The following results were obtained from experiments on mass transfer from a layer of packed particles into steady and pulsed water flows, respectively, each through 3.6cm and 7.5cm diameter glass columns packed with 5 to 8mm β-naphthol cylindrical pellets.
(1) JD-factor of mass transfer into the steady flow may be expressed with the following equation within the range tabulated in Table 1,
(2) The fractional increment of mass transfer with the pulsed intensity may be expressed with the following non dimensional equations,
for (af/u)<2.5
for (af/u)>2.5

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A centriclone is a dynamic combination of a conventional liquid cyclone and a centrifuge. To produce the required circular velocity, an internal impeller is employed instead of a tangential orifice inlet and feed pressure.
In this study, the characteristics of a centriclone were investigated. First, we examined the velocity distribution inside the centriclone with a single hole Pitot tube. Then with the experimental arrangement as shown in Fig. 8, we studied the separating characteristics of the centriclone for Al (OH)₃ slurry of 2-10 weight% conc.
The results obtained were as follows:
(1) As shown in Fig. 4, the tangential velocity in the zone of outer vortex is almost constant, and the inner vortex has a constant angular velocity like a rigid body. From the study of the velocity distribution, experimental equations such as Eqs. (3) and (4) have been obtained.
(2) The turning point of flow from outer downward vortex to inner upward one is independent of the rate of feed, but it is influenced by flow ratio rf, and can be expressed as Eq. (2).
(3 ) The effect of rotating speed of the impeller on concentration ratio rc under different conditions are shown in Figs. 11, 12, 14 and 15. In all cases, rc increases with the increase of N.
(4) From the effect of the type of impellers on rc, the impeller with a small pumping capacity has been found best to serve the purpose, as shown in figs. 11 and 12, when the flow rate of feed is small, but as the feed rate increases, the impeller with a larger capacity becomes more useful.
(5) When flow ratio rf is reduced, underflow of higher concentration is obtained as shown in Fig. 13.
(6) Theoretical consideration of the size of the particles, all of which can be caught in heavy liquid, has led us to derive the follcwing equation
where
x thus obtained is proved to be a close approximation to d50 determined experimentally.

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A model cyclone gas generator of slag tapping type was constructed and operated without any trouble, obtaining fairly good values both of effective gas amount per unit weight of raw coal and of carbon efficiency. Then the volume of effective gas which might be generated with a generator of an industrial scale was estimated by means of the author's theoretical equations in appendix.
Many factors affecting the values of carbon efficiency were analyzed, for considerably wide ranges of conditions, in three series of runs: the first run conducted for the explicit purpose of studying, combustion, the second one for gasification with the air, and the third for gasification with the oxygen (Cf. Figs. 7-12). From these experiments it was especially made clear that the mean temperature in gasification zone in the model gas generator was the most essential factor affecting the values of carbon efficiency, and that the percentage of ash amount entrained from the generator had definite relation with the carbon efficiency, as shown in Fig. 7.

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