Chapter 13 NOx Considerations Flashcards
How is NOx formed (general)
when nitrogen is exposed to elevated temperatures of gas combustion - reacts with oxygen and forms NOx compounts
How is NO formed
NO formation is most rapid at high temperatures and in fuel rich conditions (rich mixtures)
How is NO2 formed
NO2 formation is independent of the rate of primary aeration
Nitrogen exposed to elevated temps of gas combustion - reacts with oxygen to form NO2
Which NOx makes up the majority of NOx generation
NO molecules are the majority found in vent gases
list the types of gas burners from lowest NOx to highest NOx generation
Catalytic burners Infra red burners Hi premix Quench rod burners Low premix
What operating conditions tend to increase the formation of NOx
High peak flame temps
Long residence times
Reduced oxygen content in primary zone
what tends to reduce formation of NOx
gas re-burning minimizing preheating of combustion air flue gas re-circulation minimizing excess air increasing primary air
