Question 86Steam Plants - 1st Asst/Chief

The correct answer is A) no CO, low O2, and high CO2. When the burners are clean and the fuel oil is at the correct temperature, adjusting the excess air until a light brown haze is obtained is considered good practice. This indicates that the combustion process is optimized, with complete combustion and minimal excess air. With a chemical-based flue gas analyzer, the readings should show no CO (carbon monoxide), low O2 (oxygen), and high CO2 (carbon dioxide), as this signifies complete combustion with just the right amount of excess air. The other options are incorrect because: B) would indicate incomplete combustion with high unburnt fuel (CO), C) would indicate incomplete combustion with high excess air, and D) would indicate too much excess air, leading to inefficient combustion.