TABLE OF CONTENTS Increase Benefits in all areas
Do you have loops not running in the highest design mode (e.g., auto, cascade, supervisory) because of oscillations, poor control, upsets? Look for improvement by the use of auto tuners, gain scheduling, fast reproducible measurements, better loop designs, and negligible valve stick-slip.
Do you have upsets (bumps) on critical process parameters from process interactions? Look for model predictive control to decouple and anticipate upsets.
Do you have upsets from cycling back and forth across a split range point? Look for ways to eliminate split range or make transitions smoother with model predictive control.
Do you have a tool to define correlations and interactions in systems? Install a performance monitoring-system and advanced data-analysis tools.
Do you have bad measurements that you can't rely on? Improve measurements by using advanced technologies. Calculate batch averages and alert on deviations. (e.g., Don't rely on pH for endpoint detection if curve is different from previous good batches.)
Do you have areas you can't control because they are hard to measure? Calculate property estimators from other measurements and design new control schemes.
On continuous processes, do you have ratios installed on related flow loops or is everything set individually based on max feed rates? Ratio control can be installed on wastewater-to-feed rate, steam-to-column or reactor-feed rate, additives (soap, oil, anti foam)-to-filter or column-feed rate.
On set point changes, does it take a long time for the variable to really start to move and once moving does it go into an overshoot...
