Apparatus for the dewatering of sludge

A rectangular dewatering tower (2) contains a bed of sludge layers (74) formed on a belt (70) laid in loops. Between the sludge charging from the top of the open tower to in each case one loop section of the belt and the removal of belt material together with the particular sludge layer at the lower end, the sludge is dewatered automatically under its own weight, and the issuing water can flow out downwards into appropriate collection troughs (50). During the removal, the belt passes together with the sludge layer through a slatted floor (40) which is formed from rods and which takes up the load of the sludge layer present in the tower. When belt material is removed together with the particular sludge layer, the tower moves to and fro on a straight-line track, and the passage opening (44) can be kept essentially stationary in spite of the movement of the tower by retraction and insertion of slats (42) from and into the slatted floor. The apparatus makes it possible to dewater large quantities of sludge at low energy consumption.