OCR Text |
Show 10 4.2 NOx CHARACTERISTICS Fig.12 is the data at no heating material, door open (400mm), and the oxygen concentration of 3% inside the furnace. When comparing with the furnaces of the continuous type, the conditions are severer as the combustion chamber load is considerably high and also the air leakage from outside is hard to avoid, however, applying the FDI combustion, the NOx emission could be into 1/2 to 1/3. Moreover, as the results was far better than expected as the specific energy consumption, only about 80% of the rated capacity of the burner was required in case of the maximum combustion operation, and it is now operated at less combustion capacity. Therefore, NOx emission level is greatly lower than regulation value. 12A Gas, Air ratio 1.1 500 1050 Furnace Temperature 400 -0--1200 't 840 ~ ~13OO 't 0 ~ --•-- 300 -e- 1200 't (FD~ 630 0 D ~ -.-1300 't (FOI) (II Q. E E Q. Q. Q. 200 420 Q. 0x 0x z z 100 210 0 0 0 40 80 120 160 200 (465) (930) (1395) (1860) (2325) Input X1 rf kcallh, (kW) Fig.12 NOx Characteristics (Forge Furnace) 4.3 ENERGY SAVING Table 2 shows the heat balance at the continuous operation. As this type of installation handles the material to put in and out at 20 to 30 seconds interval, the door is usually open, this being quite different from the other installations. Including the holding time for die changing of forging machine, and the time for daily temperatur; raising, the specific energy consumption is about 2.5MJ/kg when using the regenerative system. This achieves energy saving of more than 50% |