For the purpose of explanation of the mechanical loss of hydrogen taking place in CO2-absorbing tower, we tried some model experiments in which gas volumes sucked at the tower bottom with circulating liquid were ascertained under various conditions. We have obtained experimental formulas as follows:
where H: depth of water layer (cm)
h: distance between the surface of water and the inlet pipe (cm)
V: Volume of water sucked (cc)
v: volume of air sucked with water (cc)
d: diameter of water pipe (cm)
D: diameter of tower (cm)
Re: Reynolds number of the outlet pipe
Previously we reported that we carried out in the case of bubbling caused by falling-water from the single tube. We used in this experiment a packing tower and introduced to approach the value of D/d to the case of the actual packing tower. The formulas above mentioned are similar to that of the single pipe.
For the purpose of the reduction of suchtion gas we researched the method of water distribu- tion by buffer plate which was placed in the bottom and attained successful results. On the other hands we perceived the considerable reduction of the suction gas also in the case of rings filled up the tower.

View full abstract

In order to estimate the effect of agitation in solid-liquid systems, the time required for the neutralization of dilute NaOH solution by benzoic acid tablets is measured on several conditions.
As a result of this studies, the following conclusions are derived.
(1) There are two types of fluidization, that is, type I and type II as shown in Fig. 1 b. c. and type I is superior in the Agitation efficiency.
(2) There is a critical agitator speeds N_c at which the solid particles are fluidized or dispersed into the liquid. At speeds lower than N_c, the neutralization velocities are greatly increased with increases in agitator speeds N, and at speeds higher than N_c, the changes in neutralization velocities with changes in N are minimized. So that this critical agitator speed N_c, is an important criterion for solid-liquid chemical systems.
(3) Baffle plates at the wall of the vessels are not effective. Several conditions of agitation are compared and the proper design methods for solied-liquid systems are discussed.

View full abstract

In the first report, it was proposed that the critical agitator speed N_c at which the solid particles are fluidized, is and important criterion for the solid-liquid chemical systems.
Now, in this report, this N_c value is adapted as the necessary speed for the mixing, and the power consumed in this speed (noted as P_c) was compared in various conditions and the optimum agitator sizes were detemined as follows.
dopt.=0.45-0.5D for Flat Bottom Vessel (F) dopt.=0.4D for Dished Bottom Vessel (D)
dopt.=0.35D for Round Bottom Vessel (R)
Also, the effects of various conditions of agitation upon the N_c values were investigated.

View full abstract

For the more clear understanding of sedimentation phenomena, a study on sedimentatios in suspensions of various divided solid particles is presented.
1) The concentration gradient along the depth of suspension, containing the solid particles the size distribution of which is represented by, can be expressed by
If the particle size distribution and the rate of sedimentation are given, we can solve this equation by a graphical method.
2) The general equation of the rate of sedimentation of such solid particles is given by
From the data obtained by our experiments using suspensions of various sized silica particles the following empirical formula is obtained;
The rate of sedimentation of the suspension of uniform particles is obtained by putting w=w0 in the previous equation; v=vsψ(w0)=cx2(1-w0/ρs)210-2.36·w0/ρs In this case the rate of sedimentation is the same as that of the subsidence of the surface of suspension.
3) The concentration gradient along the depth of dilute suspensions of silica, to which the Stokes law would be applied, is given by the following equation;
This relation shows that the rate of subsidence of the surface of suspension may be governed by the Stokes velocity of their minimum particles.

View full abstract

The factors affecting the depth of dispersed phase under a plate were studied in sieve-plate columns. Performance data were presented at various flow rates of both phases, using five liquld-liquid systems, several sieve plates and down pipes shown in Table-1. It was found that the thickness was consisted of the four kinds of heads (h_σ, h_f, h_e and h_d) and the sum of them was expressed by Eq. (5). A coefficient C in Eq. (5) was experimentally determined and was correlated with the Reynolds number through the holes (=du_dρd/μd) as shown in Fig. 4. This curve was used to calculate the values of (h_t)calc., which was compared with the observed values of h_t as shown in Fig. 5.

View full abstract