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Show SPONSORS Funding for this project was provided by Gas Technology Canada (GTC), Energy Mines and Resources Canada (IERD program) and the Ontario Ministry of Environment and Energy (Enersearch Program). PROJECT STATUS In Phase I of the R&D work various air-fuel distribution patterns were studied at firing rates of 100,000 BtuJh to 250,000 BtuJh. The furnace operating temperature varied in the range from 1800 OF to 2800 OF. The temperature of the combustion air in the range from ambient to 1200 OF. Data was also taken with conventional burners to provide a baseline for comparison of results. The effect of parameters including fuel distribution patterns, combustion air flow patterns, furnace wall temperature, combustion air temperature, firing rate and combustion air velocity on formation of NO x was studied. A proof-of-concept 250,000 BtuJh burner was developed and demonstrated to reduce the NOx emissions of conventional combustion systems of 600-1000 ppm NOx down to less than 50 ppm NOx (at 3% 02) when operating with 1200 OF preheat combustion air at furnace operating temperatures of 2800 OF. This phase was concluded in 1991. Data was provided for sizing the scale-up burner in Phase II. In Phase II (1992-1993) the developed burner technology was scaled up to 1,000,000 BtuJh and optimized to lower NOx emissions to below 30 ppm (at 3% 02) under similar operating conditions. In Phase III (1993), a commercial burner manufacture joined CGRI to produce an optimized manufacturer's prototype of the CGRI burner concept. This resulted in a working prototype burner with an input of 1,500,000 BtuJh, tum down ratio of 3: 1 with NOx and CO emissions below 20 ppm (at 3% 02) when operating with 1200 OF combustion air preheat and furnace operating temperatures of 2800 OF to 3100 of. The recommended excess air level is 2% to 10%. NOx emissions are sensitive to peak flame temperatures which in tum are sensitive to furnace operating conditions : operating temperature and combustion air preheat temperature and geometry. While obtained results at the CGRI laboratories will be directly applicable to furnaces with similar geometry and thermal conditions to the CGRI test furnace, an additional phase was planned to investigate the performance of the CGRI low NOx burner in other furnace geometries. Two sites were selected for the study. The research furnace at the Centre for Advanced Gas Combustion Technology (CAGCT), at the CGRl Low NOx burner AFRC Spring 1994 Meeting page 2 |