Spirally-stacked type sludge dehydrating machine

The utility model discloses a spirally-stacked type sludge dehydrating machine. The sludge dehydrating machine is characterized by comprising a hollow cylinder, wherein the cylinder is internally provided with a rotating shaft through which a screw conveyer is driven; an inlet is formed in the upper end of one side of the cylinder and the other end of the cylinder is provided with a backpressure plate; the screw conveyer is divided into two parts which have different pitches, wherein the pitch of one end, close to the inlet, of the screw conveyer is relatively large and the pitch of one end, close to the backpressure plate, of the screw conveyer is relatively small; two water outlet zones are arranged outside the cylinder, a plurality of water outlet holes are formed in each of the water outlet zones along the radial direction of the cylinder, and a sliding sleeve is arranged on a part, corresponding to the hollow cylinder, outside the cylinder on each water outlet zone in a sleeve manner; the two water outlet zones are located in two zones with different pitches of the screw conveyer.