FIRE-TUBE FLUE BOILER Russian patent published in 2003 - IPC

FIELD: thermal engineering. SUBSTANCE: boiler has casing, smoke tube with burner, fire tubes, and gas chambers; mounted beyond casing in a spaced relation to the latter is shell ring joined at butt ends to casing to form passages for stack gases; casing has holes in vicinity of chamber last along gas flow to provide communication between gas chamber and passage; casing surface in vicinity of passage is ribbed and shell ring is provided with nozzle for stack gas outlet. EFFECT: enhanced operating and economic efficiency, reduced size and metal input, facilitated manufacture. 1 cl, 2 dwg