Development of a multiple rotary cylindrical filter (MRCF) system for brewing and other industrial applications.

Lee, S.Y., Kemper, E.A., Karr, T.L., Thomas, D. and Patino, H.

Abstract
A novel filtration system, consisting of three rotating cylindrical metal membrane cartridges in a single cylindrical housing, is described. The rotation of the cylinders generates a complex pattern of turbulence which changes continuously in a highly chaotic manner and helps to prevent particles from settling on the membrane and fouling it. The liquid to be filtered is piped in under nitrogen pressure. The filter is kept clean by regular flushing with cold caustic solution followed by rinsing, with an occasional soaking in a warm solution of an enzyme based "biological" detergent to break down any organic residues adhering to the filter elements followed by backflushing with hot water at maximum rotation. Trials of the filter system in brewing applications (filtration of rough matured beer and recovery of residual beer from tank bottoms) are described, showing that the system described can maintain a working flux rate for a period several times longer than a stationary filter using the same membrane cartridges (9 hours for ordinary rough beer rather than 2 hours, and 7 hours 30 minutes for tank bottoms instead of only 2 minutes). The "multiple rotary cylindrical filter" (MRCF) system has been patented (US Pat. US 5387339).
Keywords : beer equipment filtration membrane performance