BOILER PLANT Russian patent published in 1996 - IPC

FIELD: flue gas cleaning and heat recovery. SUBSTANCE: plant has boiler, sections of multipass tubular air heater, regenerative gas-to-gas heat exchanger, precipitator-ash trap, device for cleaning gases of sulfur oxide. Gas-to-gas heat exchanger passes heated medium to flue gas recirculating loop provided with recirculating draft fan, its outlet being connected to flue upstream of draft fan. Some portion of cooled chimney gases cleaned of sulfur go to recirculating loop which is also supplied with hot excess air through air duct. Gases dried out by this air are heated in regenerative gas-to-gas heat exchanger and fed to inlet of draft fan together with remaining portion of gases, and in hot state they are emitted through chemney stack into atmosphere. EFFECT: improved design. 3 cl, 1 dwg