An air preheater is a heat exchange device that utilizes the waste heat from the flue gas at the 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 located in the low-temperature region of the heating furnace flue gas, reclaiming the waste heat from the flue gas, reducing the exhaust gas temperature. At the same time, the required combustion air is preheated, increasing the initial temperature of fuel and air, strengthening the ignition and combustion process of the fuel, reducing the heat loss from the fuel, and further enhancing the heat efficiency of the heating furnace.