Grey-box model calibration and validation for a continuous horizontal fluidized bed dryer

•Grey-box modeling is applied to a continuous horizontal fluidized bed dryer.•Product is displaced by a screw conveyor and fluidized by two gas chambers.•Data from a dynamically operated prototype validates the model.•Results highlight the shortcomings in the modeling assumptions.•Potential improvements to the prototype design are also raised. Fully continuous drying can improve the production flexibility and throughput of tablets manufactured by wet granulation lines. A recently developed prototype incorporates a screw conveyor to a horizontal fluidized bed dryer for pharmaceutical particles. Research on advanced process control strategies led to the publication of a two-phase tanks-in-series framework to describe its dynamics. This paper calibrates the model to replicate the prototype behavior. A grey-box identification methodology estimates the empirical and uncertain parameters using experimental input-output data. The underlying assumptions are cross-validated with time-domain comparisons, output root mean square errors and confidence intervals. Results show that the model reproduces the observed trends in general and the discrepancies result from mechanical issues on the equipment.