(572e) Coupled CFD-DEM Model of Fluidized Bed Drying of Pharmaceutical Wet Granules

Coupled CFD-DEM model of fluidized
bed drying of pharmaceutical wet granules

Here, we propose to present preliminary works to develop a
model based on Computational Fluid Dynamics (CFD) and Discrete Element Method
(DEM) coupling using opensource software for simulating gas-solid multiphase-multicomponent
flow (MMF) associated to the drug manufacturing process. MMF flow is prevalent
in a myriad of processes used in the pharmaceutical industry. Here, we seek to
understand the processes through the application of the two numerical
techniques with the overarching goal to the model the fluidized bed drying
process. The experimentally validated fluidized bed dryer model will allow for
both qualitative and quantitative study of fluidization and drying kinetics,
that is heat and mass transfer during drying. In addition, we envision to
investigate experimentally and numerically the different regimes of flow during
the drying process by systematically changing the process parameters. The software’s modular approach
permits to incorporate new models and can simulate large scale models with MPI
parallelization that would be beneficial for the engineers of Industry. The
validated and fine-tuned CFD-DEM coupling model will be beneficial as it is cost-effective,
amenable to changes in the boundary or the material properties of different
phases and finally offers better control in the processing parameters. Further,
the proposed process modeling will help reduce the drug development time
thereby preventing product delays, improve scale-up optimization and ease the
manufacturing process by serving as a priori predictive tool.

Keywords:

Multiphase-Multicomponent
flow, Fluidized bed, Powdered Material Drying, Computational Fluid Dynamics,
Discrete Element Method

Preliminary results:

The
CFD-DEM coupled model of packed bed using the opensource software CFDEM to
simulate multiphase-multicomponent flow pertaining to fluidization phenomena
has been preliminarily implanted by PI’s group. Such a model developed to
assess the capability of the simulation tool is verified to be capable to
replicate the fluidization process of varying particulate system and produce
comparable results with the empirical model available in the literature. The
force model is implemented to take into account the interaction among particles
and between particle and wall. The model used is the Gran-Hertz-History model
where a non-linear relationship is assumed between overlap distance during the collision
and normal contact force. The simplified fluid bed model has been used to assess
different coupling models, fluid-particle interaction force models, and
interdependency of mesh-particle size and volume fraction evaluation models. In
addition, different level of cohesive forces are investigated based on
simplified ‘jkr’ cohesion model to accommodate the
fluidization process of pharmaceutical powdered material.