US3663792A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method of increasing arc voltage and gas enthalpy in a self-stabilizing arc heater
Assignee: Westinghouse Electric Corp
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Filing: 1970-03-02
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Granted: 1972-05-16
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Expires: 1990-03-02
Abstract
Abstract The method includes admitting gas to be heated at a high velocity into an arc chamber through a narrow gap between spaced electrodes while maintaining across the electrodes a system or backup voltage sufficient at all times to cause electrical breakdown in the narrow gap between electrodes, while producing in the arc chamber a magnetic field having a preselected configuration to produce a beneficial effect or effects on the arc. The arc is periodically elongated by the high velocity gas until it attains such a length that the voltage required to sustain the arc exceeds the breakdown voltage of the gap whereupon the arc returns to the gap momentarily only to be blown out and elongated again. Gas is brought to the vicinity of the outside of the gap through a plurality of tangentially extending slots at spaced intervals around the entire periphery of the gap, whence it passes through the gap, the gas passing through the gap having a radial component and a tangential component. The high tangential flow component provides sufficiently large gas velocity to blow the arc from the electrode gap at a greatly reduced mass flow rate which may be of the order of one-fourth the flow rate which would be required if gas were admitted solely in a radial direction through the gap. The resulting decrease in the volume of gas to be heated results in an increased enthalpy imparted to the heated gas which may be of the order of five times that which can be obtained by purely radial gas admission. A higher arc voltage, results in a greatly improved power factor, and resulting decreased arc current results in an improvement in electrode lifetimes. Centrifugal effects in the arc chamber together with the influence of the magnetic field on the arc establish conditions wherein the arc column virtually follows the center line of the heater. Apparatus is provided for bringing gas to the gap to produce the aforementioned tangential flow coponent, and generate the magnetic field.
Inventors
- 👤 Maurice G Fey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:39
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32055; H05; H05B; H05B7/00; H05B7/18; H05B7/185; H05H; H05H1/00; H05H1/24; H05H1/48; H05H1/50
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
316 words
An improved process for heating a gas as a process material which comprises the steps of forming in an arc chamber of generally uniform cross section an annular electrical breakdown path between two spaced elements having a generally common axis and at opposite polarity with respect to each other, maintaining across said elements a system voltage sufficient to cause path breakdown initially between said elements generally parallel to said axis, the electrical breakdown between elements causing an arc to form, passing the gas to be heated at high velocity through said path at a plurality of peripherally spaced positions, said gas having a component of direction after it passes through said gap which is generally tangential to the electrical breakdown path and a component of direction which is radial to said electrical breakdown path, both said components of direction being additionally generally transverse to said axis, the tangential component reducing the mass flow rate of gas required to periodically move the arc out of the breakdown path to cause elongation of the arc primarily in a direction transverse to said axis so that the radial and tangential components produce an arc path having a major portion extending axially to the annular electrical breakdown path, with other portions of the arc path extending from the major axially extending portion and attaching to the inside surfaces of the electrodes, the cross-dimension of the arc chamber in a plane passing through the arc gap relative to the arc gap being such that the length of the arc is periodically significantly longer than the distance between the portions of the arc attached to said electrodes, whereby the electrical power required for a predetermined total volume of gas to be heated to a predetermined temperature is reduced, the arc being elongated primarily transverse to said axis until said system voltage can no longer support it whereupon a new breakdown may occur.
Claim 2
Dependent Claim
316 words
An improved process for heating a gas as a process material which comprises the steps of forming in an arc chamber of generally uniform cross section an annular electrical breakdown path between two spaced elements having a generally common axis and at opposite polarity with respect to each other, maintaining across said elements a system voltage sufficient to cause path breakdown initially between said elements generally parallel to said axis, the electrical breakdown between elements causing an arc to form, passing the gas to be heated at high velocity through said path at a plurality of peripherally spaced positions, said gas having a component of direction after it passes through said gap which is generally tangential to the electrical breakdown path and a component of direction which is radial to said electrical breakdown path, both said components of direction being additionally generally transverse to said axis, the tangential component reducing the mass flow rate of gas required to periodically move the arc out of the breakdown path to cause elongation of the arc primarily in a direction transverse to said axis so that the radial and tangential components produce an arc path having a major portion extending axially to the annular electrical breakdown path, with other portions of the arc path extending from the major axially extending portion and attaching to the inside surfaces of the electrodes, the cross-dimension of the arc chamber in a plane passing through the arc gap relative to the arc gap being such that the length of the arc is periodically significantly longer than the distance between the portions of the arc attached to said electrodes, whereby the electrical power required for a predetermined total volume of gas to be heated to a predetermined temperature is reduced, the arc being elongated primarily transverse to said axis until said system voltage can no longer support it whereupon a new breakdown may occur.
Claim 3
Dependent Claim
33 words
A process according to claim 1 in which the current producing the arc is alternating current and the arc may return to the breakdown path once peralternation at or near each current zero.
Claim 4
Dependent Claim
37 words
The process according to claim 1 including the additional step of introducing another process material to be heated into the arc zone at one end of the arc chamber by a path other than through the gap.
Claim 5
Dependent Claim
25 words
A process according to claim 1 in which the points of arc attachment are rotated around the electrodes by forces resulting from a magnetic field.
Claim 6
Dependent Claim
294 words
A process for heating gas which comprises producing an electric arc in a gap of substantially uniform width between a pair of spaced coaxially mounted annular cylindrical electrodes wherein said width is substantially smaller than the largest distance across a transverse section of said electrode which is also perpendicular to said axis of said electrodes forming a chamber of generally uniform size within said electrodes, in which said arc may be elongated, maintaining a system voltage between said pair of electrodes sufficient to cause electrical breakdown in the gap at any portion thereof, and passing gas through said gap from the outside thereof, toward the inside thereof and thence into the arc chamber continuously at a high velocity, the gas leaving the gap and entering the arc chamber having a tangential component and a radial component, both of said components being generally additionally transverse to said axis, the tangential component resulting in an arc path increasing in length until said system voltage may no longer support it whereupon a new breakdown may occur, the major portion of said arc path extending into said arc chamber with end portions attaching to an upstream electrode and a downstream electrode respectively, the total mass flow rate of gas required to move the arc out of the gap between electrodes being substantially reduced, the power in the electric arc being transferred to a smaller volume of gas per unit time so that a greater enthalpy may be imparted to the last named gas, the cross dimension of the arc chamber in a plane passing through the arc gap relative to the arc gap being such that the length of said arc is periodically significantly larger than the distance between the portions of the arc attached to said electrodes.
Claim 7
Dependent Claim
294 words
A process for heating gas which comprises producing an electric arc in a gap of substantially uniform width between a pair of spaced coaxially mounted annular cylindrical electrodes wherein said width is substantially smaller than the largest distance across a transverse section of said electrode which is also perpendicular to said axis of said electrodes forming a chamber of generally uniform size within said electrodes, in which said arc may be elongated, maintaining a system voltage between said pair of electrodes sufficient to cause electrical breakdown in the gap at any portion thereof, and passing gas through said gap from the outside thereof, toward the inside thereof and thence into the arc chamber continuously at a high velocity, the gas leaving the gap and entering the arc chamber having a tangential component and a radial component, both of said components being generally additionally transverse to said axis, the tangential component resulting in an arc path increasing in length until said system voltage may no longer support it whereupon a new breakdown may occur, the major portion of said arc path extending into said arc chamber with end portions attaching to an upstream electrode and a downstream electrode respectively, the total mass flow rate of gas required to move the arc out of the gap between electrodes being substantially reduced, the power in the electric arc being transferred to a smaller volume of gas per unit time so that a greater enthalpy may be imparted to the last named gas, the cross dimension of the arc chamber in a plane passing through the arc gap relative to the arc gap being such that the length of said arc is periodically significantly larger than the distance between the portions of the arc attached to said electrodes.
Claim 8
Dependent Claim
34 words
A process according to claim 5 in which the average arc voltage is substantially increased and the average arc current is substantially decreased while maintaining a predetermined arc power thereby improving the power factor.
Claim 9
Dependent Claim
76 words
A process according to claim 5 wherein alternating current supplies the arc, wherein the arc spot moves on the electrodes and the direction of arc spot movement on the electrodes reverses periodically as the instant polarity of the alternating current changes, and wherein the reversal of the direction of arc spot movement as the instant polarity reverses between alternations produces increased turbulence in the gas in the chamber thereby providing better mixing and improved heating efficiency.
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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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |