Typical composition of cupola dust, data in weight per cent

Coke fired cupola gas is composed primarily of N2, CO2, H2O, and CO, with smaller amounts of SO2. On conventional cupolas, where the off-gas is collected above the charging door, a distinction has to be made between the condition of the flue-gases below and above the charging door, since ambient air is entrained through the open charge door. This input significantly changes the total airflow. 

The flow of the undiluted cupola top gases is proportional to the coke consumption. Increasing the coke proportion in the charge will decrease the production rate (tonne molten metal/h) if the same blast airflow is maintained. It may then be necessary to increase the blast to maintain the production. The metal temperature will also increase. With reference to the combustion rate (C + O2 CO2), more coke and blast air will result in an increased flow of exhaust gases. 

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Table 3.5 Typical composition of cupola dust, data in weight per cent [32, CAEF, 1997] and [158, Charbonnier, et aL, 1998]...

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