Discrete particle simulations predicting mixing behavior of solid substrate particles in a rotating drum fermenter

• Published in: Biotechnology and bioengineering Vol. 75; no. 6; pp. 666 - 675
• Main Authors: Schutyser, M. A. I., Padding, J. T., Weber, F. J., Briels, W. J., Rinzema, A., Boom, R.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 20.12.2001; Wiley
• Subjects: Biological and medical sciences; Bioreactors; Biotechnology; Computer simulation; discrete particle simulations; Entropy; Fermentation; Fundamental and applied biological sciences. Psychology; Image analysis; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; mixing; scale-up baffles; Sectie Proceskunde; solid-state fermentation; Sub-department of Food and Bioprocess Engineering; Substrates; VLAG; Dimensioning; Solid substrate fermentation; Agitation; Mixing; Solid particle; Simulation
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.1192

A soft‐sphere discrete particle model was used to simulate mixing behavior of solid substrate particles in a slow rotating drum for solid‐state fermentation. In this approach, forces acting on and subsequent motion of individual particles can be predicted. The (2D) simulations were qualitatively and quantitatively validated by mixing experiments using video and image analysis techniques. It was found that the simulations successfully predicted the mixing progress as a function of the degree of filling and size of the drum. It is shown that only relatively large, straight baffles perpendicular to the drum wall (67% of the drum radius) increase the mixing performance of the rotating drum. Considering the different aspects of mixing dealt with in this work, it is concluded that the soft sphere discrete particle model can serve as a valuable tool for investigating mixing of solid substrate particles. Finally, it is expected that this model may evolve into a potential tool for design and scale‐up of mixed solid‐state fermenters. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 666–675, 2001.