摘要 |
PURPOSE:To enhance efficiency in separating excavated sediment by sending clay silt separated from water-contg. sediment to a drum-screen sludge dehydrator through an excess drilling water tank and returning the dehydrated sludge onto the sand layer on a gauze wire at the uppermost stage of a vibrating screen. CONSTITUTION:The sediment excavated by a shield machine 1 is passed through a vibrating screen 2 by a carrier water, and the water-contg. sediment passed through the relatively coarse mesh at the intermediate and lower stage is supplied to a cyclone 4 via a circulating tank 3. The sand centrifugally separated in the cyclone 4 and settled is supplied on the upper-stage mesh of the screen 2, while the main part of the clay silt is returned to the shield machine 1 through a regulating tank 5. The remaining clay silt is sent to a drum-screen sludge dehydrator 10 through an excess drilling water tank 6, dehydrated with a cylindrical screen main body 12 by its rotation and vibration and sent toward an outlet along a spiral pleat 16, and the dehydrated sludge is returned onto the sand layer formed on the gauze wire 11 at the uppermost stage of the screen 2. |