UV Disinfection of E. coli Between Concentric Cylinders: Effects of the Boundary Layer and a Wavy Wall
Authors: Forney, L. J.1; Ye, Z.1; Koutchma, T.2
Source: Ozone: Science and Engineering, Volume 30, Number 6, November 2008 , pp. 405-412(8)
Publisher: Taylor and Francis Ltd
Abstract:
UV inactivation of E. coli in a plug flow reactor between concentric cylinders was investigated. The concentration boundary layer thickness was computed for laminar, turbulent and Taylor-Couette flow in terms of the respective mass transfer Sherwood number. It is demonstrated that the concentration boundary layer is thin and that the mass transfer coefficient is large and comparable in size for both turbulent and laminar Taylor-Couette flow in contrast to laminar flow. Computation of the fluence distribution for each flow pattern indicate that turbulent and especially Taylor-Couette flow subject E. coli to an equal flux of photons corresponding to ideal plug flow. However, experiments with turbulent flow that require large axial velocities indicate that very long reactor lengths are necessary to inactivate E. coli. Finally, rotor wavy wall modifications are explored to increase the inactivation of microorganisms in Taylor-Couette flow.Keywords: UV Disinfection; Plug Flow Reactor; Laminar; Turbulent; Taylor-Couette Flow
Document Type: Research article
DOI: 10.1080/01919510802473872
Affiliations: 1: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA 2: National Center for Food Safety and Technology, Illinois Institute of Technology, Summit-Agro, IL, USA

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