US3852061A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and equipment for the treatment of a material by means of an arc discharge plasma
Assignee: Max-Planck-Gesellschaft zur Förderung der Wissenschaften eV
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Filing: 1972-11-20
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Granted: 1974-12-03
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Expires: 1992-11-20
Abstract
Abstract A process is described wherein a material, such as particulate metal oxides, is treated with an arc discharge plasma under vacuum in the presence of a magnetic field running axially between the arc electrodes, wherein the plasma rotates symmetrically about a middle magnetic field, under conditions such that in a region the product of the electron gyration frequency Omega and time Tau , within which the average electron transmits its impulse to the plasma ions, is Omega Tau > 1 at about the middle of the magnetic field, and treated material, i.e., reduced metal, is recovered radially outside the region. Apparatus is described, for carrying out the process, including a discharge vessel, two spaced annular electrodes arranged symmetrically to the axis of the vessel, a magnetic coil enclosing coaxially the space between the electrodes, and means to introduce material axially through one electrode into the space.
Inventors
- 👤 H Wulff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:49
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32055; C; C22; C22B; C22B9/00; C22B9/16; C22B9/22; C22B9/226; H01J37/32431; H01J37/32623; H01J37/3266; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; H05H1/34; H05H1/3431; H05H1/40
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
196 words
A PROCESS FOR THE TREATMENT OF MATERIAL BY MEANS OF AN ARC DISCHARGE PLASMA IN A REGION OF A DISCHARGE VESSEL BETWEEN TWO AXIALLY SPACED ELECTRODES, COMPRISING THE FOLLOWING STEPS: A. MAINTAINING DURING THE PROCESS THE AVERAGE PRESSURE IN SAID REGION AT LESS THAN ONE ATMOSPHERE; B. PRODUCING A MAGNETIC FIELD RUNNING SUBSTANTIALLY PARALLEL TO THE AXIS FORMING THE CONNECTION LINE BETWEEN SAID ELECTRODES, AND WHICH HAS IN AT LEAST ONE PART OF SAID REGION SUCH A HIGH VALUE THAT THE PRODUCT && OF THE ELECTRON GYRATION FREQUENCY && IN THE PLASMA AND THE TIME & WITHIN WHICH ON AN AVERAGE ELECTRON TRANSMITS ITS IMPULSE TO THE IONS OF THE PLASMA IS GREATER THAN 1, AND THAT THE ARC DISCHARGE PLASMA IN SAID REGION AS A WHOLE IN ITSELF ROTATES AROUND A MIDDLE MAGNETIC FIELD LINE TO WHICH THE PLASMA IS SUBSTANTIALLY SYMMETRICAL; C. BRINGING SAID MATERIAL INTO A PART OF SAID REGION CLOSE TO THE MID-POINT OF SAID MAGNETIC FIELD UNDER SAID CONDITION OF &&> 1, WHEREBY A RECIPROCAL ACTION WITH THE PLASMA OCCURS, AND SAID MATERIAL IS CENTRIFUGED RADICALLY OUTWARD; AND D. RECOVERING TREATED MATERIAL FROM THE SPACE LYING RADIALLY OUTSIDE OF SAID REGION.
Claim 2
Dependent Claim
196 words
A PROCESS FOR THE TREATMENT OF MATERIAL BY MEANS OF AN ARC DISCHARGE PLASMA IN A REGION OF A DISCHARGE VESSEL BETWEEN TWO AXIALLY SPACED ELECTRODES, COMPRISING THE FOLLOWING STEPS: A. MAINTAINING DURING THE PROCESS THE AVERAGE PRESSURE IN SAID REGION AT LESS THAN ONE ATMOSPHERE; B. PRODUCING A MAGNETIC FIELD RUNNING SUBSTANTIALLY PARALLEL TO THE AXIS FORMING THE CONNECTION LINE BETWEEN SAID ELECTRODES, AND WHICH HAS IN AT LEAST ONE PART OF SAID REGION SUCH A HIGH VALUE THAT THE PRODUCT && OF THE ELECTRON GYRATION FREQUENCY && IN THE PLASMA AND THE TIME & WITHIN WHICH ON AN AVERAGE ELECTRON TRANSMITS ITS IMPULSE TO THE IONS OF THE PLASMA IS GREATER THAN 1, AND THAT THE ARC DISCHARGE PLASMA IN SAID REGION AS A WHOLE IN ITSELF ROTATES AROUND A MIDDLE MAGNETIC FIELD LINE TO WHICH THE PLASMA IS SUBSTANTIALLY SYMMETRICAL; C. BRINGING SAID MATERIAL INTO A PART OF SAID REGION CLOSE TO THE MID-POINT OF SAID MAGNETIC FIELD UNDER SAID CONDITION OF &&> 1, WHEREBY A RECIPROCAL ACTION WITH THE PLASMA OCCURS, AND SAID MATERIAL IS CENTRIFUGED RADICALLY OUTWARD; AND D. RECOVERING TREATED MATERIAL FROM THE SPACE LYING RADIALLY OUTSIDE OF SAID REGION.
Claim 3
Dependent Claim
96 words
The process of claim 1, wherein: a. the discharge is produced between an annular first electrode and a second electrode arranged substantially symmetrical to the axis of said annular electrode and spaced at an axial distance therefrom. b. said magnetic field is substantially symmetrical to the axis of said annular electrode; c. said material is introduced through the annular electrode through into said region of the discharge space near said axis, within a hollow plasma tube produced in operation; and d. said treated material is obtained radially outside said plasma tube, terminating axially between said electrodes.
Claim 4
Dependent Claim
19 words
The process of claim 1, wherein said magnetic field has a field intensity of at least 10 kG (kilo-Gauss).
Claim 5
Dependent Claim
26 words
The process of claim 1, wherein a neutral gas is within said discharge vessel at a pressure of about 2.5 torr, before ignition of the discharge.
Claim 6
Dependent Claim
16 words
The process of claim 1, wherein said magnetic field and discharge are produced in pulsed operation.
Claim 7
Dependent Claim
23 words
The process of claim 1, wherein said material is finely-grained having substantially uniform size, in the region between 20 and 80 Mu m.
References Cited (Backward Citations)
US3005859A
Cited
US3080626A
Cited
US3304169A
Cited
US3628948A
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US3547622A
Cited
US3771585A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |