Studies were made on the development of particulate solids in the agitator.
The appearance of the development of particulate solids in the agitator changes with the variation of operating conditions. To detect these phenomena quantitatively, the relative concentration of particulate solids were measured with the photo-electric apparatus (Fig. 1).
When the rotational speed was small enough, all the particles were at the bottom of the vessel.With the increase of the rotational speed, particles came to develop in the agitator and the concentration of the particles began to increase. The critical rotational speed, as we defined it, occurred when the value of concentration of particles showed a tendency of having certain definite value above the speed, This is illustrated in Fig. 2.
Some considerations were given to this speed. Analogous to the method used in defining the rate of solution of fully developed particles in the agitator, the principal relative velocity υ, relative to the particle, was assumed as follows:
(1)
From the above relation, the measure of random external forces to the particle was expressed as follows:
(2)
The external force due to the gravity was as follows:
(3)
The ratio of the above two forces were reduced to:
(4)
We assumed that α is the value indicating the measure of appearance when the particles were developed in the agitator and at a certain definite value of α, denoted as αc, the particles made full development in the agitator.
Experimental evidence of the above consideration was procured with the vessels sized 14, 17, and 27.4cm. respectively. The solid particles were standard sand, magnetite sand and sand made of resin. Paddles, vaned disks and flat-blade turbines were used as solid-liquid contacting impellers. The experimental results are illustrated in Fig. 4. Each value of εc was calculated from the data on critical rotational speed. As was seen in the illustration, the data satisfied the following equation in practical estimation.
(5)

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To design a methane gas absorber in_which hydrocarbon oils are employed, the relation between the fugacity of methane solution and the amount of methane dissolvedin kerosene and urea-adduct-refined kerosene was studied, at various pressures (1-50atm.) and temperatures (0-30°C).
1) In pressure changes, Henry's law was confirmed to hold, that is, the mol-fraction of dissolved methane was found to be proportional to the fugacity of methane.
2) With temperature changes, it was found that the logarithms of Henry's constant (lnh) changed linearly to the reciprocals of temperature (1/T).
3) From these relations were obtained experimental equations formethane, dissolved in each solvent.
4) The straight lines of ln h-1/T were investigated thermodynamically, and the heat of methane solution in each solvent was obtained from these slopes.
5) From McDaniel's experimental values for the solubility of methane in n-hexane and n-heptane, similar straight lines were derived and the heat of respective solutions was calculated. These heat data of solutions served to prove that the increase of the carbon number in hydrocarbon solvents lowered the heat of solution.

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In the papers previously published by several other authors^{5), 7)}, the average specific resistance ofcakeatconstant pressure filtration, α_f, was represented as a function of a single variable, that is, the filtration pressure p₀. According to the results of our constant-pressure-filtration experiments with the so-called ceramic slurries, the ignition-plug slurry was the only case where α_f was a function of a single variable p₀, and α_f of all other slurries was not so simple. In this paper we report the various filtration characteristics of Gairome-Clay slurries.
Summaries of the results were as follows:
i) ε vs. p_s data obtained from the compression measurements by using a consolidometer are plott- ed in Fig. 1. (ε) was a function of p_s only, and was not influenced by the slurry concentrations. (k·S₀²)vs. ε data from permeability measurements are plotted semilogarithmically in Fig. 2, resulting in approximate empirical equations (2). m-values predicted by equation (3) were found to be a function of p0 only, as shown in Fig. 3, and α_app-values predicted by equation (4) to be a function of s as well as of p0.
ii) (Δθ/ΔV)vs. V relation at constant-pressure filtration with Gairome-Clay slurry, indicated a curve, which approached asymptotically to a straight line as V increased.
iii) The relation of (K·S₂₀)app^{·s vs. s}, of each constant-pressure filtration, showed also a curve.
iv) Applying the predicted m-values to the constant-pressure filtration results, the following empirical equations of αf were obtained.
where
aad (dimensionless)
Therefore, the average specific resistance, α_f, of the Gairome-Clay cake at constant pressure filt- ration could be represented as the sum of the term (α_app) -including variables p0 and s only-, and the correction term (α_corr) -including variables p0, s and V.
The term (α_corr) in the empirical equation of α_f indicates the influence of degree of particle flocculation, depending on the slurry concentrations; while the term (α_app) in the expression of α_f shows the occurrence of cake disflocculation due to the filtrate flow, in other words, the existence of a kind of scouring effect.

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Concerning the turbulent flow in vertical cylindrical tanks which have no baffle and are agitated with a two-blade-paddle at the centre, some experiments and calculations were carried out.
1) From the data presented by several investigators. we derived Eq. (1), regarding velocity distributions in the tank. The experimental data on the two parameters, δ and ξ, were als obtained.
2) Power consumption and torque supplied to the liquid by the paddle were measured.
3) Spreads of the coloring substance diffused along the main stream in time t were measured by means of many photographs. As the result, eddy diffusivityε, turbulence velocity √v², mixing length l and t₀ were calculated.
4) Distribution of Reynolds stress τ, rate of dissipation of energy Eτ and average size of an eddy λ were calculated, Also, eddy viscosity ε' were calculated in order to check the above results. These are shown in Fig. 5 and 6.
It is difficult to deduce a general correlation between degree of agitation and that of turbulence from these experimental results, therefore, Fig. 7 and 8 might be understood to represent rough estimation.

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