Automatic control system for unit operation

An automatic control system for a distillation column comprising:

• (a) a real distillation column wherein an average middle temperature (AMT) of the distillation column is measured in real-time intervals and an output signal corresponding to the measured AMT is obtained;
• (b) a real-time dynamic simulator of the distillation column, wherein a corresponding AMT is estimated in real-time intervals and an output signal corresponding to the estimated AMT is obtained;
• (c) a calculator for receiving the measured AMT output signal and the estimated AMT output signal and calculating their difference and then providing a calculated AMT output signal that corresponds to that difference;
• (d) mirroring controller that is capable of receiving the calculated AMT output signal from the calculator and generating a change signal to the real-time dynamic simulator, whereby the estimated AMT is updated in the real-time dynamic simulator which then generates both an updated estimated AMT to the calculator and a feed-back output signal that corresponds to the updated estimated AMT of the distillation column;
• and
• (e) feed-back control unit that is capable of receiving the feed-back output signal from the real-time dynamic simulator and then generating control output signals to both the real distillation and the real-time dynamic column simulator, said control output signals capable of adjusting the AMT in the distillation column and in the real-time dynamic simulator.

An automatic control system for anode adjustment in a chlor/alkali cell comprising:

• (a) at least one anode for a chlor/alkali cell;
• (b) means for measuring the current and the voltage for that anode;
• (c) anode adjuster for raising or lowering that anode to change the distance between that anode and the cathode of the chlor/alkali cell;
• (d) means for measuring the K-factor for that anode in real-time intervals and means for generating an output signal corresponding to that measured K-factor;
• (e) a real-time dynamic simulator of that anode and that anode adjuster where the K-factor is estimated in real-time intervals and an output signal corresponding to the estimated K-factor is obtained;
• (f) a calculator for receiving the measured K-factor signal and the estimated K-factor signal and calculating their difference and converting that difference into a calculated K-factor error output signal;
• (g) a mirroring controller capable of receiving that calculated K-factor error signal and converting it into a change signal that is sent to the real-time dynamic simulator which then generates both an updated estimated K-factor output signal to the calculator and an estimated anode position feed-back output signal;
• and
• (h) a feed-back controller that is capable of receiving that estimated anode position feed-back output signal from the real-time dynamic generator and then generating control output signals to both the anode adjuster and the real-time dynamic simulator, said control output signals capable of raising or lowering the anode adjuster in the chlor/alkali and capable of adjusting the simulated anode adjuster in the real-time dynamic simulator.

The process for controlling at least one average middle temperature in a distillation column comprising the steps of:

• (1) generating at least one measured output signal in real-time intervals for a real distillation column, said output signal or signals corresponding to a measured average middle temperature of the distillation column;
• (2) generating at least one estimated output signal in real-time intervals from a real-time dynamic simulator, said estimated output signal or signals corresponding to an estimated average middle temperature of the real-time dynamic simulator;
• (3) comparing each corresponding measured output signal and estimated output signal and calculating the difference between those signals;
• (4) converting this calculated output signal into a change signal;
• (5) generating an updated estimated output signal in the real-time dynamic simulator based on this change signal and sending this updated estimated output signal to step (3);
• (6) generating a feed-back output signal in the real-time dynamic simulator based on the change signal, wherein the feed-back signal corresponding to the updated estimated average middle temperature in said distillation column, and
• (7) converting that feed-back signal in to a control signal to the distillation column to the real-time dynamic simulator, wherein the average middle temperature distillation column and the estimate average middle temperature in the real-time dynamic simulator are both adjusted.

The process for controlling at least one variable parameter of an anode adjuster system of a chlor/alkali cell comprising the steps of:

• (1) generating at least one measured output signal in real-time intervals for an anode adjuster system of a chlor/alkali cell, said output signal or signals corresponding to a measured variable process parameter or parameters of the anode adjuster system of the chlor/alkali cell;
• (2) generating at least one estimated output signal in real-time intervals from a real-time dynamic simulator;
• said estimated output signal or signals corresponding to an estimated variable process parameter or parameters of the real-time dynamic simulator;
• (3) comparing each corresponding measured output signal and estimated output signal and calculating the difference between those signals;
• (4) converting this calculated output signal into a change signal;
• (5) generating an updated estimated output signal in the real-time dynamic simulator based on this change signal and sending this updated estimated output signal to step (3);
• (6) generating a feed-back output signal in the real-time dynamic simulator based on the change signal, wherein the feed-back signal corresponding to the updated estimated variable parameter in said anode adjuster system for the chlor/alkali cell;
• and
• (7) converting that feed-back signal into a control signal to the anode adjuster system for the chlor/alkali cell and to the real-time dynamic simulator, wherein the variable parameter of the anode adjuster system for the chlor/alkali cell and the estimated process parameter in the real-time dynamic simulator are both adjusted.