What is the role of the induced draft fan in a boiler?

The induced draft fan plays a crucial role in a boiler by supplying combustion air to the combustion chamber. Proper combustion air is necessary to ensure that the fuel burns efficiently and completely, which is essential for optimal operation of the boiler. This fan helps maintain the necessary airflow and creates a negative pressure within the combustion area, drawing in air that is required for the combustion process. By optimizing the air input, the induced draft fan contributes significantly to the overall efficiency and effectiveness of the boiler system, thus ensuring that the fuel burns correctly and the boiler operates at its designed performance levels.

The importance of supplying adequate combustion air cannot be overstated, as insufficient air can lead to incomplete combustion, resulting in lower energy output and increased emissions. In contrast, the other options do not accurately describe the primary function of the induced draft fan in the context of boiler operation. For instance, while enhancing fuel efficiency is a beneficial result of effective air supply, it is not the direct role of the fan itself.