HEATING BOILER Russian patent published in 1998 - IPC

FIELD: heating of individual houses and domestic water. SUBSTANCE: heating boiler has three horizontal partition walls 10,11 and 12 providing labyrinth flow of flue gas, heating device 3 from which flue gas flows around surfaces of heat-exchanger 2 and partition walls 10,11 and 12, along gas conduits 13,14 and 15 and is discharged from heating boiler through common gas conduit 16. High-temperature tract is lengthened by labyrinth flow of flue gas to improve heat extraction and facilitate effective utilization of combustion gas heat. Heating boiler is further provided with at least one electric heater disposed in heat-exchanger 2. EFFECT: increased efficiency, simplified construction and enhanced reliability in operation. 2 cl, 3 dwg