Increasing shaft height of CBC

Melting rate of Cupola (tonne/h) Height from tuyeres to charging door sill (m) 

Depending on the installation type, the height must be optimised to allow bum-out of the gases and efficient heating of the charge. 

Operational data are given in Table 4.6. The modification involves a doubling of the upper zone volume. This results in a reduction of coke consumption from 140 to 115 kg/tonne, which is a relative reduction of 18 %. It should be noted that in general an optimal shaft height follows the rule-of-thumb height = 5 x diameter at tuyeres . The initial situation in the example furnace was therefore sub-optimal. 

Optimisation of the furnace height needs to be performed at the design stage of the fiimace, otherwise height increases will usually only be performed during major re-building works of the furnace. 

Operational data are taken from an example plant in France. 

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