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Viscosity effects on Dean vortex membrane microfiltration
Author(s) -
Kluge Tanja,
Kalra Amrit,
Belfort Georges
Publication year - 1999
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690450909
Subject(s) - microfiltration , viscosity , laminar flow , membrane , permeation , ethylene glycol , vortex , chemical engineering , chemistry , filtration (mathematics) , polyethylene glycol , peg ratio , materials science , chromatography , thermodynamics , composite material , organic chemistry , biochemistry , physics , statistics , mathematics , finance , engineering , economics
The influence of changing viscosity by adding polyethylene glycol (PEG) during microfiltration of silica suspensions in the presence and absence of Dean vortices was determined. A new microfiltration membrane module design containing helically wound hollow fibers (with Dean vortices) was compared with a standard commercial cross‐flow module (without Dean vortices) containing 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 viscosity effected the formation and stability of vortices and, hence, wall shear rate and convective back‐flow. Second, permeation flux was reduced with increasing fluid viscosity. Flux improvements (linear vs. helical membranes) of up to 45% were observed for all value of the silica suspensions with and without PEG. The energy required to obtain these improvements, however, was considerable. Flux advantages of the helical design decreased and eventually disappeared as the viscosity of the solution increased up to 12 times that of water at 27°C. New mass‐transfer correlations for microfiltration of poly(ethylene) glycol solutions containing silica concentrations for laminar flow in a helical and a linear module were obtained with respect to the solution viscosity, for a silica particle concentration of 0.1 wt. %.