Which type of nozzle is designed to provide the quietest flame?

The hollow nozzle is designed to create a flame that is quiet and stable due to its construction and the way it atomizes the fuel. Hollow nozzles use a specific design that allows the fuel to be atomized into a fine mist, which helps to produce a smoother and less turbulent combustion process. This results in less noise when the fuel is ignited.

In contrast, solid nozzles tend to create a more intense flame and can cause more turbulence during combustion, which can lead to increased noise levels. Fan nozzles, while useful for spreading the flame over a wider area, can also add to the noise due to their design that encourages a more expansive and less controlled flow. Meanwhile, streamlined nozzles can enhance efficiency but may not inherently focus on flame quietness as their primary feature. Therefore, the hollow nozzle stands out for its ability to maintain a quieter flame while still ensuring proper combustion.