OCR Text |
Show 20 LO EO eo m % 5iraw ~coaI 1200 t200 100l 800 600 LOO 200 IC o ---..---.-......-........... --r--.-~--.---.J GOnElBORN o 20 IJJ EO 80 m a;. strow DANISH cool JOOO ItOe"'" 100l ~3% 021 1m o Type 2 flame 0% 0212(0) o Type 2 flame fiOO II X Type 1 flame LOO J( Type t f\an@ 1500 Dl o "---r-..-_....--....-..--.--....--.... ___ ..J o 1200 1:0)' 100 t5CD J( l.Q) 3oD _____- -... ___. ........ __- ' o 40 .lD CO eo 0) % straw Figure lL Effed of co-firing ratio on NOx 100l SOO o ~---.-__. ..--......,....-.--____x_. ..J 1200 m:J too fiX) 100) lQ) o o _____ ......... _.......-...--_...J o 2) 40 m eo Ol%straw Figure 12. Effed of Co-firing ratio on S02 For the high intensity Type 2 flames, an increase in HO emission from 30 up to approximately 200 mg/m3, for 00/0 straw to 4()O/0 straw respectively, was observed for all three coals. This is due to the relatively high chlorine content in the straw (0.280/0). . In general burnout decreases when co-firing is practiced. In the co-firing range of 10-20 % straw input, burnout is lower, 97-990/0, when compared to 100% coal firing. In general burnout is slightly lower for the medium volatile bituminous coal. Thus it has been demonstrated that co-firing of pulverised coal and biomass is possible and stable flames over a wide range of co-firing ratios could . be obtained. The burner design allowed for straw feeding ratios up to 500/0 through the annulus and up to 1000/0 through the centre. However, chopping, handling and feeding can be difficult and substantial engineering development is required in this area. |