US4779207A
Expired / Lapsed
US
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SO3 flue gas conditioning system
Assignee: Chemithon Corp
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Filing: 1987-01-06
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Granted: 1988-10-18
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Expires: 2007-01-06
Abstract
Abstract An air pollution control system for injecting a conditioning agent into the flue gas of a power generator. The conditioning agent changes the resistivity of particulate matter in the flue gas, rendering the particulate matter more easily able to accept an electrostatic charge. Control of the conditioning gas injection rate is monitored by periodically sampling the average input power supplied to the power supplies of the electrostatic flue gas conditioning system. A proportional-integral controller receives the signal representing the difference between the average input power and a predetermined threshold signal. The control signal produced by the proportional integral controller causes incremental changes in the rate at which the conditioning agent, such as SO3, is added to the flue gas.
Inventors
- 👤 David L. Woracek
- 👤 Robert A. Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:54
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/01; B03C3/013; B01; B01D; B01D53/00; B01D53/30; B01D53/34; B01D53/46; B01D53/48; B01D53/50
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
75 words
A system for preconditioning flue gas to be treated in an electrostatic precipitator, comprising: a source of a conditioning agent; means for controllably adding the conditioning agent to the flue gas; means for detecting an input power level to the electrostatic precipitator; and control means for monitoring the input power level and controlling the amount of conditioning agent added to the flue gas in order to substantially maintain the input power at a predetermined level.
Claim 2
Independent Claim
75 words
A system for preconditioning flue gas to be treated in an electrostatic precipitator, comprising: a source of a conditioning agent; means for controllably adding the conditioning agent to the flue gas; means for detecting an input power level to the electrostatic precipitator; and control means for monitoring the input power level and controlling the amount of conditioning agent added to the flue gas in order to substantially maintain the input power at a predetermined level.
Claim 3
Dependent Claim
54 words
The system for preconditioning flue gas of claim 1 wherein said control means comprises: means for producing a difference signal proportional to the difference between the monitored input power level and the predetermined power level; and means, responsive to the difference signal, for controlling the amount of conditioning agent added to the flue gas.
Claim 4
Dependent Claim
115 words
The system for preconditioning flue gas of claim 1 wherein said control means comprises: means for producing a difference signal proportional to the difference between the monitored input power level and the predetermined power level; clock means, responsive to a start signal, for measuring the passage of a predetermined interval of time and producing a stop signal after the passage of the interval of time; means, responsive to the stop signal, for integrating the difference signal as a function of time and for generating a control signal to adjust the amount of conditioning agent added to the flue gas, the control signal being a weighted sum of the difference signal and the integrated difference signal.
Claim 5
Dependent Claim
38 words
The system for preconditioning flue gas of claim 3 wherein the control means controls the amount of conditioning agent added to the flue gas to have a time rate of change that is proportional to the control signal.
Claim 6
Dependent Claim
17 words
The system for preconditioning flue gas of claim 1 wherein the conditioning agent is SO 3 .
Claim 7
Dependent Claim
160 words
The system for preconditionig flue gas of claim 1 wherein said control means comprises: means for producing a difference signal proportional to the difference between the monitored input power level and the predetermined power level; clock means, responsive to a start signal, for measuring the passage of a predetermined interval of time and producing a timing signal after the passage of the predetermined interval of time; means for comparing the difference signal to predetermined upper and lower levels in response to the timing signal produced by the clock means and for producing a stop signal when the difference signal is above the upper level or below the lower level; and means, responsive to the stop signal, for integrating the difference signal as a function of time and for generating a control signal to adjust the amount of conditioning agent added to the flue gas, the control signal being a weighted sum of the difference signal and the integrated difference signal.
Claim 8
Dependent Claim
16 words
The preconditioning flue gas system of claim 6 wherein the clock means produces periodic timing signals.
Claim 9
Dependent Claim
81 words
The system for preconditioning flue gas of claim 1 wherein the source of a conditioning agent is a source of liquid SO 2 and the means for controllably adding the conditioning agent to the flue gas includes a controller pump connected to the source of liquid SO 2 , a catalytic for converting the SO 2 to SO 3 , the catalytic bed being connected to the controllable pump, and SO 3 injectors connected between the catalytic bed and the flue.
Claim 10
Dependent Claim
61 words
The system for preconditioning flue gas of claim 1 wherein the source of a conditioning agent is a source of liquid SO 3 and the means for controllably adding the conditioning agent to the flue gas includes a liquid metering device connected to the source of liquid SO 3 and a vaporizer connected between the liquid metering device and the flue.
Claim 11
Dependent Claim
29 words
The system for preconditioning flue gas of claim 1 wherein the source of a conditioning agent is SO 2 produced by burning sulfur in air or in excess oxygen.
Claim 12
Dependent Claim
111 words
An air pollution control system providing for the removal of fly ash from flue gas by electrostatic precipitation, comprising: an electrostatic precipitator positioned to receive a flow of the flue gas; a source of a conditioning agent to be added to the flue gas; adjustable means for injecting the conditioning agent into the flue gas before the flue gas enters the electrostatic precipitator; means for detecting an input power level to the electrostatic precipitator; and control means for monitoring the input power level to the electrostatic precipitator and adjusting the amount of conditioning agent injected into to the flue gas to maintain the input power level substantially at a predetermined level.
Claim 13
Dependent Claim
111 words
An air pollution control system providing for the removal of fly ash from flue gas by electrostatic precipitation, comprising: an electrostatic precipitator positioned to receive a flow of the flue gas; a source of a conditioning agent to be added to the flue gas; adjustable means for injecting the conditioning agent into the flue gas before the flue gas enters the electrostatic precipitator; means for detecting an input power level to the electrostatic precipitator; and control means for monitoring the input power level to the electrostatic precipitator and adjusting the amount of conditioning agent injected into to the flue gas to maintain the input power level substantially at a predetermined level.
Claim 14
Dependent Claim
52 words
The air pollution control system of claim 11 wherein the electrostatic precipitator comprises a plurality of sections, each section receiving its power from a separate power supply, the input power level to the electrostatic precipitator being the total of the the input power levels to each of the plurality of power supplies.
Claim 15
Dependent Claim
56 words
The air pollution control system of claim 12 wherein the power supplied to each of the separate power supplies is measured by the current used by each separate power supply, and the input power level to the electrostatic precipitator is measured by summing the input currents used by at least one of the separate power supplies.
Claim 16
Dependent Claim
28 words
The air pollution control system of claim 13 wherein only the separate input currents that each exceed a separate threshold are summed to calculate the input power level.
Claim 17
Dependent Claim
16 words
The air pollution control system of claim 14 wherein the conditioning agent is SO 3 .
Claim 18
Dependent Claim
81 words
The air pollution control system of claim 11 wherein the source of a conditioning agent is a source of liquid SO 2 and the means for controllably adding the conditioning agent to the flue gas includes a controller pump connected to the source of liquid SO 2 , a catalytic bed for converting the SO 2 to SO 3 , the catalytic bed being connected to the controllable pump, and SO 3 injectors connected between the catalytic bed and the flue.
Claim 19
Dependent Claim
60 words
The air pollution control system of claim 11 wherein the source of a conditioning agent is a source of liquid SO 3 and the means for controllably adding the conditioning agent to the flue gas includes a liquid metering device connected to the source of liquid SO 3 and a vaporizer connected between the liquid metering device and the flue.
Claim 20
Dependent Claim
28 words
The air pollution control system of claim 11 wherein the source of a conditioning agent is SO 2 produced by burning sulfur in air or in excess oxygen.
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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) | 1991-10-18 | 1992-04-18 | 1992-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-18 | 1996-04-18 | 1996-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-18 | 2000-04-18 | 2000-10-18 | $7700.00 | Window Closed / Lapsed |