METHOD AND SYSTEM FOR TREATING SLUDGE TO REDUCE CHEMICAL AND PRODUCTION OF CAKE

摘要

A sludge treatment method is provided to reduce the sludge treatment cost by heating the dissolving temperature of a flocculant using waste heat generated in the sludge treatment system as a heat source, thereby treating sludge, and a sludge treatment system used in the sludge treatment method is provided. A sludge treatment system comprises: a flocculant storage tank(10); a flocculant dissolving tank(20) for mixing a flocculant supplied from the flocculant storage tank with dissolving water flown in through a dissolving water inflow line(L20); a flocculating/dehydrating apparatus(40) for mixing a flocculant dissolving liquid supplied from the flocculant dissolving tank with sludge flown in through a sludge inflow line(L40), and flocculating and dehydrating the mixture; and a heat supply unit for heating a temperature of the dissolving water or temperature in the flocculant dissolving tank. The sludge treatment system further comprises: two heat exchangers(70-1,70-2) installed in series on the dissolving water inflow line; a digestion tank(30) installed in front of the flocculating/dehydrating apparatus to digest thickened sludge flown in, the digestion tank including a first stage digestion tank(30-1) and a second stage digestion tank(30-2); a digestion tank heating boiler(50) for supplying heat to the digestion tank to increase temperature of the sludge; an exhaust gas reduction unit(60) and a waste heat recovery unit(65) installed in rear of the digestion tank heating boiler; and a digested sludge storage tank(80) for adjusting flow rate or flow amount of the sludge supplied to the flocculating/dehydrating apparatus.