Comparison between Real-Time Auto-Tuning PID and Conventional PID Controller for a Dairy Industrial Evaporation Process

Evaporation processes are commonly applied in the food industries to concentrate the liquor for future treatments. It presents challenges to the modelling and control approaches due to the system complexity, especially for the multi-effect evaporators. In this study, an industrial milk evaporation process is introduced and a mathematical model of a three-effect falling film evaporator is developed using MATLAB/Simulink with added disturbances. A real-time closed-loop auto-tuning PID and a conventional PID are both presented and applied to the model as the control strategies for the evaporation process. The simulation results are compared to illustrate the improvements from the auto-tuning PID controller.