Decarburisation rates in RH–KTB degasser of CST steel plant through physical modelling study.
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Date
2006
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Abstract
A physical model based on similarity principles was constructed to simulate the RH (Ruhrstahl–
Heraeus) degasser of CST (Companhia Sideru´rgica Tubara˜o, Vito´ ria, Brazil) to evaluate the
influence of metal circulation rate, which essentially defines the degree of exposure of the metal to
the vacuum in the chamber, on the decarburisation rate. The circulation rate in addition influences
the removal of dissolved gases such as nitrogen, and hence it is essential to optimise this
parameter to achieve maximum refining efficiency with minimum refining time, thus improving the
productivity of the secondary refining process. In the present work, simulation experiments
investigating the kinetics of decarburisation have been carried out using the CO2 adsorption–
desorption process in sodium hydroxide solution as the circulating fluid. The effect of bottom gas
flowrate and snorkel diameter in this case was also evaluated. Bottom gas injection practice,
under the upleg, improves the circulation rate. Increasing the circulation rate by bottom injection
leads to an increased degassing rate. However, degasification efficiency does not remain at the
same level. The circulation and degasification rates can be improved by an increase in diameter
of the downleg snorkel. The relative gain in degasification seems to be higher at the higher
flowrate range. The results have been translated to a prototype, to optimise the process.
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Keywords
Decarburisation, Physical modelling
Citation
SESHADRI, V. et al. Decarburisation rates in RH–KTB degasser of CST steel plant through physical modelling study. Ironmaking and Steelmaking, v. 33, n.1, p. 34-38, 2006. Disponível em: <https://www.tandfonline.com/doi/abs/10.1179/174328106X80019>. Acesso em: 20 jul. 2017.