In a rotary cup burner, what components are primarily adjusted to achieve the correct air/oil ratio?

• A. Fuel line and ignition source
• B. Metering valve, primary air, and secondary air
• C. Burner pressure and fuel temperature
• D. Ignition timing and combustion efficiency

Answer: (B)

In a rotary cup burner, achieving the correct air/oil ratio is crucial for efficient combustion and optimal burner performance. The components that are primarily adjusted to manage this ratio are the metering valve, primary air, and secondary air.

The metering valve is responsible for controlling the flow rate of the fuel oil, ensuring that the right amount of fuel is delivered to the burner. Proper adjustment of this valve allows for a precise match with the quantity of air mixed for combustion.

Primary air refers to the air that mixes with the oil before it enters the combustion chamber. This air plays a vital role in ensuring that the oil is atomized effectively and that the mixture is conducive to efficient burning. Adjusting the primary air helps in achieving the right combustion characteristics.

Secondary air is additional air that may be introduced later in the combustion process, enhancing the combustion of any excess fuel and ensuring complete burning. Adjusting this helps in optimizing combustion and minimizing pollutants.

Thus, the combination of correctly setting the metering valve along with the primary and secondary air adjustments enables operators to fine-tune the combustion process for efficiency and performance.