We have measured the overall mass transfer coefficient of oxygen from water across a hollow fiber membrane into nitrogen. The membranes are microporous, so this overall mass transfer is controlled by the individual coefficient in the water. The membranes are incorporated into modules in which the fibers are carefully spaced, including modules made from hollow fiber fabric. At low flows, these modules give mass transfer which is up to ten times faster than that in commercial modules based on similar hollow fibers. This implies that fabric-based modules can give equivalent performance with less membrane area. The performance of the fabric-based modules approaches that of modules built by hand, one fiber at a time. It approaches that inferred for a single fiber from heat transfer correlations.
Bibliographical noteFunding Information:
This work was primarily supported by the Environmental Protection Agency (MTU 00569) and by the Hoechst Celanese Corporation, Separations Products Division. Other support came from the National Science Foundation (CTS 91-23837), from DARPA (92-05112), and from General Mills. E.L. Cussler held the Amundson Professorship during a sabbatical leave at M.I.T., where he was graciously received.
- concentration polarization
- fiber membranes
- microporous and porous membranes