US3414660A - Means for protection against and/or indication of faults in coreless induction furnaces, heating furnaces and the like - Google Patents

Means for protection against and/or indication of faults in coreless induction furnaces, heating furnaces and the like Download PDF

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Publication number
US3414660A
US3414660A US510245A US51024565A US3414660A US 3414660 A US3414660 A US 3414660A US 510245 A US510245 A US 510245A US 51024565 A US51024565 A US 51024565A US 3414660 A US3414660 A US 3414660A
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US
United States
Prior art keywords
coil
furnaces
faults
indication
protection against
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
US510245A
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English (en)
Inventor
Beckius Ivar
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Norden Holding AB
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ASEA AB
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Filing date
Publication date
Application filed by ASEA AB filed Critical ASEA AB
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Publication of US3414660A publication Critical patent/US3414660A/en
Anticipated expiration legal-status Critical
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B14/00—Crucible or pot furnaces
    • F27B14/08—Details peculiar to crucible or pot furnaces
    • F27B14/14—Arrangements of heating devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D11/00—Arrangement of elements for electric heating in or on furnaces
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/22—Furnaces without an endless core
    • H05B6/24—Crucible furnaces
    • H05B6/28—Protective systems

Definitions

  • the present invention relates to a means for protection against and/or indication of faults in a coil or coils in induction furnaces of coreless crucible type, heating furnaces and the like.
  • the coils have been provided with insulation, but this has not resulted in the elimination of said disadvangages.
  • the device according to the invention gives a solution to these and other connected disadvantages, in which the coil turns are possibly surrounded by insulation and around this (or at a distance from, but concentrically with the conductor) an uninterrupted metal cover wholly or partially enclosing the conductor section and without insulating interruption in the longitudinal direction of the current conductors.
  • the device is characterised in that the cover and conductor are joined at one coil end and joined across a relay and/or a voltage measuring device at the other coil end directly or through an insulating transformer, so that upon short circuiting or some other insulation faults between the coil turns the relay is actuated and the furnace feed is disconnected and/or the fault is indicated. Through this means disconnection of the feed and/or indication of the fault is carried out quickly, be-
  • FIG. 1 shows a connection diagram of the invention
  • FIG. 2 a cross section of the coils with the cover
  • FIG. 3 an example in cross section through a coil conductor with completely closed metal cover.
  • FIG. 2 a crucible 11 is shown, containing melt or I material to be melted.
  • the different coil conductors 12-15 ing so that it wholly or partially covers the conductors.
  • the conductor and cover are joined together (see 18 in FIGS. 2 and 1) while at the other coil end the joining together is carried out across a voltage measuring device 19 and/ or a relay 20, possibly with an intercoupled insulating transformer (not shown).
  • the relay 20 is arranged to disconnect the furnace feed upon actuation.
  • the connection of coil protection and coil indication means is evident from FIG. 1.
  • the current conductors of the furnace coil is here denoted 21, while as previously the metal cover is denoted 17.
  • the furnace measurer is connected at E. Because of different flux directions the voltages induced by the flux during the operation of the furnace in the conductor 21 and the cover compensate each other, so that the discharge of the measuring device 19 will be zero during normal operation. It may be desirable on account of certain differences between the fluxes through the cover 17 and the conductor 21 to arrange a compensation coil (not shown) with corresponding flux, with a view to reducing the flux through the conductors in order to obtain full compensation.
  • FIG. 1 can also be complemented with a crucible supervisory connection according to US. Patent No. 3,185,894.
  • furnace coil is divided up into several part coils, the above can be applied on each individual part coil.
  • the invention can also be applied to heat induction furnaces with coils of water-cooled tubes.
  • Means for protection against faults in a coreless induction furnace comprising a crucible surrounded by coil turns covered by insulation, comprising, at least partly around said insulation, an uninterrupted metal cover conducting in the longitudinal direction of the current conductor, the conductor of the coil and the metal cover being coupled together at one coil end, said conductor and metal cover being coupled together at the other coil end across a voltage sensitive member, said member being affected upon short circuits or other insulation faults.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
  • General Induction Heating (AREA)
  • Furnace Details (AREA)
US510245A 1964-12-16 1965-11-29 Means for protection against and/or indication of faults in coreless induction furnaces, heating furnaces and the like Expired - Lifetime US3414660A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE15196/64A SE313129B (pt) 1964-12-16 1964-12-16

Publications (1)

Publication Number Publication Date
US3414660A true US3414660A (en) 1968-12-03

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Family Applications (1)

Application Number Title Priority Date Filing Date
US510245A Expired - Lifetime US3414660A (en) 1964-12-16 1965-11-29 Means for protection against and/or indication of faults in coreless induction furnaces, heating furnaces and the like

Country Status (5)

Country Link
US (1) US3414660A (pt)
DE (1) DE1565284B2 (pt)
FR (1) FR1469037A (pt)
GB (1) GB1123200A (pt)
SE (1) SE313129B (pt)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3780250A (en) * 1971-11-02 1973-12-18 Chisso Corp Apparatus for heating the surface of constructions
US3900695A (en) * 1973-05-18 1975-08-19 Asea Ab Electric induction furnace
US4486641A (en) * 1981-12-21 1984-12-04 Ruffini Robert S Inductor, coating and method
US5418811A (en) * 1992-04-08 1995-05-23 Fluxtrol Manufacturing, Inc. High performance induction melting coil

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1801791A (en) * 1930-03-05 1931-04-21 Westinghouse Electric & Mfg Co Induction-furnace protective circuits
US2614200A (en) * 1950-08-11 1952-10-14 Western Electric Co Leak detector for immersion heaters
US2990542A (en) * 1958-04-11 1961-06-27 Ajax Magnethermic Corp Protective device for induction furnaces
US3185894A (en) * 1960-08-17 1965-05-25 Asea Ab Means for indicating faults in the crucible of induction melting furnaces
US3214637A (en) * 1962-04-09 1965-10-26 Asea Ab Device for indicating the ceasing of super-conductivity

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1801791A (en) * 1930-03-05 1931-04-21 Westinghouse Electric & Mfg Co Induction-furnace protective circuits
US2614200A (en) * 1950-08-11 1952-10-14 Western Electric Co Leak detector for immersion heaters
US2990542A (en) * 1958-04-11 1961-06-27 Ajax Magnethermic Corp Protective device for induction furnaces
US3185894A (en) * 1960-08-17 1965-05-25 Asea Ab Means for indicating faults in the crucible of induction melting furnaces
US3214637A (en) * 1962-04-09 1965-10-26 Asea Ab Device for indicating the ceasing of super-conductivity

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3780250A (en) * 1971-11-02 1973-12-18 Chisso Corp Apparatus for heating the surface of constructions
US3900695A (en) * 1973-05-18 1975-08-19 Asea Ab Electric induction furnace
US4486641A (en) * 1981-12-21 1984-12-04 Ruffini Robert S Inductor, coating and method
US5418811A (en) * 1992-04-08 1995-05-23 Fluxtrol Manufacturing, Inc. High performance induction melting coil
US5588019A (en) * 1992-04-08 1996-12-24 Fluxtrol Manufacturing, Inc. High performance induction melting coil

Also Published As

Publication number Publication date
DE1565284A1 (de) 1970-01-15
FR1469037A (fr) 1967-02-10
GB1123200A (en) 1968-08-14
SE313129B (pt) 1969-08-04
DE1565284B2 (de) 1971-10-07

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