By Doug Cooper and Allen Houtz1 As discussed in previous articles, the purpose of the feed forward controller of the feed forward with feedback trim architecture is to reduce the impact of one specific disturbance, D, on our primary process variable, PV. An additional sensor must be located upstream in our process so we have […]

By Doug Cooper and Allen Houtz1 The most popular architectures for improved disturbance rejection performance arecascade control and the “feed forward with feedback trim” architecture introduced below. Like cascade, feed forward requires that additional instrumentation be purchased, installed and maintained. Both architectures also require additional engineering time for strategy design, implementation and tuning.

Our control objective for the jacketed stirred reactor is to maintain reactor exit stream temperature at set point in spite of disturbances caused by a changing cooling liquid temperature entering the vessel jacket. In previous articles, we have established thedesign level of operation for the reactor and explored the performance of a single loopPI controller and a PID with CO Filter controller in meeting our control objective.

Our control objective for the jacketed stirred reactor process is to minimize the impact on reactor operation when the temperature of the liquid entering the cooling jacket changes. We have previously explored the modes of operation and dynamic CO-to-PV behavior of the reactor. We also have established the performance of a single loop PI controller […]

By Bob Rice1 and Doug Cooper The control objective for the pumped tank process is to maintain liquid level at set point by adjusting the discharge flow rate out of the bottom of the tank. This process displays the distinctive integrating (or non-self regulating) behavior, and as such, presents an interesting control challenge. The process […]