Experimental evaluation of bearingless spinfilter topologies

Rotating filter membranes can increase the long term filtrate flux by efficiently and continuously removing the retained particles on a microfiltration membrane. However, the practical implementation of rotating machinery in high purity applications such as biotechnological manufacturing of proteins raises concerns about the contamination of the process fluids due to submerged bearings and imperfect sealings to the outside environment. Bearingless and hermetically sealed spinfilters provide a solution to these drawbacks, but create challenges due to the contactless operation, and consequentially, the open internal gap between the feed and the filtrate. To address this, five bearingless spinfilter topologies to reduce the remixing across the open gap are proposed, experimentally evaluated, and discussed. Three spinfilter topologies reach a filtrate purity of 100%, while the best performing concept reaches specific filtrate fluxes of over 2300Lh−1m−2.