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Show TEST FACILITY The John Zink International Research Center has 9 furnaces of various sizes and configurations for burner research and development. Full scale burners fre;fn less than 1 million Btu/hr to more than 250 million Btu/hr can be tested. In order to develop a suitable burner system, Furnace No. 8 was fitted with a flue gas ' recirculation system as shown in Figure 2. No.8 test furnace is a vertical cylindrical furnace with a combustion chamber 8 ft. (2.44 m) in diameter and 20 ft. (6.1 m) tall. The furnace wall is a double shell with water in the annulus to absorb part of the heat input to the furnace. A portion of the interior surface is insulated to control the heat absorption rate. The furnace exit temperature during all tests was about 1600°F, which is typical of many refinery process heaters. A 12 inch (305 mm) recirculation duct was installed at the furnace outlet to extract a portion of the flue gases. This duct was routed to a shell and tube -heat exchanger where the flue gases were cooled to about 500°F (260°C). A hot fan was used to draw the flue gases through the heat exchanger and inject them into the combustion air stream. The flue gas recirculation flow rate was measured with a venturi flow meter. The tests reported here were conducted with a burner designed for a nominal heat input of 10 million Btu/hr (10.55 GJ/hr). The development work involved tests over the entire operating range of the burner. The NOx emission results included in this paper are those collected with the burner operating at 10 million Btu/hr. Both ambient and preheated air were tested. A variety of fuel gases were utilized during the testing. Some of the fuel blends that have been tested are: Natural Gas Hydrogen / Natural Gas Hydrogen / Propane / Natural Gas Hydrogen / Propene / Natural Gas Hydrogen / Butane / Propane / Natural Gas Rue gas recirculation rates were varied from 0 to 35%. The excess oxygen level was varied from 0.2% to 4% 02. Data collected included fuel composition, fuel flow rate, fuel pressure, air temperature, FGR flow rate, FGR temperature, burner draft loss, furnace pressure, furnace temperature, and flue gas temperature, NOx, CO, and 02. The NOx concentrations reported here are given as PPM by volume, dry basis, and are corrected to 3% excess oxygen. 4 |