Hybrid Mechanistic-Empirical Approach to the Modeling of Twin Screw Feeders for Continuous Tablet Manufacturing

Abstract

Nowadays, screw feeders are popular equipment in the pharmaceutical industry.However, despite the increasing research in the last decade in the manufacturing of powder-based products, there is still a lack of knowledge on the physics governing the dynamic behaviour of these systems. As a result, data-driven models have often been used to address process design, optimisation and control applications.In this paper, a methodology for the modelling of twin screw feeders has been suggested. A rst order plus dead time model has been developed where a hybrid mechanistic-empirical approach has been used. Dierent powders and two screw feeder geometries have been investigated. The model predictions are in good agreement with the experimental measurements when the 35-mm diameter screws are employed. When the 20 mm-diameter screws are used, the validity range of the model is limited for the least cohesive powders, suggesting that their screw speed-dependant resistance to ow in small screws requires further investigations.

Feed factor profile prediction model for two-component mixed powder in the twin-screw feeder

“…The mixing behaviors in the feeder were modeled by residence time distribution modeling ( Van Snick et al, 2019 ; Waeytens et al, 2022 ). Physical models with lumped parameters were developed based on the pressure exerted by the powder in the hopper and powder extrusion by the screw ( Wang et al, 2017b ; Bascone et al, 2020 ). The parameters have to be determined by experimental data for each powder.…”