🔍 Key Concepts

• Fuel oil viscosity and temperature and how they affect proper atomization at the burner tip • What happens to droplet size and spray pattern when fuel is too cold or too thick • The relationship between poor atomization and the color/appearance of exhaust smoke

💭 Think About

• Think about how fuel temperature affects viscosity: if the fuel is colder, is it easier or harder to break it into a fine mist at the nozzle? • If the fuel does not atomize properly and forms larger droplets, what kind of combustion will occur in the furnace—complete or incomplete? What smoke color is usually associated with that? • Which of the answer choices sounds like a direct symptom of poor atomization at all load conditions rather than a change in how much fuel or air you need?

✅ Before You Answer

• Verify which smoke color is typically associated with incomplete combustion due to large fuel droplets and poor mixing with air. • Check whether a properly adjusted burner really "requires more fuel" or "more excess air" just because the fuel is a bit colder, or whether you would first notice a visible change in exhaust. • Focus on the option that describes a clear, observable effect at the stack of poor atomization rather than an internal adjustment you might make.