🔍 Key Concepts

• Viscosity and how temperature affects it • Requirements for proper atomization of fuel oil in burners or diesel engines • Difference between flash point and fire point of fuel oil

💭 Think About

• Think about what happens to a thick, heavy oil when you warm it up—does it flow more easily or more slowly? • For good atomization, do you want the fuel to spray in fine droplets or come out in heavy streams? How does thickness affect that? • Are flash point and fire point properties you normally want to change right before injection, or are they specified characteristics of the fuel itself?

✅ Before You Answer

• Be clear on the definition of viscosity (resistance to flow). Decide whether heating increases or decreases this. • Confirm that atomization requires a fuel that can be broken into fine droplets by the nozzle. • Remember that flash point and fire point are safety properties measured in a lab, not something routinely adjusted just before burning the fuel.