Noriaki Wakao

Discussions of Mass Transfer Coefficient

平板上で表面反応A→δB が行なわれるとき (ガス吸収, 蒸発を含める), 物質移動係数に対するpBmおよびδの影響を検討した。境膜説に基づいたShの定義, Sh≡ (kfL/D0)(pBmP) はガス吸収やδ 1では小さい。Shは濃度推進力が小さな場合はpBmに無関係であるが, 推進力が大きくなるとpBmのみならず推進力にも依存する。また, 平板面から空気流 (層流境界層) への有機溶剤の蒸発実験を行ない。理諭との比較を行った。

Wall-Film Mass Transfer Coefficients of Fixed Beds

In order to explore the film coefficient of a fluid adjacent to the inside wall of fixed beds, data were obtained on the rate of dissolution of β-naphthol, by passing water through the beds whose inside was coated with the same material.Glass beads and sand were used as packings. The experimental range of the modified Reynolds number was from 1 to 2, 000, and the Schmidt number, from 1, 000 to 1, 700.Table 1 presents the dimensions of the various solid particles and of tubes used in this work. Solution was analyzed by means of a spectrophotometer.As the result, it was made clear that under the conditions employed in this investigation, the eddy diffusion in the radial direction had little effect on the coefficients of the wall-film transfer.The experimental data and calculated results for typical runs are presented in Table 2.Fig. 3 shows a summary of the wall-film coefficients, where Sh/Sc1/3 is plotted versus Rep.In this plot the properties of the particles do not appear as a parameter. The following correlations are obtained from the lines drawn in Fig. 3.Sh=0.60Sc1/3Rep1/2 Rep 40