| OCR Text |
Show Table 2 NOx emission level of burners ( FDI, FHL-II, Baffle type ) Burner NOxppm Flame length Remarks (02=11 % conversion) (m) FDI type 35 4.8 FHL-II type 133 3.8 (Note 1) Baffle type 431 2.5 (Note 2) Note 1: Primary and secondary ratio is 50:50. Note 2: With gas velocity lOOmIs, NOx =178ppm, flame length=3.2m The NOx level is 35ppm which is nearly a quarter of that from the FHL-II and less than one tenth of the baffle type burner. For the baffle burner, higher gas velocity (lOOmIs instead of standard lOm/s), identical to that of the FDI, was also tested. Drastic reduction in NOx is observed, from 431 to 17Oppm, but the NOx level is still 5 times higher than the FDI. Burner Flow ROVER II 70 ". .. 65 f.i 60 Q~ H 45 ~~ 40 I 35 .• 30 F. 25 2 ~ 20 kW/m G! UNDER Fig. 13 Heat flux distributions In Fig. 13, heat flux distribution on to the furnace load has been compared. For FHL-II and baffle burners a sharp peak in heat flux is observed close to the burner, while for FDI tt distribution appears rather unifonn and a less intense peak is observed further down the furna If the heat flux distribution is compared to the flame length listed in table 2, further insight on FDI combustion can be obtained. The baffle burner fonns a stabilized short flame in its burner tile. A high peak flame temperature results in very high NOx level. Compared with the baffle burne, the FHL-II burner fonns a longer flame while giving higher heat flux and lower N due 12 |
