🔍 Key Concepts

• fuel oil return (recirculating) systems in auxiliary boiler burners • relationship between supply pressure and return pressure in atomizing systems • purpose of using a return flow atomizer instead of a simple pressure atomizer

💭 Think About

• Think about what happens to the portion of fuel that is NOT burned at the burner tip in a return-flow system. • If the amount of fuel actually burned is changing with load, what part of the system must change to keep atomization quality stable? • Which of the choices describes something that must stay steady so that combustion remains clean and the burner doesn’t keep ‘hunting’ or pulsing?

✅ Before You Answer

• Identify which parameter in the options is normally kept constant to ensure stable atomization. • Decide whether a boiler burner normally operates at fixed combustion rate or can modulate with steam demand. • Consider whether boiler control systems typically control pressure or temperature in the fuel supply/return lines for atomization quality.