Inducing secondary flows and vortices is known to enhance mass transport.
They can be imposed by structured flow channels for instance. In particular,
these vortices reduce fouling and concentration polarization. In this work we
present a new method of producing hollow fiber membranes with a sinusoidal
change in diameter over the fiber length. We engineered a pulsation module that
imposes a sinusoidally fluctuating bore liquid flow rate. Harmonic bore flow
conditions can be varied over a wide range. The fluctuating bore liquid flow
rate translates into axial membrane properties varying with respect to inner
bore diameter and wall thickness. The resulting narrowing and widening of the
membrane lumen channel are hypothesized to induce secondary vortices to the
liquid inside the membrane lumen known as the Bellhouse effect. Improved oxygen
transport from shell-to-lumen side prove superiority over straight hollow fiber
membranes in G/L absorption process. We anticipate the dynamic flow module to
be easily integrated into currently existing hollow fiber membrane spinning
processes
