[in Japanese]

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Temperature distribution and heat transfer coefficient by natural convection of air in an enclosed cavity (bottom plate is heated, one side plate is cooled and the others are thermally insulated) were measured experimentally under the frosting condition. In order to study the influence of mass transfer, temperature distribution and heat transfer coefficient without frosting were also measured. The present experimental results showed that the values of Nusselt number with mass transfer were approximatelly 2-3 times as large as those without mass transfer.
Temperature distribution and heat transfer coefficient were numerically obtained by solving the governing equations in case of no mass transfer. The calculated results agreed well with those of experiment.

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In a multistage inclined fluidized bed, it was investigated theoretically on heat exchange between particles and gas under some assumptions. A fairly good agreement was recognized between the theoretical and the experimental results in a three-stage inclined fluidized bed. Furthermore, effectiveness of multipling stages was confirmed on heat efficiency both theoretically and experimentally. A chart was made up on the relation between the required number of stage and optimum conditions of heat exchange.

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In order to determine friction factor and Nusselt number for laminar forced convection in arbitrary polygonal ducts, a numerical method has been proposed using Laplacians for triangular lattice. Since the presented method satisfies the boundary condition perfectly, one can be easily obtained the solution with fairly good accuracy and short time in comparison with other methods. An application to the ducts with arbitrary quadrilateral cross section is illustrated.

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An experimental study was carried out on the condensation of binary mixed vapor of miscible liquids on a horizontal tube. Vapor phase mass transfer coefficients were correlated by dimensionless equation applicable to all the system used in this study. Result of correlation for condensing heat transfer coefficients of organic solvents system showed a good agreement with that of single saturated vapor. For the system including water, however, a pronounce effect of condensate composition was found. In these calculation, interfacial conditions were assumed to be those of boiling point of condensate and it was shown by the results of correlation that this assumption was applicable. The estimation method of composition of condensate was presented at the same time.

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One of the important factor influencing on the bubble fractionation is the adsorption rate of surfactant from aqueous solution to the air-water interface.It was found that the experimental results for sodium dodecylbenzene sulfonate (D.B.S.) in tap water can be correlated with the adsorption rate equation of Langmuir's type, which is as follows:
wherer
Γ: surface excess of D.B.S.[mol/cm²]
t: time [sec]
CBA: bulk concentration of D.B.S.[mol/cm³]
Then using this adsorption rate equation, the elimination ratio of D.B.S. for a bubble fractionation equipment E=CF/CB-1 could be shown as follows:
And the experimental results agreed well with this equation.

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In the liquid extraction equipment such as a mixer settler and a spray column, the droplet bed is formed at the liquid-liquid interface. In this work, the formation mechanism of the droplet bed is studied and two models are proposed based on the theory of queues. In the model A the coalescence of drops is assumed to occur only at the top of the bed and in the model B it is assumed that the coalescence also occurs in the droplet bed.
The experiments of the spray column were carried using two distributors in toluene-water system.
It is found that the model B in which the coalescence frequencies are assumed to be proportional to the drop size agrees well with the experimental results.
The breakage frequencies of the drops in the bed are suggested to be evaluated by the measurements of the coalescence time of single drops at a plane interface.

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The mean notion and the turbulent fluctuation of the impeller jet flow region in agitated vessel have been measured by electrochemical method, and it is found that the turbulence in this region is approximately isotropic. And energy balances from those measured reveal that the mean kinetic energy given by the impeller converts to turbulent energy at first, and then dissipates into heat during being transferred by convection and diffusion, and that the energy transformation in neighbourhood of impeller is larger than that in other parts. Next it is found experimentally that the relationship between rotational and radial velocity components is linear in this region.

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Industrial crystallizers of the classified-bed type for sodium sulfate were designed by the design equation proposed by the authors. Design constant was obtained from tests of the cylindrical pilot plant, and two cone type crystallizers were designed for the different design conditions, respectively. The heights of the bed estimated by the design equation for the operational conditions, agreed with those observed on operation of these industrial crystallizers within fifteen percents.
Availability of the design equation for industrial purposes is discussed by the comparison between the model for derivation of design equations and status in industrial crystallizers, and the range of void fraction of the stable operational conditions was also shown.

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