| OCR Text |
Show - 6 - Figure 9 shows the effect of the incl ined angle a of fuel injection on the temperature distribution in the furnace. The temperature distribution is measured by thermocouples moving from the cei I ing to the bottom in vertical section in the combustion test furnace. The temperature of the fuel jet stream is low near the burner in the furnace. Especially, the temperature of the fuel jet stream near the cei I ing is very low in the case of a =30 0 because of impingement of fuel jet on the cei I ing. Ingots are usually located at the bottom of the furnace and the temperature distribution is very uniform near the ingots. As described above, the NOx decreasing effect is improved by imparting a definite amount of deviation to the combustion air and by using an incl ined type burner rather than a straight type burner, the maximum reduction of NOx is attained by using an incl ined type burner whose angle of inclination a is about 30 0 • If, however, such an inc I i ned type bu rne r with an ang I e of inc I i nat i on a of about 300 is directly used in an actual furnace, the very large angle of deviation of the injection fuel flow may sometimes result in fuel impingement to the furnace wall or the burner ti Ie bore wall (as in this combustion test) thus imposing restrictions on the practical angle of inc I i nat ion; actua I I y, ang I es of about 10 0 -200 are emp loyed. The control of the fuel/air injection velocity ratio is very important for satisfactori Iy decreasing the amount of NOx formation. 4. APPLICATION OF REGENERATIVE BURNER TO HEAVY FORGE FURNACE Furnace and Burner Figure 10 shows a regenerative burner in a heavy forge furnace. The regene rat i ve bu rne r system was supp lied by the CHUGA I RO CO. , LTD. (Hotwo rk system). The re is an 0 rig i na I bu rne r and a KOBELCO Low-NOx burner in the regenerative burner. As the KOBELCO Low-NOx burner is a slow combustion type , CO is emitted under a furnace temperature of 400 ce. The original burner is used for heating up the |
