Today in 1989, US Patent 4844932 A was issued, an invention of Iyadh S. Daoud, assigned to The Brewing Research Foundation, for his “Separation of Wort From Mash.” Here’s the Abstract:
A barrier cross-flow separation method is used to separate wort from mash in beermaking. The separator medium is preferably a cylindrical element with an internal diameter of at least 20 mm and a pore size in a range of from 10 μm to 100 μm. High gravity wort is obtainable from a four-step separation process which can handle mash free of husk and including large amounts of cereal adjunct. The wort may be clarified in a subsequent filtering step.