1) Absorption of pure CO₂ in water was investigated using a 6-cm-dia. tower, packed with 6mm, 8mm and 10mm Raschig rings. The results are shown in Figs. 2, 3, and 4 and by Eqs. (2), (3) and (4).
2) Based on the theory of penetration, the correlations of kL were studied in the form of kL[T]^1/2/ DL^1/2 to (L/a_tμ), (ρρ²g/a_t³μμ²) and (D_ta_t), where T=exposure time.
3) The data of Sherwood-Holloway, Vivian-Whitney, Deed-Schutz-Drew, Hikita and the authors were reasonably correlated as shown in Fig. 9. The center line in Fig. 9 is expressed by Eqs. (12) and (13).
4) Eq. (14) derived from Eq. (13) shows that kL is in proportion to (LD_p/μ)^1/2. By estimating the power of (Ga) roughly at 1/3, Eq. (12) has been simplified into Eq. (15), its modification Eq. (15') representing modified Sherwood number.

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Studies were made on the velocity distribution of water in a hydraulic cyclone, by taking photographs of the loci of polystyrene particies floating in the water, in various horizontal and vertical sections.
For the measurements of the absolute velocity, two spot lights were obtained by means of a special stroboscope at certain definite time intervals. Based on these photographs we have calculated tangential, radial and vertical components of velocities in various positions. For the radial velocity calculation, we have taken into account possible errors due to the centrifugal force and the density difference, when ρ_p=1.03 and d_p=70μ. The cyclone consisted of a cylindrical part, 79mm in inner diameter, 154mm in height, and 15° in angle of its conical part.
With the tangential component (Figs. 5 and 6), two domains were found to be existing, represented by Eqs. (6) and (7), just like in case of a gas cyclone. The exponent of r in Eq. (7) increased up to a unity according as the position of the cyclone went downward. As for the radial velocity, remarkable fluctuations, unsymmetries and secondary flows were observed (Figs. 7, 8 and Table 3). On the average, however, as in Fig. 9, an inward velocity zone was found both near the wall and the central air column, between them existing an outward velocity zone. There were fluctuations in the vertical velocity. When all overflow happened (R=0), there was a downward flow near the wall and upward flow within, no maximum being observed. On the other hand, in case R=1, there was a downward flow near the air column, causing a maximum upward velocity, as a consequence. When R=1/6, the flow in the upper part resembled the flow in case R=0, while in the lower part, it resembled the flow in case R=1.
The material balance of the water passing through the horizontal section was calculated, as well.

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Many analytical studies have recently been made on the behavior of viscous polymers in an extruder, regarding them as Newtonian, Bingham or pseudo-plastic materials. However, their behavior in the channel of the extruder screw is far too complicated to be made clear in this light. Thereupon, we have made somewhat different approaches to the problem of melt extrusion.
The first half of our study pertains to the visual tracing of flow curve in the extruder screw. A transparent acrylic extruder barrel is employed for extruding corn syrup containing small particles. As the result, a traverse flow is proved to exist, on some assumptions.
The second half of our study relates to the travelling time of PVC polymer through the melting zone of the extruder. (The solution of this problem is especially important in making clear the behavior of heat-unstable polymers when they are extruded.) In the experiments made with this end in view, glass powder or radioactive isotope Na²⁴ is used as a tracer. From the analysis, on some assumptions, of our experiments, the possibility of forecasting the travelling time through the extruder is revealed.

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[in Japanese]

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