(328n) Simulation Of Drying Of Pharmaceutical Powders Via Dem

Kalvoda, E. - Presenter, Graz University of Technology
Khinast, J. G. - Presenter, Research Center Pharmaceutical Engineering GmbH

Drying of powders is an important process in many industries, especially in the pharmaceutical industry. In many dryers agitators are used to improve heat and mass transfer. Neither the drying process nor particle mixing mechanisms are fully understood until now. The moisture between the particles, the non-spherical particle shapes and the particle growth in the case of crystallisation make it difficult to predict the particle flow in the dryer. This makes it hard to optimise or to scale-up processes.

To be able to understand the drying process better, computer simulations were used to examine the particle flow in the dryer and the drying process itself. In this work a discrete element method code was adapted to be able to model the powder flow in the dryer and the particle mixing mechanisms. Experimental studies were carried out in order to get more insight into particle flows and to be able to validate the computational results. [1,2]

The DEM code developed during this research project will be able to model agitated powder flows and can be used to examine segregation mechanisms and cohesion in particle flows.

[1] A. Lekhal, S.L. Conway, B.J. Glasser, J.G. Khinast, 2006, Characterization of Granular Flow of Wet Solids in a Bladed Mixer, AIChE J. 52. [2] S.L. Conway, A. Lekhal, J.G. Khinast, B.J. Glasser, 2005, Granular Flow and Segregation in a Four-bladed Mixer, Chemical Engineering Science 60.