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Show The FFR burner Applying the above results, Tokyo Gas has developed another type of FDI regenerative burner. Figure 9 shows the schematic of the FFR (Full Time FDI Regenerative Burner System). This new type regenerative burner has two significant features: compact size and continuous FDI combustion. Most of the heat storage elements (alumina balls) are contained within the burner refractory, which is Cooling High Temperature Preheated Air Gas Nozzle Rue Gas Gas+Cooling Air Air Nozzle Combustion Air /Exhaust Gas Figure 9 Schematic of FFR Burner installed in the furnace wall, thus reducing the size of the burner /regenerator package. The FFR burner has 6 air nozzles, parallel with the burner axis, in a circle surrounding a center gas nozzle and flame stabilizer. Small flows of gas and cooling air are maintained through the gas nozzle, such that a continuous pilot flame is established. This configuration provides direct ignition and continuous low N O x operation throughout the furnace temperature range without the need to change the firing mode between normal and FDI, which in turn simplifies the piping and control system. EXPERIENCE WITH PRACTICAL APPLICATIONS OF THE FDI/LNI TECHNIQUE To date there are more than 60 commercial installations in operation in the US, Europe, and Japan with more than 300 burners in total. The majority are regenerative burner installations in the aluminum and steel industries. Reported here are two forge furnaces in Tokyo, Japan which were converted from conventional to FFR burners, a ladle preheat station in the U. S. A. where oxy-fuel LNI burners replaced oxygen enriched conventional burners, and a regenerative burner fired aluminum melter in Norway. Forge Furnaces, Tokyo, Japan as <•" -r- «S2 :•;/ mM& i': Figure 10 Car Bottom Type Forging Furnace Figure 11 Small Forging Furnace Figure 10 shows a car bottom type forge furnace which has a capacity of 70 t/h and effective heating zone of 4 m wide, by 7.8 m long, by 2.7 m high. Replacing conventional oil burners, 3 pairs of FFR-700 are installed. 4 5 % energy saving was achieved with lower N O x emission level, 94 ppm, corrected to 3 % 02, at a furnace temperature of 1450K. Furthermore, C 0 2 emissions were reduced by more than 50%. Figure 11 shows a small 5 t/h forging furnace equipped with a single pair of FFR-350. The energy consumption was reduced by 5 0 % compared with the former oil firing system. It is a good example of application of regenerative burner FDI technology to a small furnace with strict space limitations. 6 |