A Scale‐up Strategy for the Fluid Flow in Biogas Plants. Issue 4 (1st March 2018)

• Record Type: Journal Article
• Authors: Annas, Sven; Jantzen, Hans-Arno; Scholz, Jürgen; Janoske, Uwe
• Is Part Of: Chemical engineering & technology. Volume 41:Issue 4(2018)
• Page Start: 739
• Page End: 746
• Publication Date: 2018-03-01
• Subjects: Biogas plant -- Computational fluid dynamics -- Mixing process -- Non‐Newtonian fluids; Chemical engineering -- Periodicals; Chemical processes -- Periodicals; 660.05
• DOI: 10.1002/ceat.201700447
• Languages: English
• ISSNs: 0930-7516

Abstract

Abstract: The mixing process in biogas plants is fundamental for effectiveness. Unfortunately, difficulties at full scale mean that research must usually be performed at lab‐scale and the results up‐scaled. This study presents a scale‐up strategy for the fluid flow in shear‐thinning non‐Newtonian fluids. Dimensional analysis was applied to connect the influencing parameters, i.e., geometric dimensions, rotational speed, and rheological properties, to key figures. By using the Reynolds and Hedström number, standards for adapting the rotational speed and rheological properties were defined as a function of the scale. A sliding‐mesh model was selected for numerical simulations of a plant with a paddle agitator at two different scales. The scale‐up approach leads to similar velocity fields, which result in equal normalized mixing times. Abstract : The mixing process in biogas plants is crucial to effectiveness. Difficult test conditions at full scale mean that experiments must be conducted at lab‐scale. To cover flow characteristics, scale‐up conditions have to be defined to transfer findings from the model to the original scale. Similarity laws are applied to find conditions necessary for achieving equal mixing processes at different scales.