Mathematical Modelling of Blast Furnace Processes for Characterisation of the Internal State

The blast furnace is a multi-phase, multi-species moving
bed metallurgical reactor with counter-current exchange
of heat and mass between gas and solid involving phase
changes and complex reactions at high temperatures.
Its dynamic behaviour, being typical of a non-linear,
distributed parameter multiple input-multiple output
(MIMO) system, defied any description and
characterisation in terms of comprehensive
understanding of the process dynamics for a long time.
Various phenomena and performance of the blast
furnace are influenced by the counter-current gas flow,
chemical reactions, descent of burden materials, gas
flow resistance and shape of the cohesive layer,
combustion and transport behaviour in the raceway
zone with or without pulverised coal injection. Based
on the first principle approach, a one-dimensional
simulation model has been developed, assuming axial
and radial symmetry in distribution of process variables.
The internal state of the furn.ace is characterised by the
simulated distribution of relevant process variables along
the furnace axis which include the temperatures of the
gas and condensed phases, composition, volumetric
flow rate, density and pressure of the gas phase, degree
of iron oxide reduction, limestone decomposition and
the coke solution loss reaction.The calculated longitudinal
profiles of the furnace process variables show good
agreement with the published data.