TY - JOUR

T1 - Generation of Dean vortices and enhancement of oxygen transfer rates in membrane contactors for different hollow fiber geometries

AU - Kaufhold, D.

AU - Kopf, F.

AU - Wolff, C.

AU - Beutel, S.

AU - Hilterhaus, L.

AU - Hoffmann, M.

AU - Scheper, T.

AU - Schlüter, M.

AU - Liese, A.

N1 - Funding information: This work is supported by the German Research Foundation (DFG), “Modulare Hohlfaserreaktoren in der Biotechnologie unter Berücksichtigung mikroskaliger Effekte” (DFG). The authors gratefully acknowledge this financial support.

PY - 2012/9/5

Y1 - 2012/9/5

N2 - This work aimed to study the enhancement of oxygen transfer rates in hollow fiber membrane contactors by applying Dean vortices. Systematic investigations of how the geometric parameters, like curve diameter, helical pitch or geometric shape, and flow rates affect the mass transport were done to assess the potential for membrane contactors. The membrane was a hydrophobic microfiltration hollow fiber (polypropylene). Helical, meander and twisted formed hollow fibers with fiber lengths from 5 to 30. cm and curvature diameters between 5 and 19. mm were constructed. The oxygen transfer rates per membrane area were investigated. The curved hollow fibers show a linear dependence between Dean number and enhancement factor and an increase of transfer rates up to an enhancement factor of 2.4. For the meander shaped fibers a critical Dean number/range between 10-20 was found, where the mass transport enhancement is adjusted rapidly to those of helical hollow fibers. Also the mass transfer in packed membrane modules was investigated, taking into account the theoretical packing densities of the different fiber geometries. It was found that a volumetric enhancement of gas transfer rates for helical and meander formed fibers can only be improved applying very small curvature diameters less than 4 mm.

AB - This work aimed to study the enhancement of oxygen transfer rates in hollow fiber membrane contactors by applying Dean vortices. Systematic investigations of how the geometric parameters, like curve diameter, helical pitch or geometric shape, and flow rates affect the mass transport were done to assess the potential for membrane contactors. The membrane was a hydrophobic microfiltration hollow fiber (polypropylene). Helical, meander and twisted formed hollow fibers with fiber lengths from 5 to 30. cm and curvature diameters between 5 and 19. mm were constructed. The oxygen transfer rates per membrane area were investigated. The curved hollow fibers show a linear dependence between Dean number and enhancement factor and an increase of transfer rates up to an enhancement factor of 2.4. For the meander shaped fibers a critical Dean number/range between 10-20 was found, where the mass transport enhancement is adjusted rapidly to those of helical hollow fibers. Also the mass transfer in packed membrane modules was investigated, taking into account the theoretical packing densities of the different fiber geometries. It was found that a volumetric enhancement of gas transfer rates for helical and meander formed fibers can only be improved applying very small curvature diameters less than 4 mm.

KW - Bubble-free aeration

KW - Dean vortices

KW - Gas-liquid contactor

KW - Hollow fiber membrane module

KW - Membrane gas absorption

UR - http://www.scopus.com/inward/record.url?scp=84867742591&partnerID=8YFLogxK

U2 - 10.1016/j.memsci.2012.08.035

DO - 10.1016/j.memsci.2012.08.035

M3 - Article

AN - SCOPUS:84867742591

VL - 423-424

SP - 342

EP - 347

JO - Journal of membrane science

JF - Journal of membrane science

SN - 0376-7388

ER -