Results were presented on the power consumption by agitation accompanied by aeration. Analysis of the power led to the introduction of dimensionless term N_A and it was found possible to correlate the power consumption withN_A.
(1)
Principal data were obtained with the impellers shown in Fig. 4. Tanks used were respectively of diameters 27.4cm, 20 and 16.5cm. The air inlet nozzles were settled beneath the center of agitation (Fig. 2). The following are the relative dimensions held throughout the experiments.
Results are summarized as follows;
1) With the paddle, the relation (1) holds good as was illustrated in Fig. 5. (P_g/P₀) first decreases with the increase of N_A and then it shows a tendency to have a definite value with N_A which is larger than 4×10^-2.
2) With a vaned disk, there exist the limiting rotational speeds n_c which are the function of D_i.
The relation (1) holds fairly good with the rotational speeds, larger than n_c.
The number of blades has remarkably important effects on power consumptions, which was shown Fig. 8.
3) With the turbine, the relation (1) holds good with engineering estimation as was illustrated in Fig. 11.
4) The position and diameters of air inlet nozzles have little effects on power characteristics.

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In the preceding paper, the authors analysed mechanism of flow of Bingham plastic materials through a screw extruder, which has a uniform channel. And equations of flow rate under various conditions were obtained in convenient forms as the function of three nondimensional terms, w, z and U. The experimental data were in good agreement with the theoretical results.
In this paper, the results of preceding study were developed so as to be applicable to a variable depth type extruder, of which the height of screw thread is a linear function of helical length of the channel. Extruder of this type is often called compression type, and it is frequently used in various chemical industry for the purpose of increasing its ability of compressing and kneading pla stic materials. The results of study obtained are as follows.
When the gradient of depth of the screw channel is very small, the pressure distribution along the channel is given by:
for the range,
for the range,
where, H₁ and H₂ are respectively the depth of channel at the inlet and outlet port.
For the rangeorthe relation between p and H is very difficult to obtain with precision, but by the aid of equations 13), 15), and non-dimensional term n, it was successfully correlated. These results are shown by curves in Fig. 6.
Equations 13), 15) and Fig. 6 are very important in and convenient for designing purpose. So an example of how to solve design problems was given for the purpose of showing concretely the results obtained.

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An Air Slide is a kind of pneumatic conveyor for transporting solid material through a slightly inclined trough.
The trough is separated into two parts by a horizontally placed porous plate. When low pressure air is blown into the lower channel, solid material, which is fed continuously on the upper channel, is aerated and flows like liquid.
Using an experimental equipment as shown in Fig. 1, we studied the mechanism of flow of materials through the trough. The characteristics of flow of standard sand, particles of alumina and bauxite were as shown in Fig. 8-11.
The velocity distribution was very different from that of the ordinary liquid, as shown in Fig. 12 and 13. Solid material slipped on the surface of the side wall of glass or steel plate. And the slip velocity was so large that the difference between the maximum velocity and the slip velocity was almost negligible for the purpose of designing the conveyor.
From this study, we concluded as follows:
(1) The coefficient of statical friction of aerated material decreases rapidly as the air velocity approaches the velocity of minimum fluidization U_mf, and the solid material begins to flow at a very slight inclination.
(2) The flow rate of aerated material through an Air Slide can be represented as water flow in an open channel, and the resistance of flow is proportional to the mean velocity.
(3) By the use of the friction factor f or characteristic constant (such as k_a) the dimension of an industrial equipment can be calculated.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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