ControlSoft strategy for cooking stations

 “Advanced Process Controllers Improve Temperature Control for Cooking Stations,” explains how this real-world project was initiated when a major food processor had problems with the heating control on a cooking station using two Scraped Surface Heat Exchangers (SSHE) in a continuous process.Traditional PID control could not eliminate final product temperature oscillation, thus creating off-spec product when the final outlet temperature exceeded a maximum temperature limit. Also, exceeding the maximum temperature limit caused fouling of the heat exchanger surface, thereby reducing heat transfer, requiring higher steam temperatures, and decreasing run time between cleanings.Advanced Process Controllers (APC) met the challenge of eliminating final product temperature oscillation and providing more responsive and tighter temperature control than the commonly used PID controller.ControlSoft was given the task of achieving the tight control needed to stabilize the system, to account for the non-linearity due to different product rates, and to adjust for inlet temperature disturbances. After implementing the chosen control strategy, the temperature variations were reduced by 60 to 80%.  Engineers and operations people may request a free copy by going to www.controlsoftinc.com and selecting AN321 from the technical papers section, where it is listed by category along with other available papers (food and beverage, fermentation and biochemical, etc.).