Absolute calorific value,19,410 kJ/kg 19 18 17 The picture shows that even at (2000F) reasonable residence times and 1090℃ temperatures a significant fraction of 1750E)合 the fuel is unburned 950C4 5ec0(1500E)● 14 680℃○ (1250E 0 ▲1090°C 13 △950C ●815C O680C 12 0 10 152025 30 Time in furnace,min D 90 UNEPThe picture shows that even at reasonable residence times and temperatures a significant fraction of the fuel is unburned