US3728526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means and method for controlling independent operating parameters in a process system
Assignee: Texaco Inc
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Filing: 1971-07-08
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Granted: 1973-04-17
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Expires: 1991-07-08
Abstract
Abstract A control system controls a process system for periodically changing the values of first and second independent operating parameters of the process by predetermined amounts when the system has determined that the increases will not cause any operating parameter of the process system to exceed a constraint value. Various variable operating parameters, including the first and second independent operating parameter, are sensed by sensors which provide corresponding signals. A pair of factors, related to resulting changes in the values of a dependent operating parameter due to changes in the independent operating parameters, is predetermined for each of the dependent operating parameters. Direct current voltages corresponding to the factors are multiplied by voltages corresponding to the predetermined changes in the independent operating parameters to provide outputs. Each output represents a resulting change in a different dependent operating parameter. Predicted signals for each dependent operating parameter are determined by summing an output with a signal from a corresponding sensor. The sensed values of the independent operating parameters are summed with the voltages corresponding to the predetermined increases to provide predicted value signals for the independent operating parameters. The predicted value of an operating parameter is compared with the operating parameter''s constraint value. When the predicted values of the operating parameters associated with an independent operating parameter do not exceed the corresponding constraint values, the independent operating parameter is changed in value by the predetermined amount. When at least one predicted value of a dependent parameter associated with an independent operating parameter exceeds a corresponding constraint value, the independent operation parameter maintains its present value.
Inventors
- 👤 D Youngblood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:03
CPC Classifications
G; G05; G05B; G05B13/00; G05B13/02; G05B13/04; G05B13/042; Y; Y10; Y10S; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
231 words
A system for controlling a process so that independent and dependent operating parameters of the process do not exceed constraint values, comprising means for providing outputs corresponding to predetermined changes in at least two independent operating parameters; means connected to the output means for providing groups of signals in accordance with the outputs from the output means, each group is associated with a different independent operating parameter and the signals in that group correspond to predicted values for different dependent operating parameters and the associated independent operating parameter; means for providing a plurality of voltages, each voltage corresponding to a constraint value for a different operating parameter; means connected to the voltage means and to the signal means for comparing each predicted value signal for an operating parameter with the voltage corresponding to the constraint value for the operating parameter and providing a corresponding output; means connected to the signal means and to the comparing means for determining if the predicted value signals for an operating parameter exceed the constraint value voltage for the operating parameter and whether an independent operating parameter may be changed in one direction with a corresponding change in the opposite direction in the other independent parameter and providing signals corresponding to the determination; and means for conTrolling the independent operating parameters in accordance with the outputs from the comparing means and signals from the determining means.
Claim 2
Independent Claim
231 words
A system for controlling a process so that independent and dependent operating parameters of the process do not exceed constraint values, comprising means for providing outputs corresponding to predetermined changes in at least two independent operating parameters; means connected to the output means for providing groups of signals in accordance with the outputs from the output means, each group is associated with a different independent operating parameter and the signals in that group correspond to predicted values for different dependent operating parameters and the associated independent operating parameter; means for providing a plurality of voltages, each voltage corresponding to a constraint value for a different operating parameter; means connected to the voltage means and to the signal means for comparing each predicted value signal for an operating parameter with the voltage corresponding to the constraint value for the operating parameter and providing a corresponding output; means connected to the signal means and to the comparing means for determining if the predicted value signals for an operating parameter exceed the constraint value voltage for the operating parameter and whether an independent operating parameter may be changed in one direction with a corresponding change in the opposite direction in the other independent parameter and providing signals corresponding to the determination; and means for conTrolling the independent operating parameters in accordance with the outputs from the comparing means and signals from the determining means.
Claim 3
Dependent Claim
130 words
A system as described in claim 1 in which the process is the fluid catalytic cracking of feedstock where the feedstock is preheated by a furnace and mixed with a fluid catalyst from a regenerator before entering a reactor, one effluent from the reactor is spent catalyst which is returned to the regenerator where air entering the regenerator from a blower aids in the regeneration of the catalyst, while another effluent from the reactor is fed to a primary fractionator which provides a variety of hydrocarbon product streams including a gas oil that is recycled by a pump to be mixed with the feedstock before the feedstock enters the reactor and a top product stream, a portion of which is converted to a gas which is fed to a compressor.
Claim 4
Dependent Claim
54 words
A system as described in claim 2 in which one independent operating parameter is the temperature of the feedstock after preheating, another independent parameter is the recycle rate of the recycle gas oil, and the other operating parameters are the blower''s speed, the regenerator''s temperature, the compressor''s speed and the fractionator top tower temperature.
Claim 5
Dependent Claim
225 words
A system as described in claim 3 in which the control means includes means having the recycle gas oil passing through it for regulating the recycle rate of the recycle gas oil, means connected to the comparing means and to the furnace for controlling the furnace to increase the preheated feedstock temperature when an output from the comparing means is of one level which corresponds to the condition that none of the one group of predicted value signals exceed a corresponding constraint value voltage, and to maintain the preheated feedstock temperature when the output is of another level which corresponds to the condition that at least one of the one group of predicted value signals exceeds a corresponding constraint value voltage; and second means connected to the comparing means and to the regulating means for controlling the regulating means to increase the recycle rate of the recycle gas oil when a second output from the comparing means is of one amplitude which corresponds to the condition that none of the other group of predicted value signals exceed a corresponding constraint value voltage, and to maintain the gas oil recycle rate when the second output from the comparing means is of another amplitude which corresponds to the condition that at least one of the other group of predicted value signals exceeds a corresponding constraint value voltage.
Claim 6
Dependent Claim
183 words
A system as described in claim 3 in which the signal means includes a plurality of sensors sensing the blower speed, the preheated feedstock temperature, the recycle rate of the recycle gas oil, the compressor speed, the regenerator temperature and the primary fractionator top tower temperature and providing signals corresponding thereto; second signal means for providing a plurality of signals, each signal corresponding to an increase in a dependent operating parameter as a function of a different independent operating parameter, and summing means, one summing means sums the first output from the output means with the signal from the sensors corresponding to the sensed preheated feedstock temperature to provide a predicted preheated feedstock temperature, another summing means sums the second output from the output means with the signal from the sensors corresponding to the sensed recycle rate of the recycle gas oil to provide a predicted gas oil recycle rate, and the remaining summing means sum each signal of the remaining signals from the sensors with corresponding signals from the second signal means to provide predicted value signals for the dependent operating parameter.
Claim 7
Dependent Claim
113 words
A system as described in claim 5 further comprising means connected to the signal means, to the comparing means and to the control means for determining if the predicted value signals for a depeNdent operating parameter exceed the constraint value voltage for the dependent operating parameter and if an independent operating parameter may be increased with a corresponding decrease in the other independent parameter and providing signals corresponding to the determination; and in which the regulating means and the temperature control means controls the recycle rate of the recycle gas oil and the preheated feedstock temperature, respectively, in accordance with the outputs from the comparing means and the signals from the determining means.
Claim 8
Independent Claim
175 words
A method for controlling a process so that independent and dependent operating parameters of the process do not exceed constraint values, which comprises providing outputs corresponding to predetermined changes in at least two independent operating parameters; providing groups of signals in accordance with the output, each group is associated with different independent operating parameters and the signals in that group correspond to predicted values for different operating parameters and the associated independent operating parameters providing a plurality of voltages, each voltage corresponds to a constraint value for different operating parameters; comparing each predicted value signal for an operating parameter with the constraint value voltage for the operating parameter; determining if the predicted values for an operating parameter exceed the operating parameter constraint value, determining in accordance with the previous determination if one independent operating parameter may be changed in one direction with a corresponding change in the opposite direction in another independent operating parameter, controlling the independent operating parameters in accordance with the comparison of the signals and the voltages and the last mentioned determination.
Claim 9
Independent Claim
175 words
A method for controlling a process so that independent and dependent operating parameters of the process do not exceed constraint values, which comprises providing outputs corresponding to predetermined changes in at least two independent operating parameters; providing groups of signals in accordance with the output, each group is associated with different independent operating parameters and the signals in that group correspond to predicted values for different operating parameters and the associated independent operating parameters providing a plurality of voltages, each voltage corresponds to a constraint value for different operating parameters; comparing each predicted value signal for an operating parameter with the constraint value voltage for the operating parameter; determining if the predicted values for an operating parameter exceed the operating parameter constraint value, determining in accordance with the previous determination if one independent operating parameter may be changed in one direction with a corresponding change in the opposite direction in another independent operating parameter, controlling the independent operating parameters in accordance with the comparison of the signals and the voltages and the last mentioned determination.
Claim 10
Dependent Claim
158 words
A method as described in claim 7 which further comprises determining if the predicted value signals for a dependent operating parameter exceed the constraint value for the dependent operating parameter controlling switch means to pass the predicted value signals for a dependent operating parameter when it has been determined that the predicted value signals have exceeded the constraint value voltage for a dependent operating parameter and to block the predicted value signals when at least one predicted value signal has not exceeded the constraint value voltage for a dependent parameter and comparing the passed predicted value signals, and increasing one independent operating parameter while decreasing the other independent operating parameter when the comparison indicates the predicted value signal for the independent operating parameter is substantially less than the other predicted value signal associated with the other independent operating parameter and maintaining both independent operating parameters at their present value when the passed predicted value signals are substantially equal.
Claim 11
Dependent Claim
139 words
A method as described in claim 7 in which the process is the fluid catalytic cracking of feedstock where the feedstock is preheated by a furnace and mixed with a fluid catalyst from a regenerator before entering a reactor, one effluent from the reactor is spent catalyst which is returned to the regenerator where air entering the regenerator from a blower aids in the regeneration of the catalyst, while another effluent from the reactor is fed to a primary fractionator which provides a variety of types of hydrocarbon stream, and a portion of one type of hydrocarbon stream which is a gas oil is recycled by a pump to be mixed with the feedstock before the preheated feedstock enters the reactor, and a portion of another hydrocarbon stream is converted to a gas which is fed to a compressor.
Claim 12
Dependent Claim
55 words
A method as described in claim 9 in which the one independent operating parameter is the temperature of the preheated feedstock, another independent operating parameter is the recycle rate of the recycle gas oil, and the other operating parameters are the blower speed, the regenerator temperature, the compressor speed and the fractionator top tower temperature.
Claim 13
Dependent Claim
104 words
A method as described in claim 10 in which the control step includes controlling the furnace to increase the preheated feedstock temperature when the comparing step indicates that none of the one group of predicted value signals exceed a corresponding constraint value voltage, and to maintain the preheated feedstock temperature when the comparing step indicates that at least one of the one group of predicted value signals exceed a corresponding constraint value voltage, and to maintain the gas oil recycle rate when the comparing step indicates that at least one of the other groups of predicted value signals exceeds a corresponding constraint value voltage.
Claim 14
Dependent Claim
174 words
A method as described in claim 11 in which the signal providing step includes sensing the blower speed, the preheated feedstock temperature, the recycle rate of the recycle gas oil, the compressor speed, the regenerator temperature and the primary fractionator top tower temperature; providing signals corresponding to the sensed blower speed, the sensed preheated feedstock temperature, the sensed recycle rate of the recycle gas oil, the sensed compressor speed, the sensed regenerator temperature and the sensed primary fractionator top tower temperature; providing a second plurality of signals, each signal corresponding to an increase in a dependent operating parameter as a function of a different independent operating parameter; summing the first and second outputs with the sensed preheated feedstock temperature signal and the sensed gas oil recycle rate signal, respectively, to provide predicted value signals for the predicted feedstock temperature and for the gas oil recycle rate, respectively, summing each signal of the remaining sensed signals with corresponding signals from the second plurality of signals to provide predicted value signals for the dependent operating parameters.
Claim 15
Dependent Claim
88 words
A method as described in claim 12 which further comprises determining if the predicted values for a dependent operating parameter exceed the dependent operating parameter''s constraint value, and determining in accordance with the previous determination if one independent operating parameter may be increased with a corresponding decrease in the other independent operating parameter, and the control step includes controlling the preheated feedstock temperature and the recycle rate of the recycle gas oil in accordance with the comparison of the signals and the voltages and the last mentioned determination.
Claim 16
Independent Claim
198 words
A system for controlling a process so that independent and dependent operating parameters of the process do not exceed constraint values, comprising means for providing outputs corresponding to changes in at least two independent operating parameters; means connected to the output means for providing groups of signals in accordance with the outputs from the output means, each group is associated with a different independent operating parameter and the signals in that group correspond to predicted values for dependent operating parameters and the associating independent operating parameter; means for providing signals corresponding to constraint values for different operating parameters; first means connected to the output means, to the predicted value signal means and to the constraint value signal means for controlling the output means to provide outputs corresponding to changes in the independent operating parameters that cause the predicted value of at least one operating parameter to be substantially equal to, but not exceed, the constraint value for that operating parameter; and second control means connected to the output means for controlling the independent operating parameters in accordance with the outputs from the output means with the output from the comparing means and the signals from the determining means.
Claim 17
Independent Claim
198 words
A system for controlling a process so that independent and dependent operating parameters of the process do not exceed constraint values, comprising means for providing outputs corresponding to changes in at least two independent operating parameters; means connected to the output means for providing groups of signals in accordance with the outputs from the output means, each group is associated with a different independent operating parameter and the signals in that group correspond to predicted values for dependent operating parameters and the associating independent operating parameter; means for providing signals corresponding to constraint values for different operating parameters; first means connected to the output means, to the predicted value signal means and to the constraint value signal means for controlling the output means to provide outputs corresponding to changes in the independent operating parameters that cause the predicted value of at least one operating parameter to be substantially equal to, but not exceed, the constraint value for that operating parameter; and second control means connected to the output means for controlling the independent operating parameters in accordance with the outputs from the output means with the output from the comparing means and the signals from the determining means.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |