Development of a High Performance Versatile Low NOx Burner

The paper describes the development process of a new Coen low NOx high performance burners and the transition from a successfully tested prototype to a commercially available product. The performance data are illustrated by the results achieved at the test facility and in numerous package and field erected boilers. The burner was the first commercial product that could fire Natural Gas with NOx emissions below 30 ppm and low carbon monoxide emissions without the use of flue gas recirculation (FGR) in a wide variety of package boilers. For the boilers with low space heat release rates the burner achieves even lower NOx in the range 15-20 ppm. The burner is specifically suited for industrial duty applications, as it does not impose any special requirements to the control system, like tight air fuel ratio, 02 trim, etc. The burner achieves 10 to 1 turn down and with some modifications allows turn down in the excess of 15 to 1. The burner can easily fire other gaseous fuels like refinery gas and does not require special gas preparation, as the typical minimum diameter for the gas discharge is more than 1/8". The versatility of the burner is also enhanced by its ability to operate with induced or selective FGR as it allows NOx reduction down to the 12-15 ppm level. While most of the burner performance can be realized when firing gaseous fuel, liquid fuels like #2 and #6 oil can also be fired separately or simultaneously with gas. Change over between fuel can be done on line.