Method for operating rotating cylindrical filters and a rotatable cylindrical filter

A filter of the rotating kind comprising a substantially cylindrical filter jacket, a substantially cylindrical filter tube which has a permeable wall and which is sealingly journalled by seals and bearings at least one axial locations, for rotation about its longitudinal axis in said filter jacket, the material to be filtered, the feed, being supplied to a first space located at one end of and between the filter jacket and the filter tube, and the filtered material, the filtrate, being tapped from the interior of the filter tube, and wherein the seals (9, 14, 20, 21) and bearings of the filter tube (1) are sterilizably arranged and constructed so as to take up axial displacement movements and forces resulting essentially from changes in the temperature of the filter tube (1), seals and bearings comprising means including a journalling and sealing unit attached to said filter tube (1) and arranged adjacent said one end (1') of said filter tube (1), said unit comprising two substantially cylindrical parts (15', 16'), one external (15') and one internal (16'), which are arranged to co-act in a sealed and axially displaceable relationship, and wherein said seals (9, 14, 20, 21) and bearings are constructed to enable said seals and bearings to be sterilized and lubricated and cooled by means of a sterilizing media.