Through the statement of the turbulent Navier-Stokes equations and a coalescence model of Saffman and Turner a mathematical model has been proposed to describe deoxidation kinetics in an R-H vacuum degassing unit. An important feature of the work was that a population balance model was used and that an allowance was made for the spatial non-uniformity of the coalescence rate.
It was found that the R-H vacuum degasser is an excellent mixer with virtually all the material contained in the ladle being involved in the overall circulation. The maximum turbulence energy dissipation occurs in the vicinity of the “down-leg” but the calculations have shown a remarkable spatial uniformity of the inclusion particles, notwithstanding the fact that the rate of coalescence was markedly non-uniform.
It is thought that the population balance approach outlined in the paper could be applied to a range of systems where the principal mechanism of deoxidation is the coalescence of the inclusion particles.