A. Effects of Pitot tube on the velocity distribution in Cyclone.
When a Pitot tube is inserted into a small Cyclone, the pressure drop, ΔH_p, decreases. It is suspected that this reductions of pressure drop may have been caused by the decreased rotating velocity of gas due to the insertion of the Pitot tube. If so, the observed values of rotating velocity must be smaller than the real velocity of whirl in the Cyclone.
In our previous paper, the pressure drop of Cyclone was given by the following eq.
(i)
where (ii)
This eq. is introduced on the assumption that the difference between the moment of momentum of gas at the inlet and outled duct is equal to the moment of friction force on the cyclone wall.
However, when a Pitot tube is inserted into Cyclone, the moment of drag force of the Pitot tube due to the collision of gas must be taken into consideration.
Thus, φ_III, φ_II, φ_I and φ₀ are introduced as showm in eq. (5), (9), (10) and (11), respectively. These values are less than φ, so the rotating velocity of gas at the circumference of the Cyclone, Vie, must also be lower, judging from the definition of φ shown in eq. (ii). Substituting φ_III, φ_II etc. for φ, the pressure drops in the Cyclone with the Pitot tube inserted can be calculated.
In other words, when the pressure drops in the Cyclone with Pitot tube inserted are known, the values of φ_III, φ_II etc. are obtained by the eq. (12). Then, the real rotating velocities can be calculated from the observed ones multiplied by the ratio φ/φ_III, φ/φ_II etc.
In the case of cylindrical Pitot tube, the length of top stem l' (see Fig 8), affects the velocity measured in the Cyclone. As described in eq. (5), the longer the length inserted into Cyclone, the lower the rotational velocity. Consequently, the longer the length l' is the higher the observed values must be. But the measured values prove to be smaller than the anticipated ones, as shown in Table I, which has led us to obtain experimentally, the relation expressed as eq (14).
Thus we are able to calculate the real rotating velocity in Cyclone by taking into consideration above two calibrations and the average calibrated values obtained with all the Pitot tubes in use. From the calibrated velocity distribution, we are able to show the existence of the potential flow (V_i·rⁿ=const. n=1) in the domain II (see Fig. 6 and 7), though in the measured velocity distribution the indexes, n, are less than 1, as shown in Fig. 4.
B. Effects of Pitot tube on the statical pressure distribution in Cyclone.
Statical pressure in Cyclone measured with Pitot tube also differs from the real statical pressure free from the influence of Pitot tube: the larger the dia, of the Pitot tube, the lower the statical pressure near the Cyclone wall, and at the same time the higher the statical pressure near the center.
We studied the method of calibration and obtained the relations as shown in eqs. (21), (22), (23) and (24). with the conclusion that the values calculated by these equations are independent of the size of Pitot tube.

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The purpose of this paper is to report the distribution of void in the packed single and double tube as the function of radius, as was observed in our experiments.
The paking used was crushed calcium carbonate, prepared by passing curbon dioxide over slaked lime. The packing in the tube was set with paraffin, and taken out of the tube. in a rod-like shape, which, then, was pared off thin in uniform thickness and divided into a certain unmber of various fractions. Each fraction was dissolved in hydro-chloric acid, so that the volume occupied by the packing might be known from the quantity of excessive hydrochloric acid employed, thus enabling us to calculate void of each fraction.
The results of the experiments are shown in Figs. 1 and 2.
Two parts were observed to exist, one having the effect of the wall, and the other having constant value of void free from the wall effect.
The experimental equations are Eqs (3) (4), and (8).

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Coke particles of uniform size into which the air was blown so as to form a fluidized bed, were gasified and the process was studied in order to make clear various experimental conditions under which the gas had been prepared.
(1) Experimental Conditions
diameter of fluidized bed D_T=5.5, 8.0cm
average diameter of coke particles D_P=0.125-1.64mm
height of fluidized bed L_f=4-40cm
height of bed, statical state L_σ=2-11cm
temperature t=592-1337°C
superficial velocity of air u_an=0.91-30.5cm/s [NTP]
(2) Range of Gas Composition Measured
O₂=0.0-12.5% CO₂=2.5-18.8% CO=2.6-30.5%
The simple equations (10) and (12) were applied to the experimental data so that the overall rate coefficient of reduction k₂ [cm/s] (C+CO₂→2CO) might be obtained, and both the effects of agglomeration of particles in fluidized bed and the chemical reaction on the overall rate coefficient of reduction were studied.

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One of the important defects of the fluidized-type reactors consists in the undesirable discharge probability of the reacting particles.
For this reason single-stage fluidized-type reactors are usually operated with relatively small reaction capacity.
In multiple-stage fluidized type reactors the defect is lessened very remarkably.
Theoretical equations for discharge probability and residence time are illustrated.
Experiments are conducted for the confimation of the equations.
With the single-stage type, u_g and D_P are varied, and the mixing efficiency of fluidized bed is found to be equal to the ideal one, under the conditions: u_g>1.6u_mf and 50-80mesh D_P.
With the double-stage separator type, the height of the slit between the two Compartments is varied. With this type there exists an optimum operation condition with no heights difference between the two neighboring beds and with good discharge probability equal to that of the theoretical double stage.

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