PURPOSE: To provide a dehydration treatment method for sludge which is easy and efficient and improves dehydration efficiency.
CONSTITUTION: The sludge is metered by a sludge metering means 1. A powder mixture composed of nonionic high polymer powder and flyashes for moisture absorption and dispersion is metered by a first additive metering means 4. The sludge and the mixture are respectively transported to a stirring and mixing device 8, by which both are properly stirred and mixed. The sludge particles flocculated by electrification are decomposed and individually adsorbed by the calcium ions of the flyashes. The nonionic high polymer compd. is crosslinked and flocculated to the particles adsorbed with the sludge particles. The mixture is transported to a dehydrating means 46 after mixing and is dehydrated by a screw press which is heated by the steam from a heating means 50. The viscosity of the sludge is lowered by the heating and the sludge in contact with the screw press is dried to lower the adhesion property. The sludge is thus efficiently and surely compressed and transported and the compression efficiency is improved. Part of the water is made into steam and the sludge is dehydrated of the water by passing the steam way. The dehydration speed is thereby accelerated and the dehydration efficiency is improved.
ISHIGE HIROSHI
OKURA TAKAO
NAGANAMI AKIRA
