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Show HIGH RADIATIVE LOW NOx FLAT FLAME OXY-FUEL BURNER Wataru Fujisaki and Tsuneaki Nakamura Tokyo Gas Co., Ltd. 1-16-25, Shibaura, Minato-ku, Tokyo 105-0023 J A P AN ABSTRACT This paper describes the investigation on the characteristics of oxygen natural gas flames, to develop high performance oxy-fuel burners for glass melters. High radiative characteristics and low N O x emission are aimed at. The experiments first tested generic burners with an annular oxygen injector and a single-hole gas nozzle in the center. The flame showed higher radiative characteristics with relatively high luminosity and high N O x emission. The experiment then tested the F D I (fuel direct injection) burners equipped with one fuel gas nozzle in the center and two parallel oxygen nozzles at upper and lower positions of the fuel nozzle. The FDI technique, which was already utilized for low N O x emission for highly preheated air combustion, showed very low N O x emission with relatively low radiative characteristics. To obtain both high radiative characteristics with low N O x emission, an innovative FDI flat flame burner equipped with one fuel gas nozzle in the center and two inclined oxygen nozzles at upper and lower positions of the fuel nozzle was tested. A few degrees inclination of the oxygen nozzles created widely spread flat flame, resulting in substantial improvement of radiative heat while maintaining N O x emission remarkably low. The results of this study was finally led the F D I flat flame oxy-fuel burner that creates high radiative heat with low N O x emission. 1. INTRODUCTION Oxy-fuel combustion is considered to be one of the most effective methods to improve thermal efficiency and reduce NOx , SOx and C O , emissions for high temperature industrial processes such as glass melters. High radiative characteristics and low N O x emission are preferred for oxy-fuel burner. However, there appears to be a lack of detailed information regarding the characteristics of oxy-natural gas flames. For example, litde is known about the effect of flame luminosity on heat transfer and the effect of self-induced E G R (exhaust gas recirculation) on N O x emission. The characteristics of oxy-natural gas flame need to be carefully studied to establish optimum design parameters for high performance oxy-natural gas burners. In this study, three types of oxy-natural gas burner were tested and investigated at a semi- 1 |