In a mechanical atomizing burner with three fixed capacity burners, why might the Intermediate and high fire burner nozzles have higher capacities?

In a mechanical atomizing burner with three fixed capacity burners, the intermediate and high fire burner nozzles are designed to have higher capacities mainly to enhance combustion stability. These nozzles allow for a more efficient and continuous fuel spray, which is crucial when burning larger quantities of fuel at higher fire rates. The ability to atomize fuel effectively at these capacities contributes to a more stable flame, reduces the chances of incomplete combustion, and ensures that the mixture of fuel and air is optimal for combustion, leading to better overall performance.

While increasing fuel efficiency, allowing for slower boiler warm-ups, and reducing emissions are all important considerations in a burner design, the primary function of the higher capacity nozzles is focused on maintaining stable combustion at varying loads. This stability is essential for ensuring consistent operational reliability, especially during periods when the boiler transitions between different firing rates.