By the time that the coke in a blast furnace charge has descended to tuyere level it has
been heated to approximately 1800 K. This coke is combusted by the oxygen of the
blast to give CO at the edge of the tuyere raceways. The flame temperature at the edge
of the tuyere raceways determines to a considerable extent the final temperature of the
slag and metal and hence it is important to understand how this flame temperature is
affected by furnace operating parameters.
Calculate, therefore, the adiabatic flame temperature at the edge of the tuyere raceways
(overall combustion to CO and H2) under the following conditions:
a. dry air blast, 300 K;
b. dry air blast, 1200 K;
c. dry blast enriched to 25% O2 by adding pure oxygen, all at 1200 K;
d. air blast containing 8 g of H2O per Nm3
of moist air, 1200 K;
e. dry air blast; 1200 K, to which fuel oil (298 K, 86 % C, 14 % H. gross heat of
combustion = -46 600 kJ