Temperature control system for a clean-in-place process in a brewery plant

This paper presents the design of a PI type controller for a clean-in-place (CIP) system in a brewery plant. A CIP process consists of an automatized system employing caustic or acid solutions to clean and disinfect other systems, especially those used in the food industry. The plant model has the steam flow entering the CIP heater and the ambient temperature as input variables, and the solution temperature at the heater exit as output variable. Our results show the system has an approximate response to a first-order system. The settling time of our model, as being relatively high, indicates that the system allows the design of slower controllers for those employed in electromechanical systems. During the design, three PI controllers candidates were tested, from which, the controller offering 19.1% of overshoot and 8.52 seconds of settling time was chosen. Results also indicate that a perturbation on the ambient temperature had a negligible effect on the controlled system.