| 摘要 |
PURPOSE:To perform a dredging work which is prevented from dispersion, by a method wherein the notched part of a screw blade is formed in the one end, located below and in the vicinity of an exhaust port at the upper part of a casing, of a spiral screw. CONSTITUTION:When sediment 16, intended to be lifted up within a casing 9 for discharge, is lifted up to a notched part 15 of a screw blade 14, lifting-up discharge function is stopped, and the sediment is stayed in the notched part 15. The position of a water content having low specific gravity and positioned at the upper part of the sediment 16 is gradually replaced with the position of a solid content having high specific gravity and positioned below to perform action to separate solid from liquid. Only a water content is dropped, and after only the condensed sediment 16 is raised to the upper part of the screw blade 14, it is discharged through a discharge port 11 to the outside. This enables a water content in the sediment to be decreased to trace amounts, and permits to effect an efficient dredging work. |
