Experimental study on mass transfer during scrap melting in the steelmaking process

Abstract

The effects of natural and forced convection on mass transfer were investigated, especially the composition-dependent material properties were used. Under natural convection, the stationary specimen became a cone. The mass transfer coefficient increased from 3.14 × 10⁻⁵ to 5.31 × 10⁻⁵ m s⁻¹ at the temperatures of 1300–1450°C. The empirical formulas Sh = 0.144(GrSc)^0.325 and k = M(Δρ)^0.325(L)^−0.025 were found within the ranges of 1 × 10⁸ < GrSc < 5 × 10⁸. Under forced convection, the rotating scrap cylinder became an irregular spiral. When the rotational speed changed from 141 to 423 r min⁻¹, the mass transfer coefficients were 7.50 × 10⁻⁵–1.72 × 10⁻⁴ m s⁻¹ at the temperatures of 1300-1400°C. The empirical formulas J_D  = 0.133(Re)^−0.356 and k = M(n)^0.644(L)^0.288 were obtained within the ranges of 1000 < Re < 4000.