Showing papers in "Journal of Chemical Engineering of Japan in 1968"
TL;DR: In this article, the average bubble diameter and conditions of bubble generation are obtained for the extreme cases when no coalescence is observed and the coalescence occurs at the maximum-rate.
Abstract: Bubbles which have been just generated from the porous plate are small and have an equal size, but sometime coalescence of these small bubbles occurs at a location slightly removed from the distributor, where the gas holdup is very large. Therefore, large and wide size distribution of bubbles are observed. This occurs easily in pure water and pure solvents. The surface active substances in water and solvents obstruct this coalescence of bubbles. In concentrated inorganic salt solutions, this obstruction is also recognized. For the extreme cases when no coalescence is observed and the coalescence occurs at the maximumrate, the correlations of the average bubble diameter and the conditions of bubble generation are obtained.
900 citations
TL;DR: In this article, the authors defined the ratio of the rate of lateral movement of fluid to the flow rate in the interior of the bed as a function of the velocity of fluid displacement normal to the wall to the normal flow rate.
Abstract: z = distance in the axial direction Greek Letters a/3 = ratio of the rate of lateral movement of fluid to the flow rate in the interior of the bed av = ratio of the rate of fluid displacement normal to the wall to the flow rate in the near-wall region ew = void fraction in the near-wall region $ = nondimensional radial distance = r/Rw y] nondimensional axial distance = z/Rw tC =ker/CpGoRw ft = viscosity of fluid [kg/m-h] v = kinematic viscosity of fluid [m2/h]
131 citations
92 citations
85 citations
TL;DR: In this paper, the extent of usefulness of the Benedict-Webb-Rubin equation (hereafter abbreviated as BWR equation) and the treatment of Leland et al. were studied.
Abstract: Vapor-liquid equilibria containing carbon dioxide: CO2-CO, CO2-Ar, CO2-CH4 and CO2-H2-CO were measured by static method at -50°C to 20°C and up to 200 atm. By using these data and the data available in literature, the extent of usefulness of the Benedict-Webb-Rubin equation (hereafter abbreviated as BWR equation) and the treatment of Leland et al. were studied. The BWR equation correctly predicted the vapor-liquid equilibria of inorganic mixtures except in the critical region, while the treatment of Leland et al. was insufficient.
80 citations
TL;DR: In this article, the authors defined coefficients in Eq. (12) and Eq (12c) for linear combinations of linear combinations in terms of the ratio of the coefficient in Eqs. (8d) and (8c) of the coefficients in each of these coefficients.
Abstract: = coefficient in Eq.(ll) = coefficients in Eq. (12) = coefficients in Eq.(l3) = feed concentration of solid = diameter = collection efficiency of cyclone = feed rate of particles = particle hold-up Ki, K2 = coefficients in Eq.(8d) kpe -coefficient in Eq.(3) [-] [-] [-] [kg-solid/kg-air] [m] [kg/kg] tkg/s] [kg] r I = length of duct = penetration of particles through cyclone = radius of curvature of curved duct = dimensionless group denned by Eq.(8d) or Eq. (8c)
58 citations
TL;DR: In this article, the behavior of suspended solid particles in the bubble column was experimentally studied and it was shown that the critical gas velocity for complete suspension of solid particles is affected by liquid flow near the gas distributor.
Abstract: The behavior of suspended solid particles in the bubble column was experimentally studied. The critical gas velocity for complete suspension of solid particles is affected by liquid flow near the gas distributor. The liquid flow is governed by the shape of the bottom of the column and the position of the gas distributor. On the other hand, gas bubbles rising through the column develop easily to large bubbles by the existence of a small amount of suspended solid particles, and therefore the gas holdup and the concentration distribution of the particles do not depend on the gas distributor and the shape of the bottom of the column. The dispersion coefficient of solid particles has the same value with that of liquid within the column without solid particles. The settling velocity of solid particles in the bubble column was correlated with the terminal velocity of those particles in stagnant liquid.
50 citations
TL;DR: In concurrent bubble columns, the longitudinal mass and thermal dispersion coefficients were determined in this paper, and it was shown that the mechanism of the dispersion in the bubble column is also governed by liquid mixing.
Abstract: In concurrent bubble columns the longitudinal mass and thermal dispersion coefficients were determined. The both coefficients agreed well with each other. This shows that the mechanism of the thermal dispersion in the bubble column is also governed by liquid mixing. The dispersion coefficient El, is correlated with experimental conditions in three regions, which are classified by the value of slip velocity of gas bubbles, us. At us>25cm/sec, El obtained in columns of the same diameter is related apparently only on the superficial gas velocity in the column, but it is independent on the liquid property and the size of gas bubbles. El is also proportional to one and a half powers of the column diameter. At us us > 25cm/sec, no correlation for El was obtained.
44 citations
40 citations
34 citations
TL;DR: In this paper, the authors proposed the empirical correlations of Cd vs ReM0'2* for the drag and d/a vs.^ReMQ'23 for the deformation.
Abstract: the sphere at low Reynolds number and Moore10>n) examined the problem at higer Reynolds number by the boundary-layer theory. The experimental works published so far were mostly on the rising velocity of the bubble in liquids of small viscosity. Harberman and Morton7) made an< extensive study of it. Tadaki and Maeda13) proposed the empirical correlations of Cd vs. ReM0'2* for the drag and d/a vs.^ReMQ'23 for the deformation. Kubota et al.9) suggested the, correlations, Cd/Cdf' vs.
TL;DR: In this article, the salt effect of calcium chloride may be utilized effectively for the separation of these alcohol-acetic ester mixtures, and the solubilities of the calcium chloride in these boiling alcohol acetic esters solutions were shown in figures.
Abstract: Vapor-liquid equilibrium data have been obtained for systems methanol-methyi acetate, ethanolethyl acetate and n-butanol-n-butyl acetate with calcium chloride at atmospheric pressure. Calcium chloride was added up to the saturated concentration. By adding salt, the increase of relative volatility of acetic ester was observed and the azeotropic composition shifted to the higher acetic ester composition in all systems. The solubilities of calcium chloride in these boiling alcohol-acetic ester solutions were shown in figures. It is suggested that the salt effect of calcium chloride may be utilized effectively for the separation of these alcohol-acetic ester mixtures.
TL;DR: In this paper, the effect of micro-mixing on the volume efficiency and properties of polymer and the type of impeller to bring the reaction field homogeneous were discussed. But it was made clear that special attention should be paid to the segregation of reaction mixture in the reactor for the reactor design of polymerization.
Abstract: Homogeneous polymerization of styrene was carried out in a continuous stirred tank reactor, and it was made clear that special attention should be paid to the segregation of reaction mixture in the reactor for the reactor design of polymerization. Both the effect of micro-mixing on the volume efficiency of reactor and on the properties of polymer and the type of impeller to bring the reaction field homogeneous were discussed.
TL;DR: In this paper, the power requirements for agitating the beds of solid particles have been investigated by a proposed model based upon the foundation capacity theory, where the ratio of inertia force to shearing stress, NM, and the power number, NP, both non-dimensional terms, have been found very important for the estimation of power requirements.
Abstract: The power requirements for agitating the beds of solid particles have been investigated by a proposed model based upon the foundation capacity theory. The ratio of inertia force to shearing stress, NM, and the power number, NP, both non-dimensional terms, have been found very important for the estimation of power requirements for agitating solid beds. They can be correlated by the following equation; NP = K1NM-1 + K2which is quite similar to those for agitating liquid in tanks. The values of the above constants have been calculated from the experimental data as K1 = 20 and K2 = 50 over the wide ranges of tank diameters, shapes of blades, rotational speeds, and various kinds of solid particles.
TL;DR: In this article, a theoretical analysis on the selectivity of gas-liquid reaction is developed by taking into account the role of mass transfer based on the film theory, and the reaction scheme considered is represented as follows: (B(liq.) + A(gas)) → R(liqs.), (R(li q.) +A(gas)→S(/iq.).
Abstract: The theoretical analysis on the selectivity of gas-liquid reaction is developed by taking into account the role of mass transfer based on the film theory. The reaction scheme considered is represented as follows: (B(liq.) +A(gas)) → R(liq.), (R(liq.) +A(gas))→S(/iq.). The rate of conversion and the relation between the yield of the intermediate product and the conversion are presented for a semibatch reactor and a continuous stirred tank reactor. It is shown that various reaction conditions such as the ratio of the rate of reaction to that of mass transfer, and the concentration of gas and liquid components have considerable effects on the selectivity.
TL;DR: In this article, it was shown that the Stokes and Oseen approximations of the Naviear-Stokes equation are very useful for dealing with the creeping flow around an object.
Abstract: It is found that the Stokes and the Oseen approximations of the Naviear-Stokes equation are very useful for dealing with the creeping flow around an object. Whenfluid is unbounded in its extent, the ratio of the inertia to the viscous term of this equation becomes larger as the distance from the object increases. For the case of a sphere, the ratio of the inertia to the viscous term, i. e., the local Reynolds number, at a point in a space is calculated3) as Voor/v. This shows
TL;DR: The relation between Np and NM in the previous paper has been extended further to the power characteristics for agitating solid beds with multiple blades of various pitches and when accompanied with upward streams of gas through the beds.
Abstract: The relation between Np and NM in the previous paper has been extended further to the power characteristics for agitating solid beds with multiple blades of various pitches and when accompanied with upward streams of gas through the beds. By using the correction factor, k, the modified nondimensional numbers in the following terms; ?? ?? can also be correlated by the same equation in the previous paper as follows, NP = 20NM-1 + 50 The gas flow rate, ump, which gives the minimum total power requirement for the upward gas flow and the mechanical agitation has been calculated mathematically and ensured experimentally.
TL;DR: A theoretical analysis of mass transfer under a reduced pressure, especially the transition regime was made on the basis of the gas kinetic theory as mentioned in this paper, and the analytical solution with the evaluated accomodation coefficient O.9 agreed well with the experimental results of sublimation of naphthalene performed by the authors.
Abstract: A theoretical analysis of mass transfer under a reduced pressure, especially the transition regime was made on the basis of the gas kinetic theory. Maxwell moment method utilizing the two-sided Maxwellian distribution function proposed by Lees et al. was applied to the mass transfer between two concentric spheres, and the accomodation coefficient was taken into account. The analytical solution with the evaluated accomodation coefficient O.9 agreed well with the experimental results of sublimation of naphthalene performed by the authors.
TL;DR: In this article, the selectivity of the intermediate product of a consecutive reaction with n-ckel catalysts was investigated and the results showed the similar trend to the theory proposed by Wheeler10), but considerable discrepancy was found between the measured selectivity and the theoretical one which was predicted by such a simple hypothesis as linear kinetics and a uniform poremodel for a catalyst.
Abstract: Consecutive hydrogenation of acetylene with n-ckel catalyst was carried out in order to investigate the selectivity of the intermediate product of a consecutive reaction. Six groups of catalysts with different diameters were prepared and the selectivity was measured for each catalyst group. The results showed the similar trend to the theory proposed by Wheeler10), but considerable discrepancy was found between the measured selectivity and the theoretical one which was predicted by such a simple hypothesis as linear kinetics and a uniform poremodel for a catalyst. More precise investigation by the authors, that is, the experimental runs about the kinetics of this reaction, the computational analysis of the selectivity based upon these observed kinetics and the microscopic observation of the catalyst, clarified that the experimental data on the obtained selectivity coincided well with the micro-macro pore model by the consecutive reaction of Langmuir-Hinshelwood rate form.