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Show Table 3 Pit eapodty 133 ton/prf Fuel: Coke oven got (COG) Heat Input Max 1350 Nm»/H Furnace temp1320*C Cotnbuttion air temp: 350 ~S00*C -•COG •Air COG Conventional burner (Spiral baffle) Modal E low NOx burner (Aiiot baffle) Fig. 25. Construction of burner unit before and after counter-measure in a coke oven gas firing top one way soaking pit. 1 2 3 4 5 Experiment Time (hr) Fig. 26. Comparison of NOx values of coke oven gas firing in a top one way soaking pit. (2) NOx values for various fuels in these burners are listed in table 3. Saving Energy (1) Radiant heat flux of these burners is larger than that of conventional burners, because of their high flame emissivity. (2) Flame temperature distribution can be controlled by changing the spray angle, spray velocity or burner types. Fuel Butane C-heavy oil COG 1 Kerosene N O x (ppm, 11% Excess O2) 30 - 50 45 - 60 45 - 60 30 - 50 (3) The fuel consumption of our burner used in our soaking pits and heating furnaces is 5 - 10% less than that of conventional burners. 3. Low NOx Air Register 3-1. Principle of reducing N O x emission of low N O x air register Fig. 27 shows the principle of reducing N O x emission of the present low N O x air register. A desired flow pattern having optimum swirl intensity and velocity is formed by a swirler located at the exit position of the air register. Fuel is sprayed to the inner side region of the outer hollow swirling air flow by the positioning of the nozzle tip. The mixing of the fuel and air is controlled to prevent too rapid mixing during the ///////////////////, Fig. 27. Principle of reducing N O x emission of low N O x air register (Flue and smoke tube boiler) 11 - 14 - |