Paavola M., El Hagrasy A., Litster J., Leiviska K., 2013, 3D Population Balance Model for Continuous Twin Screw Granulator, Chemical Engineering Transactions, 32, 2077-2082.
Continuous processes could be applied to improve cost-efficiency of pharmaceutical manufacturing that has traditionally relied on batch processing due to regulatory requirements and small lot sizes. However, in order to utilize this new approach and to meet the end-product requirements, understanding of the dominating granulation sub-processes is needed. One tool for gaining such knowledge is population balance (PB) modeling. This paper describes initial steps in developing a three dimensional PB model for a continuous twin screw granulator. The focus is on the modeling of the rate processes considered dominant in the screw elements of the granulator, namely consolidation and aggregation. In formulating the three-dimensional PB the particle properties (size, porosity and saturation) are presented in terms of volumes of solid, liquid and gas. The results demonstrate correct behavior of the model and thus, the proposed solution could be used as a basis for further development.
