Patent ID: 7828961
Filing Date: 2010-11-09
Classification: B01D,B30B,C02F

Abstract:
1. A sludge thickening device comprising: a differential rate rotary thickener, provided with a screw in a rotatable outer cylinder screen, for filtering raw slurry sludge being fed to a feed end of the outer cylinder screen, and for discharging thickened sludge from a discharge end of the outer cylinder screen, while rotating the screw at a variable speed; a thickened-sludge-concentration detecting section configured to detect a sludge concentration of the thickened sludge discharged from the differential rate rotary thickener; a flocculant-feeding section provided with a flocculant-feeding pump for feeding flocculant to the raw slurry sludge; and a control section configured to control a rotational speed C of the outer cylinder screen, a rotational speed S of the screw, and an amount of the flocculant to be fed by the flocculant-feeding pump; wherein: the differential rate rotary thickener includes an outer cylinder driving machine configured to rotate the outer cylinder screen, and a screw driving machine configured to rotate the screw; the thickened-sludge-concentration detecting section includes a sludge receiver tank configured to store the thickened sludge discharged from the differential rate rotary thickener, and a power detector configured to detect the sludge concentration of the thickened sludge and to send an electric signal to the control section; and the control section includes: