Air Pre Heater

Air Pre-heaters are heat exchangers installed in the exit flue gas duct of the boiler. The purpose of the air preheater is to recover the heat from the boiler flue gas, which increases the boiler's thermal efficiency by reducing the useful heat lost in the flue gas. Consequently, the flue gases are also conveyed to the flue gas stack (or chimney) at a lower temperature,  allowing a simplified design of the conveyance system and the flue gas stack. It also allows control over the temperature of gases leaving the stack.