bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compressions of liquids. II. Critical evaluation of new n‐alkane data: n‐Heptane to n‐tetracontane
Authors: Doolittle Arthur K. , Doolittle Dortha B. 
Published: June 2004

AbstractNew measurements of the volumes of liquid n‐alkanes of 7, 9, 11, 13, 17, 20, 30, and 40 carbon atoms over a range of temperatures from 20° to 300°C. and pressures from 0 to 4,000 kg./sq. cm. have been made. These volume measurements are here reduced to compressions (vol)/(vol°T), and the accuracy of the measurements has been determined. Analysis of the data for n‐heptane and n‐eicosane shows that the order of accuracy of the compressions of each of these compounds appears to be approximately 3 parts in 10,000. Evaluation of random multiple measurements on the remaining six compounds indicates that their over‐all accuracy is likewise of this same order.
Compressions of liquids. III. Temperature and molecular weight dependence of the Hudleston parameters for the n‐alkanes
Authors: Doolittle Arthur K. , Doolittle Dortha B. 
Published: June 2004

AbstractGeneral equations for the temperature dependence of the parameters of the Hudleston equation are given which were deduced from a study of n‐alkane compression data. Empirical expressions for the molecular‐weight dependence of the constants of these equations are likewise given which are applicable only to n‐alkanes. By use of these relations in the Hudleston equation the compressions of the family of liquid n‐alkanes over ranges of T, P, and m were calculated on an IBM‐650 computer. The over‐all standard percentage error (SPE) of the computer calculations for n‐alkanes of 7 to 20 carbons up to temperatures not exceeding their normal boiling points was 0.10%. The over‐all SPE for n‐alkanes of 7 to 40 carbons up to temperatures substantially above their normal boiling points (but not exceeding 300°C.) was 0.21%.
Temperature measurements in a spherical field: Transfer coefficients and corrections for thermocouples in boundary flows
Authors: Short W. W. , Sage B. H. 
Published: June 2004

AbstractA study was made of the deviation between the temperature of thermocouple junctions and the temperature of the fluid surrounding them which arises as a result of conduction along the thermocouple leads. Measurements around a 1/2‐in. heated sphere in the plane of the equator normal to an air stream having a velocity of 16 ft./sec. were made with a 0.001‐in.‐diam. thermocouple of platinum and platinum rhodium. Air temperatures in the boundary flows of the sphere were predicted from the indications of the thermocouple. The method of prediction employed also determined the heat transfer coefficients for the thermocouple wire in the boundary layer. These local heat transfer coefficients are lower than those observed in a uniform stream having a velocity equal to the estimated local velocity in the boundary layer.
Simultaneous mass transfer and equilibrium chemical reaction
Authors: Olander Donald R. 
Published: June 2004

AbstractEquations predicting the effect of various types of equilibrium chemical reactions on the liquid‐phase mass transfer coefficient have been derived. In each case the reacting species were assumed to be present in equilibrium concentrations at all points along the diffusion path. Equations were derived for both the film and surface‐renewal theories of simple mass transfer in conjunction with these equilibrium reactions.The well‐known Hatta equation for the rapid second‐order irreversible reaction was shown to be a limiting case of the general equilibrium reaction A + B ⇌ E.The calculated mass transfer coefficients were found to be functions of the concentration driving force and the average concentration level over the diffusion path as well as of the magnitude of the equilibrium constant and the diffusivities of the reacting species.
The compressibility of carbon dioxide‐argon mixtures
Authors: Abraham William H. , Bennett C. O. 
Published: June 2004

AbstractThe compressibility factor has been measured at 50°C. and 50 to 1,000 atm. for each of seven mixtures of carbon dioxide and argon containing 12.9 to 83.1 mole % carbon dioxide. The compressibility factors are reported as smoothed values at even pressures and also in the form of empirical smoothing expressions which fit the experimental values with an average absolute deviation of 0.1%. Various methods of predicting gas‐mixture compressibility are tested, and activity coefficients calculated from the experimental data are reported.
Diffusion in compressed binary gaseous systems
Authors: Berry V. J. , Koeller R. C. 
Published: June 2004

AbstractApparatus is described for experimentally determining diffusion coefficients in dense‐gas systems to pressures of 15,000 lb./sq. in. abs. Tests were made with the hydrogen‐nitrogen and methane‐ethane systems at 104°, 139°, and 171°F. to 10,000 lb./sq. in. abs. and with the nitrogen‐methane and nitrogen‐ethane systems at 104°F. to 2,500 lb./sq. in. abs. In all cases it was found that diffusion coefficients predicted on the basis of the Lennard‐Jones model with Thorne's dense‐gas correction diverged below the experimental data in the high‐density region. Coefficients predicted from the Slattery‐Bird reduced‐state correlation showed better agreement with the experimental data. The temperature dependence of the results is better described by the exponential form for liquids than by the form of the dense‐gas theory.
Mechanisms by which ultrasonic energy affects transfer rates in liquid‐liquid extraction
Authors: Woodle H. A. , Vilbrandt F. C. 
Published: June 2004

AbstractConcurrent and spray‐tower studies have been accomplished that illustrate the effects of ultrasonic insonation on transfer rates in liquid‐liquid extraction. Stage efficiencies and over‐all transfer rates in the system toluene‐methyl alcohol‐water were determined with and without insonation of the system at frequencies of 40 and 800 kc.Insonation was shown to have a positive effect on mass transfer in both concurrent and spray‐tower operations. Insonation of the system provides for increased interfacial area between the two phases, removal of relatively stagnant liquid layers at the interface, and increased circulation currents within a single liquid phase. Low‐frequency insonation favors local agitation and mixing of the phases, and high‐frequency insonation favors induced circulation currents.
Momentum and heat transfer in laminar boundary‐layer flows of non‐Newtonian fluids past external surfaces
Authors: Acrivos Andreas , Shah M. J. , Petersen E. E. 
Published: June 2004

AbstractA theoretical analysis for the laminar flow past arbitrary external surfaces of non‐Newtonian fluids of the power‐law model is presented. The main problem which is considered is how to predict the drag and the rate of heat transfer from an isothermal surface to the fluid. Inspectional analysis of the modified boundary‐layer equations yields a general relationship both for the drag coefficient and for the Nusselt number as functions of the generalized Reynolds and Prandtl numbers. The flow past a horizontal flat plate is studied in detail numerically.
Limiting velocities, holdup, and pressure drop at flooding in packed extraction columns
Authors: Venkataraman Gopal , Laddha G. S. 
Published: June 2004

AbstractCriterion for flooding which was found to be reproducible in packed columns has been described. Limiting velocities, holdup, and pressure drop at flooding have been experimentally determined for binary liquid systems in a countercurrent extraction column packed with raschig rings, Berl saddles, Lessing rings, and spheres. Generalized correlations have been suggested, with the experimental data taken into account along with, published data of other workers for the estimation of limiting velocities, holdup, and pressure drop at flooding.
Longitudinal mixing in fluidization
Authors: Cairns E. J. , Prausnitz J. M. 
Published: June 2004

AbstractLongitudinal mixing properties in liquid‐solid fluidized beds were investigated by means of a salt‐solution tracer technique. The electrical conductance breakthrough curves were measured with very small electrical conductivity probes for a step‐function input of salt‐solution tracer. Longitudinal eddy diffusivities were determined for 1.3‐ and 3.0‐mm. lead spheres and 3.2‐mm. glass spheres in 2‐ and 4‐in.–diameter beds at a distance of 5 bed diam. from the injector and for various radial positions.The longitudinal mixing properties are strongly affected by particle concentration; maximum mixing occurs at a fraction voids of 0.7. Longitudinal eddy diffusivity increases with particle density and with decreasing dp/D ratio. Velocity profiles markedly influence the eddy‐diffusivity profiles.
General short‐cut equation for equilibrium stage processes
Authors: Smith Buford D. , Brinkley W. K. 
Published: June 2004

AbstractAn equation for the prediction of the separation of a multicomponent mixture in equilibrium stage processes is presented. The equation is applicable to extraction processes with up to three feeds (an intermediate feed, a feed at the extract end, and the solvent feed at the raffinate end) and both raffinate and extract reflux. In its simplest form (simple extraction, stripping, or absorption) the equation reduces to the familiar Kremser equation. The use of the equation to solve multicomponent distillation and extraction problems is illustrated by examples.
Entrainment and pressure drop in concurrent gas ‐ liquid flow: I. Air ‐ water in horizontal flow
Authors: Wicks Moye , Dukler A. E. 
Published: June 2004

AbstractExperimental equipment and data are reported for entrainment and energy loss in annular, two‐phase flow of water and air. Measurements were made with a sample withdrawal technique in 1‐ and 3‐in. horizontal tubes. A knowledge of entrainment is necessary to an understanding of various mass transfer, heat transfer, and separation problems in two‐phase flow. A preliminary correlation is presented.
On the steady state activity levels in a reactor‐regenerator system
Authors: Petersen E. E. 
Published: June 2004

AbstractA method is proposed for computing the steady state activity levels at various points within a reactor‐regenerator system in which the residence time distribution functions in the reactor and regenerator, the permanent deactivation function, and the temporary deactivation and activation functions are arbitrarily specified. A particularly simple solution to these equations is obtained when the temporary activation and deactivation functions are of exponential form. The latter equations are used to calculate values of the mean activity in the reactor for the limiting cases of piston type of flow and complete mixing under a variety of conditions.
The kinetics of the absorption of phosgene into water and aqueous solutions
Authors: Manogue W. H. , Pigford R. L. 
Published: June 2004

AbstractPure phosgene gas was dissolved in short laminar jets of aqueous solution, and the results were interpreted with an unsteady state absorption‐plus‐reaction theory. Absorption rates of sulfur dioxide and carbon dioxide into water in the same equipment support this interpretation. The solubility of phosgene in water at 25°C. has been estimated from the absorption rates as 0.069 g.mole/(liter) (atm.). The estimated heat of solution is 6,800 cal./g.mole. At 16° and 25°C. the effect of a chemical reaction between phosgene and water on the absorption rate in a jet appears to be almost negligible, but at 45°C. a first‐order reaction rate constant of 75 sec.−1 can be derived from the absorption rates.From absorption measurements with short jets and sodium hydroxide solutions so strong that a pseudo‐first‐order reaction accompanied absorption, the reaction rate constant for the bimolecular reaction between dissolved phosgene and the hydroxyl ion was estimated. A value of 1.6 × 104 liters/(g. mole) (sec.) was obtained at 25°C. in 1‐N sodium hydroxide; at 35°C. in the same solution the estimated value was 2.9 × 104. There appears to be a slight increase in the reaction‐rate constant with the ionic strength of the solution.
Axial diffusion of liquids in packed beds and end effects
Authors: Liles A. W. , Geankoplis C. J. 
Published: June 2004

AbstractExperimental data were obtained on the effect of bed length of packed spheres on axial diffusion coefficients with the frequency response technique used. Lengths of packed section of 6 to 174 cm. were used. The end effects were eliminated by using a novel experimental technique for analyses of the inlet and outlet streams. No effects of length on DL were found.When the end effects were artificially introduced by using void analytical sections at the two ends, then large effects of length on DL were found. These void sections were the cause of length effects found by other experimenters. The DL drops as the length of bed is increased. Above about 65 cm. length the DL remains constant with increase in length. The over‐all results are in general agreement with the data of others.
Heat and mass transfer transients in cylinder drying: Part I. Unfelted cyclinders
Authors: Nissan A. H. , Hansen David 
Published: June 2004

AbstractAn investigation has been made of transient heat transfer and water removal on an unfelted cylinder dryer. This investigation has included the development of a theory for describing conduction of heat in the drying material and an experimental testing of the adequacy of the theory.The theory describes the heat transfer and evaporation of water in terms of a second‐order partial‐differential equation and appropriate boundary conditions. Numerical solutions obtained on a digital computer are presented.The experimental work, performed on a specially constructed laboratory dryer, included measurements of temperatures at internal points in a drying sheet and also measurements of water removed during drying.Good agreement was found between theory and experiment, and the usefulness of the theory is demonstrated in the analysis of water removal in some drying experiments.Although the work was primarily concerned with a description of the paper drying process, the methods should apply equally well to the drying of other materials on heated cylinders.
A computational model for predicting and correlating the behavior of fixed‐bed reactors: I. Derivation of model for nonreactive systems
Authors: Deans H. A. , Lapidus Leon 
Published: June 2004

AbstractA mathematical model is developed for predicting the mixing characteristics of fixed beds of spheres. The model is based on a two‐dimensional network of perfectly stirred tanks. By means of the conventional partial differential equation description of flow in fixed beds, the predictions of the new model are compared with experimentally observed axial and radial mixing characteristics. The introduction of a capacitance effect is shown to enable the model to predict the abnormally low axial Peclet numbers observed in liquid‐phase systems in the unsteady state.The mathematical model developed in the first part of this paper is extended to cover chemical reaction in a cylindrical fixed bed of porous catalyst spheres. The mathematical effect on the model of various controlling rate steps, nonconstant property values, and multiple, non‐first‐order reactions is discussed. After the general discussion a simplified system is chosen to indicate the practical advantages of the model. A single, first‐order, irreversible, exothermic reaction is considered to proceed according to an effectively homogeneous rate expression, which varies exponentially with the inverse of absolute temperature. Both steady state and transient cases are calculated for a reactor, the walls of which are maintained at constant temperature.
Mixing in a jet‐stirred reactor
Authors: Bartok William , Heath Carl E. , Weiss Malcolm A. 
Published: June 2004

AbstractMeasurements were made of the over‐all mixing in a gas phase flow reactor stirred by the entering feed jets. The mixing was studied by following the decrease in exit concentration after sharp cutoff of a radioactive tracer gas krypton −85. The data showed that over the entire range of average residence times investigated, about 0.4 to 16 sec., the reactor behaved as though 85% of its volume was perfectly stirred and the remaining 15% was in piston flow in series with the stirred region. Relocation of the feed jets would probably increase the fraction of volume that is effectively perfectly stirred to about 95%.
A note on multicomponent diffusion
Authors: Shain Stephen A. 
Published: June 2004

AbstractThe problem of defining an average diffusion coefficient of a gas arises in the application of the film resistance model for mass transfer to systems involving multicomponent mixtures of simultaneously diffusing gases and in the application of mass, momentum, and heat transfer analogies in such systems. It is shown that, in some cases, integration of the diffusion equation with an average value of the diffusion coefficient will not be valid. An approximate solution of the diffusion equation is obtained with the concentration dependence of the diffusion coefficient taken into account. Some numerical examples are constructed for comparison of this method and several methods for defining an average diffusion coefficient with an exact solution of the Stefan‐Maxwell relations.
Phase relations of miscible displacement in oil recovery
Authors: Hutchinson C. A. , Braun Philip H. 
Published: June 2004

AbstractMiscible displacement as an oil recovery process has received wide interest in the literature recently. Essentially three basic processes have been proposed for attaining miscible displacement in our oil reservoirs: high pressure gas, enriched gas, and miscible slug processes.The present paper relates and compares the phase relations and mass transfer mechanisms of these various basic miscible displacement processes. It also discusses the effects of the various operating variables, such as pressure, temperature, injected gas composition, etc., on the applicability of the process and considers the pertinent conditions that restrict the application of each process. It is to be recognized that at times a miscible displacement may be attempted but not attained, or unforeseen conditions may destroy miscibility once it has been attained. The authors discuss the results of such conditions. The mechanisms of the miscible displacement processes are explained in a conceptual analysis based on the triangular phase diagram. Although the multicomponent reservoir fluid system cannot be represented rigorously from a thermodynamics standpoint by these diagrams, they are useful for cenceptual analysis. Their limitations are presented by the authors along with data supporting the concepts developed.
The effect of mixer design on the efficiency of a pump‐mix mixer‐settler
Authors: Davis A. T. , Colven T. J. 
Published: June 2004

AbstractThe mixing efficiency of simple and pitched paddles, marine propellers, and centrifugal and disk impellers was determined by a heat transfer method in a single stage of a large pump‐mix mixer‐settler. The mixing devices were from 3 to 5 in. in diameter and were tested with a refined kerosene as the organic phase and water as the aqueous phase.A heat conductance was calculated from flow parameters and the efficiency and was correlated against impeller design and speed variables. For centrifugal and disk impellers UA was proportional to n1.2L3b0.3; for the paddles UA was proportional to n1.67L2.5b0.42. At normal operating speeds controlled variation of the internal recirculation of mixed phases through a centrifugal impeller did not change the efficiency.
Thermodynamics of solvent selectivity in extractive distillation of hydrocarbons
Authors: Prausnitz J. M. , Anderson Ralph 
Published: June 2004

AbstractThe selectivity of a polar solvent is expressed in terms of an approximate theory of solutions. The theoretical results are insufficiently precise for the accurate prediction of activity coefficients, but the analysis shows that in the absence of chemical effects selectivity depends primarily on the difference in molar volumes of the hydrocarbons to be separated and on the polar energy density of the solvent. The effectiveness of a solvent is related to its polarity (which should be large) and to its molecular size (which should be small). In cases where chemical effects are important or where the molar volumes of the hydrocarbons to be separated are only slightly different, selectivity also depends on the relative ability of the hydrocarbons in acting as electron donors and on the ability of the solvent to act as an electron acceptor in forming acid‐base complexes. The theoretical conclusions, which are based on modern thermodynamics and on the theory of intermolecular forces, are in agreement with experimental observations. The results obtained in this work provide theoretical criteria for the selection of an optimum solvent for a given separation and give semiquantitative explanations of solution phenomena related to extractive distillation.
Vapor‐liquid equilibrium in ammonia complex systems
Authors: Muendel C. H. , Linford H. B. , Selke W. A. 
Published: June 2004

AbstractThe vapor‐liquid equilibrium in ammonia complex systems has been studied with a view toward design methods for separational and leaching processes. It is felt that the previously reported equilibrium constants for these systems are subject to considerable question with regard to the method used to measure the activity of the free ligand, or coordinating species. It is shown how this difficulty can be surmounted by the use of ammonia vapor pressure measurements and fugacities. A method of correlating complex equilibrium data from measurements of over‐all metal concentration and free metal ion concentration is proposed. Vapor liquid equilibrium measurements have been made on the systems copper hydroxide, ammonia, water, nitrogen and nickel hydroxide, ammonia, water, nitrogen at 40° and 60°C. under 1 atm. total pressure with a continuously recirculating batch contactor. The correlation method is illustrated with the data of these measurements.
Temperature depressions for evaporating spheres at low pressures
Authors: Madden A. J. , Halfen F. J. 
Published: June 2004

AbstractThe evaporation of naphthalene spheres into air in the micron pressure range may be accompanied by an appreciable surface temperature depression. The magnitude of the effect is shown to depend upon the geometry of the experimental system and the pressure level. Such effects are of interest in studies aimed at determining evaporation coefficients.
Heats of mixing: Alcohol‐ aromatic binary systems at 25°, 35°, and 45°c.
Authors: Mrazek Robert V. , Van Ness H. C. 
Published: June 2004

AbstractA new isothermal calorimeter with no vapor space is described. It allows the accurate and rapid determination of heats of mixing of endothermic liquid systems. Data are presented for eighteen binary systems composed of a lower alcohol and a simple benzene derivative at 25°, 35°, and 45°C. Precise equations for representing these data are also presented.
Mass transfer between isobutanol and water in concurrent flow through a packed column
Authors: Leacock James A. , Churchill Stuart W. 
Published: June 2004

AbstractLocal and mean rates of transfer of isobutanol into the water‐rich phase and of water into the isobutanol‐rich phase were measured in concurrent upward flow through a column packed with glass spheres. The use of a two‐component system permitted determination of the individual‐phase coefficients. These are the first rate measurements for concurrent flow in a packed bed. Because the flow rates are not limited by flooding, much higher rates of transfer are attainable than in countercurrent flow.