What is the function of an economizer in a boiler?

The function of an economizer in a boiler is to recover waste heat from the flue gases and improve overall efficiency. When combustion occurs in a boiler, a significant amount of heat is lost through the flue gases that are vented to the atmosphere. An economizer captures some of this waste heat before the gases are expelled, utilizing it to preheat the feedwater entering the boiler. This process not only raises the temperature of the water before it enters the boiler, thereby reducing the amount of fuel needed to reach the desired steam temperature, but also optimizes the boiler's thermal efficiency.

By leveraging the heat that would otherwise be lost, an economizer helps lower fuel costs and reduce carbon emissions associated with using additional fuel to achieve the same output. This makes it a critical component for enhancing energy efficiency in steam generation systems. Other options such as increasing water pressure, enhancing safety controls, or removing scale relate to different systems or processes in boiler operation, but they do not pertain to the primary role of an economizer.