O. Morineau-thomas et al., Comparison of two types of flows (crossflow and swirling flow) in ultrafiltration modules - Influence of the wall constraint, CAN J CH EN, 78(1), 2000, pp. 248-260
This work consists of evaluating the performances of a new membrance separa
tion process: an annular, swirling, decaying flow induced by a tangential i
nlet. For this purpose, we have compared the permeation flux obtained in sw
irling flow with that of a crossflow. We ultrafiltered a model suspension o
f bentonite in order to compare the performances of the two modules for dif
ferent operating conditions. Parameters such as flow rate, Reynolds number
and wall velocity gradient were studied, and this last one appears to be a
significant hydrodynamic parameter to compare the performances of the two c
onfigurations. Indeed, this parameter takes into account the flow field nat
ure and, more precisely, the shear stress at the membrane surface. improvem
ent of the permeation flux induced by the swirling, decaying flow in compar
ison with that observed in cross-flow can reach more than 30% under specifi
c conditions. The study of the energy consumption of these two cells allows
us to confirm the interest of the swirling, decaying flow in order to desi
gn new types of membrane separation modules.