US4218629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
MHD Power generator
Assignee: Hokkaido University
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Filing: 1978-07-11
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Granted: 1980-08-19
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Expires: 1998-07-11
Abstract
Abstract An MHD power generator includes a pair of electrode units between which a plasma stream flows from a plasma stream generating source. Each electrode unit comprises a plurality of segmented electrodes connected with each other with an insulating material disposed between the next adjacent segmented electrodes. The segmented electrode is made of magnetic material such as iron and cooled by an electrode cooling device. A pair of electrically insulating plates are mounted i.e. one on the upper surface of the electrode units and the other on the lower surface of the electrode units to define a plasma passage. A plurality of lead wires are each connected to a corresponding segmented electrode so as to take out an electric power which is generated in the plasma passage.
Inventors
- 👤 Naoyuki Kayukawa
- 👤 Yasutomo Ozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:19
CPC Classifications
H; H02; H02K; H02K44/00; H02K44/08; H02K44/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
80 words
An MHD power generator comprising means for generating a weakly ionized plasma stream, a pair of electrodes made of magnetic material and arranged opposite to each other, means for defining a plasma passage between the pair of electrodes through which the plasma stream flows from the plasma stream generating means, means for cooling the pair of electrodes, and a plurality of output lines each connected to the mutually facing electrodes so as to take out an electric power generated therebetween.
Claim 2
Dependent Claim
80 words
An MHD power generator comprising means for generating a weakly ionized plasma stream, a pair of electrodes made of magnetic material and arranged opposite to each other, means for defining a plasma passage between the pair of electrodes through which the plasma stream flows from the plasma stream generating means, means for cooling the pair of electrodes, and a plurality of output lines each connected to the mutually facing electrodes so as to take out an electric power generated therebetween.
Claim 3
Dependent Claim
19 words
An MHD power generator according to claim 1, in which said pair of electrodes are made of ferromagnetic materials.
Claim 4
Dependent Claim
32 words
An MHD power generator according to claim 1, in which said pair of electrodes each comprises a plurality of segmented electrodes with an insulating material disposed between the next adjacent segmented electrodes.
Claim 5
Dependent Claim
49 words
An MHD power generator according to claim 1, in which said pair of electrodes are made of ferromagnetic materials and said cooling means is adapted to permit the temperature of those surfaces of the electrodes which are in contact with the plasma stream to be maintained at 1200-1800 K.
Claim 6
Dependent Claim
48 words
An MHD power generator according to claim 1, in which said pair of electrodes each comprises a plurality of segmented electrodes with an insulating material disposed between the next adjacent segmented electrodes, the segmented electrodes each having a recess at that surface in contact with the plasma stream.
Claim 7
Dependent Claim
23 words
An MHD power generator according to claim 2, in which said ferromagnetic material has a maximum specific magnetic permeability of more than 1000.
Claim 8
Dependent Claim
29 words
An MHD power generator according to claim 1, in which that surface of the electrodes which is in contact with the plasma stream is coated with a coating material.
Claim 9
Dependent Claim
16 words
An MHD power generator according to claim 7, in which said coating material is a ceramic.
Claim 10
Dependent Claim
117 words
An MHD power generator comprising means for generating a weakly ionized plasma stream, a pair of electrodes arranged opposite to each other and comprising a block made of magnetic material and frame means made of an electrically and thermally conductive material and adapted to cover the block, a cooling medium passage provided in said frame means, means for defining a plasma passage between the pair of electrodes through which the plasma stream flows from the plasma stream generating means, means for supplying a cooling medium into the cooling medium passage to cool the electrodes, and a plurality of output lines each connected to the mutually facing electrodes so as to take out an electric power generated therebetween.
Claim 11
Dependent Claim
117 words
An MHD power generator comprising means for generating a weakly ionized plasma stream, a pair of electrodes arranged opposite to each other and comprising a block made of magnetic material and frame means made of an electrically and thermally conductive material and adapted to cover the block, a cooling medium passage provided in said frame means, means for defining a plasma passage between the pair of electrodes through which the plasma stream flows from the plasma stream generating means, means for supplying a cooling medium into the cooling medium passage to cool the electrodes, and a plurality of output lines each connected to the mutually facing electrodes so as to take out an electric power generated therebetween.
Claim 12
Dependent Claim
19 words
An MHD power generator according to claim 9, in which said pair of electrodes are made of ferromagnetic material.
Claim 13
Dependent Claim
35 words
An MHD power generator according to claim 9, in which said pair of electrodes are each constituted by a plurality of segmented electrodes connected so that an insulator is disposed between the adjacent segmented electrodes.
Claim 14
Dependent Claim
56 words
An MHD power generator according to claim 9, in which said pair of electrodes are made of ferromagnetic material and said cooling medium supply means serves to permit the temperature of those contact surfaces of the electrodes which are in contact with the plasma stream to be maintained within a range of 1200 to 1800 K.
Claim 15
Dependent Claim
25 words
An MHD power generator according to claim 9, in which said ferromagnetic material has a maximum specific magnetic permeability μ max of more than 1000.
Claim 16
Dependent Claim
28 words
An MHD power generator according to claim 9, in which those surfaces of the electrodes which are in contact with the plasma stream are coated with coating material.
Claim 17
Dependent Claim
16 words
An MHD power generator according to claim 15, in which said coating material is a ceramic.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-19 | 1984-02-18 | 1984-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-19 | 1988-02-18 | 1988-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-19 | 1992-02-18 | 1992-08-19 | $7700.00 | Window Closed / Lapsed |