Mass-Transfer from Solid Metal Cylinder into Liquid Metal

1) Mass-transfer coefficient, k, from rotated or static solid metal cylinder surface into liquid metal, was measured chemically or gravimetrically.In this report, steel-Al, steel-Zn, Cu-Pb, Zn-Hg and Sn-Hg were employed as the combination of solid metal cylinder-liquid metal bath.Correlation of mass-transfer coeff. to the physical properties of liquid metal, diffusion coeff., characteristic length of the cylinder and experimental conditions (temperature, speed of rotation, etc.) was analysed non-dimensionally.Results obtained are as follows:Jd=(k/U)(Sc)2/3=0.065(Re)-0.25: rotated cylinder(Sh)=0.124 (Gr·m×Sc)1/3: static cylinder2) These equations were rearranged to estimate the mass-transfer coeff. in the dissolution process of steel cylinder into liquid Fe-C alloy at about 1400°C.k=9.14×10-4 (L)-0.25(U)0.75: rotated cylinderk=1.17×10-2 (Δρ) 0.333: static cylinderExperimental results fairly agreed with the estimated values in the case of rotated cylinder but were about 30% lower than estimated values in the case of static cylinder, as averaged k.3) It would be concluded that the non-dimensional correlation of mass-transfer, predicted in common fluid at lower temperature, holds fairly well even with high temperature liquid metal such as Fe-C alloy at 1400°C in spite of technical difficulties of experiment at high temperature (especially in free convection) and the lack of the fundamental data on physical properties, diffusion coeff. of liquid metals.