US3905874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fractionator column control system
Assignee: Applied Automation Inc
•
Filing: 1972-08-14
•
Granted: 1975-09-16
•
Expires: 1992-08-14
Abstract
Abstract A system for controlling the operation of a petroleum fractionator column is disclosed wherein two control loops are used to maintain the liquid level at the fractionator bottom and the rate of liquid flow onto an intermediate tray at desired levels through adjustment of the rate at which slurry is recycled to the fractionator and the rate at which light cycle oil is withdrawn from an intermediate point in the column. The system may include means for reducing the interaction between the two control loops and means for altering the operation of the control loops to compensate for transient conditions in the fractionator following an alteration in the feed rate. Means are also provided for indirectly calculating the rate of fluid flow onto the intermediate tray.
Inventors
- 👤 Donald E Griffin
- 👤 Byron T Brown
- 👤 William H Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:49
CPC Classifications
B; B01; B01D; B01D3/00; B01D3/42; B01D3/4211; B01D3/4255; Y; Y10; Y10S; Y10S203/00; Y10S203/19; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
177 words
THE METHOD OF CONTROLLING THE OPERATION OF A PETROLEUM FRACTIONATOR INCLUDING A PLURALITY OF VERTICALLY DISPOSED TRAYS AND COMPRISING THE STEPS OF: GENERATING A FIRST SIGNAL RESPONSIVE TO THE RATE OF LIQUID FLOW ONTO A FIRST OF SAID TRAYS LOCATED AT A FIRST INTERMEDIATE POSITION IN SAID RFRACTIONATOR, GENERATING A SECOND SIGNAL RESPONSIVE TO THE LIQUID LEVEL AT THE BOTTOM OF SAID FRACTIONATOR, CONTROLLING THE RATE AT WHICH A BOTTOM APRODUCT OF SAID FRACTIONATOR IS RECYCLED THROUGH A HEAT TRANSFER APPARATUS TO SAID FRACTIONATOR IN RESPONSE TO SAID FIRST SIGNAL, CONTROLLING THE RATE AT WHICH FLUID IS WITHDRAWN FROM SAID FRACTIONATOR FROM A SECOND OF SAID TRAYS LOCATED AT A SECOND INTERMEDIATE POSITION IN SAID FRACTIONATOR IN RESPONSE TO SAID SECOND SIGNAL, AND FUTHER CONTROLLING THE RATE AT WHICH THE BOTTOM PRODYUCT OF SAID FRACTIONATOR IS RECYCLED TO SAID FRACTIONATOR THROUGH SAID HEAT TRANSFER APPARATUS IN RESPONSE TO SAID SECOND SIGNAL AND THE RATE AT WHICH FLUID IS WITHDRAWN FROM SAID SECOND TRAY IN RESPONSE TO SAID FIRST SIGNAL TO REDUCE THE INTERACTION BETWEEN SAID CONTROLLING STEPS.
Claim 2
Independent Claim
177 words
THE METHOD OF CONTROLLING THE OPERATION OF A PETROLEUM FRACTIONATOR INCLUDING A PLURALITY OF VERTICALLY DISPOSED TRAYS AND COMPRISING THE STEPS OF: GENERATING A FIRST SIGNAL RESPONSIVE TO THE RATE OF LIQUID FLOW ONTO A FIRST OF SAID TRAYS LOCATED AT A FIRST INTERMEDIATE POSITION IN SAID RFRACTIONATOR, GENERATING A SECOND SIGNAL RESPONSIVE TO THE LIQUID LEVEL AT THE BOTTOM OF SAID FRACTIONATOR, CONTROLLING THE RATE AT WHICH A BOTTOM APRODUCT OF SAID FRACTIONATOR IS RECYCLED THROUGH A HEAT TRANSFER APPARATUS TO SAID FRACTIONATOR IN RESPONSE TO SAID FIRST SIGNAL, CONTROLLING THE RATE AT WHICH FLUID IS WITHDRAWN FROM SAID FRACTIONATOR FROM A SECOND OF SAID TRAYS LOCATED AT A SECOND INTERMEDIATE POSITION IN SAID FRACTIONATOR IN RESPONSE TO SAID SECOND SIGNAL, AND FUTHER CONTROLLING THE RATE AT WHICH THE BOTTOM PRODYUCT OF SAID FRACTIONATOR IS RECYCLED TO SAID FRACTIONATOR THROUGH SAID HEAT TRANSFER APPARATUS IN RESPONSE TO SAID SECOND SIGNAL AND THE RATE AT WHICH FLUID IS WITHDRAWN FROM SAID SECOND TRAY IN RESPONSE TO SAID FIRST SIGNAL TO REDUCE THE INTERACTION BETWEEN SAID CONTROLLING STEPS.
Claim 3
Dependent Claim
97 words
The method of claim 1 further comprising the steps of generating a plurality of third signals responsive to the rates of fluid withdrawal from said second tray corresponding to the rates at which feed is supplied to said fractionator at a plurality of preceding times, combining Said third signals to form a fourth signal responsive to said fluid withdrawal rates, combining said second and fourth signals to form a fifth signal responsive to said second and fourth signals, and controlling the rate at which fluid is withdrawn from said second tray in response to said fifth signal.
Claim 4
Dependent Claim
273 words
Apparatus for controlling the operation of a petroleum fractionator, said fractionator comprising a plurality of vertically disposed trays, and comprising: first means for generating at an output a first signal responsive to the rate of liquid flow onto a first of said trays located at a first intermediate position in said fractionator; second means for generating at an output a second signal responsive to the liquid level at the bottom of said fractionator; third means for controlling the rate at which a bottom product of said fractionator is recycled to said fractionator through a heat transfer apparatus in response to the signal present at an input of said third means, said input of said third means being coupled to said output of said first means to form a first control loop; fourth means for controlling the rate at which fluid is withdrawn from said fractionator from a second of said trays located at a second intermediate position in said fractionator in response to the signal present at an input of said fourth means, said input of said fourth means being coupled to said output of said second means to form a second control loop; and fifth means for coupling the output of said first means to the input of said fourth means and coupling the output of said second means to the input of said third means and causing the operation of said first control loop to be responsive to said second signal and causing the operation of said second control loop to be responsive to said first signal and effecting a reduction in the interaction between said first and second control loops.
Claim 5
Dependent Claim
273 words
Apparatus for controlling the operation of a petroleum fractionator, said fractionator comprising a plurality of vertically disposed trays, and comprising: first means for generating at an output a first signal responsive to the rate of liquid flow onto a first of said trays located at a first intermediate position in said fractionator; second means for generating at an output a second signal responsive to the liquid level at the bottom of said fractionator; third means for controlling the rate at which a bottom product of said fractionator is recycled to said fractionator through a heat transfer apparatus in response to the signal present at an input of said third means, said input of said third means being coupled to said output of said first means to form a first control loop; fourth means for controlling the rate at which fluid is withdrawn from said fractionator from a second of said trays located at a second intermediate position in said fractionator in response to the signal present at an input of said fourth means, said input of said fourth means being coupled to said output of said second means to form a second control loop; and fifth means for coupling the output of said first means to the input of said fourth means and coupling the output of said second means to the input of said third means and causing the operation of said first control loop to be responsive to said second signal and causing the operation of said second control loop to be responsive to said first signal and effecting a reduction in the interaction between said first and second control loops.
Claim 6
Dependent Claim
102 words
The apparatus of claim 3 further comprising means for generating a first plurality of signals responsive to the rates at which feed is supplied to said fractionator at a plurality of preceding times, means for generating a second plurality of signals responsive to the steady state rates at which fluid is withdrawn from said second tray corresponding to said feed rates, means for generating a third signal responsive to said second plurality of signals, and means for coupling said third signal to said second control loop and causing the operation of said second control loop to be responsive to said third signal.
References Cited (Backward Citations)
US3150064A
Cited
US3249519A
Cited
US3143643A
Cited
US3296097A
Cited
US3428528A
Cited
US3359185A
Cited
US3401092A
Cited
US3449215A
Cited
US3420748A
Cited
US3503854A
Cited
US3600282A
Cited
US3748448A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |