US3671655A - Electrical transfer type plasma arc melting furnace - Google Patents

Electrical transfer type plasma arc melting furnace Download PDF

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Publication number
US3671655A
US3671655A US100729A US3671655DA US3671655A US 3671655 A US3671655 A US 3671655A US 100729 A US100729 A US 100729A US 3671655D A US3671655D A US 3671655DA US 3671655 A US3671655 A US 3671655A
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US
United States
Prior art keywords
furnace
plasma arc
transfer type
arc melting
type plasma
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
US100729A
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English (en)
Inventor
Toshio Adachi
Masayoshi Onishi
Kiyohide Hayashi
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.)
Daido Steel Co Ltd
Original Assignee
Daido Steel Co Ltd
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 Daido Steel Co Ltd filed Critical Daido Steel Co Ltd
Application granted granted Critical
Publication of US3671655A publication Critical patent/US3671655A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • 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
    • H05B7/06—Electrodes

Definitions

  • the cathode In a conventional transfer type plasma arc furnace, the cathode is placed in the center of a plasma jet torch and molten metal functions as the anode.
  • the plasma arc current flows between the plasma jet torch and molten metal; therefore, the molten metal must be contacted to a bottom electrode connected with an electrical source.
  • the said bottom electrode (ordinally made of graphite) which is usually placed in the furnace hearth, is often broken by the erosion caused by chemical reaction between the electrode and molten metal, overheating of molten metal or electrical joule heat. As, the said damage often appears at the early stage just after the charge of scraps, a stable plasma are cannot be maintained and the plasma arc melting cannot be 2 actually continued.
  • rectifier 9 and a transformer 10, all of which are suitably arranged.
  • this furnace will not have such a direct contact between the molten metal and the carbon electrode as seen in any conventional transfer type plasma arc melting furnace. Therefore, no increase of carbon content in the molten metal results. Moreover, a relatively small power loss caused by possible electric resistance of the metal electrode is incurred.
  • plasma arc current can be stabilized and also plasma arc melting can be smoothly carried out.
  • Results shown in Table 1 indicate operational conditions between a furnace of the present invention and a conventional furnace.
  • the data in the table highlights the advantages of the present invention.
  • the metal electrode 3 keeps a solid form with its one part in contact to the kneaded refractory 8 and semi-molten fonn 'IABLE 1 Assured Carbon eon- Electrodc eon- Melting plasma are tent in the sumption time Typo ol' furnace used currents (A) molten metal (kg/charge) (lr./r.)
  • a metal electrode 3 is fixed in the cone shaped refractory 2 which, for example, is made of baked or unbaked magnesia, and contacts directly with scraps or molten metal 1.
  • Electrically conductive materials 8 comprising refractory and carbon powder properly kneaded together are inserted between the said metal electrode 3 and the graphite electrode 4.
  • the above described defects can be avoided and suitable electric conductivity can also be maintained by preparing the combined electrode composed of the metal electrode 3, compounded refractory 8 and the carbon electrode 4. This furnace, as shown in the drawing,
  • furnace body 5 has a furnace body 5, a furnace cover 6, a plasma jet torch 7, a
  • the metal electrode 3 which is in semi-molten form will be a little lost after tapping, quicker melting operation can be obtained by only exchanging the used metal electrode with a new one.
  • An electrical transfer type plasma arc melting furnace with an upper cathode and a lower anode characterized in that said anode is a combined electrode composed of a metallic portion which directly contacts the scrap or molten metal in said furnace, a carbon portion which is connected to the electric source and an intermediate portion which comprises a,

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Discharge Heating (AREA)
  • Furnace Details (AREA)
US100729A 1969-12-25 1970-12-22 Electrical transfer type plasma arc melting furnace Expired - Lifetime US3671655A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP44104607A JPS5031524B1 (fr) 1969-12-25 1969-12-25

Publications (1)

Publication Number Publication Date
US3671655A true US3671655A (en) 1972-06-20

Family

ID=14385091

Family Applications (1)

Application Number Title Priority Date Filing Date
US100729A Expired - Lifetime US3671655A (en) 1969-12-25 1970-12-22 Electrical transfer type plasma arc melting furnace

Country Status (6)

Country Link
US (1) US3671655A (fr)
JP (1) JPS5031524B1 (fr)
BE (1) BE760918A (fr)
CH (1) CH533688A (fr)
GB (1) GB1311320A (fr)
SE (1) SE390825C (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742132A (en) * 1970-05-23 1973-06-26 Nippon Electric Co Drum servo system of a video tape recorder for an electronic editing
US4217479A (en) * 1977-04-29 1980-08-12 Swiss Aluminium Ltd. High temperature reactor
US4317984A (en) * 1978-07-07 1982-03-02 Fridlyand Mikhail G Method of plasma treatment of materials
EP0056225A1 (fr) * 1981-01-08 1982-07-21 VOEST-ALPINE Aktiengesellschaft Four de fusion à plasma
EP0132711A2 (fr) * 1983-07-28 1985-02-13 BBC Aktiengesellschaft Brown, Boveri & Cie. Dimensionnement d'une électrode de fond pour un four à arc à courant continu afin de minimaliser les pertes
EP0133926A1 (fr) * 1983-07-28 1985-03-13 BBC Aktiengesellschaft Brown, Boveri & Cie. Electrode de fond pour four à arc à courant continu
US4540433A (en) * 1982-10-04 1985-09-10 Council For Mineral Technology Treatment of ferromanganese
WO1988009388A1 (fr) * 1987-05-26 1988-12-01 The University Of Toronto Innovations Foundation Procede de traitement de metaux liquides
US4940486A (en) * 1987-05-26 1990-07-10 The University Of Toronto Innovations Foundation Process for treating liquid metals
US4964973A (en) * 1988-10-14 1990-10-23 Brunswick Corporation Method and apparatus for producing titanium
US5283383A (en) * 1992-02-13 1994-02-01 The United States Of America As Represented By The Department Of Health And Human Services Antitumor compound, compositions and method of use

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE452690B (sv) * 1983-07-07 1987-12-07 Asea Ab Likstroms-ljusbagsugn

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3290542A (en) * 1963-07-26 1966-12-06 Gen Electric Triggered vacuum discharge device
US3524006A (en) * 1967-10-19 1970-08-11 Qualitats Und Edelstahl Kom Ve Method and apparatus for controlling arc discharge in plasma arc furnaces
US3547622A (en) * 1968-06-12 1970-12-15 Pennwalt Corp D.c. powered plasma arc method and apparatus for refining molten metal

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3290542A (en) * 1963-07-26 1966-12-06 Gen Electric Triggered vacuum discharge device
US3524006A (en) * 1967-10-19 1970-08-11 Qualitats Und Edelstahl Kom Ve Method and apparatus for controlling arc discharge in plasma arc furnaces
US3547622A (en) * 1968-06-12 1970-12-15 Pennwalt Corp D.c. powered plasma arc method and apparatus for refining molten metal

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742132A (en) * 1970-05-23 1973-06-26 Nippon Electric Co Drum servo system of a video tape recorder for an electronic editing
US4217479A (en) * 1977-04-29 1980-08-12 Swiss Aluminium Ltd. High temperature reactor
US4317984A (en) * 1978-07-07 1982-03-02 Fridlyand Mikhail G Method of plasma treatment of materials
EP0056225A1 (fr) * 1981-01-08 1982-07-21 VOEST-ALPINE Aktiengesellschaft Four de fusion à plasma
US4540433A (en) * 1982-10-04 1985-09-10 Council For Mineral Technology Treatment of ferromanganese
EP0132711A2 (fr) * 1983-07-28 1985-02-13 BBC Aktiengesellschaft Brown, Boveri & Cie. Dimensionnement d'une électrode de fond pour un four à arc à courant continu afin de minimaliser les pertes
EP0133926A1 (fr) * 1983-07-28 1985-03-13 BBC Aktiengesellschaft Brown, Boveri & Cie. Electrode de fond pour four à arc à courant continu
EP0132711A3 (fr) * 1983-07-28 1985-03-13 BBC Aktiengesellschaft Brown, Boveri & Cie. Dimensionnement d'une électrode de fond pour un four à arc à courant continu afin de minimaliser les pertes
WO1988009388A1 (fr) * 1987-05-26 1988-12-01 The University Of Toronto Innovations Foundation Procede de traitement de metaux liquides
US4940486A (en) * 1987-05-26 1990-07-10 The University Of Toronto Innovations Foundation Process for treating liquid metals
US4964973A (en) * 1988-10-14 1990-10-23 Brunswick Corporation Method and apparatus for producing titanium
US5283383A (en) * 1992-02-13 1994-02-01 The United States Of America As Represented By The Department Of Health And Human Services Antitumor compound, compositions and method of use

Also Published As

Publication number Publication date
BE760918A (fr) 1971-05-27
GB1311320A (en) 1973-03-28
JPS5031524B1 (fr) 1975-10-13
SE390825C (sv) 1981-09-28
CH533688A (fr) 1973-02-15
SE390825B (sv) 1977-01-24

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