In oil burner terminology hollow or semi-solid refers to which component?

• A. nozzle
• B. electrode
• C. atomizer
• D. valve

Answer: (A)

The nozzle is the component whose spray pattern is described as hollow or semi-solid. In oil burner operation, the nozzle shapes and atomizes the fuel as it leaves the tip. A hollow cone nozzle produces a ring-shaped spray with a central void, while a solid (or semi-solid) pattern delivers fuel more densely toward the center. This spray quality affects how the fuel mixes with air, flame shape, and combustion stability. The ignition electrode, valve, and atomizer don’t define this spray pattern, so the descriptor specifically points to the nozzle.