🔍 Key Concepts

• Return-flow (recirculating) type atomization – part of the fuel is sent back to the return line instead of all going to the nozzle for burning • Difference between pressure that feeds the burner vs. devices that simply control spray quality or atomizing medium (steam/air) • How a recirculating/return line affects the actual quantity of fuel burned at the nozzle

💭 Think About

• Ask yourself: in a return-flow system, what component actually decides how much fuel goes to the flame and how much goes back to the return line? • Which option directly changes the proportion of fuel burned versus fuel returned, rather than just changing atomization quality? • If supply or back pressure changes slightly but the system is designed to recirculate excess fuel, which part is specifically used to control firing rate (amount burned)?

✅ Before You Answer

• Identify which choice is directly associated with the return flow / recirculation path of the fuel, not just general pressure control. • Distinguish between controls that affect atomizing steam and those that affect fuel flow rate to the nozzle. • Verify which device is normally adjusted when you want to change boiler firing rate in a return-flow atomizing burner.