A mini-module with embedded spacers for high-throughput ultrafiltration

Abstract

Ultrafiltration membrane modules suffer from performance losses that arise during filtration from concentration polarization and fouling. Such performance losses are frequently mitigated by controlling the hydrodynamic conditions at the membrane/fluid interface. For instance, the hydrodynamic conditions are manipulated using mesh spacers that act as a static mixer. The design of such spacers is rarely optimized to effectively maintain mass transport through the membrane. Also, the spacer is an additional part added to the feed channel of the membrane module, improving mass transport in general, yet accepting less transport in dead zones. Here, we present a mini module with spacers embedded in the module housing of a flat-sheet ultrafiltration membrane to attain high permeation rates. The performance of two new embedded spacer geometries – staggered herringbone and sinusoidal corrugation – prove experimentally that indeed a CFD-simulated flux increase can be realized during bovine serum albumin (BSA) filtration. The flow characteristics inside the mini module are further investigated using magnetic resonance velocity imaging. The new embedded sinusoidal corrugation spacers outper- form conventional mesh spacer inlays. The fabrication of such module-embedded spacers has been conceptually implemented through an in-silico design and a 3D-printing production process. The latter can be easily realized using injection molding processes, as is now done for the Sartorius ambra(R) crossflow product line.