WO1998043030A1 - Dispositif de protection d'electrodes de graphite dans un four electrique a arc - Google Patents

Dispositif de protection d'electrodes de graphite dans un four electrique a arc Download PDF

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Publication number
WO1998043030A1
WO1998043030A1 PCT/EP1998/001582 EP9801582W WO9843030A1 WO 1998043030 A1 WO1998043030 A1 WO 1998043030A1 EP 9801582 W EP9801582 W EP 9801582W WO 9843030 A1 WO9843030 A1 WO 9843030A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrode
furnace
electric arc
respect
metal charge
Prior art date
Application number
PCT/EP1998/001582
Other languages
English (en)
Inventor
Carlo Vecchiato
Original Assignee
Acciai Speciali Terni S.P.A.
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 Acciai Speciali Terni S.P.A. filed Critical Acciai Speciali Terni S.P.A.
Priority to AU67304/98A priority Critical patent/AU6730498A/en
Publication of WO1998043030A1 publication Critical patent/WO1998043030A1/fr

Links

Classifications

    • 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
    • F27D1/00—Casings; Linings; Walls; Roofs
    • F27D1/18—Door frames; Doors, lids, removable covers
    • F27D1/1808—Removable covers
    • F27D1/1816—Removable covers specially adapted for arc furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/52—Manufacture of steel in electric furnaces
    • 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
    • H05B7/12—Arrangements for cooling, sealing or protecting electrodes
    • 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
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
    • F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
    • F27B3/24—Cooling arrangements
    • 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
    • F27D9/00—Cooling of furnaces or of charges therein
    • F27D2009/0002—Cooling of furnaces
    • F27D2009/001—Cooling of furnaces the cooling medium being a fluid other than a gas
    • F27D2009/0013—Cooling of furnaces the cooling medium being a fluid other than a gas the fluid being water
    • F27D2009/0016—Water-spray
    • 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
    • Y02P10/20—Recycling

Definitions

  • the present invention refers to a device to protect graphite electrodes in metallurgic electric furnaces and, more particularly, refers to a procedure to decrease the consumption of electrode lateral face when operating the furnace.
  • the furnace is loaded with solid metal scraps, with a liquid alloy bed and with other materials like slags, additional alloys (to obtain the desired final composition), etc.: at that time, through suitable holes on the furnace roof, one or more electrodes, generally made of graphite, are lowered till they contact the charged metal material, and finally current is allowed to flow in order to generate an electric arc between electrodes and charge, thus melting the latter.
  • the electric arc generates a pseudo-plasma, so that nearby temperatures are extremely high, up to 3000-3500 °C.
  • the atmosphere inside the furnace is oxidizing.
  • the number of electrodes essentially depends on the current being used; usually, a three-phase alternate current is preferred, so that there will be three electrodes, but it is also possible to use direct current furnaces, which require only one electrode. In the present description, anyway, for ease of understanding, only one electrode will be referred to, being understood that what is referred thereto is valid for each one of the electrodes being used.
  • the above-mentioned operating conditions cause the electrode to be subjected to a consumption due, as regards its later face , essentially to oxidation.
  • the electrode consumption is quite important, because it can sum up to a few percentage points over the total process cost.
  • a device for protecting said at least one electrode from oxidation consumption, characterized in that it is composed of a ring-shaped water delivering device, placed next to the furnace roof, external thereto and around the opening housing each electrode, and equipped with a plurality of spraying nozzles, oriented towards the side electrode surface to deliver pressurized water against said surface.
  • said delivering device is composed of a pipe, bent in a semicircle, and at least part of the spraying holes is upwardly oriented, with an angle of about 45° with respect to the electrode surface.
  • the nozzles are such as to deliver semi-nebulized water jets with spraying angle comprised between 0 and 30 degrees.
  • ⁇ Fig. 1 shows a schematic sectional view of part of a furnace roof, including an electrode
  • ⁇ Fig. 2 shows a schematic plan view of the central part, called arch, of the arc electric furnace roof, with the three electrodes.
  • roof 1 of the furnace includes a central part 2, called arch, in which bodies 3, generally frustoconically shaped, are housed, these bodies being arranged with their own vertical axis passing through the arch and having an axial hole to allow the passage of electrodes 4; the axial hole of the body 3 has a diameter that is slightly greater than the electrode one, in order to allow the electrode itself to be placed into the hole and to slide therein without problems, but at the same time to prevent an excessive exchange of atmosphere with the outside environment.
  • a tubular member 5 is located, closed as a semicircle and connected to a water-feeding duct 6; each duct 6 is in turn connected to a manifold 7, supplied by a single tubing 8.
  • Tubular members 5 are not closed as a ring, but have two opposed ends, separated by a gap 9, to prevent them from acting as spires and emanating electric fields generated by the strong electromagnetic field existing around the electrodes.
  • tubular members 5 are equipped with a plurality of holes, oriented towards the electrodes, at least part of them being oriented upwardly with an angle of about 45 degrees, with respect to the electrode surfaces.
  • a layer of cooling water is created that flows downwards on the electrode surface and penetrates inside the furnace through the gap existing between the electrode and the frustoconical body 5, thereby cooling the electrode for a length, inside the furnace, of about two meters.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Resistance Heating (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)

Abstract

Dans un four électrique, chaque électrode est entourée d'un conduit en anneau ouvert, qui est fixé sur le toit du four, à partir duquel de l'eau sous pression est distribuée selon différents angles par rapport à la surface de l'électrode. Ainsi, on obtient un effet refroidissant qui s'ajoute à l'effet connu, depuis l'eau distribuée immédiatement sous le dispositif de serrage. En conséquence, l'oxydation des électrodes est encore plus réduite.
PCT/EP1998/001582 1997-03-25 1998-03-16 Dispositif de protection d'electrodes de graphite dans un four electrique a arc WO1998043030A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU67304/98A AU6730498A (en) 1997-03-25 1998-03-16 Device to protect graphite electrodes in an electric arc furnace

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITRM97A000164 1997-03-25
IT97RM000164A IT1291117B1 (it) 1997-03-25 1997-03-25 Dispositivo per la protezione degli elettrodi di grafite nei forni elettrici metallurgici

Publications (1)

Publication Number Publication Date
WO1998043030A1 true WO1998043030A1 (fr) 1998-10-01

Family

ID=11404894

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1998/001582 WO1998043030A1 (fr) 1997-03-25 1998-03-16 Dispositif de protection d'electrodes de graphite dans un four electrique a arc

Country Status (3)

Country Link
AU (1) AU6730498A (fr)
IT (1) IT1291117B1 (fr)
WO (1) WO1998043030A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6741826B2 (en) 2002-06-26 2004-05-25 Xerox Corporation Cam motion design without drivetrain backlash reversal
EP1817435A2 (fr) * 2004-10-29 2007-08-15 Systems Spray-Cooled, Inc. Systeme et procede de refroidissement de four metallurgique ameliores
CN101839628A (zh) * 2010-05-31 2010-09-22 莱芜钢铁集团有限公司 电弧炉中心小炉盖的冷却装置
WO2012134036A1 (fr) * 2011-03-30 2012-10-04 현대제철 주식회사 Voûte pour four électrique
US10694592B1 (en) 2018-10-15 2020-06-23 Chemtreat, Inc. Methods of protecting furnace electrodes with cooling liquid that contains an additive
US11979968B2 (en) 2018-10-15 2024-05-07 Chemtreat, Inc. Spray cooling furnace electrodes with a cooling liquid that contains surfactants

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4852120A (en) * 1988-11-08 1989-07-25 Nikko Industry Co., Ltd. Cooling apparatus for electric arc furnace electrodes
US4941149A (en) * 1987-03-17 1990-07-10 Nippon Carbon Co., Ltd. Method of melting and/or refining metals and cooling device for the graphite electrode used for the same
DE3940848A1 (de) * 1989-12-11 1991-06-13 Foseco Int Verfahren und vorrichtung zum verschliessen des spaltes zwischen elektrode und ofendeckel eines elektro-schmelzofens
JPH05114479A (ja) * 1991-10-23 1993-05-07 Aichi Steel Works Ltd 製鋼用電気炉の電極冷却水噴出用リング
DE19608532A1 (de) * 1996-02-09 1997-08-14 Eisenbau Essen Gmbh Verfahren zum Kühlen einer oder mehrerer Elektroden in einem Lichtbogenofen

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4941149A (en) * 1987-03-17 1990-07-10 Nippon Carbon Co., Ltd. Method of melting and/or refining metals and cooling device for the graphite electrode used for the same
US4852120A (en) * 1988-11-08 1989-07-25 Nikko Industry Co., Ltd. Cooling apparatus for electric arc furnace electrodes
DE3940848A1 (de) * 1989-12-11 1991-06-13 Foseco Int Verfahren und vorrichtung zum verschliessen des spaltes zwischen elektrode und ofendeckel eines elektro-schmelzofens
JPH05114479A (ja) * 1991-10-23 1993-05-07 Aichi Steel Works Ltd 製鋼用電気炉の電極冷却水噴出用リング
DE19608532A1 (de) * 1996-02-09 1997-08-14 Eisenbau Essen Gmbh Verfahren zum Kühlen einer oder mehrerer Elektroden in einem Lichtbogenofen

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
HEINEN K.H.: "Elektrostahlerzeugung, 4th edition", 1997, VEREIN DEUTSCHER EISENHÜTTENLEUTE, VDEH, DÜSSELDORF, DE, XP002071672 *
PATENT ABSTRACTS OF JAPAN vol. 017, no. 473 (E - 1423) 27 August 1993 (1993-08-27) *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6741826B2 (en) 2002-06-26 2004-05-25 Xerox Corporation Cam motion design without drivetrain backlash reversal
EP1817435A2 (fr) * 2004-10-29 2007-08-15 Systems Spray-Cooled, Inc. Systeme et procede de refroidissement de four metallurgique ameliores
EP1817435A4 (fr) * 2004-10-29 2008-09-10 Systems Spray Cooled Inc Systeme et procede de refroidissement de four metallurgique ameliores
CN101839628A (zh) * 2010-05-31 2010-09-22 莱芜钢铁集团有限公司 电弧炉中心小炉盖的冷却装置
WO2012134036A1 (fr) * 2011-03-30 2012-10-04 현대제철 주식회사 Voûte pour four électrique
US10132566B2 (en) 2011-03-30 2018-11-20 Hyundai Steel Company Roof for electric furnace
US10694592B1 (en) 2018-10-15 2020-06-23 Chemtreat, Inc. Methods of protecting furnace electrodes with cooling liquid that contains an additive
US11140755B2 (en) 2018-10-15 2021-10-05 Chemtreat, Inc. Methods of protecting furnace electrodes with cooling liquid that contains an additive
US11653426B2 (en) 2018-10-15 2023-05-16 Chemtreat, Inc. Methods of protecting furnace electrodes with cooling liquid that contains an additive
US11979968B2 (en) 2018-10-15 2024-05-07 Chemtreat, Inc. Spray cooling furnace electrodes with a cooling liquid that contains surfactants

Also Published As

Publication number Publication date
ITRM970164A1 (it) 1998-09-25
AU6730498A (en) 1998-10-20
IT1291117B1 (it) 1998-12-29

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