Abstract: A method of welding porous tube ends onto a tube sheet is disclosed, wherein tube ends projecting over the tube sheet are fused into a melt. Part of the melt is conducted to the outside in a radial direction, so that it lies on the end face of the tube sheet. Melt and tube sheet are then welded together. The tube end is preferably cooled from the inside by a metal pin is inserted into the tube end.

Abstract: Fermented beverages of a reduced alcohol contents are made by causing the fermented beverage having a normal alcohol contents as produced in the fermentation to flow along one face of a dialysis membrane at a pressure differential below 5.0 bar while simultaneously a dialysate liquid which is substantially alcohol-free is passed along the other face of the dialysate membrane. An apparatus for carrying out the process comprises a housing in which two separate chambers are provided. Each chamber has separate inlet and outlet ducts. The inlet ducts are connected to separate feeding devices for liquids. Separate regulating devices are arranged for regulating the flow through each of said two chambers and means are provided for regulating the pressure differential between the two chambers.