Modelagem, simulação e avaliação de estratégias de controle na secagem de resina de PVC em leito fluidizado

Abstract

Fluidized bed dryers are relevant equipment in the drying stage of PVC resin. In light of this, this study described the development process of modeling and simulating the drying process of PVC resin in a fluidized bed with a single perfectly homogeneous zone with adaptation for multiple zones. The process was represented by a two-fluid model. The first fluid is the gas flowing forcibly through the bed of fluidized particles, hypothetically in a plug-flow regime. The second fluid is the particulate phase treated as a globally homogeneous mixture. The mathematical model was based on the conservation equations of mass and energy for the two fluids in transient regime. The model was numerically solved using the Euler method and finite differences, implemented in a computational code in Python language. Several simulations were performed by applying disturbances to process variables in order to analyze the dynamic aspects of the implemented model, such as sensitivity and response speed. The analyses of these dynamic responses, as desired, showed adherence to operational data from the plant.