Patent ID: 6117203
Filing Date: 2000-09-12
Classification: C02F,F28D,F28F

Abstract:
A pre-digestion pathogen reduction system for treating sludge prior to the sludge being directed into a digester in a wastewater treatment system, comprising:a) an inlet for directing the incoming sludge into the system;b) a series of reactors for receiving the incoming sludge as a series of batches, holding the batches of incoming sludge for a predetermined time to produce a pathogen-reduced sludge, and discharging the batches of treated sludge in a manner so as to form a continuous outflow of treated sludge to the digester, each reactor being operative to assume the feeding, holding, and discharge modes in sequence;c) a sludge-to-sludge heat exchanger disposed on an inlet side of the reactors for receiving both the incoming sludge and the treated pathogen reduced sludge and transferring the heat associated with the treated sludge to the incoming sludge;d) an outlet for directing the treated sludge from the reactors to the sludge-to-sludge heat exchanger prior to the sludge being directed to the digester such that as the treated sludge passes through the sludge-to-sludge heat exchanger, the heat associated therewith is transferred to the incoming sludge so as to heat the incoming sludge while at the same time cooling the treated sludge; ande) at least one additional heat exchanger for cooling the treated sludge leaving the reactors, the additional heat exchanger being a wastewater effluent heat exchanger that is coupled to a source of wastewater effluent wherein the wastewater effluent effectively cools the treated sludge.