Today in 1987, US Patent EP 0208450 A2 was issued, an invention of Ronald Shackleton, for his “Beer Filtration.” Here’s the Abstract:
It has been proposed to filter beer or tank bottoms using crossflow filtration. In accordance with the invention, this crossflow filtration is achieved using ceramic membranes. In a particular form shown in figure 1, a two stage filtration process combines the functions of clarification and recovery from tank bottoms. Beer is drawn from a tank 1 by a centrifugal pump 2 to a primary filtration stage comprising a circuit in- cludinga a circulating centrifugal pump 3, a ceramic membrane filter 4 and a cooler 5. A proportion of the circulating liquid is drawn off by a positive pump 8, and passed to a secondary filtration stage, again comprising a circuit including a circulating positive pump 9, a ceramic membrane filter 11 and a cooler 12. A proportion of the retentate is drawn off via a line 14. This retentate is of a pasty consistency and normally has a commercial value, in that it is free of kieselguhr or other filter aid.