MULTI-PASS TUBULAR AIR PREHEATER Russian patent published in 2003 - IPC

FIELD: power engineering; recovery of waste gas heat in fuel burning industrial plants working on high-sulfur fuels. SUBSTANCE: multi-pass tubular air preheater with counter crossing flow of heat exchange media includes sections of heat exchange surfaces which are located in gas exhaust duct of industrial fuel burning plant and are successively interconnected by medium to be heated (air); proposed air preheater is also provided with blast fan and heat exchanger for preheating entire flow of atmospheric air; hot air from air fed from preheater outlet is used as heating medium flowing through said heat exchanger; air flow of hot air is controllable; heat exchanger is connected to suction end of blast fan by medium to be heated (air). Last cold section in way of flow of flue gases has lesser flow section. Said air preheater ensures effective operation without preheating air of water steam. EFFECT: enhanced efficiency and reliability. 2 cl, 1 dwg