Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part II—Model and process analysis

In part I of this study, a mathematical model for the top-spray fluidised bed coating process was presented. In this second part, the capabilities of the model are illustrated by performing a detailed sensitivity analysis. The results clearly show that, besides the fluidisation air temperature and volumetric flow rate, the atomisation air pressure and temperature have a significant impact on the fluidised bed’s thermodynamic operation point. Considering the sensitivity of both the thermodynamic characteristics of the bed and the energetic efficiency of the coating process, the spraying rate was found to be main control variable for future model-based control applications in fluidised bed coating. Finally, increasing the relative size of the spraying region or increasing particle mixing has a narrowing effect on the coating mass distribution, which could be used in obtaining particles with a required coating distribution.