| 摘要 |
PURPOSE:To dehydrate sludge efficiently by decreasing gradually the pitch of the screw vanes provided to a screw shaft and narrowing gradually sludge passages thereby increasing compressive force. CONSTITUTION:The screw vanes 1 fitted to a screw shaft 2 are constituted of the 1st stage vanes 1-1 formed by winding and projecting spiral bodies at a relatively large pitch to a relatively thin-walled sleeve 3-1, the 2nd stage vanes 1-2 formed by winding and projecting the spiral bodies at a relatively small pitch to a slightly thick-walled sleeve 3-2 and the 3rd stage vanes 1-3 formed by winding and projecting the spiral bodies at the much smaller pitch to the further thicker-walled sleeve 3-3. The inside circumference of a cylinder 4 enclosing the vanes 1 is formed to a section having a disk tooth shape. Sludge is supplied through an inlet part 15 into the dehydrator constituted in such a way and cake is discharged through an outlet part 16, by which the sludge is dehydrated at a high dehydration rate and the combustion assistant in incineration disposition is decreased. |
