bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass and heat transfer from drops in liquid‐liquid extraction
Authors: Handlos A. E. , Baron T. 
Published: June 2004

AbstractMass and heat transfer rates in extraction are studied theoretically and experimentally for the practical range of the variables involved. For the particular but typical case of liquid drops moving through another liquid a simple correlation for the over‐all mass transfer coefficient is presented, which holds with a probable error of 20%.Included are systems in which the rate is limited by either coefficient, as well as systems in which both coefficients are significant. The correlation, valid for both directions of transfer with either phase dispersed, is useful for the extrapolation of performance from system to system in a given piece of equipment. Also, together with correlations for transfer area and effective driving force, it is part of the information needed for design.
Froth‐frothate concentration relations in foam fractionation
Authors: Kevorkian Victor , Gaden Elmer L. 
Published: June 2004

AbstractConcentration relations between foams and their residual liquids (frothates) have been examined.Clean air streams of 88, 91, and 96% water saturation were bubbled into aqueous solutions of isobutyl alcohol. The concentration of the alcohol in the collected and collapsed foam was plotted against its concentration in the bulk liquid.Varying the saturation of the air stream resulted in both positive and negative enrichment of the foam with the surface‐active alcohol. This suggests that where froth‐frothate‐concentration relations are unfavorable, a change in operating conditions may advantageously affect these relations and allow the mixture to be foam separated.
Interaction between a turbulent air stream and a moving water surface
Authors: Hanratty Thomas J. , Engen James M. 
Published: June 2004

AbstractThe interaction between a turbulent air stream and a water film flowing parallel to it was studied. The variables explored were the liquid flow rate, the gas flow rate, and the film height. The data were correlated in terms of a liquid and a gas Reynolds number. Thinner films or films having a lower Reynolds number were more stable. For the experiments reported in this research the transition from a smooth surface to a surface possessing two‐dimensional waves occurs at hUτρliquid/µliquid of about 520. Transition from two‐dimensional waves to a “pebbled” surface occurs at a value of this parameter of about 600. Theories presented in the literature for the initiation of waves on a liquid surface do not adequately describe the experimental results.
Evaluation of the heat requirements in batch distillation operations
Authors: Stiehl J. G. , Weber James H. 
Published: June 2004

AbstractA rigorous method is presented for the evaluation of the heat requirements in binary batch fractionations which involve negligible column hold up. The method, in which the additional variables of the discontinuous process are taken into account, is a modification of the methods of Ponchon and Savarit for continuous operation. Two examples, one for a fractionation in which the composition of the product is constant and the other in which the reflux ratio is constant, are given as illustrations of the method.The application of the method permits more accurate evaluation of reboiler and condenser heat loads and, in turn, better design.
Liquid‐liquid extraction accompanied by chemical reaction
Authors: Fujinawa K. , Maruyama T. 
Published: June 2004

AbstractFrom time to time, A.I.Ch.E. Journal is going to present translations of certain technical articles written by our Japanese colleagues in their own language. These translations are to be made by Kenzi Etani, who received his B.S. in chemical engineering in 1953 at the Tokyo Institute of Technology and his M.S. in 1955 at M.I.T. He is associated with Stone & Webster and is an associate member of American Institute of Chemical Engineers. He is also a member of the Society of Chemical Engineers, Japan, and the Japan Oil Chemists' Society. His offer to help break down the language barrier is acknowledged.The following article (two will follow in the September and December issues, respectively) was published in Chemical Engineering (Japan), volume 21, pages 75—79 (1957).Abstracts, notation, literature cited, tables, and figure captions not published here appear in English in the original paper. No figures will be be reproduced in these translations.
Regular solution theory for gas‐liquid solutions
Authors: Prausnitz J. M. 
Published: June 2004

AbstractRegular‐solution equations developed by Hildebrand and others are useful for obtaining semiquantitative estimates of phase equilibria in nonpolar systems. These equations, however, do not take into account the volume change on mixing and therefore require modification for solutions of gases in liquids. The required modifications are presented in this paper, and the resulting equations give reasonable estimates of the solubilities of gases and of the temperature coefficient of solubility. In the modified form the regularsolution theory may be used to estimate gas‐liquid phase equilibria at high pressures.
A general index of fractional distillation power for hydrocarbon mixtures
Authors: Geddes R. L. 
Published: June 2004

AbstractResults from precise calculations for fractionation of multicomponent hydrocarbon mixtures show that the relative separations between components are rationalized in a simple manner in terms of the relative volatilities. A quantitative criterion for sharpness of fractionation with complex mixtures, the Fractionation Index, is suggested. This function is useful for general correlation purposes. It also enables prediction of the detailed compositions of the products from a proposed fractionation and thereby simplifies the computation procedures.
Axial mixing and extraction efficiency
Authors: Sleicher C. A. 
Published: June 2004

AbstractThe effect of back mixing of either phase in an extraction column, which decreases the extraction efficiency, is analyzed theoretically by means of an idealized diffusion model that can be characterized by four dimensionless parameters: a Peclet number of each phase, a mass transfer number, and the usual extraction factor. Calculations for a wide range of these parameters were performed on a digital computer.The principal results, presented in a table, will be useful in the design and scale up of extraction columns and in the interpretation of experimental results from extractors and from some reactors in which a first‐order reaction occurs.
Turbulent flow of non‐newtonian systems
Authors: Dodge D. W. , Metzner A. B. 
Published: June 2004

AbstractA theoretical analysis for turbulent flow of non‐Newtonian fluids through smooth round tubes has been performed for the first time and has yielded a completely new concept of the attending relationship between the pressure loss and mean flow rate. In addition, the analysis has permitted the prediction of non‐Newtonian turbulent velocity profiles, a topic on which the published literature is entirely silent.To confirm the theoretical analysis, experimental data were taken on both polymeric gels and solid‐liquid suspensions under turbulent‐flow conditions. Fluid systems with flow‐behavior indexes between 0.3 and 1.0 were studied at Reynolds numbers as high as 36,000. All the fully turbulent experimental data supported the validity of the theoretical analysis. The final resistance‐law correlation represents a generalization of von Karman's equation for Newtonian fluids in turbulent flow and is applicable to all non‐Newtonians for which the shear rate depends only on shear stress, irrespective of rheological classification. All the turbulent experimental data for the non‐Newtonian systems were correlated by this relationship with a mean deviation of 1.9%.
Studies on entrainment
Authors: Aiba Shuichi , Yamada Toyokazu 
Published: June 2004

AbstractAfter application of a biochemical technique, size distribution of liquid drops from air bubbles blown through water and a butanol and glycerine solution filled to a certain depth in a glass cylinder 9.6 cm. in diameter and 47 cm. in length was measured.The initial vertical velocity of drops was estimated from the experimental results, with reference to its trajectory.
Maximum stable droplets in dispersoids
Authors: Mugele R. A. 
Published: June 2004

AbstractMaximum stable droplet size in nonuniform dispersoids may be ignored or treated as a statistical‐limiting parameter or as a physically significant quantity. In this paper the author shows that treatment as a physically significant quantity is always permissible and in most cases advantageous. It is found that maximum stable droplet size as well as a mean droplet size can be calculated in some cases from theory and in other cases from correlated experimental data; this is illustrated with examples involving sprays and emulsions.
The application of boundary‐layer theory to power‐law pseudoplastic fluids: Similar solutions
Authors: Schowalter W. R. 
Published: June 2004

AbstractTwo‐ and three‐dimensional boundary‐layer equations have been developed for pseudoplastic non‐Newtonian fluids which can be characterized by a power‐law relationship between shear stress and velocity gradient. The types of potential flows necessary for similar solutions to the boundary‐layer equations have been determined. For two‐dimensional flow the results are similar to those obtained for Newtonian fluids. For three‐dimensional flow, however, the possibility of similar solutions depends on the nature of the expression which describes effective viscosity of the fluid. At most, similar solutions are possible only for the case of flow past a flat plate where the potential velocity vector is not perpendicular to the leading edge of the plate; this is a much more restrictive condition than is obtained for Newtonian fluids.
The effect of dynamic surface tension on nucleate boiling coefficients
Authors: Jontz P. D. , Myers J. E. 
Published: June 2004

AbstractA study was made of the effects the surface tension of aqueous solutions of surface‐active agents had on the bubble‐formation characteristics of these solutions. Bubbles were formed by two processes: by passing air through a horizontal orifice submerged in the solution and by nucleate boiling at an electrically heated surface. The experimental measurements taken with the air‐bubble system were used to determine the nature of the surface‐tension effect on air‐bubble formation. This knowledge was then applied to the interpretation of boiling measurements made with the same solutions. The boiling coefficients of the Tergitol‐water solution were found to vary inversely with dynamic surface tension. Boiling coefficients for Aerosol‐water solutions, however, varied in a manner which could not be related to surface‐tension effects.
The effects of superheat and surface roughness on boiling coefficients
Authors: Kurihara H. M. , Myers J. E. 
Published: June 2004

AbstractThe effects of liquid superheat and surface roughness on boiling coefficients were investigated in a series of experiments in which water, acetone,n‐hexane, carbon tetrachloride, and carbon disulfide were boiled on a flat plate. In addition to the usual thermal measurements, the number of active boiling centers was determined, whenever possible, by visual means, and a quantitative measure of surface roughness was made. It was found that the number of active boiling centers on the plate increased with increasing surface roughness and that the calculated boiling coefficients were proportional to the one‐third power of the number of bubble columns rising from the heated surface.An equation has been derived relating boiling coefficients to fluid properties and the number of active boiling centers on a surface. A second equation, based on the theory of thermal fluctuations, has been proposed to relate the number of active boiling centers to the independent variables of surface‐roughness and temperature‐difference driving force. The limited data available have been found to follow this proposed relation.The results of this work suggest a quantitative method of relating the boiling coefficient to the character of the surface which may explain the discrepancies observed in the slopes of boiling curves reported in the literature and in the actual values reported for the boiling coefficients measured on different surfaces.
Density fluctuations in fluidized beds
Authors: Baumgarten P. K. , Pigford R. L. 
Published: June 2004

AbstractThe effectiveness of fluidized beds is limited by the presence of density fluctuations such as those caused by gas bubbles. The size and frequency of such bubbles were measured in airfluidized beds of glass beads and silica‐alumina catalyst with a gamma‐ray absorption technique used.The results showed that the gas bubbles developed owing to an influx of gas from the continuous dense phase. With increasing elevation in the bed the volumetric rate of bubble flow approached as a limit the total air flow minus the flow through the dense phase corresponding to minimum fluidization. The growth rate of bubble diameter was as much as 0.17 in./in. of elevation. Fluidization was most uniform with the cracking catalyst, for which the apparent density of the dense phase decreased with increasing gas velocity.
Compressions of liquids. I. Apparatus and method of measurement
Authors: Doolittle Arthur K. , Simon Ivan , Cornish Raymond M. 
Published: June 2004

AbstractA novel type of piezometer used to measure the compressions of liquids from 20° to 300°C. and from 1 to 4,000 kg./sq. cm. is described. The accuracy anticipated is 4 parts in 10,000.
On the separation of gas mixtures in a jet
Authors: Gose Earl E. 
Published: June 2004

AbstractIn 1954 Becker found that the components of a gas mixture could be separated by allowing a jet of the gas mixture to expand in a low‐pressure chamber. The heavier molecules would concentrate near the center of the jet and the lighter ones near the edge. Thus the jet could be split into two streams, one containing more of the heavy component and one containing more of the light component. In this paper it will be shown that this effect can be predicted from the kinetic theory of gases and that the predicted magnitude of the effect agrees favorably with the experimental data of Becker.
Elutriation of solid particles from a dense‐phase fluidized bed
Authors: Wen Chin Yung , Hashinger Richard F. 
Published: June 2004

AbstractThe elutriation of fines from fluidized beds of two‐ and multiparticle systems is investigated. Materials used are glass beads and coal powder with air and helium as the elutriating gases.A specific elutriation rate constant which takes into consideration the particle stratification and thus is nearly independent of the bed dimensions is employed in the correlation of the elutriation of fines.The proposed generalized correlation applicable to a system of two particle sizes and to more complex ones is presented. Recorrelation of pertinent literature data by the dimensionless equation indicates good agreement in spite of a diversity of bed geometries. The effect of fluidized‐bed parameters on the rate of elutriation is examined, and applications and limitations of the correlation are shown.
Use of momentum balance in calibrating orifices for flow of gases
Authors: Martin J. J. , Pabbi V. R. 
Published: June 2004

AbstractA method of determining the absolute calibration of a gas‐flow orifice without the use of gas holders or any comparative device is described. The method is based on the application of the momentum balance, as well as the energy balance, to the flow of the gas. The application requires the measurement of pressures on the face of the orifice in addition to the usual pressure‐drop measurements along the axis of flow.Orifice coefficients determined by the force‐momentum principle are shown to agree within an average deviation of 1.4% with those determined by other standard techniques. Also the application of the force‐momentum principle demonstrates clearly why orifice coefficients are much less than unity.
Suspension of slurries by mechanical mixers
Authors: Weisman Joel , Efferding L. E. 
Published: June 2004

AbstractThe production of essentialy homogeneous sluries involves both initial solids suspension and expension of the particle bed to fill the container. When geometry and solids concentration are held constant, both phenomena are found to be controlled by similar dimensionless groupings of power per unit volume, density, and relative velocity between the fluid and particle. The dimensionless group applicable to bed expansion is shown to be consistent with hydro‐dynamic theory. Design equations for use with the paddle type of impeller are presented.
A theoretical analysis of laminar natural convection heat transfer to non‐Newtonian fluids
Authors: Acrivos Andreas 
Published: June 2004

AbstractAn equation is given for the local Nusselt number in laminar convection heat transfer to power‐law non‐Newtonian fluids. This expression, which even for Newtonian fluids (n = 1) does not appear to have been derived before, is obtained from the exact asymptotic solution of the appropriate laminar boundary layer equations and is applicable to any two‐dimensional surface or a surface of revolution about an axis of symmetry when, as is usually the case, Npr > 10.
Pressure drop and power requirements in a stirred fluidized bed
Authors: Leva Max 
Published: June 2004

AbstractThe paper reports fundamental observations on the effect which stirring of fluidized solids has on the pressure drop. Typical power requirements are also given.The experimental pilot unit was of 6‐in. diameter and 12 in. high. A special blade or paddle type of stirrer had been built which permitted the evaluation of the effects of blade positioning, blade spacing relative to sense of rotation, as well as the effect of stirrer immersion and rotational speed.The observations disclosed that blade positioning relative to sense of rotation had a very profound effect on pressure drop as well as on power requirements. When the solids circulation pattern as normally induced by the stirrer was of the same general character as that ordinarily encountered in a dense phase fluidized charge, the resulting pressure drop was always considerably lower than the conventional unstirred fluidized bed pressure drop. Furthermore for this type of stirrer the power requirements were also lowest. For other stirrer designs and other induced solids convection patterns the pressure drop was less influenced and the power requirements were much greater.The solids used for the study were a relatively coarse silica sand for which both pressure drop as well as power requirement data were reported. Power requirement data were also obtained for a much finer alumina powder. When one emphasized the effect which particle properties, especially surface characteristics may have the level of the power data was much lower, although the data were of the same character as the characteristic values pertaining to the sand.
Drag coefficients at low Reynolds numbers for flow past immersed bodies
Authors: Jones A. M. , Knudsen J. G. 
Published: June 2004

AbstractDrag coefficients were determined at low Reynolds numbers for cylinders (0.1 ⩽ Re ⩽ 1.0) and flat plates (0.05 ⩽ Re ⩽ 2.0) moving through a viscous medium. The drag coefficient was calculated from the force required to move the immersed body through the fluid, and preliminary work on spheres was used to calibrate the apparatus. For all bodies studied the drag coefficient was inversely proportional to the Reynolds number. The data were analyzed by a least‐squares method to obtain the relationship between drag coefficient and Reynolds number.The diameter of the tank containing the viscous fluid had a very definite effect upon the drag coefficient of the various cylinders and flat plates studied. In the range of DT/D (tank diameter/cylinder diameter) studied the relationships recommended by White involving the wall effect and the end correction agree with experimental data for values of L/D (cylinder length/cylinder diameter) greater than 16. At L/D ratios less than this drag coefficients are lower than those predicted by White's equations, and the experimental curves are recommended for these ratios.For flat plates in perpendicular flow no effect of the W/L (plate width/plate length) was detected in the range studied. The tank diameter however had a considerable effect, and a curve is proposed to predict drag coefficients for flat plates in perpendicular flow in the range of experimental conditions studied.
The mechanics of vertical moving liquid‐liquid fluidized systems: II. Countercurrent flow
Authors: Beyaert Bruce O. , Lapidus Leon , Elgin J. C. 
Published: June 2004

AbstractIn a previous publication it has been shown that for the case of liquid droplets moving through a second quiescent liquid the holdup vs. slip‐velocity ratio could be predicted on the basis of analogous rigid sphere fluidization data. The present paper extends these results to cover the countercurrent flow of both liquid phases. As long as the system is operated below the flooding point, the behavior of the spray column can be predicted from the corresponding solids fluidized data.
Heat transfer in a chemically reacting system (nitrogen tetroxide‐dioxide)
Authors: Irving J. P. , Smith J. M. 
Published: June 2004

AbstractThe effect of chemical reaction on heat transfer was investigated analytically for the dissociating system N2O4 \documentclass{article}\pagestyle{empty}\begin{document}$ \rightleftharpoons$\end{document} 2NO2 in turbulent pipe flow. The Reynolds, Colburn, and Deissler analogies were adapted to reacting systems to determine local values of h′/h, the ratio of the heat transfer coefficient for a reacting system to that for the same system under frozen nonreacting conditions. The coefficient h′ was determined by using effective thermal conductivities and heat capacities composed of a frozen and a reacting contribution. The equations for the effective properties, derived in this paper from heat transfer considerations, are in agreement with those developed from thermodynamics and statistical mechanics.The effective properties vary significantly with temperature. Hence, the adaptation of Deissler's analogy, which was originally developed to consider the radial variation of physical properties across the pipe radius for an inert system, would be expected to give the most reliable results in this reacting system. In the range of variables studied it is found that the heat transfer coefficient for a reacting system may be as much as eighteen times the coefficient for a similar, frozen system. The results from the approximate Reynolds and Colburn analogies, which are evaluated by the use of mean physical properties, yield maximum values of h′/h of about 9.The study covers a Reynolds number range of 10,000 to 200,000 and tube wall temperatures of 300° to 370°K.
Mass transfer from single solid spheres by free convection
Authors: Garner F. H. , Hoffman J. M. 
Published: June 2004

AbstractRates of mass transfer by free convection have been measured for spheres of three organic acids dissolving in three solvents, water, n‐butanol and benzene. The results fell into two groups, one in which flow is completely laminar and one in which turbulence had set in in the boundary layer. Turbulence appears to set in at N′Ra crit ∼ 6 × 108.