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Show 4 The performance of the burner is assessed by emissions measurements taken at the exit of the furnace stack. The emissions sample is transported through a water drop-out prior to delivery to the emissions sampling system. Carbon monoxide and carbon dioxide concentrations are measured using two non-dispersive infrared analyzers. A flame ionization detector is used to detect hydrocarbons, and a paramagnetic analyzer is used for oxygen measurement The nitrogen oxides are measured using a chemiluminescence analyzer. All the emissions analyzers are manufactured by Horiba Instruments, Inc. Figure 3 shows the sample train and the emissions instruments in relation to the burner. Bumer Traverse RESULTS CO/C02 L....,;"..;;...;::;;.......;~ Analyzer Figure 3: Emissions Sampling Train HC/02 Analyzer N9x Analzyer The NOx emissions (corrected to 3% 02) and combustion efficiencies, 11, for each nozzle over their stability limits are shown in Figure 4. The top surfaces, in light gray represent the combustion efficiencies and the lower surfaces, in darker gray, represent the NOx concentrations. Although present for all three nozzles to some degree, the tradeoff between combustion efficiency and NOx is most easily seen for the co-swirl nozzle, i.e., decreased NOx results in decreased efficiency. From this plot, the complexity inherent in minimizing NOx and maximizing efficiency is readily apparent. Conditions where performance is "good" are difficult to identify due to the need to optimize two variables, namely NOx and 11· |