%0 Journal Article %A Rangel, Leonardo P. %A Fletcher, L. M. %A Pourkashanian, M. %A Williams, A. %D 2006 %I Begell House %N 3 %P 187-202 %R 10.1615/InterJEnerCleanEnv.v7.i3.10 %T EXPERIMENTAL INVESTIGATIONS OF COUNTERFLOW DOUBLE FLAMES APPLICABLE TO AN INDUSTRIAL NATURAL GAS-FIRED BURNER %U https://www.dl.begellhouse.com/journals/6d18a859536a7b02,4a467dbf7cf032fb,5510833c096d989a.html %V 7 %X Rapid mixing of the fuel and oxidizer has led burner manufacturers to consider design applications that employ a system of "partial premix." Previous computational fluid dynamics studies on a novel low-NOx industrial burner, employing a system of partial premix, showed a considerable reduction in exhaust NOx concentration for high degrees of secondary air staging. Thus, in order to further understand the physical and chemical interaction produced by the partial premix system, a laboratory-scale counterflow system was constructed for a CH4-air mixture. Different mixture configurations were applied and exhaust gas concentrations of typical combustion species (O2, CO2, CO, and NOx) and flame temperatures were measured via standard techniques. Experimental observation indicated that double flames appeared to play an important role regarding the amount of exhaust NOx generated. By varying the equivalence ratio and air strain rates, the partial premix configuration of the double flame changed the reaction zone location, helping to reduce NOx formation. %8 2007-03-23