GB1240056A - Control system for electric arc furnace - Google Patents

Control system for electric arc furnace

Info

Publication number
GB1240056A
GB1240056A GB8443/69A GB844369A GB1240056A GB 1240056 A GB1240056 A GB 1240056A GB 8443/69 A GB8443/69 A GB 8443/69A GB 844369 A GB844369 A GB 844369A GB 1240056 A GB1240056 A GB 1240056A
Authority
GB
United Kingdom
Prior art keywords
tap
contacts
electrode current
changer
current
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
Application number
GB8443/69A
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.)
CBS Corp
Original Assignee
Westinghouse Electric Corp
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 Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Publication of GB1240056A publication Critical patent/GB1240056A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00—Variable transformers or inductances not covered by group H01F21/00
    • H01F29/02—Variable transformers or inductances not covered by group H01F21/00 with tappings on coil or winding; with provision for rearrangement or interconnection of windings
    • H01F29/04—Variable transformers or inductances not covered by group H01F21/00 with tappings on coil or winding; with provision for rearrangement or interconnection of windings having provision for tap-changing without interrupting the load current
    • 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
    • H05B7/00—Heating by electric discharge
    • H05B7/02—Details
    • H05B7/144—Power supplies specially adapted for heating by electric discharge; Automatic control of power, e.g. by positioning of electrodes
    • H05B7/148—Automatic control of power
    • H05B7/152—Automatic control of power by electromechanical means for positioning of electrodes
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Furnace Details (AREA)
  • Discharge Heating (AREA)

Abstract

1,240,056. Automatic control of arc furnaces. WESTINGHOUSE ELECTRIC CORP. Feb. 17, 1969 [March 8, 1968]. No. 8443/69. Heading G3R. In an electric arc furnace, any deviation of the electrode current and voltage from a predetermined ratio causes a polarized error signal to be developed across resistor 132 which is connected to amplifier 136. The amplified signal is applied a motor 146 for shifting the electrode position until the ratio between electrode current and voltage returns to the pre-selected value. A supply transformer 20 has tap-changing apparatus 62, a signal for changing taps initiating a modification in the regulator circuit to reduce the electrode current, and to delay the actual tapchanging operation for a period to allow the electrode current to reach its lower operating value. This reduced current condition is maintained until the tap-change cycle has been completed, the regulator then returning to its original state. This current reduction is effected by simulating a reduction in the electrode-to-hearth voltage, a resistor 86 in the detector circuit being associated with contacts 98, 100. Contacts 98 are opened as soon as a tap-changing operation is started, while contacts 100 open after a short delay and remain open until the cycle is completed. A selector switch 178 may be set to operate the tap-changer from a switch 174 which is adapted to be adjusted to a "lower" position in which relays A1, TD, are energised. Contacts 98 are opened, and, after a period, relay L responds to start the tap-changing motor 164. Relay A11 is energized to open the contacts 100, a light 196 indicating that the switch 174 may now be released. When the tap-changer reaches its new operating position, contact TC1 opens to de-energize the relays L and A11, a brake relay B being kept energized for a short period so that both coils 186, 180, of the motor 164 are excited to stop the tap-changer in the selected position. Operation to adjust the tap-changer to a "higher" position is similar to that described. In another arrangement, the electrode current is reduced prior to and during a tap-change by connecting a resistor in the circuit which measures the current.
GB8443/69A 1968-03-08 1969-02-17 Control system for electric arc furnace Expired GB1240056A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US71162468A 1968-03-08 1968-03-08

Publications (1)

Publication Number Publication Date
GB1240056A true GB1240056A (en) 1971-07-21

Family

ID=24858845

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8443/69A Expired GB1240056A (en) 1968-03-08 1969-02-17 Control system for electric arc furnace

Country Status (4)

Country Link
US (1) US3493664A (en)
DE (1) DE1911026A1 (en)
FR (1) FR2003521A1 (en)
GB (1) GB1240056A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006050624A1 (en) * 2006-10-26 2008-04-30 Siemens Ag Reactance connecting device for transformer in electric arc furnace, has induction coil and standalone load switch for adjusting reactance of induction coil under load, where induction coil is provided with multiple tapping points

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3657455A (en) * 1970-04-30 1972-04-18 Continental Oil Co Temperature regulator
US4131754A (en) * 1977-05-02 1978-12-26 Consarc Corporation Automatic melt rate control system for consumable electrode remelting
DE2732873A1 (en) * 1977-07-21 1979-02-15 Leybold Heraeus Gmbh & Co Kg ARRANGEMENT FOR REGULATING THE DEPTH OF SUBMERGING OF MELTING ELECTRODES IN ELECTRO-SLASK MELTING FURNACES
US4677643A (en) * 1984-03-09 1987-06-30 Licentia Patent-Verwaltungs-Gmbh Device for feeding one or a plurality of electrodes in an electrothermal furnace
DE3512177C2 (en) * 1985-04-03 1997-01-16 Mannesmann Ag Method for symmetrizing electrical quantities in three-phase arc furnaces and device for carrying out the method
EP3591821B1 (en) * 2018-07-04 2023-06-07 Vestas Wind Systems A/S Controlled switching current of an on-load tap changer of a wind turbine

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3043894A (en) * 1958-05-16 1962-07-10 British Iron Steel Research Electric arc furnaces
US3204176A (en) * 1961-04-26 1965-08-31 Mc Graw Edison Co Tap changing furnace transformer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006050624A1 (en) * 2006-10-26 2008-04-30 Siemens Ag Reactance connecting device for transformer in electric arc furnace, has induction coil and standalone load switch for adjusting reactance of induction coil under load, where induction coil is provided with multiple tapping points
US8023550B2 (en) 2006-10-26 2011-09-20 Siemens Aktiengesellschaft Reactance ballast device

Also Published As

Publication number Publication date
FR2003521A1 (en) 1969-11-07
US3493664A (en) 1970-02-03
DE1911026A1 (en) 1970-02-26

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