JP2907675B

PURPOSE:To provide a screw type dehydrater in which whole surface of discharge water screens is surely cleaned by a few pipings. CONSTITUTION:A material to be dehydrated (a) thrown in an annular space 3 from a throw in hole 10 provided on the base end part of an outside cylinder 2 is compressed and dehydrated, the dehydration resulting water is discharged to the outside through the discharge water screen 9 of the outside cylinder 2 and the dehydrated material (a) is discharged to the outside through a discharging port 11 provided on the front end side of the outside cylinder 2 by driving to rotate a ribbon shaped screw 4 arranged in the annular space 3 between the inside and outside cylinders 1 and 2 in a freely turnable state. A piping 5 having a cleaning water ejecting nozzle 5a opposite the discharge water screen 9 is arranged outside the outside cylinder 2 and a piping driving device 12 by which the piping 5 is moved back and forth within a specific angle is provided.