Scaling of continuous twin screw wet granulation

Juan G. Osorio, Ridade Sayin, Arjun V. Kalbag, James D. Litster, Laura Martinez-Marcos, Dimitrios A. Lamprou, Gavin W. Halbert

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)
78 Downloads (Pure)


Scaling rules were developed and tested for a continuous twin screw wet granulation process using three scales (11, 16, and 24 mm barrel diameter) of twin screw granulators (TSG). The distributive feed screw configuration used produced high porosity granules (50-60%) with broad bimodal size distributions, especially in the 16 and 24 mm TSGs. Three dimensionless numbers, Froude number (Fr), liquid-to-solid ratio (LSR), and powder feed number (PFN), were identified and their effect on granule size distribution (GSD), porosity and liquid distribution tested. Granule size increased with increasing LSR as expected. However, Fr and PFN had no significant effect on d10 or d50 and only a small effect on d90. In contrast, granulator scale had a strong effect on GSD, with d90 increasing almost linearly with barrel diameter. This is consistent with breakage of large granules being a dominant mechanism and directly controlled by the geometry of the screw.

Original languageEnglish
Number of pages12
JournalAIChE Journal
Early online date19 Aug 2016
Publication statusE-pub ahead of print - 19 Aug 2016


  • continuous manufacturing
  • powders
  • scaling
  • twin screw granulation

Cite this