METHOD AND DEVICE FOR HEAT TREATMENT OF SEWAGE SLUDGE Russian patent published in 2019 - IPC C02F11/12 F26B15/06 F26B3/06 

FIELD: water treatment.

SUBSTANCE: invention relates to methods and devices for processing sewage sludge. Method of heat treatment of sewage sludge includes its drying and cooling, moving in layers located one above the other, pouring it from top to bottom, filtering gases through its layers. After the middle layer, a portion of the spent coolant is removed through the side duct 17 and combined with another part after the top layer, forming recirculated. Most of the obtained recirculate is sent to the mixture with flue gases with the formation of a hot coolant. Second part of the recirculate is sent to the lower layer, and the third – to the drying and cooling, followed by feeding under the lower layer in the cooling zone. Resulting hot coolant is distributed into three streams: one part is sent for drying the upper layer, the second part, intended for drying the middle layer, mixed with the coolant, passed through the bottom layer, and the third part is mixed with the second part of the recirculate and sent for drying the bottom layer. Device for heat treatment of sewage sludge includes drying chamber 22 with conveyors 14 installed in it and perforated bottoms 23, a system of boxes for supplying hot heat carrier 2, 3, 16, 31, 32, 35 and recirculated materials 1, 12, 17 with fans 20, 36, means for loading 5 sewage sludge and discharging 15 the treated sludge, heat generator-mixer 34, cooler-dryer 13 with a system for supplying dried and cooled recirculate to the cooling zone of the lower layer. Conveyors 14 and perforated bottoms 23 with partitions 6 of drying chamber 22 above and below perforated bottoms 23 form chambers 9, 11, 25, 28, 29, 30. Box 1 for supplying most of the recirculate, flue gas box and distribution box 33 is connected to heat generator-mixer 34. Additional box 35 for supplying recirculation to hot coolant supply box 32 is installed in front of heat generator-mixer 34 under lower perforated bottom 23. Between middle perforated bottom 23 and partition 6 above it in the side wall of drying chamber 22, an opening is made to exit the spent heat carrier to side duct 8. Hole 26 is made above lower perforated bottom 23 in the side wall of drying chamber 22, to which a hot heat transfer duct 32 adjoins.

EFFECT: invention allows for efficient heat treatment of sewage sludge without heat costs for drying due to the receipt of combustible gases from the dried material and to significantly reduce environmental pollution.

4 cl, 2 dwg