US3597519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic-field rotating-electrode electric arc furnace apparatus and methods
Assignee: Westinghouse Electric Corp
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Filing: 1970-02-05
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Granted: 1971-08-03
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Expires: 1990-02-05
Abstract
Abstract Magnetic field generating means sets up a field within a mold having at least partially electrically conductive material therein to form a melt, the field lines extending through at least a portion of the mold. A rotating electrode has at least the portion thereof which forms the arcing surface rotating in a predetermined plane with respect to the surface of the melt, and an arc takes place between electrode and melt. Where the mold is composed of electrically conductive material, the magnetic field stirs the melt by interaction with current filaments extending from the instant point of arc attachment on the melt to the wall of the mold. The magnetic field focuses the arc between electrode and melt, renders the arc uninfluenced by stray magnetic fields and spurious discharges, assists in preventing glow discharges at reduced pressures, and by creating a magnetic field barrier between the arcing surface of the electrode and the wall of the mold inhibits the arc from striking to the mold. Embodiments include magnetic field generating means mounted adjacent the wall of the mold, or adjacent the wall of a larger furnace enclosure, or on the electrode. A still further embodiment employs a rotating electrode with magnetic field generating means within the electrode.
Inventors
- 👤 George A Kemeny
- 👤 Ronald R Akers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:09
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/34; F; F27; F27D; F27D11/00; F27D11/08; H05B2213/00; H05B2213/02
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
123 words
In electric arc furnace apparatus in combination, a mold adapted to have at least partially electrically conductive material fed thereto, a rotatable electrode having a supporting column mounted in predetermined position with respect to the mold, the electrode having a generally disc-shaped tip forming an arcing surface, the tip lying in a predetermined plane with respect to the surface of a melt in the mold, the material and the electrode being adapted to be connected to terminals of opposite polarity of a source of potential to produce and sustain an arc between the electrode and the material to be melted, and means mounted adjacent the wall of the mold for generating a magnetic field with field lines extending generally axially through the mold.
Claim 2
Dependent Claim
123 words
In electric arc furnace apparatus in combination, a mold adapted to have at least partially electrically conductive material fed thereto, a rotatable electrode having a supporting column mounted in predetermined position with respect to the mold, the electrode having a generally disc-shaped tip forming an arcing surface, the tip lying in a predetermined plane with respect to the surface of a melt in the mold, the material and the electrode being adapted to be connected to terminals of opposite polarity of a source of potential to produce and sustain an arc between the electrode and the material to be melted, and means mounted adjacent the wall of the mold for generating a magnetic field with field lines extending generally axially through the mold.
Claim 3
Dependent Claim
94 words
Apparatus according to claim 1 in which the mold is composed of electrically conductive material and in which the magnetic field generating means is so positioned axially of the mold that a strong magnetic field exists in the space between the disc-shaped arcing surface and the surface of the melt, and throughout the space existing radially between the periphery of the tip and the inside wall of the mold, said magnetic field focusing the arc between tip and melt and inhibiting the arc from striking from the tip to the wall of the mold.
Claim 4
Dependent Claim
92 words
Apparatus according to claim 1 in which the mold is composed of electrically conductive material and forms a part of the arc current path, and in which the means for generating the magnetic field is so positioned along the axis of the mold that the magnetic field produced thereby exerts a force on current filaments in the melt having components extending from the site of the arc spot on the melt to the wall of the mold and produces a swirling and vortex motion in at least a portion of the melt.
Claim 5
Dependent Claim
39 words
AppAratus according to claim 1 in which the magnetic field generating means is so positioned axially along the mold that field lines extend from the surface of the melt to the electrode, focusing the arc between electrode and melt.
Claim 6
Dependent Claim
112 words
Apparatus according to claim 1 in which the disc-shaped tip lies in a plane substantially parallel to the surface of the melt and the tip is spaced from the melt, in which the mold is composed of conductive material, and in which the magnetic field generating means is so positioned axially along the mold that field lines extend substantially parallel to the axis of the mold through the annular space between the outer periphery of the electrode tip and the inside wall of the mold, field lines in this space tending to prevent the arc from striking across the field lines and forming an arc path between the electrode and the mold.
Claim 7
Dependent Claim
75 words
Apparatus according to claim 4 in which the atmosphere in the furnace apparatus is adapted to be controlled including a reduced pressure therein, the furnace apparatus including vacuum pump means for producing and maintaining said reduced pressure, field lines extending between electrode and melt focusing the arc, assisting in preventing the arc from going into glow, and tending to cause the arc between electrode and melt to go into a more diffused mode of operation.
Claim 8
Dependent Claim
51 words
Apparatus according to claim 1 additionally characterized as having means for feeding material continually or intermittently to the melt, and the magnetic field generated by the field generating means is so positioned and so shaped that it assists in stirring the melt and speeds consumption and dispersal of the fed material.
Claim 9
Dependent Claim
75 words
Apparatus according to claim 1 in which the mold is composed of electrically conductive material and forms a part of the current path, and in which the magnetic field generating means has an axially adjustable position along the mold, and the position thereof is selected to perform at least one of the functions of stirring the melt, focusing the arc between arcing surface and melt, and inhibiting arc flare to the wall of the mold.
Claim 10
Dependent Claim
176 words
Furnace apparatus comprising in combination, a furnace enclosure including a mold composed of conductive material and adapted to have at least partially electrically conductive material deposited therein to be melted, an electrode mounted in the furnace enclosure over the melt in the mold, the electrode including a rotating wheel forming an arcing surface positioned horizontally over the melt so that the periphery of the wheel is substantially equally spaced at a predetermined distance from the melt around the circumference of the wheel, the electrode and the mold being adapted to be connected to terminals of opposite polarity of a source of potential to produce and sustain an arc between the electrode wheel and the melt, and means mounted adjacent one of the walls of the mold and furnace enclosure for generating a magnetic field with field lines extending generally axially for at least a portion of the distance through the mold, the magnetic field giving improved furnace performance by performing at least one of the functions of controlling the arc and providing stirring of the melt.
Claim 11
Dependent Claim
176 words
Furnace apparatus comprising in combination, a furnace enclosure including a mold composed of conductive material and adapted to have at least partially electrically conductive material deposited therein to be melted, an electrode mounted in the furnace enclosure over the melt in the mold, the electrode including a rotating wheel forming an arcing surface positioned horizontally over the melt so that the periphery of the wheel is substantially equally spaced at a predetermined distance from the melt around the circumference of the wheel, the electrode and the mold being adapted to be connected to terminals of opposite polarity of a source of potential to produce and sustain an arc between the electrode wheel and the melt, and means mounted adjacent one of the walls of the mold and furnace enclosure for generating a magnetic field with field lines extending generally axially for at least a portion of the distance through the mold, the magnetic field giving improved furnace performance by performing at least one of the functions of controlling the arc and providing stirring of the melt.
Claim 12
Dependent Claim
29 words
Apparatus according to claim 9 additionally characterized as being adapted to maintain a controlled atmosphere in the furnace enclosure, and vacuum pump apparatus operatively connected to the furnace enclosure.
Claim 13
Dependent Claim
61 words
Apparatus according to claim 9 in which the magnetic field generating means is so positioned axially along a wall in accordance with the level of the melt in the mold that the field lines extending transverse to current filament components in the melt exert a stirring force on the molten portion of the melt and cause rotation of the molten portion.
Claim 14
Dependent Claim
141 words
In electric arc furnace apparatus, in combination, means forming a furnace enclosure, a mold within the furnace enclosure in predetermined position therein, the mold being adapted to have at least partially electrically conductive material fed thereto, a rotatable electrode having a supporting column mounted in predetermined position with respect to the mold, the electrode having a generally disk-shaped tip forming an arcing surface, the tip lying in a predetermined plane with respect to the surface of a melt in the mold, the material and the electrode being adapted to be connected to terminals of opposite polarity of a source of potential to produce and sustain an arc between the electrode and the material to be melted, and means mounted adjacent the wall of the enclosure forming means for generating a magnetic field with field lines extending generally axially through the mold.
Claim 15
Dependent Claim
141 words
In electric arc furnace apparatus, in combination, means forming a furnace enclosure, a mold within the furnace enclosure in predetermined position therein, the mold being adapted to have at least partially electrically conductive material fed thereto, a rotatable electrode having a supporting column mounted in predetermined position with respect to the mold, the electrode having a generally disk-shaped tip forming an arcing surface, the tip lying in a predetermined plane with respect to the surface of a melt in the mold, the material and the electrode being adapted to be connected to terminals of opposite polarity of a source of potential to produce and sustain an arc between the electrode and the material to be melted, and means mounted adjacent the wall of the enclosure forming means for generating a magnetic field with field lines extending generally axially through the mold.
Claim 16
Dependent Claim
19 words
Apparatus according to claim 12 in which the disk-shaped top is a rotating wheel positioned horizontally over the mold.
Claim 17
Dependent Claim
114 words
Furnace apparatus including means forming a furnace enclosure and a mold adapted to receive at least partially electrically conductive material to be melted, an electrode mounted in the furnace enclosure in predetermined position with respect to the mold, the electrode including a rotating electrode wheel forming an arcing surface and lying in a predetermined plane with respect to the surface of the melt, means for producing an arc between electrode and melt, and magnetic field generating means mounted on top of the rotating electrode wheel, the field generated thereby performing at least one of the functions of assisting in producing relative movement between the electrode and the arc and producing focusing of the arc.
Claim 18
Dependent Claim
114 words
Furnace apparatus including means forming a furnace enclosure and a mold adapted to receive at least partially electrically conductive material to be melted, an electrode mounted in the furnace enclosure in predetermined position with respect to the mold, the electrode including a rotating electrode wheel forming an arcing surface and lying in a predetermined plane with respect to the surface of the melt, means for producing an arc between electrode and melt, and magnetic field generating means mounted on top of the rotating electrode wheel, the field generated thereby performing at least one of the functions of assisting in producing relative movement between the electrode and the arc and producing focusing of the arc.
Claim 19
Dependent Claim
168 words
Electric arc furnace apparatus including a mold adapted to contain at least partially electrically conductive material to be melted, a rotatable electrode mounted in predetermined position with respect to the mold, the electrode including a fluid cooled annular tip forming an arcing surface, and a magnetic field coil mounted in the tip, the magnetic field coil in the tip generating a magnetic field which extends in a radial direction across the tip substantially parallel to the arcing surface in substantially uniform strength around the entire periphery of the tip, the electrode and melt being adapted to be connected to terminals of opposite polarity of a source of potential to produce an arc between electrode and melt, the magnetic field extending substantially transverse to the arc path and exerting a force on the arc which causes it to move substantially continuously around the arcing surface of the tip in a predetermined angular direction, and means operatively connected to the electrode for rotating the electrode in a predetermined angular direction.
Claim 20
Dependent Claim
168 words
Electric arc furnace apparatus including a mold adapted to contain at least partially electrically conductive material to be melted, a rotatable electrode mounted in predetermined position with respect to the mold, the electrode including a fluid cooled annular tip forming an arcing surface, and a magnetic field coil mounted in the tip, the magnetic field coil in the tip generating a magnetic field which extends in a radial direction across the tip substantially parallel to the arcing surface in substantially uniform strength around the entire periphery of the tip, the electrode and melt being adapted to be connected to terminals of opposite polarity of a source of potential to produce an arc between electrode and melt, the magnetic field extending substantially transverse to the arc path and exerting a force on the arc which causes it to move substantially continuously around the arcing surface of the tip in a predetermined angular direction, and means operatively connected to the electrode for rotating the electrode in a predetermined angular direction.
Claim 21
Dependent Claim
88 words
Apparatus according to claim 15 in which the arc is produced by direct current and the magnetic field coil is energized by direct current, in which the arc rotates in one angular direction and the electrode rotates in the opposite angular direction the constant rotation of the arc in one angular direction by the field coil and the constant rotation of the electrode in the opposite angular direction producing a sustained increase in the speed of movement of the arc relative to the arcing surface of the tip.
Claim 22
Dependent Claim
29 words
Apparatus according to claim 15 in which the electrode is so mounted that the plane of the arcing surface lies at an angle to the surface of the melt.
Claim 23
Dependent Claim
23 words
Apparatus according to claim 17 in which the field coil is energized by direct current and the arc is produced by alternating current.
Claim 24
Independent Claim
47 words
The method of operating an electric arc furnace including producing an arc from a rotating electrode to a melt and generating in the arcing zone a magnetic field produced by field generating means mounted on top of that portion of the electrode which forms an arcing surface.
Claim 25
Independent Claim
47 words
The method of operating an electric arc furnace including producing an arc from a rotating electrode to a melt and generating in the arcing zone a magnetic field produced by field generating means mounted on top of that portion of the electrode which forms an arcing surface.
Claim 26
Independent Claim
62 words
The method of operating an electric arc furnace which includes producing an arc from an electrode rotating in one direction while generating a magnetic field by means within the electrode which exerts a force on the arc which causes the arc to rotate around the arcing surface of the electrode in a direction opposite to the direction of rotation of the Electrode.
Claim 27
Independent Claim
62 words
The method of operating an electric arc furnace which includes producing an arc from an electrode rotating in one direction while generating a magnetic field by means within the electrode which exerts a force on the arc which causes the arc to rotate around the arcing surface of the electrode in a direction opposite to the direction of rotation of the Electrode.
Claim 28
Independent Claim
40 words
The method of operating an electric arc furnace which includes producing substantially continuous relative motion between an arc and a rotatable electrode and generating in the arcing zone a magnetic field produced by field generating means independent of the electrode.
Claim 29
Independent Claim
40 words
The method of operating an electric arc furnace which includes producing substantially continuous relative motion between an arc and a rotatable electrode and generating in the arcing zone a magnetic field produced by field generating means independent of the electrode.
Claim 30
Independent Claim
70 words
The method of operating an electric arc furnace including the steps of forming an arc from a rotating electrode to a melt composed of at least partially electrically conductive material, and generating a magnetic field with field lines extending from electrode to melt and focusing the arc, and other field lines extending through the space around the periphery of the electrode and inhibiting the arc from stricking through said space.
Claim 31
Independent Claim
70 words
The method of operating an electric arc furnace including the steps of forming an arc from a rotating electrode to a melt composed of at least partially electrically conductive material, and generating a magnetic field with field lines extending from electrode to melt and focusing the arc, and other field lines extending through the space around the periphery of the electrode and inhibiting the arc from stricking through said space.
References Cited (Backward Citations)
US2951890A
Cited
US3461214A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |