A device for filtering liquids comprising two shafts which are parallel to each other or at an acute angle wherein each shaft carries a stack of disks that extend perpendicularly to the shaft axis and are rotated thereby. The disks of one stack are engaged in the intermediate spaces of an adjacent disk stack and at least one of the shafts is driven. At least one of the shafts is hollow and is provided with bores and some of the disks have channels therein which are fluidly connected to the inside of their respect hollow shaft. A support ring is oversized in relation to the shaft so that a channel is formed between the inner surface of the support ring and the outer surface of the shaft and this channel extends over at least part of the length of the shaft.