An air preheater is a heat exchange device that utilizes the waste heat from the flue gas at the tail end of a heating furnace to heat the air required for combustion, aiming to reduce flue gas temperature and improve the overall thermal efficiency of the heating furnace.

The air preheater is positioned in the low-temperature area of the boiler flue gas, reclaiming the waste heat of the flue gas, reducing the exhaust gas temperature, and simultaneously preheating the required air, enhancing the initial temperature of fuel and air, strengthening the ignition and combustion process of the fuel, reducing incomplete heat loss of the fuel, and further improving the thermal efficiency of the heating furnace.