US3461339A - Electric arc stabilization in electric arc melting using carbon electrodes - Google Patents

Electric arc stabilization in electric arc melting using carbon electrodes Download PDF

Info

Publication number
US3461339A
US3461339A US573867A US3461339DA US3461339A US 3461339 A US3461339 A US 3461339A US 573867 A US573867 A US 573867A US 3461339D A US3461339D A US 3461339DA US 3461339 A US3461339 A US 3461339A
Authority
US
United States
Prior art keywords
arc
substance
electric arc
electrode
metal
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
US573867A
Other languages
English (en)
Inventor
Alfred Gordon Evans Robiette
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.)
Foseco International Ltd
Original Assignee
Foseco International 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 Foseco International Ltd filed Critical Foseco International Ltd
Application granted granted Critical
Publication of US3461339A publication Critical patent/US3461339A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00Heating by electric discharge
    • H05B7/02Details
    • H05B7/06Electrodes
    • H05B7/08Electrodes non-consumable
    • H05B7/085Electrodes non-consumable mainly consisting of carbon
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00Heating by electric discharge
    • H05B7/02Details

Definitions

  • An arc melting method for use in the melting of metal and in the production of metal from metal-containing ore and a reducing agent, in an arc furnace.
  • the method stabilizes an are formed between the metal in the furnace and at least one carbon electrode by providing the electrode with a core including a substance which, under the action of the arc, ionises to increase the electrical conductivity of the arc.
  • the substance included in the core of the carbon electrode may be lithium, barium, calcium, magnesium, chromium, manganese, silicon, potassium, sodium, rubidium, or caesium or compounds such as oxides, carbonates, or silicates of such elements.
  • Such substance is added in particular form and bonded with a binder such as tar, pitch, or a paste or anthracite, tar and pitch.
  • This invention relates to the stabilisation of electric arcs and to the provision of electric arc apparatus, and more particularly electric arc furnace apparatus capable of conferring improved stability to the arc.
  • a method for the stabilisation of an electric which comprises introducing into the arc a substance which under the action of the arc generates, or is converted into, a vapour or median which increases the electrical conducitvity of the arc.
  • the introduction of the said substance may be eiiected by any of a number of different methods.
  • the substance may be included in or on one or more arc electrodes or the substance may be introduced into the are as gasborne particles, e.g. by spraying the substance into the arc, e.g. through a hollow electrode or introducing it via a lance, 'or the substance may be provided as a solid rod which is continuously fed into the arc at a rate balancing its rate of consumption in the arc.
  • a plurality of the foregoing methods may be used in combination in order to ensure a sufficient supply of the substance to create ionised particles thereof in the arc and thus to increase the conductivity in the path of the arc.
  • the invention further includes electric arc apparatus and more particularly electric arc furnace apparatus wherein at least one of the arc electrodes carries or embodies a substance as aforesaid and/ or wherein means are ice provided to introduce a said substance into the are from an external source.
  • the invention is of particular value where the arc electrode or electrodes are formed essentially of carbon (e.g. graphite).
  • the substance for inclusion in the electrode or electrodes should be had to the purpose to which the arc is being put, so that materials deleterious to that purpose are avoided. Specifically it is desirable to select a material of relatively low cost, which is readily worked (and, if a metal compound, is readily reduced) and which provides adequate vapour or other medium of suflicient conductivity. Where an electric arc furnace apparatus used for melting metal is concerned, the selected substance should be one which has no contaminant or other deleterious effect on the metal to be melted or on the furnace structure. Within these desiderata a wide range of substances is available for use. Generally it is convenient to use metals per se and these may be included from relatively low melting metals e.g. lithium, metals of medium melting point e.g. barium, calcium and magnesium, and metals of high melting point, e.g. chromium and manganese. Certain nonmetals, e.g. silicon, may also be employed.
  • relatively low melting metals e.g. lithium
  • a compound of the metal or for example of silicon, may be employed with reliance on other ingredients present in the electrode to cause reduction of the said compound.
  • metal oxides, carbonates and silicates are very useful.
  • the electrode or electrodes are formed essentially of carbon this may itself serve as the reducing agent.
  • other reducing agents may be employed, e.g. for the reduction of manganese dioxide, silicon or aluminium may be included.
  • the substance relied on for the provision of the conductive vapour may be included in the electrode or electrodes in any convenient way. Thus it may be included as an ingredient of the composition of which the electrode is made or it may be provided as a sleeve or core to the electrode. Generally it will be present in particulate form and bonded together with a binder which may be for example, tar or pitch, or a paste made from anthracite, tar and pitch.
  • a binder which may be for example, tar or pitch, or a paste made from anthracite, tar and pitch.
  • the substance of choice has been found to be a potassium salt, e.g. potassium carbonate alone or with other substances, in a carbon electrode.
  • the electrode control system need not be so sensitive or responsive and can, therefore, be of a more simple design.
  • Example I A test was carried out on a 150 kva. single phase indirect arc furnace, i.e. a furnace in which the arc is struck between two carbon electrodes.
  • the electrodes in this case were of graphite and were 4 inches in diameter.
  • the electrodes were bored with a concentric hole 1% inch diameter which was packed with a core consisting of 60% anthracite, 20% pitch with a melting point of 50 C., 16% powdered glass and 4% potassium carbonate. These materials were premixed and rammed into the hole in the electrode which had previously been scored to provide a mechanical key for the core and was heated to 40-50 C.
  • the maximum length of arc obtainable in the test furnace approximately 2" was immediately attained and held for 7 minutes, before switching the furnace off. Appreciable amounts of fumes were observed up to a period of approximately 5 minutes. Again considerable reduction in noise resulted and during the whole period the kva. reading remained steady at 25.
  • Electrodes containing composition (3) were then used. Again considerable improvement resulted, the kva meter being steady at 22 and a maximum arc length of 2 was obtained immediately. Copious white fumes were observed for a period of 7 minutes and the furnace left on for 15 minutes without any fluctuations occurring. After 15 minutes, the kva. reading had increased to 18.
  • a method for the stabilization of an electric arc comprising forming the are between said metal and at least one electrode which is a carbon electrode having a core including a proportion 'of a substance which, under the action of the arc, ionises to increase the electrical conductivity of the arc, the said substance being selected from the group consisting of lithium, barium, calcium, magnesium, chromium, manganese and silicon.
  • a method for the stabilization of an electric which comprises forming the are between said metal and at least one electrode which is a canbon electrode having a core including a proportion of a substance which, under the action of the arc, ionises to increase the electrical conductivity of the arc, the said substance being selected from the group consisting of oxides, carbonates and silicates of lithium, barium, calcium, magnesium, chromium, manganese and silicon.
  • a method for the stabilization of an electric arc which comprises forming the are between said metal and at least one electrode which is a carbon electrode having a core including a proportion of a substance which, under the action of the arc, ionises to increase the electrical conductivity of the arc, the said substance being selected from the group consisting of compounds of lithium, sodium, potassium, rubidium, and caesium.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Silicon Compounds (AREA)
  • Discharge Heating (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Furnace Details (AREA)
US573867A 1965-08-26 1966-08-22 Electric arc stabilization in electric arc melting using carbon electrodes Expired - Lifetime US3461339A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB36717/65A GB1160556A (en) 1965-08-26 1965-08-26 Electric Arc Stabilization

Publications (1)

Publication Number Publication Date
US3461339A true US3461339A (en) 1969-08-12

Family

ID=10390620

Family Applications (1)

Application Number Title Priority Date Filing Date
US573867A Expired - Lifetime US3461339A (en) 1965-08-26 1966-08-22 Electric arc stabilization in electric arc melting using carbon electrodes

Country Status (5)

Country Link
US (1) US3461339A (cs)
JP (1) JPS4910020B1 (cs)
DE (1) DE1565538A1 (cs)
GB (1) GB1160556A (cs)
SE (1) SE347102B (cs)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3787336A (en) * 1970-04-21 1974-01-22 Foseco Int Electrodes for arc furnaces
US4003615A (en) * 1975-02-03 1977-01-18 Shigeru Suga Coated carbon electrode having an inner coating of low resistance material
US4006379A (en) * 1975-12-19 1977-02-01 Shigeru Suga Carbon electrodes for an ultraviolet arc lamp for use in a light-fastness tester
US4924135A (en) * 1988-07-18 1990-05-08 Vapor Technologies Inc. Electrode for vapor deposition and vapor-deposition method using same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2442567A1 (fr) * 1978-11-22 1980-06-20 Siderurgie Fse Inst Rech Electrodes pour le chauffage et la fusion des metaux

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1189265A (en) * 1913-07-19 1916-07-04 Westinghouse Electric & Mfg Co Electrode.
US1428510A (en) * 1920-06-26 1922-09-05 Sperry Gyroscope Co Ltd Concentrated flaming arc lamp for projectors
US1439016A (en) * 1919-07-28 1922-12-19 Nat Carbon Co Inc Projector electrode
US1920921A (en) * 1928-01-27 1933-08-01 Nat Carbon Co Inc Arc carbon
US2140881A (en) * 1935-01-25 1938-12-20 Cie Lorraine De Charbons Pour Intensive electric arc carbon
US2185679A (en) * 1937-12-22 1940-01-02 Lorraine Carbone Arc lamp cathodes
US2229227A (en) * 1939-01-25 1941-01-21 Nat Carbon Co Inc Direct current carbon arc system
US2422038A (en) * 1942-01-17 1947-06-10 Lorraine Carbone Anodes for intensive arcs
US3272963A (en) * 1962-03-21 1966-09-13 Eutectic Welding Alloys Flux-coated carbide welding rod
US3313976A (en) * 1963-10-18 1967-04-11 Union Carbide Corp Joined arc carbons

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1189265A (en) * 1913-07-19 1916-07-04 Westinghouse Electric & Mfg Co Electrode.
US1439016A (en) * 1919-07-28 1922-12-19 Nat Carbon Co Inc Projector electrode
US1428510A (en) * 1920-06-26 1922-09-05 Sperry Gyroscope Co Ltd Concentrated flaming arc lamp for projectors
US1920921A (en) * 1928-01-27 1933-08-01 Nat Carbon Co Inc Arc carbon
US2140881A (en) * 1935-01-25 1938-12-20 Cie Lorraine De Charbons Pour Intensive electric arc carbon
US2185679A (en) * 1937-12-22 1940-01-02 Lorraine Carbone Arc lamp cathodes
US2229227A (en) * 1939-01-25 1941-01-21 Nat Carbon Co Inc Direct current carbon arc system
US2422038A (en) * 1942-01-17 1947-06-10 Lorraine Carbone Anodes for intensive arcs
US3272963A (en) * 1962-03-21 1966-09-13 Eutectic Welding Alloys Flux-coated carbide welding rod
US3313976A (en) * 1963-10-18 1967-04-11 Union Carbide Corp Joined arc carbons

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3787336A (en) * 1970-04-21 1974-01-22 Foseco Int Electrodes for arc furnaces
US4003615A (en) * 1975-02-03 1977-01-18 Shigeru Suga Coated carbon electrode having an inner coating of low resistance material
US4006379A (en) * 1975-12-19 1977-02-01 Shigeru Suga Carbon electrodes for an ultraviolet arc lamp for use in a light-fastness tester
US4924135A (en) * 1988-07-18 1990-05-08 Vapor Technologies Inc. Electrode for vapor deposition and vapor-deposition method using same

Also Published As

Publication number Publication date
SE347102B (cs) 1972-07-24
GB1160556A (en) 1969-08-06
JPS4910020B1 (cs) 1974-03-07
DE1565538A1 (de) 1970-07-09

Similar Documents

Publication Publication Date Title
US3461339A (en) Electric arc stabilization in electric arc melting using carbon electrodes
US2515559A (en) Arc welding in inert atmospheres
US4360757A (en) Electrode activating compound for gas discharge tube
US4079185A (en) Method and apparatus for the melt reduction of iron oxides
US2640135A (en) Electrode
GB1446507A (en) Electrode for plasma arc working of conductive materials
US2744183A (en) Inert gas-shielded arc welding
US3024102A (en) High-vacuum titanium a. c. arc melting
JPS6035419B2 (ja) 電気接点材料およびその製造方法
US3730961A (en) Arc ignition by seeded gas
GB1499748A (en) Electrode for arc welding
US1127578A (en) Arc-lamp electrode.
US3262005A (en) High intensity carbon electrode
US3313976A (en) Joined arc carbons
US2229227A (en) Direct current carbon arc system
US2422038A (en) Anodes for intensive arcs
US2282533A (en) Direct current negative carbon
US1189265A (en) Electrode.
US2747128A (en) Direct current negative carbon electrode
US3391238A (en) Preparation for smelting of metals and compounds with high melting points
US1754116A (en) Electrode suitable for arc welding
RU2087982C1 (ru) Материал для катода сильноточных электронных приборов
SU1379317A1 (ru) Состав дл вспенивани шлака в дуговой печи
US2514386A (en) Electrode coating composition
JPS5589414A (en) Refining method of molten steel