US3891828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Graphite-lined inert gas arc heater
Assignee: Westinghouse Electric Corp
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Filing: 1973-10-18
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Granted: 1975-06-24
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Expires: 1993-10-18
Abstract
Abstract An arc heater has a pair of spaced electrodes at the ends of a cooled copper cylinder with means for admitting an inert gas to be heated at one end of the cylinder and a gas exhaust at the other end of the cylinder. The inside wall of the cooled copper cylinder is lined with pyrolytic graphite either in the form of a cylinder or a series of closely stacked discs. The anisotropic structure of pyrolytic graphite results in high thermal conductivity in the direction radial to the axis of the cylinder and a very low thermal conductivity in a direction parallel to the axis of the cylinder. On the other hand, the electrical resistance of the pyrolitic graphite in the latter direction is quite high, being of the order of 0.2 ohms per inch whereas the electrical resistance of the graphite in the radial direction is very low, being of the order of 1.8 X 10 4 ohms per inch. Accordingly, the pyrolytic graphite lined cylinder offers substantial electrical resistance in the direction of the arc between the two electrodes with a small resistance loss through the graphite in that direction.
Inventors
- 👤 Corso Serafino M De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:39
CPC Classifications
H; H05; H05B; H05B7/00; H05B7/18; H05B7/185
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
164 words
An arc heater comprising, first and second spaced electrodes adapted to have an electrical arc struck therebetween for heating gas, said electrodes being electrically insulated from each other, a hollow housing means having an elongated arc chamber disposed between said electrodes and electrically insulated therefrom, pressure means for admitting gas to be heated by said electric arc into said chamber and means for exhausting gas from said chamber, a pyrolytic graphite liner for the inner wall of said chamber, said graphite liner being characterized by high thermal conductivity in a direction transverse to the longitudinal axis of said arc chamber and by relatively low thermal conductivity in the direction parallel to the axis of the chamber, said graphite liner being characterized by high electrical resistance in the direction parallel to said longitudinal axis of said arc chamber compared to the electrical resistance in a direction transverse to the axis of said arch chamber, mounting means for supporting together the elements of the arc heater.
Claim 2
Dependent Claim
164 words
An arc heater comprising, first and second spaced electrodes adapted to have an electrical arc struck therebetween for heating gas, said electrodes being electrically insulated from each other, a hollow housing means having an elongated arc chamber disposed between said electrodes and electrically insulated therefrom, pressure means for admitting gas to be heated by said electric arc into said chamber and means for exhausting gas from said chamber, a pyrolytic graphite liner for the inner wall of said chamber, said graphite liner being characterized by high thermal conductivity in a direction transverse to the longitudinal axis of said arc chamber and by relatively low thermal conductivity in the direction parallel to the axis of the chamber, said graphite liner being characterized by high electrical resistance in the direction parallel to said longitudinal axis of said arc chamber compared to the electrical resistance in a direction transverse to the axis of said arch chamber, mounting means for supporting together the elements of the arc heater.
Claim 3
Dependent Claim
18 words
A liner according to claim 1 in which the pyrolytic graphite is in the form of a cylinder.
Claim 4
Dependent Claim
22 words
A liner according to claim 1 in which the pyrolytic graphite is in the form of a plurality of stacked annular discs.
Claim 5
Dependent Claim
18 words
A liner according to claim 3 including in addition a refractory coating on each of the said discs.
Claim 6
Dependent Claim
23 words
An arc heater according to claim 1 in which the graphite lining is additionally characterized as being in the form of a cylinder.
Claim 7
Dependent Claim
35 words
An arc heater according to claim 1 in which the graphite liner is additionally characterized as being a plurality of closely spaced annular discs extending the length of the inner wall of said arc chamber.
Claim 8
Dependent Claim
54 words
An arc heater according to claim 1 in which at least one of the electrodes is additionally characterized as including a field coil disposed therein, said field coil producing a magnetic field which causes the arc to rotate substantially continually around the annular arcing surface of one of said first and said second electrodes.
Claim 9
Dependent Claim
22 words
An arc heater according to claim 1 in which the gas admitted to said arc chamber is additionally characterized as being inert.
Claim 10
Dependent Claim
22 words
An arc heater according to claim 1 in which the gas admitted to said arc chamber is additionally characterized as being non-oxidizing.
Claim 11
Dependent Claim
23 words
An arc heater according to claim 1 including in addition fluid inlet means for cooling said arc chamber and fluid outlet means therefor.
Claim 12
Dependent Claim
59 words
An arc heater according to claim 1 in which the graphite liner comprises annular discs, said discs normally having arcs formed at the junctions therebetween by current flow, said arcs formed at the junctions of said disc being moved toward the downstream end of the arc heater by the force of the flow of gas within said arc chamber.
Claim 13
Dependent Claim
19 words
An arc heater according to claim 1 in which the downstream electrode is additionally characterized as being fluid cooled.
Claim 14
Dependent Claim
23 words
An arc heater according to claim 1 in which both the upstream electrodes and downstream electrodes are additionally characterized as being fluid cooled.
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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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |