[in Japanese]

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The terminal velocity and the variation of the and the shape of ellipsoidal single air bubbles rising in eleven liquids of low-viscosity were measured.
The path of a single bubble was zig-zag in many cases, but in purified water and in some organic liquids it was spiral when the diameter of the bubble was small. The period and the amplitude of the zig zag and spiral motion of the path was correlated, as a relation between dimensionless groups, irrespective of the modes of the motion.
The period of the variation of the shape which was measured as the ratio of the major and the minor axes of a bubble was approximately half as that of variation of the path.
The period of the variation of the angle betwe the major axis of the bubble and the horizontal axis was also measured and just the same as that of the path, but the phase difference existed between these two variations.
Taking into considerations above experimental.results, the two-dimensional models of rising in low viscosity liquids were proposed.

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To know the fundamental aspects of particle-fluid contacting operations, the relative movement of tracer particle in the swarm of bed particles has been investigated experimentally by using a liquid fluidized bed, where the tracer particle has a size different from that of bed particles. The quantity Φ as defined by Eq.(10) to give the slip velocity of the tracer particle is found a sole function of void fraction of the bed when the particle Reynolds number is in the range of 20-500. For lower Reynolds number (b varies with both of the Reynolds number and the void fraction. The quantity ql is also shown to) give a good description for the relative rate of settling of particles with mixed particle sizes.

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The author previously reported an analytical theory for mass transfer through a laminar boundary layer on a flat plate with flowing interface. The present paper discusses the application of the theory to continuous phase mass transfer from single drops. In addition, the approximate equation to evaluate the interfacial velocity of the drops is derived for a wide range of physical properties and Reynolds number.
The existing data for continuous phase mass transfer from single drops is rearranged and compared with the theoretical results. It is found that the exitsting data agree well with the theoretical results and is well correlated as a reasonable additional function of the interfacial velocity with the same degree of accuracy as that of the data for single solid spheres
The results should yield much useful information for future studies of interfacial mass transfer.

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The relation between drop behavior and masstransfer inside a drop was experimentally clarified, using the systems of toluene drop-water and n-butanol drop-water. In the range of drops with small diameter, mass-transfer rate is controlled by the degree of mixing inside a drop caused by circulation flow and turbulence. For the drop accompanied with oscillation, mass-transfer coefficients both for continuous and dispersed phases are correlated by a same equation and mass-transfer resistance is controlled by oscillation.
Based on the above experimental results, a model was proposed, which express mass-transfer rate through a drop in states from mild to violent mixing inside the drop. For oscillating drops, the empirical equation for mass-transfer coefficient was compared with Angelos' generalized penetration model and the equation derived on surface renewal model. It was clarified that Angelos' equation explains well the observed results, apparently.

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The mechanism of size separation in the wet classifier was studied fundamentally, and the effects of solid content and/or particle size distribution in the feed suspensions and the flow pattern in the continuous classifier on the classification efficiency such as partial classification efficiency and/or solid removal percent.
Based on the above considerations and experimental results, we have developed the high efficiency classifier as “Multi-recirculation-wet classifier”.

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The experimental transient responses obtained on a 3-in. i.d. five plate absorption column operating with the system air-carbondioxide-water-sodium carbonate. The theoretical model which contain unsteady state hydraulics is given for unsteady state behaviour of a plate gas absorption column and theoretical transient responses are derived. The experimental responses are good agreement with theoretical responses.
The first, the patterns of the responses are influenced by the structure factors such as a free area and this phenomena shows a residence of the backward flow for step increase in gas flow rate. The second, the greater absorption rate, gas and liquid flow change more influence upon the dynamics. The third, the time constants of hydraulics are not negligible small compared with mass-transfer time constants.

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Salt effect in vapor-liquid equilibria was studied on methanol-ethanol-water system with calcium chloride (16.7wt.% and saturation at room temperature) at atmospheric pressure. Relative volatility of methanol to ethanol decreases, but that of ethanol to water increases by calcium chloride

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Solubility curve and tie-lines were determined for the systems acetic acid+water+benzene and acetic acid+water+toluene at 25°C. The concentration of acetic acid at plait point was obtained from extrapolation of the following correlation line, logxw, vs.(yw-xw)/xw
where xw is acid concentration (wt. fraction) in hydrocarbon layer and y, is acid concentration (wt. fraction) in water layer.
For the acetic acid+water+hydrocarbon systems, it seems there is a qualitative relation between concentration of acid at plait point and solubility of hydrocarbon in pure water as follows.

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Vapor-liquid equilibrium data of nine binaries and two ternaries of hydrocarbons were obtained at atmospheric pressure. By using these data, the binary-interaction parameters of Wilson equation were determined and these parameters were shown to be capable of predicting vapor-liquid equilibria of ternary systems.
The prediction of vapor-liquid equilibria by BWR equation were also attempted for these systems.

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Using our experimental data and Soviet literature data, we obtained the experimental equations for the maximum allowable gas (vapor) velocity (U_gm) in plate tower without downcomer.
Classifying the plates in two groups:(a) perforated plates (F_c≥0.16), (b) grid plates and perforated plates (F_e<0.16), we derived the calculating formula for each group.
For (a) group, two equations are obtained for the ranges of pg/pl × 10³≤0.838 and ≥0.838 (error ±13%), and also for (b) group, two equations are obtained for the range of pg/pl×10³≥1.20 and ≤1.20 (error ±15%).

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This study deals with the continuous phase mass transfer from bubbles and a further application of the mass transfer theory counted with flowing interface which the authors previously reported.
The theoretical results agrees favorably with the experimental results by Redfield-Houghton and by Calderbank-Lochiel on the continuous phase mass transfer rate from single bubbles, and with the data by Calderbank-Moo-Young on the continuous phase mass transfer from bubbles in aerated mixing vessels.
The above comparisons suggests that the future study of interphase mass transfer should pay particular attention to the interfacial velocity.

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