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Show -4- SOLUTION To overcome the time constraint, several prototype burners were built and the burner development project began with a series of screening trials to determine the best candidate designs. Once a promising design was identified a series of optimization trials were conducted. These were facilitated by designing the prototypes in a manner that permitted easy modification of the desired design factors. The bulk of the tests were run using natural gas with selected tests using mixtures with hydrogen when the natural gas trials suggested that the design warranted further investigation. The final trials included two promising designs, with one design eventually proving to be slightly better in performance and also somewhat simpler to fabricate. In the end the final design was very effective, operating successfully with any fuel mixture from natural gas to 100 mole percent hydrogen and producing NOx levels well below the required 40 PPM level. Patent application restrictions limit the amount of detail that can be disclosed, however, the burner utilizes many of the design considerations outlined in the INFURNOx™ technology paper. TEST SETUP The burners were tested in John Zink furnace No. 12 which is a small rectangular box furnace. The furnace is lined with refractory fiber and is fitted with adjustable water cooled tubes to simulate a process load and maintain the desired furnace temperature. A single, full scale burner was fitted to the furnace for testing. Figure 2 is a schematic flow diagram of the furnace, the fuel system, the forced draft combustion air supply system and the data measurement elements. Rotameters were used for metering the fuel components, velocity thermocouples were used to measure the furnace exit gas temperature and the stack temperature. Oxygen, carbon monoxide and NOx meters were used to analyze the stack gases which were sampled using a water cooled probe. Air pressure measurements were made using |