METHOD FOR PURIFYING MEAT HOUSE SEWAGE WATER AND OBTAINING FAT CONCENTRATE Russian patent published in 2002 - IPC

FIELD: meat house sewage processing industry. SUBSTANCE: method involves separating fat mass by pressure flotation without using reactants; providing thermal treatment of obtained fat mass in two stages under vacuum while mixing it: at first stage, thermal treatment is conducted at temperature of 70-90 C and residual pressure of 30-40 kPa to complete dehydration of product, and at second stage, dehydrated fat mass is heated at temperature of 130-150 C and residual pressure of 15-20 kPa for 0.5-1.0 hour; cooling and pouring ready product, i.e., fat concentrate; providing additional purifying of remaining sewage water by known method. Pressure flotation is performed at excessive pressure of 0.3-0.4 MPa at air content of 1.0-4.0 wt. % in air-water emulsion. Basic fatty component is removed after reactant-free flotation, with fat content in sewage water at inlet end being within the range of 1,500-2,000 mg/l and at outlet end up to 110-150 mg/l. EFFECT: increased efficiency in purifying sewage water and provision for obtaining fat concentrate free of contaminants and having fat-and-acid content corresponding to that of inedible fat. 5 cl, 1 ex