A Study of Dynamic Lining Temperature Variations in the Taphole Region of a Blast Furnace

• The thermal behavior of the blast furnace hearth with special focus on the taphole regionwas studied. The original lining is in this region assumed to be replaced with tap clay,which influences the dynamic lining temperature variations. A heat transfer modelpreviously developed has been used to study the effect of the size and shape of the tapclay layer around the taphole. Four different cases have been calculated: one referencecase and three cases different tap clay layer geometries. It was found that the calculatedpeak-to-peak amplitudes of the lining temperatures during the tap cycles at the location ofa thermocouple can be approximated as a linear function of the tap clay layer thicknessesfor all calculated cases: the R2-value of the linear approximations were in the range 0.9-0.98. Modeling was also done where both the 90th and the 10th percentile of the observedpeak-to-peak values of the studied tap cycles were included to describe the behavior ofthe operating furnace. The calculation results show that the taphole region can be dividedinto three categories based on how well the model can describe the measured processdata: below, at and above taphole level. Below the taphole level, the measured liningtemperature variations are smaller than for the calculated results. At the taphole level, themodel can describe the behavior of the operating furnace. Above the taphole level, themeasured lining temperature variations are larger than for the calculated results. It wasconcluded, that in order to make a more accurate heat transfer model of the tapholeregion, the presence of a skull build-up below the taphole, erosion above the taphole andthe bath level variations need to be taken into account.

Keyword

Blast furnace

mathematical model

heat transfer

taphole

tap cycles

tap clay

Publication and Content Type

vet (subject category)

art (subject category)