(428d) Automated Process Control Laboratory Experience: Simultaneous Temperature and Level Control in a Continuously Stirred Tank Reactor System

A process control laboratory experience has been developed using a continuously stirred tank reactor system that permits simultaneous level and temperature control using water as the process medium.  This work was originally completed as a senior honors thesis project, and the resulting system has been successfully incorporated into the process control block of a junior-level unit operations laboratory course.  Use of the apparatus over multiple laboratory sessions provides students with a hands-on experience that illustrates the concepts of system characterization (e.g., calibration, determining operating ranges, understanding electromechanical component specifications, etc.), open-loop process response measurements, and closed-loop response and PID tuning.  A controller program to interface with the valves and sensors and to perform data logging was constructed in LabView, employing a graphical user interface.  As part of the experience, all sensors and valves of the system are to be characterized and calibrated.  The two system processes—i.e., temperature and height—are run in an open loop manner, with data collection providing a means to determine appropriate process models.  Process parameters from these models permit the estimation of controller tuning values (i.e., controller gain and time constants) through formula- or software-driven means (e.g., Control Station Loop-Pro).  SISO configurations are then employed to test various control settings for tuning purposes, with the use of hand-tuning techniques to refine these values.  The system can ultimately be operated in a MIMO configuration without and with decoupling gains; the typical oscillatory behavior without decoupling is demonstrated due to the inherent process interactions.