Viscosity effects on Dean vortex membrane microfiltration

Citation
T. Kluge et al., Viscosity effects on Dean vortex membrane microfiltration, AICHE J, 45(9), 1999, pp. 1913-1926
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemical Engineering
Journal title
AICHE JOURNAL
ISSN journal
0001-1541 → ACNP
Volume
45
Issue
9
Year of publication
1999
Pages
1913 - 1926
Database
ISI
SICI code
0001-1541(199909)45:9<1913:VEODVM>2.0.ZU;2-I
Abstract
The influence of changing viscosity by adding polyethylene glycol (PEG) dur ing microfiltration of silica suspensions in the presence and absence of De an vortices was determined A new microfiltration membrane module design con taining helically wound hollow fibers (with Dean vortices) was compared wit h a standard commercial cross-flow module (without Dean vortices) containin g linear hollow fibers during filtration of poly(ethylene) glycol solutions and silica suspensions. The influence of solution viscosity on permeation flux behavior was evident through two separate effects. First, increased vi scosity effected the formation and stability of vortices and hence, wall sh ear rate and convective back-flow. Second permeation flux was reduced with increasing fluid viscosity. Flux improvements (linear us. helical membranes ) of up to 45% were observed for all value of the silica suspensions with a nd without PEG. The energy required to obtain these improvements, however w as considerable. Flux advantages of the helical design decreased and eventu ally disappear-ed as the viscosity of the solution increased Lip to 12 time s that of water at 27 degrees C. New mass-transfer correlations for microfi ltration of poly(ethylene) glycol solutions containing silica concentration s for laminar flow in a helical and a linear module were obtained with resp ect to the solution viscosity, for a silica particle concentration of 0.1 w t. %.