What is the primary reason for increasing air to the burner before fuel in a power boiler?

Increasing air to the burner before fuel in a power boiler is primarily aimed at ensuring complete combustion. When air is introduced first, it allows for a more thorough mixing with the fuel when it is subsequently introduced. This optimal mixture of fuel and air is crucial for achieving a combustion reaction that burns the fuel completely, producing maximum energy and minimizing unburned fuel emissions.

Complete combustion contributes to improved efficiency and reduced emissions, as it minimizes the release of pollutants, such as carbon monoxide and unburned hydrocarbons. Ensuring that there is adequate air supply prior to the fuel not only supports effective combustion but also enhances the overall safety and performance of the boiler system.

While enhancing efficiency and increasing operational pressure are beneficial outcomes of proper air and fuel management, they are secondary to the fundamental requirement of complete combustion. Cooling down the furnace is not a relevant factor in this context, as the primary goal is to maintain optimal combustion conditions for energy production.