US4695358A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removing SO2, NOX and particles from gas mixtures using streamer corona
Assignee: Florida State University
•
Filing: 1985-11-08
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Granted: 1987-09-22
•
Expires: 2005-11-08
Abstract
Abstract A method for converting sulfur dioxide and/or nitrogen oxide gases to acid mist and or particle aerosols is disclosed in which the gases are passed through a streamer corona discharge zone having electrodes of a wire-cylinder or wire-plate geometry.
Inventors
- 👤 Akira Mizuno
- 👤 Judson S. Clements
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:36
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/0892; B; B01; B01D; B01D53/00; B01D53/32; B01D53/34; B01D53/46; B01D53/60; B01J; B01J19/00; B01J19/08; B01J19/087; B01J19/088; B03; B03C; B03C3/00; B03C3/017; B03C3/0175; B03C3/34; B03C3/38; B03C3/66; B01J2219/00; B01J2219/08; B01J2219/0803; B01J2219/0805; B01J2219/0845; B01J2219/0849; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
101 words
A method for converting sulfur dioxide and/or nitrogen oxides in a mixture thereof with at least one other gas to separable forms comprising: passing said mixture of gass through a streamer corona discharge zone defined by spaced electrodes; periodically dissipating in said zone pulses of electrical power of sufficiently high voltage to establish therein a continuous pulsed streamer corona discharge whereby the sulfur dioxide and/or nitrogen oxides are converted to acid mist and/or particle aerosols; the improvement comprising establishing a streamer corona discharge by applying fast-rising narrow pulses in a zone defined by electrodes spaced in a wire-cylinder or wire-plate geometry.
Claim 2
Independent Claim
101 words
A method for converting sulfur dioxide and/or nitrogen oxides in a mixture thereof with at least one other gas to separable forms comprising: passing said mixture of gass through a streamer corona discharge zone defined by spaced electrodes; periodically dissipating in said zone pulses of electrical power of sufficiently high voltage to establish therein a continuous pulsed streamer corona discharge whereby the sulfur dioxide and/or nitrogen oxides are converted to acid mist and/or particle aerosols; the improvement comprising establishing a streamer corona discharge by applying fast-rising narrow pulses in a zone defined by electrodes spaced in a wire-cylinder or wire-plate geometry.
Claim 3
Dependent Claim
14 words
The of claim 1 including the step of separating said aerosols from said mixture.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said at least one other gas is air.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said mixture of gases is a stack gas.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein said mixture of gases is effluent from an industrial process.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein said mixture of gases is exhaust from an internal combustion engine.
Claim 8
Dependent Claim
20 words
The method of claim 1 wherein said wire-cylinder geometry comprises a wire discharge electrode coaxially disposed within a cylindrical electrode.
Claim 9
Dependent Claim
44 words
The method of claim 7 wherein the diameter of said wire electrode is in the range of from about 0.1 mm to about 5 cm, and the diameter of said cylinder is in the range of from about 1 cm to about 1 m.
Claim 10
Dependent Claim
22 words
The method of claim 1 wherein said wire-plate geometry comprises a row of parallel wire discharge electrodes disposed between parallel plate electrodes.
Claim 11
Dependent Claim
65 words
The method of claim 9 wherein the diameter of said wire discharge electrodes is in the range of from about 0.1 mm to 5 cm, and where the wire to wire separation is in the range of from about 1 mm to about 30 cm, and where the parallel plate electrode separation is in the range of from about 1 cm to about 1 m.
Claim 12
Dependent Claim
25 words
The method of claim 1 wherein said power has a pulse repetition frequency in the range of from about 1 Hz to about 10 kHz.
Claim 13
Dependent Claim
24 words
The method of claim 1 wherein said pulses have a peak voltage in the range of from about 1 kV to about 500 kV.
Claim 14
Dependent Claim
39 words
The method of claim 1 wherein said narrow pulses have a width in the range of from about 10 ns to about 10 μs, and rise time in the range of from about 100 V/ns to about 100 kV/ns.
Claim 15
Dependent Claim
14 words
The method of claim 1 wherein said narrow pulses are of the same polarity.
Claim 16
Dependent Claim
10 words
The method of claim 1 wherein said polarity is positive.
Claim 17
Dependent Claim
10 words
The method of claim 1 wherein said polarity is negative.
Claim 18
Dependent Claim
38 words
The method of claim 1 wherein a bias potential is maintained across said zone, said voltage being less than that required to produce back corona or sparkover and of sufficient magnitude to remove gas ions from said zone.
Claim 19
Dependent Claim
22 words
The method of claim 17 wherein the polarity of said bias potential voltage is changed synchronously with each dissipation of a pulse.
Claim 20
Dependent Claim
23 words
The method of claim 17 wherein said bias potential voltage is in the range of from about 100 V to about 100 kV.
Claim 21
Dependent Claim
20 words
The method of claim 17 wherein said bias potential voltage is dc voltage of the same polarity as the pulses.
Claim 22
Dependent Claim
20 words
The method of claim 17 wherein said bias potential voltage is dc voltage of the opposite polarity as the pulses.
Claim 23
Dependent Claim
13 words
The method of claim 17 wherein said bias potential voltage is ac voltage.
Claim 24
Dependent Claim
16 words
The method of claim 1 wherein at least one additive is added to the gas mixture.
Claim 25
Dependent Claim
11 words
The method of claim 23 wherein said additive is particulate matter.
Claim 26
Dependent Claim
11 words
The method of claim 23 wherein said additive is particulate matter.
Claim 27
Dependent Claim
17 words
The method of claim 23 wherein said particulate matter is lime (CaO) or limestone (CaCO 3 ).
Claim 28
Independent Claim
122 words
A method for converting sulfur dioxide and/or nitrogen oxides and/or particulate matter in a mixture thereof with at least one other gas to separable forms comprising: passing said mixture of gases and/or particulate matter through a streamer corona discharge zone defined by discharge and collector electrodes spaced in a geometry comprising wire-cylinder or wire-plate, respectively; (1) periodically dissipating in said zone pulses of electrical power of sufficiently high voltage to establish therein a continuous pulsed streamer corona discharge and (2) establishing in the zone a high voltage bias potential; whereby the sulfur dioxide and/or nitrogen oxide are converted to acid mist and/or particle aerosols; and the aerosols and/or particulate matter is electrically charged and driven to and collected on the collection electrode.
Claim 29
Independent Claim
122 words
A method for converting sulfur dioxide and/or nitrogen oxides and/or particulate matter in a mixture thereof with at least one other gas to separable forms comprising: passing said mixture of gases and/or particulate matter through a streamer corona discharge zone defined by discharge and collector electrodes spaced in a geometry comprising wire-cylinder or wire-plate, respectively; (1) periodically dissipating in said zone pulses of electrical power of sufficiently high voltage to establish therein a continuous pulsed streamer corona discharge and (2) establishing in the zone a high voltage bias potential; whereby the sulfur dioxide and/or nitrogen oxide are converted to acid mist and/or particle aerosols; and the aerosols and/or particulate matter is electrically charged and driven to and collected on the collection electrode.
Claim 30
Dependent Claim
22 words
The method of claim 27 wherein said cylindrical collector electrode has a high resistivity layer on or adjacent to its interior surface.
Claim 31
Dependent Claim
14 words
The method of claim 27 wherein said at least one other gas is air.
Claim 32
Dependent Claim
14 words
The method of claim 27 wherein said mixture of gases is a stack gas.
Claim 33
Dependent Claim
12 words
The method of claim 27 wherein said particulate matter is fly ash.
Claim 34
Dependent Claim
20 words
The method of claim 27 wherein said wire-cylinder geometry comprises a wire discharge electrode coaxially disposed within a cylindrical electrode.
Claim 35
Dependent Claim
43 words
The method of claim 32 wherein the diameter of said wire electrode is in the range of from about 0.1 mm to about 5 cm, and the diameter of said cylinder is in the range of from about 1 cm to 1 m.
Claim 36
Dependent Claim
22 words
The method of claim 27 wherein said wire-plate geometry comprises a row of parallel wire discharge electrodes disposed between parallel plate electrodes.
Claim 37
Dependent Claim
65 words
The method of claim 34 wherein the diameter of said wire discharge electrodes is in the range of from about 0.1 mm to 5 cm, and where the wire to wire separation is in the range of from about 1 mm to, about 30 cm and where the parallel plate electrode separation is in the range of from about 1 cm to about 1 m.
Claim 38
Dependent Claim
24 words
The method of claim 27 wherein said power has pulse repetition frequency in the range of from about 1 Hz to about 10 kHz.
Claim 39
Dependent Claim
24 words
The method of claim 27 wherein said narrow pulses have a peak voltage in the range of from 1 kV to about 500 kV.
Claim 40
Dependent Claim
39 words
The method of claim 27 wherein said narrow pulses have a width in the range of from about 1 ns to about 10 us, and a rise time in the range from about 100 V/ns to about 100 kV/ns.
Claim 41
Dependent Claim
14 words
The method of claim 27 wherein said narrow pulses are of the same polarity.
Claim 42
Dependent Claim
10 words
The method of claim 39 wherein said polarity is positive.
Claim 43
Dependent Claim
32 words
The method of claim 27 wherein said high voltage bias potential is less than that required to produce back corona and of sufficient magnitude to charge and remove particles from said zone.
Claim 44
Dependent Claim
24 words
The method of claim 41 wherein said high voltage bias potential is in the range of from about 1 kV to about 100 kV.
Claim 45
Dependent Claim
22 words
The method of claim 42 wherein said high bias potential voltage is dc voltage of the same polarity as the narrow pulses.
Claim 46
Dependent Claim
21 words
The method of claim 27 wherein said aerosols and/or particles are not removed from said mixture of gases but are agglomerated.
Claim 47
Dependent Claim
16 words
The method of claim 27 wherein at least one additive is added to the gas mixture.
Claim 48
Dependent Claim
16 words
The method of claim 45 wherein said additive is ammonia (NH 3 ) or water vapor.
Claim 49
Dependent Claim
11 words
The method of claim 45 wherein said additive is particulate matter.
Claim 50
Dependent Claim
17 words
The method of claim 49 wherein said particulate matter is lime (CaO) or limestone (CaCO 3 ).
Claim 51
Dependent Claim
22 words
The method of claim 27 wherein the polarity of said bias potential voltage is changed synchronously with each dissipation of a pulse.
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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) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |