US3798408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods and devices for plasma production
Assignee: Bpifrance Financement SA
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Filing: 1971-12-20
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Granted: 1974-03-19
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Expires: 1991-12-20
Abstract
Abstract A plasma generating installation comprises a pilot generator and nozzles supplying respectively convergent gas flows. These nozzles are inserted in a circuit capable of being completed across these flows by reducing the electrical resistance therein. This circuit and the supply circuit for the pilot generator are connected in parallel to a single current source. The installation is suitable for generation of plasmas of large volume. The invention relates to methods and devices for the production of plasma jets in the midst of convergent fluid flows giving rise to a main flow of plasma and of which at least certain of them are supplied through nozzles devoid of their own electrical supply.
Inventors
- 👤 C Bonet
- 👤 M Foex
- 👤 R Delmas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:12
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
254 words
An installation for producing a principal flow of hot gases which comprises a first nozzle for producing at least one elementary flow of fluid, said first nozzle including a channel with an outlet and an electrode disposed substantially along the longitudinal axis of said channel and having a front extremity which extends to a plane at least flush with respect to the end of said channel, the annular space formed within said channel and around the electrode forming the ejection channel for said elementary flow; at least one second nozzle for producing another fluid flow said first nozzle and second nozzle being positioned relative to each other so as to cause said elementary flow to converge with said another fluid flow for producing a principal flow resulting from the convergence of said elementary flow and said another fluid flow; said electrode and said second nozzle being connected in a normally open electrical circuit including an external voltage source which is capable of producing a voltage sufficient to cause completion of said circuit through said elementary flow and said another fluid flow when the electrical resistance therein is reduced; and means for producing a plasma flow having a cross section greater than that of said elementary flow and said another fluid and so positioned as to permit ionization of the atmosphere in which said elementary flow and said another fluid flow are formed to thereby cause a reduction of the electrical resistance in, and an ionisation of, said elementary flow and said another fluid flow.
Claim 2
Dependent Claim
254 words
An installation for producing a principal flow of hot gases which comprises a first nozzle for producing at least one elementary flow of fluid, said first nozzle including a channel with an outlet and an electrode disposed substantially along the longitudinal axis of said channel and having a front extremity which extends to a plane at least flush with respect to the end of said channel, the annular space formed within said channel and around the electrode forming the ejection channel for said elementary flow; at least one second nozzle for producing another fluid flow said first nozzle and second nozzle being positioned relative to each other so as to cause said elementary flow to converge with said another fluid flow for producing a principal flow resulting from the convergence of said elementary flow and said another fluid flow; said electrode and said second nozzle being connected in a normally open electrical circuit including an external voltage source which is capable of producing a voltage sufficient to cause completion of said circuit through said elementary flow and said another fluid flow when the electrical resistance therein is reduced; and means for producing a plasma flow having a cross section greater than that of said elementary flow and said another fluid and so positioned as to permit ionization of the atmosphere in which said elementary flow and said another fluid flow are formed to thereby cause a reduction of the electrical resistance in, and an ionisation of, said elementary flow and said another fluid flow.
Claim 3
Dependent Claim
39 words
A process according to claim 1 wherein said means for producing a plasma flow having a section greater than that of said elementary flow and said another fluid flow essentially comprises a pilot plasma torch having a diverging anode.
Claim 4
Dependent Claim
21 words
An installation according to claim 2 wherein the electrical supply of said plasma torch is independent from the said electrical circuit.
Claim 5
Dependent Claim
44 words
An installation according to claim 2, wherein said voltage external source is a DC generator and comprises a positive terminal connected to at least one of the electrodes of the plasma torch and a negative terminal connected to the electrode of said first nozzle.
Claim 6
Dependent Claim
42 words
An installation according to claim 2, wherein said voltage external source is an AC generator and comprises one terminal connected to at least one of the electrodes of the plasma torch and another terminal connected to the electrode of said first nozzle.
Claim 7
Dependent Claim
47 words
An installation according to claim 2 which furtHer comprises an annular member whose axis coincides substantially with that of said plasma torch, and which exhibits a conical surface flaring out towards the pilot torch for insuring the proper centering of said plasma flow of greater cross section.
Claim 8
Dependent Claim
28 words
An installation according to claim 1 wherein said second nozzle is a plasma torch, said voltage source being connected to one of the electrodes of said plasma torch.
Claim 9
Dependent Claim
215 words
An installation for producing a principal flow of hot gases which comprises at least two nozzles for producing a corresponding number of elementary flows of fluid, each of said nozzles including a channel with an outlet and an electrode disposed substantially along the longitudinal axis of said channel and having a front extremity which extends at least to a plane flush with respect to the end of said channel, the annular space formed within the channel and around the electrode forming the ejection channel for the corresponding elementary flow; said nozzles being positioned relative to one another so as to cause their respective elementary flows to converge with one another for producing a principal flow resulting from the convergence of said elementary flows; the electrodes of said nozzles being connected in a normally open electrical circuit including an external voltage source which is capable of producing a voltage sufficient to cause completion of said circuit through said elementary flows when the electrical resistance therein is reduced; and means for producing a plasma flow having a section greater than that of said elementary flows and so positioned as to ionize the atmosphere in which said elementary flows are formed to thereby cause a reduction of the electrical resistance in, and an ionization of, said elementary flows.
Claim 10
Dependent Claim
215 words
An installation for producing a principal flow of hot gases which comprises at least two nozzles for producing a corresponding number of elementary flows of fluid, each of said nozzles including a channel with an outlet and an electrode disposed substantially along the longitudinal axis of said channel and having a front extremity which extends at least to a plane flush with respect to the end of said channel, the annular space formed within the channel and around the electrode forming the ejection channel for the corresponding elementary flow; said nozzles being positioned relative to one another so as to cause their respective elementary flows to converge with one another for producing a principal flow resulting from the convergence of said elementary flows; the electrodes of said nozzles being connected in a normally open electrical circuit including an external voltage source which is capable of producing a voltage sufficient to cause completion of said circuit through said elementary flows when the electrical resistance therein is reduced; and means for producing a plasma flow having a section greater than that of said elementary flows and so positioned as to ionize the atmosphere in which said elementary flows are formed to thereby cause a reduction of the electrical resistance in, and an ionization of, said elementary flows.
Claim 11
Dependent Claim
33 words
An installation according to claim 8 wherein said means for producing a plasma having a section greater than that of said elementary flows essentially comprises a pilot plasma torch having a diverging anode.
Claim 12
Dependent Claim
19 words
An installation according to claim 9 wherein the supply of said plasma torch is independent from said electrical circuit.
Claim 13
Dependent Claim
68 words
An installation according to claim 9, which comprises n of said nozzles and wherein said voltage external source is a polyphase current generator having n + 1 phases, one of the phases of said polyphase generator being connected to at least one of the electrodes of the plasma torch, the n other phases of said polyphase generator being respectively connected to the electrodes associated with the n nozzles.
Claim 14
Dependent Claim
19 words
An installation according to claim 9, wherein the electrodes of said nozzles are formed from an electron emitter metal.
Claim 15
Dependent Claim
12 words
Installation according to claim 12, wherein said electron emitter metal is tungsten.
Claim 16
Dependent Claim
34 words
An installation according to claim 8 which comprises two of said nozzles, said voltage source being a DC generator whose positive and negative terminals are respectively connected to the electrodes of the two nozzles.
Claim 17
Dependent Claim
35 words
An installation according to claim 8 which comprises two of said nozzles and wherein said voltage source is an AC generator and the terminals thereof are respectively connected to the electrodes of the two nozzles.
Claim 18
Dependent Claim
44 words
An installation according to claim 8 wherein said voltage source comprises a polyphase source having a number of phases equal to the number of said nozzles, each of said nozzles having the electrode associated therewith connected to a corresponding phase of said polyphase source.
Claim 19
Dependent Claim
99 words
An installation according to claim 9 wherein said nozzles form several groups, the nozzles of a same group being positioned such that the flows which they deliver converge substantially at a point on the axis of the plasma flow produced by said pilot plasma torch, the points of convergence of the elementary flows produced by the nozzles of said different groups being located at different distances of said torch, and the electrodes of the nozzles in each of said groups being provided within an electrical circuit exclusively associated witH that group and having a separate, individual external voltage source.
Claim 20
Dependent Claim
22 words
An installation according to claim 8 wherein the front extremity of each said electrode protrudes beyond the end of the ejection channel.
Claim 21
Dependent Claim
64 words
An installation according to claim 9 wherein the supply circuit of the pilot plasma torch is connected in parallel to the terminals of said external voltage source and said supply circuit comprises a resistance having a sufficiently high value for the current generated by said external voltage source to pass preferentially in the circuit in which the electrodes associated with the nozzles are connected.
Claim 22
Dependent Claim
33 words
An installation according to claim 19, wherein said resistance has a value such that the completion of said normally open circuit through said elementary flows involves the self-extinction of the pilot plasma torch.
Claim 23
Dependent Claim
35 words
An installation according to claim 19 which comprises two of said nozzles and wherein said external voltage source is a DC generator whose terminals are respectively connected to the electrodes associated with the two nozzles.
Claim 24
Dependent Claim
37 words
An installation according to claim 19 which comprises two of said nozzles and wherein said external voltage source is an AC generator and the electrodes of the pilot plasma torch are both constituted by efficiently cooled parts.
Claim 25
Dependent Claim
19 words
Installation according to claim 22, wherein the two parts of the pilot generator are constituted of a same material.
Claim 26
Dependent Claim
11 words
Installation according to claim 23, wherein said same material is copper.
Claim 27
Dependent Claim
62 words
An installation according to claim 19, wherein said voltage source is a polyphase current generator having a number of phases equal to the number of said nozzles, each of the electrodes associated with said nozzles being connected to a corresponding phase of said polyphase generator, and wherein said supply circuit is connected to two of the phases of said polyphase current generator.
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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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |