Process Control: Modeling, Design, and Simulation

M8.1. Background

Chemical reactors often have significant heat effects, so it is important to be able to add or remove heat from them. In a jacketed CSTR (continuous stirred-tank reactor) the heat is added or removed by virtue of the temperature difference between a jacket fluid and the reactor fluid. Often, the heat transfer fluid is pumped through agitation nozzles that circulate the fluid through the jacket at a high velocity; an example recirculating jacket system is shown in Figure M8-1. Notice that cascade control is shown, with a primary controller (reactor temperature) and a secondary controller (jacket temperature). The output of the reactor temperature controller is the jacket temperature setpoint. The output of the jacket temperature ...