US3725653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling chemical processes
Assignee: Gulf Research and Development Co
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Filing: 1968-04-11
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Granted: 1973-04-03
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Expires: 1988-04-11
Abstract
Abstract Method and apparatus for controlling complex chemical processes comprising the use of a detailed model, a dynamic simulation, and intermediate steps to generate both a simplified monitoring model which will anticipate process responses and a dynamics compensation model, which are joined together to control the process in real time.
Inventors
- 👤 N Carr
- 👤 S Kramer
- 👤 D Stahlfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:14
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/48; G06G7/58; Y; Y10; Y10S; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
199 words
A method of automatically and continuously controlling an output response variable of a chemical process that is housed in a vessel and is characterized by a substantial exchange of heat and no substantial unaccountable heat loss from the vessel, comprising the steps of continuously measuring the values of a plurality of critical input variables of said process in real time, continuously generating a first signal representative of a combined value of a first combination of values of said critical input variables in said plurality of critical input variables, continuously generating a second signal representative of a combined value of a second combination of values of said critical input variables in said plurality of critical input variables, continuously generating a third signal indicative of said output response variable from said first and second signals in real time, continuously comparing said third signal to a signal proportional to a predetermined value of said output response variable to generate a correction signal in real time, and utilizing said correction signal to control said output response variable by adjusting at least one of said critical input variables to thereby cause said process to operate at said predetermined value of said output response variable.
Claim 2
Independent Claim
199 words
A method of automatically and continuously controlling an output response variable of a chemical process that is housed in a vessel and is characterized by a substantial exchange of heat and no substantial unaccountable heat loss from the vessel, comprising the steps of continuously measuring the values of a plurality of critical input variables of said process in real time, continuously generating a first signal representative of a combined value of a first combination of values of said critical input variables in said plurality of critical input variables, continuously generating a second signal representative of a combined value of a second combination of values of said critical input variables in said plurality of critical input variables, continuously generating a third signal indicative of said output response variable from said first and second signals in real time, continuously comparing said third signal to a signal proportional to a predetermined value of said output response variable to generate a correction signal in real time, and utilizing said correction signal to control said output response variable by adjusting at least one of said critical input variables to thereby cause said process to operate at said predetermined value of said output response variable.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein said chemical process is a hydrocracker and said output response variable is conversion per pass.
Claim 4
Dependent Claim
101 words
The method of claim 2, the feed to said process consisting of a plurality of feed stocks, said plurality of critical input variables consists of the percentage of said feed stocks in total feed, total feed rate, total quench flow rate, and inlet and outlet temperatures, said first combination of critical input variables consisting of the percentage of said feed stocks in total feed, said total feed rate and said inlet temperature, and said second combination of said critical input variables consisting of said quench, said inlet temperature, said total feed rate, and the difference between said inlet and outlet temperatures.
Claim 5
Dependent Claim
20 words
The method of claim 1, wherein said at least one of said critical input variables is total quench flow rate.
Claim 6
Dependent Claim
144 words
In combination, a continuous chemical process that is housed in a vessel, which process produces a temperature gradient therein, and includes means to prevent any unaccountable substantial heat loss from the vessel, a special purpose analog computer, means to feed signals to said computer proportional to the values of selected critical input variables of said chemical process in real time, said computer comprising means to determine present value of a selected output response variable of said process in real time from said signals and means to generate a correction signal from said present value and a signal proportional to a pre-set value of said selected output response variable, and means to feed said correction signal to said process to control at least one of said critical input variables to cause said process to operate at said pre-set value of said selected output response variable.
Claim 7
Dependent Claim
144 words
In combination, a continuous chemical process that is housed in a vessel, which process produces a temperature gradient therein, and includes means to prevent any unaccountable substantial heat loss from the vessel, a special purpose analog computer, means to feed signals to said computer proportional to the values of selected critical input variables of said chemical process in real time, said computer comprising means to determine present value of a selected output response variable of said process in real time from said signals and means to generate a correction signal from said present value and a signal proportional to a pre-set value of said selected output response variable, and means to feed said correction signal to said process to control at least one of said critical input variables to cause said process to operate at said pre-set value of said selected output response variable.
Claim 8
Dependent Claim
40 words
The apparatus of claim 5, wherein said chemical process is a hydrocracking process, said selected input variables comprising total feed rate, inlet and outlet temperatures, and total quench flow rate, and said selected output response variable comprising conversion per pass.
Claim 9
Dependent Claim
33 words
The apparatus of claim 6, the feed to said process consisting of a plurality of feed stocks, said selected input variables further comprising the percentage of said feed stocks in the total feed.
Claim 10
Independent Claim
146 words
A method of interfacing a closed loop process controller comprising process variable control means and a control device for operating said process variable control means with a control computer by the use of an adding relay, comprising the steps of continuously generating a first signal in said computer proportional to the desired value of the setting of the variable control means in the control loop, continuously generating a second scaling signal in said computer, continuously generating a third signal in manual setting means proportional to a predetermined value of the process variable controlled by said control loop, feeding said first, second, and third signals to said adding relay to continuously generate a fourth signal proportional to and scaled to the computer determined value of the process variable being controlled, and feeding said fourth signal from said adding relay to the control device in said control loop.
Claim 11
Independent Claim
146 words
A method of interfacing a closed loop process controller comprising process variable control means and a control device for operating said process variable control means with a control computer by the use of an adding relay, comprising the steps of continuously generating a first signal in said computer proportional to the desired value of the setting of the variable control means in the control loop, continuously generating a second scaling signal in said computer, continuously generating a third signal in manual setting means proportional to a predetermined value of the process variable controlled by said control loop, feeding said first, second, and third signals to said adding relay to continuously generate a fourth signal proportional to and scaled to the computer determined value of the process variable being controlled, and feeding said fourth signal from said adding relay to the control device in said control loop.
Claim 12
Dependent Claim
125 words
In combination an analog control computer a pre-existing control loop comprising process variable control means and a control device adapted to operate said process variable control means, an adding relay, means to feed a first control signal and a second scaling signal from said computer to said adding relay, means to feed a third signal proportional to a predetermined set-point of the process variable controlled by said control loop to said adding relay, means to feed a fourth signal from said adding relay to the control device in said control loop, said fourth signal being generated in accordance with the relationship, Z A-C+B, wherein A represents said first signal, C represents said second signal, B represents said third signal, and Z represents said fourth signal.
Claim 13
Dependent Claim
125 words
In combination an analog control computer a pre-existing control loop comprising process variable control means and a control device adapted to operate said process variable control means, an adding relay, means to feed a first control signal and a second scaling signal from said computer to said adding relay, means to feed a third signal proportional to a predetermined set-point of the process variable controlled by said control loop to said adding relay, means to feed a fourth signal from said adding relay to the control device in said control loop, said fourth signal being generated in accordance with the relationship, Z A-C+B, wherein A represents said first signal, C represents said second signal, B represents said third signal, and Z represents said fourth signal.
Claim 14
Dependent Claim
64 words
The apparatus of claim 9, said signal feeding means for said first and second signals including automatic cut-out means adaptable to nullify the effect of said first and second signals in the event of failure of said computer, whereby such a failure will cause minimal disruption of the process by causing said process variable to automatically come under the control of said third signal.
Claim 15
Dependent Claim
45 words
The apparatus of claim 10, wherein a pneumatic control medium is utilized, said cut-out means comprising pneumatic relief valves adapted to automatically vent the pneumatic pressure in the lines carrying said first and second signals to atmosphere in the event of failure of said computer.
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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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |