the flux modifier (4) and its short stroke positioner (8) ; this movement constitutes the primary width adjustment of the inductor relative to a specific strip width as illustrated in Figures la and lb. If necessary the flux modifier can then be adjusted over a short distance as required to trim the inductor performance to suit the particular type of strip material.
In an industrial installation it is preferred that all the actuators should be of the remote control type. This makes it possible rapidly to set up the pattern of shading plate and flux modifier positions which result in the desired distribution of heating for a strip of given width and characteristics, either by selection from a previously gathered database or by direct control from devices such as scanning pyrometers which monitor the temperature profile across the strip.

Claims

1. An adjustable transverse flux induction heating system for metal strip, comprising a fixed pole assembly, and at least one movable assembly including an auxiliary pole piece and/or a shading plate, at each side of the strip path.
2. A transverse flux induction heating system for metal strip according to claim 1 in which there are a pair of movable assemblies each of which is positioned at or towards one side of the strip path and is transversely movable towards the centre of the path.
3. A transverse flux induction heating system according to claim 1 or claim 2 in which the or each movable assembly includes a carrier on which the corresponding auxiliary pole piece and/or shading plate is or are adjustably mounted.
4. A transverse flux induction heating system according to claim 1 or claim 2 in which the or each movable assembly includes a carrier on which an auxiliary pole piece and a shading plate are so mounted that their relative positions are adjustable.
5. A transverse flux induction heating system for metal strip including a fixed pole assembly and at least one transversely movable carrier at each side of the path of the strip, which is slidably mounted for movement across the strip path, and carries a shading plate; first actuator means for controlling the position of the carrier; an auxiliary pole piece mounted in the carrier, and second actuator means for moving the pole piece in the carrier.
PCT/GB1996/000387 1995-02-21 1996-02-20 Variable-width induction heater WO1996026296A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP96903117A EP0812366A1 (en) 1995-02-21 1996-02-20 Variable-width induction heater
GB9717645A GB2314246A (en) 1995-02-21 1996-02-20 Variable-width induction heater
JP8525489A JPH11500262A (en) 1995-02-21 1996-02-20 Variable width induction heater

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB9503390.8A GB9503390D0 (en) 1995-02-21 1995-02-21 "Variable-width induction heater
GB9503390.8 1995-02-21

Publications (1)

Publication Number Publication Date
WO1996026296A1 true WO1996026296A1 (en) 1996-08-29

Family

ID=10769969

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1996/000387 WO1996026296A1 (en) 1995-02-21 1996-02-20 Variable-width induction heater

Country Status (4)

Country Link
EP (1) EP0812366A1 (en)
JP (1) JPH11500262A (en)
GB (2) GB9503390D0 (en)
WO (1) WO1996026296A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000052965A2 (en) * 1999-03-01 2000-09-08 Avestapolarit Aktiebolag (Publ) A method of heating metal strip and apparatus therefor
WO2004103595A1 (en) * 2003-05-23 2004-12-02 Thyssenkrupp Nirosta Gmbh Device for warming a metal strip and systems for producing hot-rolled metal strips, fitted with said type of device
WO2009129239A3 (en) * 2008-04-14 2010-01-21 Inductotherm Corp. Variable width transverse flux electric induction coils
EP2538748A4 (en) * 2010-02-19 2015-12-02 Nippon Steel & Sumitomo Metal Corp Transverse flux induction heating device
US9462641B2 (en) 2013-12-20 2016-10-04 Ajax Tocco Magnethermic Corporation Transverse flux strip heating with DC edge saturation
EP3077562B1 (en) 2013-12-06 2019-03-06 Fives Celes Continuous processing line for processing a non-magnetic metal strip including a galvannealing section and method for induction heating of said strip in said galvannealing section
US10563282B2 (en) 2014-09-03 2020-02-18 Nippon Steel Corporation Induction heating device for metal strip

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU733892B2 (en) * 1998-03-24 2001-05-31 Kitashiba Electric Co., Ltd. Induction heating apparatus

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3313907A (en) * 1963-09-06 1967-04-11 Deutsche Edelstahlwerke Ag Apparatus for inductively heating metal strip
DE2728296A1 (en) * 1976-06-26 1977-12-29 Toyo Aluminium Kk INDUCTION HEATING DEVICE
EP0080921A1 (en) * 1981-11-24 1983-06-08 Alsthom Method and arrangement for realizing a transversal heating homogeneity by electromagnetic induction of long, thin, continuously advancing products
GB2144609A (en) * 1983-08-03 1985-03-06 Davy Mckee Variable width inductor for induction heating
GB2182230A (en) * 1985-10-25 1987-05-07 Nippon Light Metal Co Electromagnetic strip induction heating
WO1990014742A1 (en) * 1989-05-17 1990-11-29 Giovanni Arvedi Induction furnace for heating and temperature homogenization in hot-rolling of thin steel strips
EP0407660A1 (en) * 1989-07-14 1991-01-16 Mitsubishi Jukogyo Kabushiki Kaisha Induction heating apparatus

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3313907A (en) * 1963-09-06 1967-04-11 Deutsche Edelstahlwerke Ag Apparatus for inductively heating metal strip
DE2728296A1 (en) * 1976-06-26 1977-12-29 Toyo Aluminium Kk INDUCTION HEATING DEVICE
EP0080921A1 (en) * 1981-11-24 1983-06-08 Alsthom Method and arrangement for realizing a transversal heating homogeneity by electromagnetic induction of long, thin, continuously advancing products
GB2144609A (en) * 1983-08-03 1985-03-06 Davy Mckee Variable width inductor for induction heating
GB2182230A (en) * 1985-10-25 1987-05-07 Nippon Light Metal Co Electromagnetic strip induction heating
WO1990014742A1 (en) * 1989-05-17 1990-11-29 Giovanni Arvedi Induction furnace for heating and temperature homogenization in hot-rolling of thin steel strips
EP0407660A1 (en) * 1989-07-14 1991-01-16 Mitsubishi Jukogyo Kabushiki Kaisha Induction heating apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
R.JC. IRESON: "Variable width inductor for transverse flux induction annealing of strip", STEEL TIMES - INCORPORATING IRON & STEEL, vol. 222, no. 9, September 1994 (1994-09-01), LONDON GB, pages 352 - 354, XP000467512 *

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000052965A2 (en) * 1999-03-01 2000-09-08 Avestapolarit Aktiebolag (Publ) A method of heating metal strip and apparatus therefor
WO2000052965A3 (en) * 1999-03-01 2000-12-28 Avesta Sheffield Aktiebolag Pu A method of heating metal strip and apparatus therefor
US6608290B1 (en) 1999-03-01 2003-08-19 Avesta Sheffield Aktiebolag Method of heating metal strip and apparatus thereof
WO2004103595A1 (en) * 2003-05-23 2004-12-02 Thyssenkrupp Nirosta Gmbh Device for warming a metal strip and systems for producing hot-rolled metal strips, fitted with said type of device
EP2283496A4 (en) * 2008-04-14 2014-10-29 Inductotherm Corp Variable width transverse flux electric induction coils
EP2283496A2 (en) * 2008-04-14 2011-02-16 Inductotherm Corp. Variable width transverse flux electric induction coils
WO2009129239A3 (en) * 2008-04-14 2010-01-21 Inductotherm Corp. Variable width transverse flux electric induction coils
US9445460B2 (en) 2008-04-14 2016-09-13 Inductotherm Corp. Variable width transverse flux electric induction coils
EP3852493A1 (en) * 2008-04-14 2021-07-21 Inductotherm Corp. Variable width transverse flux electric induction coils
EP2538748A4 (en) * 2010-02-19 2015-12-02 Nippon Steel & Sumitomo Metal Corp Transverse flux induction heating device
US9578693B2 (en) 2010-02-19 2017-02-21 Nippon Steel & Sumitomo Metal Corporation Transverse flux induction heating device
US10085306B2 (en) 2010-02-19 2018-09-25 Nippon Steel & Sumitomo Metal Corporation Transverse flux induction heating device
EP3077562B1 (en) 2013-12-06 2019-03-06 Fives Celes Continuous processing line for processing a non-magnetic metal strip including a galvannealing section and method for induction heating of said strip in said galvannealing section
US9462641B2 (en) 2013-12-20 2016-10-04 Ajax Tocco Magnethermic Corporation Transverse flux strip heating with DC edge saturation
US10563282B2 (en) 2014-09-03 2020-02-18 Nippon Steel Corporation Induction heating device for metal strip

Also Published As

Publication number Publication date
JPH11500262A (en) 1999-01-06
GB9717645D0 (en) 1997-10-22
GB2314246A (en) 1997-12-17
GB9503390D0 (en) 1995-04-12
EP0812366A1 (en) 1997-12-17

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