US3575633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc heater having a spirally rotating arc
Assignee: Westinghouse Electric Corp
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Filing: 1968-10-01
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Granted: 1971-04-20
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Expires: 1988-10-01
Abstract
Abstract An arc heater has two radially spaced axially coincident electrodes providing a radially extending arc path. One of the electrodes has an arcing surface tapering in diameter, or frustoconical in shape, whereby the arc path increases in length from the upstream ends of the electrodes to the downstream ends thereof. An arc initiated at the minimum gap, which is at the upstream end, is blasted toward the downstream direction due in part to an azimuthal magnetic field produced by a portion of the current path in the inner electrode which is substantially at a 90* angle with respect to the longitudinal axis of the inner electrode, but the arc is moved downstream primarily by a ''''Jacob''s ladder'''' effect in which current paths in the electrodes set up magnetic fields which are vectorily added to the magnetic field set up by the arc current in the arc itself, on the upper side only, with a resulting force on the arc which moves it down the electrodes, and the arc path is rotated around the inner electrode by an externally applied direct current axial magnetic field, the combined effects producing a spiral pattern of movement for the arc.
Inventors
- 👤 Kue H Yoon
- 👤 Charles B Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:23
CPC Classifications
H; H05; H05B; H05B7/00; H05B7/18; H05B7/185
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
247 words
An arc heater comprising, in combination, inner and outer electrodes spaced from each other, the inner and outer electrodes being adapted to be electrically connected to a source of potential to produce a substantially continuous radially extending arc therebetween, means for bringing gas to be heated in an annular path to the space between electrodes where said space between electrodes is substantially narrowest, electrical connections to the inner and outer electrodes being made at axial positions not farther downstream than the position where the space between electrodes is narrowest, one of the electrodes having a substantially cylindrical arcing surface, the other of said electrodes having an arcing surface which tapers in diameter along the length thereof whereby a relatively short space exists between the arcing surface of the inner electrode and the arcing surface of the outer electrode at the upstream ends of said electrodes and a relatively large space exists between said arcing surfaces at the downstream ends of the electrodes, means for exhausting heated gas from the arc chamber, the arc between electrodes being initiated in the minimum gap area at the upstream ends of the electrodes and blasted toward the downstream direction due to the magnetic fields of the currents in the electrodes and in the arc, and magnetic-field-producing means disposed near the arcing surface of the outer electrode for producing a substantially continuous magnetic field for rotating the arc between electrodes, said arc following a spiral path on the surfaces of the electrodes.
Claim 2
Dependent Claim
247 words
An arc heater comprising, in combination, inner and outer electrodes spaced from each other, the inner and outer electrodes being adapted to be electrically connected to a source of potential to produce a substantially continuous radially extending arc therebetween, means for bringing gas to be heated in an annular path to the space between electrodes where said space between electrodes is substantially narrowest, electrical connections to the inner and outer electrodes being made at axial positions not farther downstream than the position where the space between electrodes is narrowest, one of the electrodes having a substantially cylindrical arcing surface, the other of said electrodes having an arcing surface which tapers in diameter along the length thereof whereby a relatively short space exists between the arcing surface of the inner electrode and the arcing surface of the outer electrode at the upstream ends of said electrodes and a relatively large space exists between said arcing surfaces at the downstream ends of the electrodes, means for exhausting heated gas from the arc chamber, the arc between electrodes being initiated in the minimum gap area at the upstream ends of the electrodes and blasted toward the downstream direction due to the magnetic fields of the currents in the electrodes and in the arc, and magnetic-field-producing means disposed near the arcing surface of the outer electrode for producing a substantially continuous magnetic field for rotating the arc between electrodes, said arc following a spiral path on the surfaces of the electrodes.
Claim 3
Dependent Claim
79 words
An arc heater according to claim 1 including in addition arc start button means on the arcing surface of one of the inner and outer electrodes in the minimum gap area to provide a shortened gap length between the button means and the opposite electrode to insure that the gap has a breakdown voltage which will result in gap breakdown when the arc is near its most elongated state at a position near the downstream ends of the electrodes.
Claim 4
Dependent Claim
44 words
Apparatus according to claim 1 in which the arc heater is additionally characterized as having a heat shield upstream of the outer electrode and an additional heat shield downstream of the outer electrode, both of the heat shields being insulated from the outer electrode.
Claim 5
Dependent Claim
182 words
Apparatus according to claim 1 in which the arc heater is additionally characterized as having at least one heat shield adjacent the upstream end of the inner electrode, said heat shield having an inside diameter greater than the outside diameter of the adjacent end of the inner electrode, the inner electrode having an upstream portion of large diameter relative to the portion thereof which forms an arcing surface, the lead between the source of potential and the inner electrode being connected to the outer surface of the portion of larger diameter of the inner electrode whereby the arc current tends to follow a path along the outside surface of the inner electrode between the lead and the arcing surface, said current path including at least one 90* bend at at least one of the points where the inner electrode changes in diameter, the arc current at the 90* bend producing a magnetic field the lines of force of which lie in a direction to move an arc between the inner electrode and the outer electrode toward the downstream end of thinner electrode.
Claim 6
Dependent Claim
43 words
An arc heater according to claim 1 in which the upstream end of the outer electrode has a central aperture of smaller diameter than the diameter of said aperture at the downstream end of said outer electrode to form a tapering arcing surface.
Claim 7
Dependent Claim
52 words
Arc heater apparatus according to claim 1 in which the diameter of the outer electrode is substantially uniform throughout and the diameter of the inner electrode is substantially larger at the upstream end thereof than the diameter of the inner electrode at the downstream end thereof to form a tapering arcing surface.
Claim 8
Dependent Claim
92 words
Apparatus according to claim 1 in which the magnetic-field-producing means includes a field coil disposed within the outer electrode for setting up a magnetic field which tends to rotate the arc as the arc is moved toward the downstream ends of both electrodes, in which the source of potential for producing the arc is alternating current and the arc follows a spiral path in a clockwise direction during one alternation of the alternating current and follows a counterclockwise spiral path during the next alternation of the alternating current which supplies the arc.
Claim 9
Dependent Claim
81 words
Apparatus according to claim 5 in which the source of potential for producing the arc is alternating current and the arc follows a spiral pattern in a clockwise direction during one alternation of the alternating current as it moves from the upstream end to the downstream end, and follows a spiral path in a counterclockwise direction as it moves from the upstream ends of the electrodes to the downstream ends thereof during the alternation of opposite polarity of the alternating current.
Claim 10
Dependent Claim
151 words
Apparatus according to claim 1 in which both the arc current is a direct current and the magnetic-field-producing means includes a direct current source, the arc being initiated between the inner and outer electrodes at the minimum gap area at a short arc gap and being rotated by the magnetic field as it moves from the upstream ends of the electrodes toward the downstream ends thereof, the arc becoming elongated as it moves from the upstream ends of the electrodes toward the downstream ends thereof as the distance between arcing surfaces increases, the arc at last reaching a position where the breakdown strength of the minimum gap is less than the arc voltage required to maintain the arc at a downstream position, the direct current arc thereafter being transferred to a position at the minimum gap and the process of being moved down the electrodes in a spiral path being repeated.
Claim 11
Dependent Claim
169 words
In an arc heater including a pair of coaxially mounted radially spaced electrodes so shaped that the distance between the arcing surfaces of the electrodes increases as the axial distance from the upstream ends of the electrodes increases, the electrodes being adapted to be connected at the upstream ends thereof to a source of potential to produce a substantially continuous arc therebetween, an arc chamber, and means for bringing fluid to be heated to the arc chamber and conducting fluid after heating from the arc chamber, the improvement comprising means providing at the upstream ends of the electrodes a minimum gap for arc initiation, and means including magnetic field generating means so positioned with respect to the electrodes that a substantially constant substantially axially extending magnetic field is produced in the space between electrodes for causing the arc to thereafter move to a position whereat the arc is elongated to such a length that the voltage required to sustain the arc equals the breakdown voltage of the minimum gap.
Claim 12
Dependent Claim
169 words
In an arc heater including a pair of coaxially mounted radially spaced electrodes so shaped that the distance between the arcing surfaces of the electrodes increases as the axial distance from the upstream ends of the electrodes increases, the electrodes being adapted to be connected at the upstream ends thereof to a source of potential to produce a substantially continuous arc therebetween, an arc chamber, and means for bringing fluid to be heated to the arc chamber and conducting fluid after heating from the arc chamber, the improvement comprising means providing at the upstream ends of the electrodes a minimum gap for arc initiation, and means including magnetic field generating means so positioned with respect to the electrodes that a substantially constant substantially axially extending magnetic field is produced in the space between electrodes for causing the arc to thereafter move to a position whereat the arc is elongated to such a length that the voltage required to sustain the arc equals the breakdown voltage of the minimum gap.
Claim 13
Dependent Claim
44 words
An arc heater according to claim 10 in which the arc is initiated at the gap, wherein the arc current is diRect current and wherein the arc is periodically transferred to the gap and periodically moves to a position where the arc is elongated.
Claim 14
Dependent Claim
133 words
An arc heater of the type employing inner and outer electrodes radially spaced and so shaped that the distance between the arcing surface of one electrode and the arcing surface of the other electrode increases as the axial distance from the upstream ends of the electrodes increases, the electrodes being adapted to be connected to a source of potential for producing a substantially continuous arc therebetween with means for bringing fluid to be heated to an arc chamber and conducting fluid after heating from the arc chamber, comprising the improvement of means for providing for an axial blast of the arc due to a self-induced azimuthal magnetic field, said last-named means including means for generating a substantially continuous magnetic field for rotating the arc which extends radially between the inner and outer electrodes.
Claim 15
Dependent Claim
133 words
An arc heater of the type employing inner and outer electrodes radially spaced and so shaped that the distance between the arcing surface of one electrode and the arcing surface of the other electrode increases as the axial distance from the upstream ends of the electrodes increases, the electrodes being adapted to be connected to a source of potential for producing a substantially continuous arc therebetween with means for bringing fluid to be heated to an arc chamber and conducting fluid after heating from the arc chamber, comprising the improvement of means for providing for an axial blast of the arc due to a self-induced azimuthal magnetic field, said last-named means including means for generating a substantially continuous magnetic field for rotating the arc which extends radially between the inner and outer electrodes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |