Patent US3915672A successfully refreshed from Google Patents.
US3915672A
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Electrostatic precipitator
Assignee: Individual
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Filing: 1973-10-18
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Granted: 1975-10-28
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Expires: 1993-10-18
Abstract
Abstract An electrostatic precipitator particularly for removing dusts of high electrical resistivity from a gas stream. The precipitator includes parallel, grounded plate electrodes with high voltage corona wires suspended between the plate electrodes. Corona from the wires electrically charges the dust particles, and the electric field adjacent the grounded plates drives the charged particles onto the plates. In order to prevent the occurrence of back-corona due to high resistivity of the dust, the high voltage corona discharges are produced in short pulses with longer intervals between the pulses, and auxiliary electrodes are provided to maintain the necessary electric field during the intervals between pulses. Electrical circuits and control means are also provided for applying a high voltage to the corona wires in short pulses, and for applying a high voltage to the nondischarging auxiliary electrodes during the intervals between pulses with a low voltage on the auxiliary electrodes during the pulses.
Inventors
- 👤 Gaylord W Penney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:45
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/34; B03C3/38
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
120 words
A METHOD FOR ELECTRICALLY CHARGING GAS-BORNE DUST PARTICLES AND EFFECTING DEPOSITION THEREOF OF A GROUNDED SURFACE, SAID METHOD COMPRISING PRODUCTING SHORT PULSE OF CORONA DISCHARGED IN THE GAS TO CAUSE A CORONA CURRENT TO FLOW IN THE GAS AND THE DEPOSITED DUST TO SAID GROUNDED SURFACE, THE INTERNALS BETWEEN PULSES BEING NOT LESS THAN THREE TIMES DURATION OF A PULSE AND NOT GREATER THAN THE ELECTRICAL TIME CONSTANT OF SAID DEPOSITED DUST, AND INDEPENDENTENLY PRODUCING A UNIDIRECTIONAL ELECTRIC FIELD WWITH NO DISCHARGES IN THE SPACE ADJACENT THE GROUNDED SURFACE DURING SAID INTERVALS BETWEEN PULSES, SAID ELECTRIC FIELD BEING OF THE SAME POLARITY AS SAID DISCHARGES AND OF HIGH ENOUGH VOLTAGE TO DRIVE THE CHARGED DUST PARTICLES TO THE GROUNDED SURFACE.
Claim 2
Independent Claim
120 words
A METHOD FOR ELECTRICALLY CHARGING GAS-BORNE DUST PARTICLES AND EFFECTING DEPOSITION THEREOF OF A GROUNDED SURFACE, SAID METHOD COMPRISING PRODUCTING SHORT PULSE OF CORONA DISCHARGED IN THE GAS TO CAUSE A CORONA CURRENT TO FLOW IN THE GAS AND THE DEPOSITED DUST TO SAID GROUNDED SURFACE, THE INTERNALS BETWEEN PULSES BEING NOT LESS THAN THREE TIMES DURATION OF A PULSE AND NOT GREATER THAN THE ELECTRICAL TIME CONSTANT OF SAID DEPOSITED DUST, AND INDEPENDENTENLY PRODUCING A UNIDIRECTIONAL ELECTRIC FIELD WWITH NO DISCHARGES IN THE SPACE ADJACENT THE GROUNDED SURFACE DURING SAID INTERVALS BETWEEN PULSES, SAID ELECTRIC FIELD BEING OF THE SAME POLARITY AS SAID DISCHARGES AND OF HIGH ENOUGH VOLTAGE TO DRIVE THE CHARGED DUST PARTICLES TO THE GROUNDED SURFACE.
Claim 3
Dependent Claim
121 words
An electrostatic precipitator comprising a plurality of parallel, grounded plate electrodes, a plurality of corona-emitting electrodes and a plurality of non-discharging auxiliary electrodes, said emitting and auxiliary electrodes being disposed in a plane between said plate electrodes and substantially parallel thereto, means for applying high voltage pulses of one polarity to said corona-emitting electrodes at predetermined intervals of time to produce corona discharges and for maintaining a lower voltage on the emitting electrodes during the intervals between pulses, said intervals being of much longer duration than the pulses, and means for applying a high unidirectional voltage of said polarity to said auxiliary electrodes during said intervals between corona-producing pulses and for maintaining low voltage on the auxiliary electrodes during said pulses.
Claim 4
Dependent Claim
121 words
An electrostatic precipitator comprising a plurality of parallel, grounded plate electrodes, a plurality of corona-emitting electrodes and a plurality of non-discharging auxiliary electrodes, said emitting and auxiliary electrodes being disposed in a plane between said plate electrodes and substantially parallel thereto, means for applying high voltage pulses of one polarity to said corona-emitting electrodes at predetermined intervals of time to produce corona discharges and for maintaining a lower voltage on the emitting electrodes during the intervals between pulses, said intervals being of much longer duration than the pulses, and means for applying a high unidirectional voltage of said polarity to said auxiliary electrodes during said intervals between corona-producing pulses and for maintaining low voltage on the auxiliary electrodes during said pulses.
Claim 5
Dependent Claim
44 words
An electrostatic precipitator as defined in claim 2 having a plurality of parallel, grounded plate electrodes, said corona-emitting electrodes being disposed between parallel plate electrodes in a plane substantially parallel thereto, and said auxiliary electrodes being disposed in said plane between the corona-emitting electrodes.
Claim 6
Dependent Claim
30 words
An electrostatic precipitator as defined in claim 3 in which the duration of the intervals between high voltage pulses is not less than three times the duration of a pulse.
Claim 7
Dependent Claim
52 words
An electrostatic precipitator as defined in claim 2 in which at least portions of said emitting electrodes are adapted to produce corona at the voltage applied in said high voltage pulses, and the auxiliary electrodes are of such configuration that no discharges occur at the high voltage applied to the auxiliary electrodes.
Claim 8
Dependent Claim
24 words
An electrostatic precipitator as defined in claim 5 in which the corona-emitting electrodes comprise lengths of wire, and the auxiliary electrodes are rod members.
Claim 9
Dependent Claim
137 words
An electrostatic precipitator including a plurality of parallel, grounded plate electrodes, at least one corona-emitting electrode and at least one auxiliary electrode, said emitting and auxiliary electrodes being disposed between the plate electrodes in a plane substantially parallel thereto, a first circuit for applying a unidirectional voltage to said corona-emitting electrode, a second circuit for applying a unidirectional voltage of the same polarity to said auxiliary electrode, and means for controlling said circuits to cause the first circuit to apply short pulses of a sufficiently high voltage to cause emission of corona and to maintain a lower voltage for predetermined intervals of longer duration between pulses, said controlling means causing said second circuit to apply a high voltage to the auxiliary electrode during the intervals between said pulses and to maintain a low voltage during the pulses.
Claim 10
Dependent Claim
137 words
An electrostatic precipitator including a plurality of parallel, grounded plate electrodes, at least one corona-emitting electrode and at least one auxiliary electrode, said emitting and auxiliary electrodes being disposed between the plate electrodes in a plane substantially parallel thereto, a first circuit for applying a unidirectional voltage to said corona-emitting electrode, a second circuit for applying a unidirectional voltage of the same polarity to said auxiliary electrode, and means for controlling said circuits to cause the first circuit to apply short pulses of a sufficiently high voltage to cause emission of corona and to maintain a lower voltage for predetermined intervals of longer duration between pulses, said controlling means causing said second circuit to apply a high voltage to the auxiliary electrode during the intervals between said pulses and to maintain a low voltage during the pulses.
Claim 11
Dependent Claim
48 words
An electrostatic precipitator as defined in claim 7 in which the configuration of said auxiliary electrodes is such that no corona discharges occur on them and the higH voltage applied to the auxiliary electrodes is of sufficient magnitude to maintain a substantial electric field adjacent the plate electrodes.
Claim 12
Dependent Claim
82 words
An electrostatic precipitator as defined in claim 7 in which each of said circuits includes a first capacitor connected to the respective electrode to maintain a substantially constant bias voltage thereon, a second capacitor in series relation with the first capacitor, means for controlling the polarity of said second capacitor to place it in additive relation with the first capacitor to supply the high voltage and to reverse the polarity of the second capacitor for applying a low voltage to the electrode.
Claim 13
Dependent Claim
56 words
An electrostatic precipitator as defined in claim 9 in which said second capacitor is connected in an oscillatory circuit, said oscillatory circuit including electric valve means of opposite polarities, and in which said controlling means includes means for firing said electric valve means at predetermined times to control the reversals of polarity of the second capacitor.
Claim 14
Dependent Claim
24 words
An electrostatic precipitator as defined in claim 10 and including means for supplying energy to said oscillatory circuit during the periods of low voltage.
Claim 15
Dependent Claim
49 words
An electrostatic precipitator as defined in claim 11 in which said means for supplying energy comprises a third capacitor in series relation with one of said electric valve means, said third capacitor being of large capacitance as compared to the second capacitor, and means for charging the third capacitor.
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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |