EP0106767A1 - Vorrichtung zur Messung der Lichtbogenspannung in einem elektrischen Ofen - Google Patents

Vorrichtung zur Messung der Lichtbogenspannung in einem elektrischen Ofen Download PDF

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Publication number
EP0106767A1
EP0106767A1 EP83402004A EP83402004A EP0106767A1 EP 0106767 A1 EP0106767 A1 EP 0106767A1 EP 83402004 A EP83402004 A EP 83402004A EP 83402004 A EP83402004 A EP 83402004A EP 0106767 A1 EP0106767 A1 EP 0106767A1
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EP
European Patent Office
Prior art keywords
measuring
measuring device
electrode
voltage
wire
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.)
Granted
Application number
EP83402004A
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English (en)
French (fr)
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EP0106767B1 (de
Inventor
Pascal Maes
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.)
Clecim SAS
Original Assignee
Clecim SAS
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 Clecim SAS filed Critical Clecim SAS
Priority to AT83402004T priority Critical patent/ATE20800T1/de
Publication of EP0106767A1 publication Critical patent/EP0106767A1/de
Application granted granted Critical
Publication of EP0106767B1 publication Critical patent/EP0106767B1/de
Expired legal-status Critical Current

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    • 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
    • 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
    • H05B7/10—Mountings, supports, terminals or arrangements for feeding or guiding electrodes
    • H05B7/101—Mountings, supports or terminals at head of electrode, i.e. at the end remote from the arc

Definitions

  • the present invention relates to a device for measuring, on each of the electrodes. the arc voltage during operation of an electric furnace intended for the melting or transformation of scrap.
  • the electric arc furnace is a device which aims to melt a metallic charge, put in the form of loose scrap, to obtain a molten steel bath.
  • This liquid metal may or may not be refined in the arc furnace itself to make it a steel of given characteristics. Above all, and this trend is becoming more and more marked in modern steelworks, the electric arc furnace is a tool for melting scrap.
  • An arc furnace is equipped with three vertical graphite electrodes.
  • the electrodes are each equipped with an individual raising and lowering means which allows, during the melting of a scrap charge, to be at all times at the right distance from the scrap.
  • the arcs are established between each of the electrodes and the charge to be melted.
  • the current which circulates in the electrodes is a three-phase alternating current, normally balanced, or almost, whose value is calculated in tens of thousands of amperes.
  • the current supply circuit has a non-negligible impedance in front of the arc impedance, which means that the arc voltage represents only about 70 to 90% of the voltage across the transformer.
  • the impedance of the current supply circuit is above all reactive, and its value is not constant because it depends on the geometry of the circuit, essentially deformable by the fact that the electrodes oat ⁇ possibilities of vertical translation of several meters during by the time the arcs are established.
  • the measurement of the arc voltage comes from a calculation starting from a measured voltage value, either at the terminals of the supply transformer, or at the downstream ends of the cables for bringing the current leaving from these terminals.
  • the result of this measurement is very imprecise because the impedance of the circuit is variable and its value cannot be determined when calculating the arc voltage; for this calculation, it is assumed to have a constant mean value, which is necessarily inaccurate.
  • the results are not better, because then the measured voltage is false, due to the strong influence of the power currents which induce voltages error in the measurement circuit.
  • the measuring device of the invention allows a more precise arc voltage measurement than those carried out until now. It is applicable to electric ovens provided with electrodes the upper part of which is metallic and cooled by circulation of water, as described for example in US patent 4,121,042, and it is characterized in that it comprises a wire measurement starting from the fixing part of the graphite part of the electrode, passing in the longitudinal axis of the cooled metal part of said electrode, then passing inside one of the supply or return pipes of cooling water, then leading to an electronic assembly for transforming the received signal into light, or another electromagnetic wave, the thus transformed signal then being routed, for example by optical fiber, to the control room.
  • the electrode 1 is held by a clamp 6 placed at the end of a support arm 7.
  • the arm 7 is itself carried by a mast 8 adjustable in height by a conventional device not shown.
  • the electrical voltage from one of the three terminals of the secondary of the three-phase supply transformer is applied to the metal clamp 6 using power cables 9 and 10.
  • the metal part 4 of the electrode 1 is cooled by a cir cooked water circulation comprising a flexible water supply tube 11 terminating in the axis of the electrode, and a flexible water return tube 12 starting from the upper side.
  • an electrical measuring wire 16 starts from the connecting piece 5, or "Nipple”, circulates along the axis of the cooled metal part 4, then passes inside the supply pipe of water 11, to lead to an electronic box 14 placed at the upstream end of the support arm 7.
  • the electronic box 14 includes a device measuring the instantaneous voltage at point 5, that is to say at the downstream end of the cooled metal part 4, transforming this measured voltage value into an effective voltage value, then converting this measurement into a optical signal which is then transmitted using an optical fiber 15 to the control room. The received signal is then used to regulate the vertical position of the mast 8, that is to say ultimately the arc power.
  • the invention allows a greatly improved measurement of the arc voltage.
  • the voltage is in fact measured on the connection piece 5, that is to say very close to the end of the electrode 1; the measuring wire 16 passes through the center of the metal part 4 and the induction is zero there because the electromagnetic field is zero at the center of a conductor.
  • the wire 16 then continues on its way inside the conduits 11 for supplying cooling water to the electrode. On this portion of the path, parasitic induction exists but is attenuated by the fact that the measurement cable 16 is carefully shielded by the material of the pipes. The measured voltage is converted into light in the box 14 then, transmitted by optical fiber 15, is no longer disturbed.
  • FIG. 2 shows the detail of the connections of the downstream part of the measurement cable 16 and of the water supply hose 11 with the cooled metal part 4.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
  • Discharge Heating (AREA)
  • Furnace Details (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)
  • Radiation Pyrometers (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)
EP83402004A 1982-10-15 1983-10-14 Vorrichtung zur Messung der Lichtbogenspannung in einem elektrischen Ofen Expired EP0106767B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT83402004T ATE20800T1 (de) 1982-10-15 1983-10-14 Vorrichtung zur messung der lichtbogenspannung in einem elektrischen ofen.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8217253 1982-10-15
FR8217253A FR2534691A1 (fr) 1982-10-15 1982-10-15 Dispositif de mesure de tension d'arc sur un four electrique

Publications (2)

Publication Number Publication Date
EP0106767A1 true EP0106767A1 (de) 1984-04-25
EP0106767B1 EP0106767B1 (de) 1986-07-16

Family

ID=9278288

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83402004A Expired EP0106767B1 (de) 1982-10-15 1983-10-14 Vorrichtung zur Messung der Lichtbogenspannung in einem elektrischen Ofen

Country Status (7)

Country Link
US (1) US4559630A (de)
EP (1) EP0106767B1 (de)
JP (1) JPS5991696A (de)
AT (1) ATE20800T1 (de)
DE (1) DE3364532D1 (de)
ES (1) ES8405957A1 (de)
FR (1) FR2534691A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0127568B1 (de) * 1983-05-26 1989-03-15 MANNESMANN Aktiengesellschaft Kühlungsvorrichtung für Elektrodennippelverbindung an Lichtbogenöfen

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4977576A (en) * 1988-09-22 1990-12-11 Great Lakes Carbon Corporation Safety flow stopper for water-cooled electrode
EP0537669A1 (de) * 1991-10-14 1993-04-21 Nof Corporation Fluoroalkyl-enthaltendes Polymer, Verfahren zu seiner Herstellung, Oberflächenaktivmittel, Mittel zur Behandlung einer Oberfläche und Überzugszusammensetzung
IT1288858B1 (it) * 1996-02-29 1998-09-25 Danieli Off Mecc Dispositivo adattatore per elettrodi, con funzione di reattanza ausiliaria, in un forno elettrico ad arco.
IT1288992B1 (it) * 1996-09-27 1998-09-25 Danieli Off Mecc Sistema di raffreddamento per catodi per forni elettrici ad arco in corrente continua
KR20080022585A (ko) * 2005-07-22 2008-03-11 지멘스 악티엔게젤샤프트 전기 아크로의 하나 이상의 상태 변수의 결정 방법
IT1396173B1 (it) * 2009-03-25 2012-11-16 Tenova Spa Apparecchiatura di misura della posizione degli elettrodi in un forno elettrico
DE102010025236A1 (de) * 2010-02-18 2011-08-18 SMS Siemag AG, 40237 Elektrodentragarm eines schmelzmetallurgischen Ofens

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1048649B (de) * 1957-08-24 1959-01-15 W C Heraeus Einrichtung zur Messung der Bogenlaenge in Lichtbogenschmelzanlagen
DE2511929A1 (de) * 1974-03-26 1975-10-02 Union Carbide Corp Spannungsmesschaltung fuer eine lichtbogen-schweissdraht-zufuehrregelung
US4168392A (en) * 1976-09-01 1979-09-18 The Steel Company Of Canada, Limited Composite electrode with non-consumable upper section

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3610601A (en) * 1969-10-01 1971-10-05 Allegheny Ludlum Steel Apparatus for positioning a consumable lance
US4121042A (en) * 1976-09-01 1978-10-17 The Steel Company Of Canada Limited Composite electrode with non-consumable upper section
DE2725537A1 (de) * 1977-06-06 1978-12-14 Korf Stahl Elektrode fuer lichtbogenoefen

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1048649B (de) * 1957-08-24 1959-01-15 W C Heraeus Einrichtung zur Messung der Bogenlaenge in Lichtbogenschmelzanlagen
DE2511929A1 (de) * 1974-03-26 1975-10-02 Union Carbide Corp Spannungsmesschaltung fuer eine lichtbogen-schweissdraht-zufuehrregelung
US4168392A (en) * 1976-09-01 1979-09-18 The Steel Company Of Canada, Limited Composite electrode with non-consumable upper section

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0127568B1 (de) * 1983-05-26 1989-03-15 MANNESMANN Aktiengesellschaft Kühlungsvorrichtung für Elektrodennippelverbindung an Lichtbogenöfen

Also Published As

Publication number Publication date
FR2534691B1 (de) 1984-12-28
US4559630A (en) 1985-12-17
ES526467A0 (es) 1984-06-16
ES8405957A1 (es) 1984-06-16
ATE20800T1 (de) 1986-08-15
EP0106767B1 (de) 1986-07-16
JPS5991696A (ja) 1984-05-26
DE3364532D1 (en) 1986-08-21
FR2534691A1 (fr) 1984-04-20

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