| 摘要 |
<p>PURPOSE:To reduce the treating cost by adding a setting retarder to cement sludge to reduce the water content below a specified value, adding a specified amt. of the sludge with respect to cement to the concrete to be newly mixed and forming the mixture in the cement activating time. CONSTITUTION:Concrete is injected into a centrifugal formwork 1 for a concrete product and formed into a desired product, and the cement sludge collected around the rotating shaft is introduced into a sludge receiver 2. The sludge is charged into a sludge concn. adjusting tank 3, and a setting retarder such as an oxycarboxylate is supplied from a retarder feeder 11 to adjust the concn. appropriate for dehydration. The sludge is dehydrated by a dehydrator 4 to <=65% water content, sent to a dehydrated sludge receiver 5, and placed in a dehydrated sludge measuring tank 6. Meanwhile, sand, ballast, water and an additive are supplied to a concrete mixer 10 from a concrete material bin 9 and mixed. At this time, the dehydrated sludge in the tank 6 is supplied to the mixer 10 by <=20% the unit cement amt., and the mixture is discharged as mixed concrete B which is then formed in the activating time.</p> |
