Mathematical Model Analysis on Three-dimensional Gas Flow in Blast Furnace

Abstract

A mathematical model of three-dimensional gas flow in a blast furnace has been developed in which three-dimensional layer structure and permeability distribution are considered, using the finite element method.
Cohesive zone profile and pressure distribution were simultaneously measured in an actual blast furnace and compared with the computed results.
Good correspondence between them confirms the adequateness of the mathematical model analysis.
The principal results of the circumferential distribution analysis are as follows.
(1) On the side of high stockline, pressure increases and gas flow rate decreases.
(2) Gas flow rate varies with the permeability distribution that depends on thickness ratio of ore and coke layeres, but pressure is almost constant.
(3) With deviated cohesive zone profile, the level of the maximal variance of pressure distribution corresponds to the sectional average level of the cohesive zone, where pressure is high on the side of high melting level. In the lumpy zone, gas flow rate is low on the side of high melting level.
(4) Blast rate distribution is smoothed through the dropping zone and has no effect on the gas flow distribution in the lumpy zone. On the other hand, pressure drop through tuyere is important to equalize the blast rate distribution.