Unwanted NOx Formation

A candle flame is a miniature example of a type F long, luminous, laminar flame. Author Reed has often demonstrated some of the features of type F flames with a candle—polymerization soot formation, flame quenching, flame holders, starved air incineration, natural convection, particulate emission, streams in laminar, transition, and turbulent flows, aeration (by exhaling through a tiny straw across the blue base of the candle flame) changes it to a compact, all-blue flame that demonstrates combustion roar. Some of these demonstrations were recently found to have been alluded to in Professor Michael Faraday s famous candle lectures of the 1850s r erence 19). 

Luminous flames can transfer about 7% more heat than nonluminous flames. However, modem nonluminous flame and heat transfer techniques, together, can be more effective overall than luminous flames. 

In many cases, space limits the firing rate and the type of flame so it is necessary to use type E burners, which have very short flames with large diameters. For larger firing rates, ATP burners can vary the flame length from short to very long for the needed temperature profile across the length of the space. 

Low NOx injection (LNl) of fuel and air into the furnace chamber provides the highest potential efficiency and lowest NOx. The LNl system takes advantage of the furnace itself, which is the largest source of free flue gas recirculation (FOR) to produce uniquely low NOx emissions from high-temperature systems. 

Corvertioral forward, feather-shaped flame. No swirl Little recirculatian. Axial jet. Moderate to fast mixing. Used In all-purpose combustion chambers. 

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