A semi-theoretical model for simulating the temporal evolution of moisture-temperature during industrial fluidized bed granulation
Moisture plays a major role in determining the attributes of granules prepared by fluidized bed granulation (FBG). Here, a semi-theoretical droplet-based evaporation rate model was developed and incorporated into moisture mass-enthalpy balances to simulate the temporal evolution of bed moisture-temperature.
Experimental data from a GPCG30 unit were used to fit the model parameters. With only two fitting parameters, the model demonstrated excellent capability to describe the moisture-temperature evolution for a wide range of operating conditions. Then, in a global process model (GPM) approach, the evaporation parameters were fitted to multi-linear functions of inlet air temperature, binder concentration, and spray rate.
The GPM was validated successfully by simulating a different data set which was not used in its calibration. As the GPM demonstrated a good predictive capability, it was further used to investigate the impacts of process parameters. Numerical simulations suggest that the proposed GPM predicts the experimentally well-established trends of moisture-temperature profiles in previously published data, proving the applicability of the GPM approach. This study has demonstrated the capabilities of simple process models as a practical approach to predict time-wise evolution of bed moisture-temperature profiles in industrial FBG modeling, while also pointing out their limitations.
Hossein Amini, Xiaorong He, Yin-Chao Tseng, Gulsad Kucuk, Robert Schwabe, Leon Schultz, Martin Maus, Daniela Schröder, Pavol Rajniak, Ecevit Bilgili, A semi-theoretical model for simulating the temporal evolution of moisture-temperature during industrial fluidized bed granulation, European Journal of Pharmaceutics and Biopharmaceutics,
Volume 151, 2020, Pages 137-152, ISSN 0939-6411, https://doi.org/10.1016/j.ejpb.2020.03.014.