Designing an Optimum Controller for a Spray Drying Process that Produces Micro-particles

Spray dryers represent an important unit operation in many industries such as pharmaceuticals and food. However, the approach to the design and control of spray dryers has been based primarily on heuristics. The traditional, serial approach to process design and control ignores the effect that the process design has on the control structure synthesis. Thus, it is not surprising that the achievable control performance is limited by the process design decisions. One approach to address this issue is to solve the design and control problems simultaneously. However, the simultaneous strategy can lead to a large and numerically intractable problem. In this work, a spray drying process that produces micro-particles is used to investigate optimum controller designs using different approaches. The first approach assumes that both the process and controller designs are to be found sequentially, while the second seeks to couple the controller design to the process design. Results, using the spray dryer system, are presented to show the potential of using the coupled strategy to satisfy finding a design that admits a feasible controller.