Question 153Steam Plants - Assistant Engineer

The correct answer is A) fuel oil pressure. The amount of oil atomized by a straight mechanical fuel oil burner depends on the fuel oil pressure. Increasing the fuel oil pressure will result in a finer atomization of the oil, which is important for efficient combustion. The other options (forced draft pressure, oil return pressure, and furnace air pressure) do not directly affect the atomization of the fuel oil in a straight mechanical fuel oil burner. These other factors may influence the combustion process in other ways, but the primary determinant of the oil atomization is the fuel oil pressure.