Showing papers in "Journal of Chemical Engineering of Japan in 1972"
TL;DR: In this article, the longitudinal dispersion coefficient of solid particles and liquid based on actual mean slurry velocity, the mean settling velocity, and the concentration of the solid particles at the top of the column, respectively, were correlated with dimensionless groups.
Abstract: The longitudinal concentration distribution of solid particles and liquid mixing in 6.6, 12.2 and 21.4 cm i. d. bubble columns were measured and were analyzed by using diffusion model. The longitudinal dispersion coefficient of solid particles and liquid based on actual mean slurry velocity, the mean settling velocity of solid particles, and the concentration of solid particles at the top of the column, respectively, were correlated with dimensionless groups. From these correlations empirical equations were obtained. The values of concentration of solid particles calculated from the empirical equations agreed with the observed values within ±20%.
142 citations
TL;DR: In this article, the hydraulic radius model was applied to laminar flow in a packed bed and assuming that mass transfer in the packed bed is analogous to that between a pipe surface and a stream of liquid with steady velocity profile, liquid-phase mass transfer from the packed solid sphere was analyzed and an approximate solution was proposed.
Abstract: Applying the hydraulic radius model to laminar flow in a packed bed and assuming that mass transfer in the packed bed is analogous to that between a pipe surface and a stream of liquid with steady laminar velocity profile, liquid-phase mass transfer from the packed solid sphere was analyzed and an approximate solution is proposed. Further liquidfilm mass transfer coefficients were measured for benzoic acid-water system. From these results, together with previous data, it was found that the proposed equation agrees with data in Re'^10, both this equation and Carberrys equation can be applied for ]0100.
118 citations
TL;DR: In this paper, the effects of these scales on the magnitude of turbulence velocity components are examined, and the magnitudes are evaluated with a set of values of scales which seem most appropriate to each particle motion.
Abstract: Turbulent motion of particles suspended in water in a stirred tank and that of drops supplied to turbulent pipe flow of water are studied with emphasis on their scales. The scales considered are 1) sampling time scale : the very small time interval in which the displacement of a particle is measured, 2) measuring time scale : the time-duration during which a continuous measurement is run, and 3) sampling spatial scale : the width of a location in which the displacement of a particle is followed. The effects of these scales on the magnitude of turbulence velocity components are examined, and the magnitudes are evaluated with a set of values of scales which seem most appropriate to each particle motion. The magnitudes are correlated uniformly in both dispersions with particle diameters and energy dissipation rates of surrounding liquid.
75 citations
TL;DR: In this article, the collision and coalescence of drops are studied in turbulent liquid flow, and the random motion of drops is found quite analogous to that of molecules assumed in simple gas kinetic theory.
Abstract: The collision and coalescence of drops are studied in turbulent liquid flow. From the standpoint of collision frequency, the random motion of drops is found quite analogous to that of molecules assumed in simple gas kinetic theory. The process of coalescence of drops is followed, and it is found that two drops will coalesce immediately on collision in the case when they will finally coalesce. The coalescence fraction may be determined by the kinetic energy at the instant of collision, but the fraction is surprisingly small and cannot accede to the order of 10-1 in the range observed.
68 citations
TL;DR: In this paper, features of the phase equilibria of hydrogen-light hydrocarbon mixtures were discussed, and the Benedict-Webb-Rubin equation was successfully applied to predict the vapor-liquid equilibrium of the present systems above the normal boiling point.
Abstract: The vapor-liquid equilibrium relations of the hydrogen-methane, the hydrogen-ethylene, The hydrogen-ethane, the hydrogen-methane-ethylene and the hydrogen-ethylene-ethane systems were determined by a static method at several temperatures from -25°C to -170°C and at pressures up to 100 atm. From the data obtained, features of the phase equilibria of hydrogen-light hydrocarbon mixtures are discussed. The Benedict-Webb-Rubin equation was successfully applied to predict the vapor-liquid equilibria of the present systems above the normal boiling point of the heaviest hydrocarbon.
59 citations
TL;DR: In this article, the authors studied theoretically and experimentally the T. D. H for both continuous and batch fluidized beds, and found that the theoretical elutriation rate of fine above T.D. H, defined as Z at V = 1.01Vt, coincided fairly well with the present and reported experimental results.
Abstract: Transport Disengaging Height (T. D. H.) was studied theoretically and experimentally for both continuous and batch fluidized beds. The theoretical elutriation rate of fines above the T. D. H., Vt, was calculated by use of the Maxwell-Bolzmann energy distribution, and it showed good agreement with the experimental value for the continuous fluidized bed. The theoretical values of the T. D. H., which were defined as Z at V=1.01Vt, coincided fairly well with the present and reported experimental results. The elutriation height coefficients a were found empirically to increase with increase in particle diameter and with decrease in superficial velocity.
55 citations
TL;DR: In this paper, the authors compared three light source models, i.e., radial, specular, and diffuse line source, for light intensity profile, overall rate of reaction, and radial scale-up ratio of annular photochemical reactors, with the assumptions of constant absorption coefficient and constant quantum efficiency.
Abstract: Three light source models, i.e., radial, specular, and diffuse line source models, are compared for light intensity profile, overall rate of reaction, and radial scale-up ratio of annular photochemical reactors, with the assumptions of constant absorption coefficient and constant quantum efficiency. The necessary condition for the radial light model to hold is that, when the ratio of inner radius to height of the reactor m, is 0.1, that of outer radius to inner radius ρ should be less than 3, and that when m is larger ρ should be close to 1. Published reaction data are analyzed according to this condition.
47 citations
TL;DR: In this paper, isothermal vapor-liquid equilibrium data are presented for methyl acetate-methanol system at 35°C and 45°C, respectively, and for methylacetate-ethanol systems at 45° and 55°C.
Abstract: Isothermal vapor-liquid equilibrium data are presented for methyl acetate-methanol system at 35°C and 45°C and for methyl acetate-ethanol system at 45° and 55°C. Excess enthalpy data for the two systems are obtained at 45°C. Simultaneous fit of these thermodynamic quantities was successfully accomplished by using the NRTL equation whose parameters were assumed to be a linear function of temperature.
25 citations
TL;DR: In this article, an analysis of ligament-type disintegration was made by equating the rate of dissipation of kinetic energy, surface energy and viscous deformation energy of disturbance of the liquid film to the motive power by centrifugal force at the edge of a rotating disk.
Abstract: An analysis of ligament-type disintegration was made by equating the rate of dissipation of kinetic energy, surface energy and viscous deformation energy of disturbance of the liquid film to the motive power by centrifugal force at the edge of a rotating disk. The number of ligaments generated in disintegration of liquid film is given as a function of the Weber number and the stability number. This analysis gives an interpretation on the basis of the energy balance for the experimental results by Hinze and his co-worker, who used a rotating cup and represented the same expression as the present paper.
24 citations
TL;DR: In this paper, the authors obtained an equation for maximum drop diameter as a result of atomization experiments on film type disintegration of aqueous millet jelly solution by a rotating disk.
Abstract: The following equation was obtained for maximum drop diameter as a result of atomization experiments on film type disintegration of aqueous millet jelly solution by a rotating disk. dmax/r0=1.1We-3(ρQ2/σT03)0.15(Q/υr0)-0.15 This result was studied on the basis of film extension and thickness of liquid film at the leading edge of the film. The thickness of the liquid film at the leading edge of the film can be approximated by a simple relation. This relation supports the appropriateness of the results of the atomization experiment. Thickness of liquid film and maximum drcp diameter are proportional.
20 citations
TL;DR: In this paper, a rotating-disk gas-liquid contactor with wire mesh disks was used to study the rate of oxygen absorption into water, where liquid films were formed on the surface of disks rotating around the horizontal axis.
Abstract: Rates of oxygen absorption into water were studied in a rotating-disk gas-liquid contactor, in which liquid films were formed on the surface of disks rotating around the horizontal axis. When plain disks were used, values of the liquid-phase mass transfer coefficient kL were lower than those predicted from the penetration model. However, with disks made of appropriate wire mesh, kL, values agreed quite well with prediction by the penetration model for the range of gas-liquid contact time from 0.2 to 1.5 seconds.This type of gas-liquid contactor equipped with wire mesh disks seems to be a useful apparatus for studies of liquid-phase mass transfer in gas absorption.
TL;DR: In this paper, the authors investigated the behavior of particles in pipe bends by the effect of gravitational and centrifugal forces and the secondary flow of fluid and found that both polystyrene and glass particles showed additional pressure drop, which was nearly constant regardless of the flow rate, similar to the case of horizontal pipe bends.
Abstract: Hydraulic transport of solid materials through pipe bends was investigated experimentally. Four kinds of 90° pipe bends of which the radii of curvature were 0, 12, 24 and 48cm, were made of polyacrylate pipe. The pressure drops were measured over sections of about 5 m, each including a pipe bend. The solid particles used in this experiment were glass beads (0.5-2.0mm diameter) and polystyrene particles (1.0mm diameter). The behavior of particles in pipe bends was found to be very much complicated by the effect of gravitational and centrifugal forces and the secondary flow of fluid. The results of the pressure-drop measurement were as follows, a) The horizontal pipe Bend : In the case of polystyrene particles, even though delivered particle concentration exceeded about 20%, the effect of particle concentration mc on the pressure drop did not appear to be the same as in the case of a straight pipeline. On the other hand, in the case of glass particles the additional pressure drop, which was nearly constant regardless of flow rate, increased with increasing particle concentration except where R=0 and 12cm. Moreover, the additional pressure drop was correlated by the dimensionless term Um2/gR (ρs/ρw-1) and mc. b) The vertical pipe bend : It was found from experiment that both polystyrene and glass particles showed additional pressure drop, which was nearly constant regardless of the flow rate, similar to the case of horizontal pipe bends.
TL;DR: In this paper, the vapor-liquid equilibrium compositions and temperatures were determined experimentally under isobaric conditions of 550, 350, and 150 mmHg pressures for DMSO-H2O system.
Abstract: The vapor pressures of pure DMSO were measured from 30 to 150°C by ths isoteniscopic method. An empirical equation for P-T correlation is given and molal heats of vaporization are calculated. The vapor-liquid equilibrium compositions and temperatures were determined experimentally under isobaric conditions of 550, 350, and 150 mmHg pressures for DMSO-H2O system. The activity coefficients are correlated to liquid compositions by Chao and Hougen''s equation.
TL;DR: In this paper, the rate of net flow and the composition of the net flow for both stripping and rectifying sections can be calculated from the limiting conditions of the separation desired, and the larger of the two values shall be defined as the minimum reflux ratio of the system.
Abstract: In an azeotropic distillation column, the rate of net flow and the composition of net flow for both stripping and rectifying sections can be calculated from the limiting conditions of the separation desired The pinch points are dotted on the radial lines starting from the point of net flow composition by trial and error, and locus of the pinch points are traced on the triangular diagram by the way of connecting the pinch points Each minimum reflux ratio of stripping and rectifying sections can be calculated from the quantitative ratio of vapor and liquid of the operating line passing the point of intersection of locus line and feed line, and the larger of the two values shall be defined as the minimum reflux ratio of the system For example, we illustrate the graphical calculation method for AcOH-H2O-BuOAc system and AcOH-H2O-EtOAc system
TL;DR: In this paper, the characteristics of a mixing apparatus with two agitator axes having multidisks as a high viscosity polymer finisher were studied from a practical point of view.
Abstract: The characteristics of a mixing apparatus with two agitator axes having multidisks as a high viscosity polymer finisher was studied from a practical point of view, 1) Holdup : it could be correlated by using a term of (μnD/δ). 2) Power consumption and mixing time : the results were compared with those of other high-viscosity equipment. 3) Residence time distribution and dead space : the former almost agreed with the tanks-inseries model. The latter seemed to be small. 4) Surface renewal action : the rate of surface renewal was determined from the gas absorption and also estimated by the observation of liquid flow. As a model reaction polycondensation polymerization of polyamide in the presence of water and viscosity stabilizer is discussed.
TL;DR: In this article, holdup of gas bubbles and longitudinal dispersion coefficient of solid particles were measured in 3.2, 7.9, 12.0 and 19.5 cm inside-diameter fluid beds of F.C. particles.
Abstract: Holdup of gas bubbles and longitudinal dispersion coefficient of solid particles were measured in 3.2, 7.9, 12.0 and 19.5cm inside-diameter fluid beds of F.C.C. particles. Holdup of gas bubbles based on the emulsion bed height (Le) was dependent on superficial gas velocity (uf) and bed diameter (DT). Le was determined as the bed height obtained by extrapolating the constant rate sedimentation curve to zero time. In the range of Uf ?? 2 cm/sec, Le did not vary with uf and DT, and it was about 9% larger than the completely settled bed height for the particles used in this experiment. The experimental and literature data of the longitudinal dispersion coefficient of F.C.C.particles based on the mean density of fluidizing bed (E*s) were correlated with Peclet number (Pe=uf DT/E*s), Froude number (Fr=uf/√gDT ) and (DT+0.23), and the following empirical equation was obtained for bed diameter ranging from 0.032 to 1.5 m. Pe=19(DT+0.23)Fr/(1+6.5Fr0.8)where the unit of DT is meters.
TL;DR: In this paper, the authors measured flow patterns in a mixing vessel, circulation capacity and fluid deformations which cover information about energy dissipation were correlated with the homogenizing time, and a measure of an averaged dimensionless shear rate number √Pυgc/μ/n was plotted against the dimensionless nearest distance between moving part and fixed wall in the mixing vessel.
Abstract: There exists no universally accepted technique for evaluating the functional status of equipment for high-viscosity mixing based upon generalized basic information such as flow patterns and shearing deformation characteristics. This paper deals with the measurement of flow patterns. After obtaining the overall flow patterns in a mixing vessel, circulation capacity and fluid deformations which cover information about energy dissipation were correlated with the homogenizing time. The physical meanings of C1=nTM and C2=TM √Pυgc/μ are interpreted by using a concept of striation thickness. A measure of an averaged dimensionless shear rate number √Pυgc/μ/n is plotted against the dimensionless nearest distance between moving part and fixed wall in the mixing vessel. This diagram could give an useful comparison as to averaged shear rate characteristics for any device for high-viscosity mixing regardless of geometrical configuration. A novel technique is also proposed for quick evaluation of the shear distribution in a given apparatus.
TL;DR: In this article, heat transfer coefficients from a jacket wall (hj) and to a rotating coil impeller (hc) were studied in highly viscous non-Newtonian liquids.
Abstract: Heat transfer coefficients from a jacket wall (hj) and to a rotating coil impeller (hc) were studied in highly viscous non-Newtonian liquids. Correlated equations were determined for both hj and hc in laminar and turbulent regions. It was observed that hc was almost three times as large as hj. An explanationis presented for this phenomenon.
Journal Article•
TL;DR: In this paper, the average diameter of bubbles generated from a porous plate in pure liquid and in aqueous solutions of inorganic electrolyte were measured at various gas flow rates by taking photographs of bubbles the size of which was controlled by bubble coalescence on and above the plate.
Abstract: The average diameter, d, of bubbles generated from a porous plate in pure liquid and in aqueous solutions of inorganic electrolyte were measured at various gas flow rates by taking photographs of bubbles the size of which was controlled by bubble coalescence on and above the plate. For the extreme case when coalescence occurred at the maximum rate such as in water and in pure organic liquid, the empirical equations for d based on previous data and those from this experiment are proposed. The addition of inorganic electrolyte to water reduced the coalescence and thus simultaneously reduced d. The average bubble diameter in the aqueous solutions is well correlated to the experimental conditions with an empirical equation including the non-dimensional group proposed by Marrucci and also corresponding to the controlling factor of the bubble coalescence.
TL;DR: In this article, the basic integro-differential equation describing comminution process is analytically solved by the use of a certain form of selection function and breakage function, and the rate constant of the selection function is considered in relation to the stress field produced within a powder bed and to the strength of material crushed.
Abstract: The basic integro-differential equation describing comminution process is analytically solved by the use of a certain form of selection function and breakage function. The result agrees well with previous experience. The rate constant of the selection function is considered in relation to the stress field produced within a powder bed and to the strength of material crushed. A resulting equation expressing the selection function as a function of particle size, magnitude of force applied and some operational variables as well as material properties is compared with reference data.
TL;DR: In this paper, the vapor-liquid equilibrium data for the quaternary ethanol-isopropanol-ethyl acetate, isopropyl acetate system were determined at 760 mmHg.
Abstract: Vapor-liquid equilibrium data at 760 mmHg were determined for the quaternary ethanol-isopropanol-ethyl acetate-isopropyl acetate system. Following hypothetical reaction is considered for the quaternary system.EtOH+AcOiPr→←iPrOH+AcOEt The system could be treated as a system accompanied by chemical reaction. That is, vapor-liquid equilibria for the quaternary system could be calculated from the vapor-liquid equilibrium data for the binary and ternary systems at conversion 0 or 1. Similar results were obtained for the methanol-ethanol-methyl acetate-ethyl acetate system.
TL;DR: Alkylation of benzene with straight-chain olefins (from hexene to decene) in the presence of strong sulfuric acid was studied at a carefully controlled low temperature as discussed by the authors.
Abstract: Alkylation of benzene with straight-chain olefins (from hexene to decene) in the presence of strong sulfuric acid was studiedat a carefully controlled low temperature. The rate determinations were carried out under the condition of complete elimination of masstransfar resistance. The reaction was found to occur by a homogeneous mechanism in acid phase alone, and reasonable correlation of reaction rates with sulfuric acid strength and reactant concentrations was also obtained. In addition to the carbonium ion mechanism, all the isomeric ions were found to have equal stabilities when they attained the equilibrium distribution before the attack on benzene.
TL;DR: In this article, an experimental study was carried out on direct-contact mass and heat transfer between vapor and liquid with change of phase, that is, simultaneous condensation of organic vapor and evaporation of water or water alone in a bubble column equipped with gas dispersion nozzles.
Abstract: Experimental study was carried out on direct-contact mass and heat transfer between vapor and liquid with change of phase, that is, simultaneous condensation of organic vapor and evaporation of water or evaporation of water alone in a bubble column equipped with gas dispersion nozzles. The systems used in this experiment were carbon tetrachloride-water and trichloroethylene-water, which were immiscible in the liquid phase. Volumetric coefficients of vaper phase mass transfer were measured and compared with previous work. From the experimental results, condensation and evaporation rates were calculated under the given operating conditions and the effects of these specified operating conditions on these rates were made clear.
TL;DR: In this paper, the correlation of heat transfer coefficients to heating and cooling jackets and the determination of an adequate value of the exponent to the viscosity correction term was investigated. But the authors were concerned with the correlation between heat and cooling and not with the coefficient of the heat transfer coefficient.
Abstract: This paper is concerned with the correlation of heat transfer coefficients to heating and cooling jackets and also with the determination of an adequate value of the exponent to the viscosity correction term.
TL;DR: In this paper, a fully developed turbulent flow of an electrolyte solution in a porous-wall tube with suction or injection flow through the wall was experimentally studied and the measurements of mass transfer rates at the wall were made by an electrochemical method.
Abstract: A fully developed turbulent flow of an electrolyte solution in a porous-wall tube with suction or injection flow through the wall was experimentally studied. The measurements of mass transfer rates at the wall were made by an electrochemical method. Reynolds number were varied from 7900 to 21, 000 and Schmidt numbers were 750, 1100, 1920 and 2100. The mass flow ratios ρvw/ρU ranged from -2.13×10-5 to 5.59×10-5. It was recognized that mass transfer coefficients at the wall rise with increase of suction rate and fall with increase of injection rate. The results are in good agreement with predictions by film theory.
TL;DR: In this paper, the transfer rate of oxygen into sodium sulphite solution was investigated and the over-all volumetric absorption coefficient KGawas approximately in proportion to power consumption per unit volume Pv.
Abstract: To stabilize the flow pattern and to evaluate capability as a gas absorber, experiments were performed with baffled vessels. Apparatuses used were three geometrically similar batch horizontal stirred vessels. Studies were madeon the transfer rate of oxygen into sodium sulphite solution. Results obtained were :1) In the experiments, Froude No. was varied over a wide range to correlate the overall volumetric absorbtion coefficient KGa. The relation between KGa and Froude No. fora baffled vessel accorded with the one obtaind for a non-baffled vessel in state A1 corresponding to the limited range of Froude No., in which the liquid is splashed violently by the impeller.2) The over-all volumetric absorption coefficient KGawas approximately in proportion to power consumption per unit volume Pv. It was expressed by:KGA=KPV : Dt=10.6-18.4, e=0.3-0.7, PV=5X100-2X102: K=5.5X109 (oxygen-sodium sulphite solution system)where Dt is diameter of vessel, e is ratio of volume of liquid to volume of vessel.