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Show CONCLUSIONS This research has shown that the ring stabilizer significantly improves the operating range of a conventional burner, permitting stable combustion of lean premixed flames at . . equivalence ratios as low as 0.55. Moreover, ring stabilizers also improve the burner turndown ratio. Turndown for the base case of a laminar rim stabilized burner was only 4.9:1. With a ring stabilizer in place, the turndown ratio rose to beyond the range of the current measurement equipment and was conservatively estimated to be 20: 1. Most important is the fact that the expected reductions in pollutant emissions for lean flames have been fully realized. With ring G 1 in place (gap size between the outer edge of the ring stabilizer and the inner edge of the burner rim equals 0.8 mm), for 0.72<4><0.88, NOx and CO emissions were simultaneously reduced to levels well below legislated standards. Concentrations of NOx met and exceeded the limit set by the South Coast Air Quality Management District in California -- the most stringent NOx legislation in the world. FUTURE WORK A project is currently underway to retrofit an existing forced air furnace with the ring stabilizer technology. More extensive pollutant emissions testing will be conducted and efficiencies at various equivalence ratios and powers will be simultaneously measured. Optimization of efficiency, NOx and CO emissions, turndown, design simplicity, etc. will be considered. The ring stabilizer holds a great deal of promise in a variety of commercial applications. Several avenues for new research have been opened for investigation. The potential to significantly reduce NOx and CO emissions from stationary combustion sources should be exploited as much as possible. 16 |
