Question 331Steam Plants - Assistant Engineer

The correct answer is D) less excess air. Compared to a return flow oil burner system, an internally mixed steam atomizer requires less excess air to operate effectively. This is because the steam atomizer relies on the mechanical force of the steam to break up and atomize the fuel oil, rather than relying on the air velocity and turbulence as in a return flow burner. As a result, the internally mixed steam atomizer can operate with lower air flow and less excess air, improving the efficiency of the combustion process. The other answer choices are incorrect because an internally mixed steam atomizer does not require higher air velocity (A), higher fuel oil viscosity (B), or greater turbulence in the air/oil stream (C) compared to a return flow oil burner system.