Hydrodynamics and Metzner–Otto correlation in stirred vessels for yield stress fluids

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 125; no. 1; pp. 15 - 24
• Main Authors: Anne-Archard, D., Marouche, M., Boisson, H.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2006; Elsevier
• Subjects: Applied sciences; Chemical engineering; Energy; Engineering Sciences; Exact sciences and technology; Fluid mechanics; Fluids mechanics; Hydrodynamics of contact apparatus; Laminar flow; Mechanics; Mixing; Non-Newtonian fluids; Numerical analysis; Fluid mechanics; Mixing; Numerical analysis; Non-Newtonian fluids; Energy; Laminar flow; Non Newtonian fluid; Energy consumption; Stirred vessel; Correlation; Approximation; Shear; Anchor agitator; Shear flow; Hydrodynamics; Modeling; Power law fluid; Correlation analysis; Numerical simulation; Yield stress
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2006.08.002

This paper investigates the hydrodynamics and power consumption in laminar stirred vessel flow using numerical computation. The Metzner–Otto correlation was established for mixing in power-law fluids. This paper focuses on its application to yield stress fluids. Distributions of shear rates and their link to power consumption for helical and anchor agitators are discussed. Insight is sought from the analytical formula for Taylor–Couette flows. Laws are established for Bingham, Herschel-Bulkley and Casson fluids and reveal similar results. Fully or partially sheared flow situations with plug regions are considered. Depending on the fluid model, the concept is valid or constitutes a satisfactory approximation for fully sheared flows. When the flow is partially sheared, the expression depends on the Bingham number and the concept must be adapted. The results of the numerical simulations are interpreted in the light of this analysis and results from the literature.