Control and Optimization of a Multiple Effect Evaporator

Multiple effect evaporator control is a problem that has been widely reported in the pulp and sugar industries. Evaporators are the largest heat users and major contributors to losses in sugar cane factories. These factors make effective evaporator control crucial to overall factory efficiency. The complexity and large number of interactions make single loop PID control (the conventional proportional, integral and derivative control) difficult and often sub-optimal. A Model Predictive Control (MPC) algorithm is presented as a different approach to solving the multiple input, multiple output problem. This technique has been applied successfully in other multiple station industries and is being applied to a dynamic model of the evaporator station at Triangle Limited.