What is the purpose of an air preheater in a combustion system?

The primary purpose of an air preheater in a combustion system is to improve combustion efficiency by preheating the air before it enters the combustion chamber. By raising the temperature of the incoming air, the air preheater reduces the amount of fuel needed to achieve the desired combustion temperature, which leads to more complete combustion. This not only enhances the thermal efficiency of the system but also reduces emissions since more of the fuel is converted into usable energy rather than being wasted as unburned hydrocarbons.

Preheating the intake air allows for a more efficient chemical reaction to occur during combustion, which is crucial especially in large-scale industrial applications. The increased temperature of the preheated air means it can mix better with the fuel, ensuring a more uniform and complete burn. This results in better utilization of the fuel and can lead to significant cost savings in fuel consumption.

In contrast, enhancing oxygen levels for combustion is not the function of an air preheater; it is more about Increasing the temperature of the air. Similarly, cooling the combustion gases and controlling humidity in the combustion area are not related to the role of an air preheater.