Patent US3586905A successfully refreshed from Google Patents.
US3586905A
Expired / Lapsed
US
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Plasma arc heating apparatus
Assignee: Canadian Titanium Pigments Ltd
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Filing: 1969-06-03
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Granted: 1971-06-22
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Expires: 1989-06-03
Abstract
Abstract Plasma arc gas heating apparatus comprising in combination: a helically wound high frequency induction coil, means coaxially mounting said coil in a tubular enclosure open at one end for exit of heated gas and closed at the opposite end, a pair of spaced electrodes mounted in said closed end of said tubular enclosure, means for injecting a flow of gas therein between said electrodes and thence through and over said coil, additional means for injecting gas into said tubular enclosure at a point between said electrodes and said coil, and electrical connections to said electrodes for impressing a gas ionizing voltage therebetween.
Inventors
- 👤 Rodolphe Bignell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:07
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; H05H1/34; H05H1/36
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
102 words
Plasma arc gas heating apparatus comprising in combination: a helically wound high frequency induction coil, means coaxially mounting said coil in a tubular enclosure open at one end for exit of heated gas and closed at the opposite end, a pair of spaced electrodes mounted in said closed end of said tubular enclosure, means for injecting a flow of gas therein between said electrodes and thence through and over said coil, additional means for injecting gas into said tubular enclosure at a point between said electrodes and said coil, and electrical connections to said electrodes for impressing a gas ionizing voltage therebetween.
Claim 2
Dependent Claim
102 words
Plasma arc gas heating apparatus comprising in combination: a helically wound high frequency induction coil, means coaxially mounting said coil in a tubular enclosure open at one end for exit of heated gas and closed at the opposite end, a pair of spaced electrodes mounted in said closed end of said tubular enclosure, means for injecting a flow of gas therein between said electrodes and thence through and over said coil, additional means for injecting gas into said tubular enclosure at a point between said electrodes and said coil, and electrical connections to said electrodes for impressing a gas ionizing voltage therebetween.
Claim 3
Dependent Claim
57 words
Apparatus according to claim 1, wherein said pair of electrodes comprise a conically tipped anode electrode mounted coaxially with said coil and axially spaced therefrom, and an annular cathode electrode disposed between said anode and said coil and mounted coaxially therewith, said cathode spanning said tubular enclosure, and the conical tip of said anode facing said cathode.
Claim 4
Dependent Claim
31 words
Apparatus according to claim 2, wherein said anode electrode is provided with passageways extending therethrough and means are provided for injecting gas through said passageways into the space between said electrodes.
Claim 5
Dependent Claim
64 words
Apparatus according to claim 1, wherein successive turns of said coil are more closely spaced at the ends thereof than in the portion intermediate said ends, for intensifying the magnetic field produced at said coil ends as compared to said intermediate portion when said coil is traversed by electrical current and for thereby concentrating a plasma arc within said intermediate portion of said coil.
Claim 6
Dependent Claim
33 words
Apparatus according to claim 4, wherein successive coil turns are equispaced at each of said coil ends and are equispaced throughout said intermediate portion but at greater spacing than at said coil ends.
Claim 7
Dependent Claim
27 words
Apparatus according to claim 1, wherein said coil is a helically wound metal tube, and wherein means are provided for circulating a coolant fluid through said tube.
Claim 8
Dependent Claim
71 words
Apparatus according to claim 1, wherein voltage energizing means are connected between said spaced electrodes for periodically impressing therebetween unidirectional voltage pulses of magnitude to ionize gas flow in the gap between said electrodes for discharge thence of ionized particles through and about said coil, and wherein a source of sustained high frequency voltage is connected between said coil ends whereby a plasma arc is initiated and sustained within said coil.
Claim 9
Dependent Claim
106 words
Apparatus according to claim 7, wherein said voltage energizing means comprises a grid controlled thyratron tube having a series resonant inductance and capacity discharge circuit bridged between its cathode and anode electrodes, and having connected in parallel therewith a charging circuit including a direct current voltage source and a charging impedance in series, for charging said capacity to the voltage of said source, pulsing means for periodically firing said thyratron to discharge said capacity and produce unidirectional current pulses in said resonant discharge circuit, and means electrically coupling said spaced electrodes disposed in said tubular enclosure, respectively, to points of potential difference in saId resonant circuit.
Claim 10
Dependent Claim
28 words
Apparatus according to claim 8, wherein said spaced electrodes disposed in said tubular enclosure are transformer coupled to said resonant discharge circuit through a two-winding saturatable core transformer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |