The effect of radial impeller geometry on the link between power and flow numbers

• Published in: AIChE journal Vol. 68; no. 1
• Main Authors: John, Thomas P., Fonte, Claudio P., Kowalski, Adam, Rodgers, Thomas L.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.01.2022; American Institute of Chemical Engineers
• Subjects: Angular momentum; Computational fluid dynamics; Computer applications; Dimensional analysis; Dimensionless numbers; Flow; Fluid dynamics; fluid mechanics; Hydrodynamics; Impellers; Mathematical analysis; mathematical modeling; Mixers; mixing; Power consumption; Prediction models; Vessels
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.17405

Impellers in stirred vessels are often characterized by dimensionless numbers such as the power and flow numbers. These are often crucial in determining mixing performance. Previous studies for high‐shear mixers have yielded correlations between the power, flow, and mixer geometries, since in these mixers the flow can be independently varied. For stirred vessels, dimensional analysis is typically used to develop such correlations, leading to less accurate predictive models. Here, we combine an analysis based on a balance of angular momentum balance with computational fluid dynamics simulations to comprehensively study the effect of impeller geometry on the relationship between power and flow. The results allow for the prediction of the flow generated by the impeller based on the easily measurable impeller power consumption and the geometrical dimensions of the impeller. The models are accurate over a wide range of geometries. Furthermore, we are able to predict both the primary and total flows.