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Showing papers in "Journal of Chemical Engineering of Japan in 1974"


Journal ArticleDOI
TL;DR: In this paper, mass transfer coefficients of suspended particles were measured in agitated vessels and in bubble columns and correlated the surface factor using the Schmidt number as Sh=[2+0.4(edp4/ν3)1/4•Sc1/3]•φc with a standard deviation of 30.8% for the Sherwood number.
Abstract: Mass transfer coefficients of suspended particles were measured in agitated vessels and in bubble columns. Four sizes of agitated vessels (diameter: 9.5, 17.5, 20, 40 cmO) including both fully baffled and non-bafHed conditions and two sizes of bubble columns (diameter: 10, 20cmO) were used. Particle sizes ranged from 60 to 1100 μO including both spherical beads (ion exchange resin) and granules (benzole acid, KMnO4, and β-naphthol). We correlated the mass transfer coefficients using the surface factor as Sh=[2+0.4(edp4/ν3)1/4•Sc1/3]•φcwith a standard deviation of 30.8% for the Sherwood number. Sh[-]: Sherwood number, e [cm2/sec3]: rate of energy dissipation, dp [cm]: specific surface diameter, v [cm2/sec3]: kinematic viscosity, Sc [-]: Schmidt number and Oc [-]: surface factor.

207 citations


Journal ArticleDOI
TL;DR: In this article, the modified Redlich-Kwong equation of state was used to calculate vapor-liquid equilibria of binary systems containing carbon dioxide, which provided fairly good agreement with experiment.
Abstract: Vapor-liquid equilibrium data for binary systems containing carbon dioxide: CO2-C2H6, CO2-C3H8, CO2-n-C4H10, CO2-iso-C4H10, CO2-C2H4, CO2-C3H6 and CO2-1-C4H8 were determined by the vapor recirculation method in the low-temperature range (-41.6°C-0°C). The CO2-C2H4 and CO2-C2H6 systems formed minimum-boiling azeotropes. The modified Redlich-Kwong equation of state was used to calculate vapor-liquid equilibria of these systems. It provided fairly good agreement with experiment.

106 citations


Journal ArticleDOI
TL;DR: In this paper, the diffusion process of water and the volumetric shrinkage of a polyvinyl alcohol (PVA) aqueous solution is studied theoretically and experimentally, focusing on the diffusion processes of water.
Abstract: Drying of coated film of polyvinylalcohol (PVA) aqueous solution is studied theoretically and experimentally, focusing on the diffusion process of water and the volumetric shrinkage of film occurring by evaporation of water The diffusion coefficients were measured over the whole range of concentration by three methods, and drying experiments of coated films using hot air were performed Numerical solutions were obtained from a set of transport equations for water using the observed diffusion coefficients and were compared with the experimental results

96 citations



Journal ArticleDOI
TL;DR: In this article, the authors measured instantaneous profiles of the velocity and the intensity of turbulent flow in a tube and classified them into two groups by means of a certain critical period of pulsation.
Abstract: Pulsating turbulent flow in a tube was studied experimentally. Measured instantaneous profiles of the velocity and the intensity of turbulence can be clearly classified into two groups by means of a certain critical period of pulsation. At longer periods of pulsation, the shapes of the velocity profiles are similar to those for steady flow, while the intensity of turbulent fluctuation does not pulsate ; whereas at shorter periods, the velocity profiles are not similar to those for steady flow, while the intensity of turbulent fluctuation pulsates oppositely to the velocity. From measuring the time intervals between bursts in both steady and pulsating turbulent flows, it was clarified that the range of burst periods occurring in pulsating flow was the same as the preferred range of burst periods in steady flow. If the pulsation period is longer than the upper limit of this range, the mean burst period is equal to that of steady flow, but if the pulsation period is included in the range of burst periods for steady flow, the bursting of the same period as the pulsation period dominates.

64 citations


Journal ArticleDOI
TL;DR: In this paper, a simple technique is proposed to determine the intraparticle diffusivities of adsorbents from concentration change in an agitated tank, where pore diffusion and rectangular isotherm are assumed to derive the theoretical solutions.
Abstract: A simple technique is proposed to determine the intraparticle diffusivities of adsorbents from concentration change in an agitated tank. Pore diffusion and rectangular isotherm are assumed to derive the theoretical solutions, which are then compared with the experimental results. The theory gave a good prediction for the transient concentration profile in the tank. The effective diffusivities of 2•dodecylbenzene sulfonate in four different activated carbon particles are determined by the proposed technique.

52 citations


Journal ArticleDOI
TL;DR: In this article, the authors made measurements for nitrogen adsorption on molecular-sieving carbons at 60, 100 and 150°C for several different nitrogen surface coverages.
Abstract: Chromatographic measurements were made for nitrogen adsorption on molecular-sieving carbons at 60, 100 and 150°C for several different nitrogen surface coverages. Apparent adsorption equilibrium constants were determined from the retention times of the peaks for different concentrations, and the adsorption equilibrium isotherms were then determined. The peak width gave the intra-microparticle diffusivity where the effects of all the other possible transport processes were taken into account. The strong dependence of the diffusivity on the amount adsorbed was explained in terms of chemical potential gradient as a driving force of the diffusion.

49 citations


Journal ArticleDOI
TL;DR: In this article, a column packed with glass spheres of 3 different sizes (2.59-12.2 mm) was measured for two-phase cocurrent flow of O2-water and CO2-NaOH systems.
Abstract: Volumetric absorption coefficient (ka)lg, specific interfacial area alg and mass transfer coefficient klg were measured for two-phase cocurrent flow of O2-water and CO2-NaOH systems in a column packed with glass spheres of 3 different sizes (2.59-12.2 mm). Values of (ka)lg observed were so high as to be that can be hardly attainable in conventional gas-liquid contactors. This is due to large alg of small bubbles dispersed in liquid where alg very often exceeds the geometrical surface area of packing. Values of klg range from 2 to 8×10-4m/sec, which are comparable to that of circulating bubbles in the usual systems. The effect of superficial gas velocity on (ka)lg and alg is much greater than that in a countercurrent packed column, while the effect of liquid velocity is approximately same. A liquid-phase energy loss El per unit volume of liquid contained in a bed was newly defined as a measure of microscopic flow intensity and was used for discussion and correlation of mass transfer properties. It was found that the bubble diameter is proportional to El-2/5.

49 citations


Journal ArticleDOI
TL;DR: In this article, the macroscopic relations between the pressure drop and the flow rate were found to be in fairly good agreement with the results obtained by application of the conventional variational principle.
Abstract: Non-Newtonian fluid flow in an eccentric annulus was studied for high polymer aqueous solutions of CMC, HEC and MC. The macroscopic relations between the pressure drop and the flow rate were found to be in fairly good agreement with the results obtained by application of the conventional variational principle. Velocity profiles were measured by a hydrogen bubble method in which photographs were taken of the hydrogen bubbles. The authors observed very interesting secondary flows in the eccentric non-Newtonian fluid flow which may be due to the viscoelastic effect of the high polymer aqueous solution. The authors could not observe such secondary flows for non-Newtonian fluids in a concentric annulus or Newtonian fluids in an eccentric annulus. The authors present an equation giving the relation between the flow rate and the pressure drop for the flow of a non-Newtonian fluid in an eccentric annulus in terms of the experimental data for flow in a circular tube.

47 citations



Journal ArticleDOI
TL;DR: In this article, various theoretical solutions including the author's for the thickness of a viscous liquid film on a rotating disk are presented in terms of two dimensionless parameters and are compared with experimental results.
Abstract: Various theoretical solutions including the author''s for the thickness of a viscous liquid film on a rotating disk are presented in terms of two dimensionless parameters and are compared with experimental results. The film thickness on the disk was measured by a micrometer which is movable with a needle used as a surface detector. The numerical solution of the equations as simplified by von Karman''s method and Bruin''s solution agree well with the experimental results in a wide range of operating conditions. Polynomial approximation with orders up to fourth and fifth degree is usable to predict the film thickness.


Journal ArticleDOI
TL;DR: In this paper, the authors measured the adsorption equilibria of various gases and vapors on molecular-sieving carbon and correlated the data with the Dubinin-Astakhov equation.
Abstract: Adsorption equilibria of various gases and vapors on molecular-sieving carbon were measured. The data were correlated by the Dubinin-Astakhov equation: W=W0 exp [-(A/E0)n], and the characteristic values of adsorption were determined. The equation covers the adsorption of various kinds of gases and vapors. The exponent n in the equation is about 3 for organic gases and lies between 2 and 3 for inorganic gases. The charactersitic energy of adsorption is expressed as E=β(ΔH0)s, where (ΔH0)s is the standard heat of vaporization of a standard material such as benzene and the coefficient β is approximately equal to the ratio of the parachor of the adsorbate to that of the standard material. Studies are made of three different types of deviations from the Dubinin-Astakhov equation, observed in the course of experiment.

Journal ArticleDOI
TL;DR: In this paper, a method of determining rational design margin of unit operation in a process is developed by taking account of parameter uncertainties usually involved in actual process system design, which is applied to design of a simple chemical reaction process with recycle, and the result obtained by this method is compared with that obtained by the method proposed previously by the authors.
Abstract: A method of determining rational design margin of unit operation in a process is developed by taking account of parameter uncertainties usually involved in actual process system design. Since decision variables which are to be determined in process system design consist of design variables and manipulating variables, design may be estimated rationally by considering admissible ranges of manipulating variables. The method proposed in this paper is applied to design of a simple chemical reaction process with recycle, and the result obtained by this method is compared with that obtained by the method proposed previously by the authors.


Journal ArticleDOI
TL;DR: In this article, the authors present a list of the most cited works in the field of chemistry and physics of carbon, including the work of M. Dubinin, M. M. and V. A. Romankov.
Abstract: Literature Cited 1) Astakhov, V.A., M. M. Dubinin and P. G. Romankov: Theor. Osn. Khim. Techn., 3, 292 (1969) 2) Dubinin, M. M.: Chem. Rev., 60, 235 (1960) 3) Dubinin, M. M. : \"Chemistry and Physics of Carbon\", Vol. 2 (P. L. Walker ed.) p. 51, Marcel Dekker (1966) 4) Dubinin, M. M.: \"Adsorption-Desorption Phenomena\" (Ricca ed.), p. 3, Academic Press (1972) 5) Dubinin, M. M. and V. A. Astakhov: \"Molecular Sieve Zeolites II\", Adv. Ser. 102, p 69 (1971) 6) Eguchi, Y.: Kagaku Kojo, 13, No. 9, 45 (1969) 7) Eguchi, Y.: /. Japan Petrol Inst., 13, 106 (1970) 8) Kawazoe, K., Y. A. Astakhov, T. Kawai and Y. Eguchi: Kagaku Kogaku, 35, 1006 (1971) 9) Kawazoe, K. and T. Kawai: Seisan Kenkyu, 25, 513 (1973)

Journal ArticleDOI
TL;DR: In this paper, the effects of intraparticle flow resulting from an axial pressure gradient in a flow reactor are investigated theoretically and experimentally, and an equation which gives the effectiveness factor under the combined effects of flow and diffusion is presented and the results are compared with experiments using an ion exchange reaction.
Abstract: The effects on solid-catalyzed reaction of intraparticle flow resulting from an axial pressure gradient in a flow reactor are investigated theoretically and experimentally. First, an equation which gives the effectiveness factor under the combined effects of flow and diffusion is presented and the results are compared with experiments using an ion exchange reaction. From the analyses the large effects of intraparticle flow on reaction are proved, and it is found that a packed bed of catalyst pellets permitting intraparticle flow is the most suitable reactor for reducing reactor volume and flow resistances.


Journal ArticleDOI
TL;DR: In this article, the tensile strength and strain behavior of agglomerates bound together by liquid bridges was investigated. But the authors focused on the tensil strength and the strain in the whole region of liquid saturation, and not only on the region of saturation, but also on the stable and unstable regions of the stress-strain curves.
Abstract: This paper deals with the tensile strength and strain behavior of agglomerates. For moist agglomerates the tensile strength in the whole region of liquid saturation may be described. The theory agrees well with the experimental results. For agglomerates bound together by liquid bridges, a model which reproduces the force-displacement behavior of agglomerates under unidirectional loading is proposed. The validity of this model is demonstrated with the help of a specially developed apparatus which enables the strain for a given force to be measured. The theoretically and experimentally determined stable and unstable regions of the stress-strain curves of the agglomerates are discussed.

Journal ArticleDOI
TL;DR: In this paper, the gas holdup and pressure drop of a multistage vibrating disk column with cocurrent gas-liquid flow are measured and the effects of column geometry and operating variables are determined for the evaluation of column performance.
Abstract: The gas holdup and pressure drop of a multistage vibrating disk column with cocurrent gas-liquid flow are measured and the effects of column geometry and operating variables are determined for the evaluation of column performance. Among the operating variables, the vibrating speed of the disks Av (amplitude A multipled by vibrating frequency v) has a definite effect on the gas holdup and pressure drop at speeds higher than a certain critical speed Avr. At speeds lower than Avc, disk vibration has little effect on gas holdup and pressure drop. The gas holdup and pressure drop are correlated successfully by the addition of increased values due to disk vibration to those in the absence of vibration.

Journal ArticleDOI
TL;DR: In this paper, the effect of resin diameter, the degree of crosslinking and the concentration and valence of ionic species on resin-phase diffusivity was studied with a macroscopic model by which the diffusivities may be predicted.
Abstract: Resin-phase diffusivity in isotopic ion exchange was measured by the single-particle method. The effect of resin diameter, the degree of crosslinking and the concentration and valence of ionic species on resin-phase diffusivity were studied with a macroscopic model by which the diffusivity may be predicted. From these results, the estimating equation of resin-phase diffusivity for sulfonated styrene type resin in the range of the degree of crosslinking 3-16% was obtained.



Journal ArticleDOI
TL;DR: In this article, the equilibrium constants of the several elementary reactions which influence the overall partition were measured for the range of 10° to 80°C and theoretically analyzed by an approximate method.
Abstract: The overall partition of iodine between air and aqueous solution containing sodium hydroxide is very complicated due to the complex reactions of iodine dissolved in the aqueous phase. The equilibrium constants of the several elementary reactions which influence the overall partition were measured for the range of 10° to 80°C. Then the dependencies of the overall partition of iodine upon both temperature and concentration were theoretically analyzed by an approximate method.

Journal ArticleDOI
TL;DR: In this article, the liquid-phase mixing characteristics of a multistage vibrating-disk column with a concurrent gas-liquid flow are studied by means of a step response method and a moment analysis.
Abstract: The liquid-phase mixing characteristics of a multistage vibrating-disk column with a concurrent gas-liquid flow are studied by means of a step response method and a moment analysis. The mixing characteristics can be expressed by the back-flow model. The model parameter (the back-flow ratio) is well correlated by a dimensionless equation of the experimental variables. The correlation is definitely affected by the wave form of the disk vibration.

Journal ArticleDOI
TL;DR: In this paper, a solution theory of Flory-Huggins type is used to describe the excess quantity of nitrogen in two mixed solvents, cyclohexane-iso-octane and n-propanol-iso octane, at 25°C and atmospheric pressure.
Abstract: Solubility measurements of nitrogen in two mixed solvents, cyclohexane-iso-octane [1] and n-propanol-iso-octane [2], were performed at 25°C and atmospheric pressure. The experimental "excess quantity" over Henry''s constant averaged in the volume fraction of solvent (lnκ) is slightly positive for both systems. Based upon the solution theory of Flory-Huggins type, the excess quantity lnκ is described by the following three terms; (a) size term based upon the difference of solvent molar volumes (positive), (b) physical interaction term (negative), and (c) association term (negative). For system [1] the association term is zero. Each term is calculated from the characteristic properties of the binary liquid mixture and the molar volume of solute gas, and agreement between the calculated and experimental values for lnκ is very satisfactory. Contribution of term (a) to the excess quantity κ is the largest for the systems investigated. For the solubility of nitrogen in mixture [2] the contribution of the association term (c) to r is smaller than that of term (b), whereas the association term contributes more than 90% in the excess Gibbs energy for the binary mixture [2].

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the effect of the free-radical chain reaction mechanism on the initial product distribution of normal paraffinic hydrocarbons and showed that the amount of reaction products hydrogen, ethylene and ethane are considerably affected by the reaction conditions.
Abstract: normal paraffinic hydrocarbons was proposed on the basis of the free-radical chain reaction mechanism. It was then assumed that all ethyl radicals produced in each reaction step converted to ethane via intermolecular H-atom abstraction reaction. The assumption holds well in the relatively low temperature range up to about 500°C and near atmospheric pressure. In practice, however, hydrocarbons are sometimes pyrolyzed at higher temperatures and under lower partial pressures. In such cases, the decomposition of ethyl radicals would occur competitively with the H-atomabstraction reaction8>n). As a result, the amounts of reaction products hydrogen, ethylene, and ethane are considerably affected by the reaction conditions. Nevertheless, no calculations have been published based on both H-atom abstraction and ethyl radical decomposition reactions, except for w-butane pyrolysis shown by Pacey and Purnell10). In this paper, the authors investigated the effect of the ethyl radical decomposition reaction on initial product distribution. By introducing the ethyl radical decomposition reaction into the previously proposed model9\\ the initial product distribution under various reaction conditions can be predicted.

Journal ArticleDOI
TL;DR: In this article, mass transfer characteristics of a cocurrent multistage vibrating disk column are studied by the absorption of pure carbon dioxide into water, and axial mixing in the liquid phase is taken into account by using a back-flow model.
Abstract: Mass transfer characteristics of a cocurrent multistage vibrating disk column are studied by the absorption of pure carbon dioxide into water. Axial mixing in the liquid phase is taken into account by using a back-flow model. Disk vibration definitely enhances the mass transfer rate at low gas velocity and high liquid velocity. On the other hand, at high gas velocity and low liquid velocity, disk vibration does not noticeably improve the mass transfer characteristics, and even worsens them in some cases. The increase in absorption rate by disk vibration can be well estimated by information on the gas holdup characteristics, the mass transfer characteristics without vibration, the gas bubble size data and the axial mixing characteristics in the liquid phase.

Journal ArticleDOI
TL;DR: In this paper, a successive contact mechanism has been introduced to account for the influence of dilute phase catalyst on overall conversion of reaction in fluid beds, and a theory has been given, as a simpler version of the proposed model, for an isothermal and irreversible first order reaction.
Abstract: A concept of successive contact mechanism has been introduced to account for the influence of dilute phase catalyst on overall conversion of reaction in fluid beds. A theory has been given, as a simpler version of the proposed model, for an isothermal and irreversible first order reaction. To test the concept, axial distribution of bed density has been measured for small scale fluid beds. Rather freely suspended catalyst particles are observed in the dilute phase in enough amount to contribute to the progress of reaction. The theory has revealed for the progress of reaction that the catalyst particles located in the bubble phase are interchangeable with those suspended in the dilute phase and vice versa.

Journal ArticleDOI
TL;DR: In this article, the relative velocity distribution in the isotropic turbulent field at low turbulent Reynolds number (Reλ = 30-100) is measured by hot-wire anemometry, and empirical equations of the velocity distribution are proposed.
Abstract: For the last three decades much attention has been focused on Kolmogoroff9s theory for the local structure of the isotropic turbulent field. Many investigators have tried experimental verification of the theory, but their results are considered insufficient. This is mainly due to the fact that, in experimental and industrial apparatus, turbulent Reynolds number Rex of fluid flow is generally not as high as Kolmogoroff assumed in his theory. In this study, relative velocity distribution in the isotropic turbulent field at low turbulent Reynolds number (Reλ = 30-100) is measured by hot-wire anemometry, and empirical equations of the velocity distribution are proposed. These equations contain two parameters which represent the characteristics of isotropic turbulence-Reλ and microscale λg of turbulence. Relations between λg and integral scale Ag, velocity-correlation function g(r) and one-dimensional power spectrum E1(k1) can be calculated from these equations. These calculated values agree well with experimental data obtained by many investigators. Furthermore, a few examples of the other calculated spectra of turbulence, such as three-dimensional power spectrum E(k) and energy-transfer functions F(k) and S(k), are also shown. The empirical equations are considered to be usefully applicable to turbulent flow over a wide range of Reλ, from 30 to 800 or more.