bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid extraction in an agitated vessel
Authors: Overcashier R. H. , Kingsley H. A. , Olney R. B. 
Published: June 2004

AbstractThis investigation was undertaken to show how the efficiency of solute transfer between two immiscible liquids is influenced by the type, size, and submergence and rotational speed of the impeller and the degree of baffling, residence time, and phase ratio. The system water‐kerosene‐n‐butylamine solute was agitated in a continuous‐flow 14 3/4‐in. ‐diam. vessel using propellers, spiral turbines, and flat‐blade turbines from 4 to 10 in. in diameter. The feed streams were introduced at the wall at the bottom of the vessel and left at the top of the vessel.On the basis of the power required for a given level of stage efficiency, the best agitator design is any impeller that has a diameter about 40% of the vessel diameter and is centered in the unbaffled vessel. Without baffles the impeller type and depth of submergence have little effect on performance. The power increase required by the addition of baffles is small at the highest stage efficiencies, especially with the larger radial‐flow impellers, but may be severalfold at efficiency levels of 70 to 90%. This presumably results from the lowered mass transfer driving force caused by the increase in end‐to‐end mixing due to wall baffles. Whether baffles have such a large adverse effect if the feed is introduced into the impeller rather than at the vessel wall is not fully established, but there is some evidence that baffling is also undesirable in this case. For baffled operation, impeller type and submergence do affect performance.A correlation of stage efficiency is presented in terms of Reynolds number and power number. In addition, energy input per volume of total flow is correlated in terms of residence time and stage efficiency for one size of baffled propeller.Spot samples taken from the vessel showed large, random‐concentration fluctuations out to 20 residence times and perhaps indefinitely. Reproducible results were obtained by taking time‐averaged samples.
Two‐phase flow of hydrogen in horizontal tubes
Authors: Rogers John D. 
Published: June 2004

AbstractSemirigorous equations are developed for flow of flashing liquids in pipe lines. These relations are applied to the flow of hydrogen, and computed correlations are presented for the pressure drop and vapor fraction. The calculations have been carried out as functions of the parameters: diameter, 3/8 to 4 in.; mass rate per unit area, 0.0528 to 682 lb./(sq. ft.) (sec.); pressure, 14 to 30 lb./sq. in. abs.; vapor fraction, 0.005 to 0.65; and heat leak, equivalent to 0 to 0.0224 B.t.u./(sq. ft.) (sec.) for a 3/4‐in. line.
Phase separation and mass transfer in a liquid‐liquid cyclone
Authors: Simkin D. J. , Olney R. B. 
Published: June 2004

AbstractLiquid‐liquid phase separation and mass transfer studies were made in a 4‐in.‐diam. cyclone of conventional construction. The cyclone was tested with oil‐water volume phase ratios ranging from values of 1/3 to 9/1 and for total flows up to 24 gal./min., although most variables were studied at a feed rate of 10 gal./min. Kerosene or a white oil (vis. 9 centipoises at 77°F.) was used as the oil phase. Valve or line premixing was used to disperse the feed. Valve pressure drops were in the range of 0.1 to 1.0 lb./sq.in., and inlet drop sizes, where determined, were about 1 mm. The optimum cyclone geometry (volume, diameter of inlet, overflow and underflow lines) and the optimum split (overflow/underflow) were determined in terms of a phase‐separation efficiencyEs.At optimum geometry and split a number of mass transfer runs were made in which monobutylamine solute was transferred from the kerosene to the water phase. These runs indicated thatEsdecreased but mass transfer efficiency increased as the feed rate or pressure drop across the mixing valve was increased.
Agitation of non‐Newtonian fluids
Authors: Metzner A. B. , Otto R. E. 
Published: June 2004

AbstractSince the shear rate of a non‐Newtonian fluid is of importance in fixing the rheological or viscometric behavior of such a material, the present study has been concerned with the development of a general relationship between impeller speed and the shear rate of the fluid. The resulting relationship was then used to interpret and correlate power‐consumption data on three non‐Newtonian fluids by use of a generalized form of the conventional power‐number–Reynolds‐number plot for Newtonians.Flat‐bladed turbines from 2 to 8 in. in diameter were used exclusively. Tank diameters ranged from 6 to 22 in. and power inputs from 0.5 to 176 hp./1,000 gal. The study encompassed a 130‐fold range of Reynolds numbers in the laminar and transition regions. The results to date indicate that power requirements for the rapid mixing of non‐Newtonian fluids are much greater than for comparable Newtonian materials.
Calculated performance of a dissolved—gas‐drive reservoir by a phase‐behavior method
Authors: Brinkman F. H. , Weinaug C. F. 
Published: June 2004

AbstractA phase‐behavior approach to the prediction of the performance characteristics of a dissolved‐gas–drive reservoir is unique in that the problem of choosing flash, differential, or composite‐solution gas‐oil ratios and formation‐volume factors has been circumvented. Data required are a compositional analysis of the reservoir fluid, the bubble point of this fluid, and the relative‐permeability curves for the reservoir rock.Gas‐oil ratios and formation‐volume factors were calculated under conditions duplicating the performance of the reservoir. A comparison was then made between these results and those obtained by calculations involving a differential, a flash, and a composite process. A vital factor in the solution of the problem is the accuracy of the calculated equilibrium constant. Agreement within 3% was obtained when a calculated differential formation‐volume curve was compared with an experimentally determined curve.
Heat transfer in the critical region
Authors: Bringer R. P. , Smith J. M. 
Published: June 2004

AbstractHeat transfer coefficients were measured experimentally for carbon dioxide in turbulent flow in an 0.18‐in. I.D. pipe. The pressure was 1,200 lb./sq. in. abs. and the bulk temperature varied from 70° to 120°F. In this critical region the coefficients between fluid and tube wall ranged from 300 to 2,600 B.t.u./(hr.)(sq. ft./°F.) over a Reynolds number interval of 30,000 to 300,000.Existing empirical and semitheoretical correlations were found inadequate in this region, where the thermal conductivity, viscosity, density, and specific heat are all varying rapidly and nonuniformly with temperature. A method of integrating the heat and momentum transfer equations with variable physical properties, recently proposed by Deissler, was applied to the experimental data and found to fit well. The application required extensive calculations, which were carried out with an Electrodata digital computer.A simplified procedure was proposed for estimating heat transfer coefficients in the critical region by using a semitheoretical equation developed for zero heat flow. Simple rules were suggested for estimating the temperature at which to evaluate the physical properties when this equation is applied to the realt case of finite heat transfer. The method worked well when compared with the computed heat transfer coefficients of Deissler for supercritical wate but showed about 30% deviation when compared with the carbon dioxide results. This discrepancy is believed due to the fact that the carbon dioxide was very close to the critical point (reduced pressure = 1.1) but the water was somewhat further removed (reduced pressure = 1.6).
Viscosity of suspensions of spherical and other isodimensional particles in liquids
Authors: Ting Andrew Pusheng , Luebbers Ralph H. 
Published: June 2004

AbstractThe viscosity of a suspension is related to the properties of the suspending liquid and the suspended particles by measuring the viscosity of suspensions made up of closely sized materials such as glass spheres, plastic Zeolite spheres, blasting sand, and salt cubes in a wide range of concentrations in liquids of varying properties made up of castor oil, tetrabromoethane and carbon tetrachloride, or corn syrup and water. The measurements were made under carefully controlled conditions by means of a Brookfield viscometer, and the reproducibility of results was demonstrated by repetitive runs.Equations are derived to describe the viscosities of these various suspensions in terms of the viscosity and density of the suspending liquid and of the shape, size distribution, density, and concentration of solid particles. The range of concentration covered is from infinite dilution to near infinite viscosity.The results obtained can best be explained by postulating nonuniform distribution of particles in a suspension in a network of tetrahedral and simple cubical packings.
Dynamics of liquid agitation in the absence of an air‐liquid interface
Authors: Laity David S. , Treybal Robert E. 
Published: June 2004

AbstractThe dynamics of agitating single‐ and two‐phase liquid mixtures in the absence of an air‐liquid interface was compared with that of similar systems with an interface. Two geometrically similar cylindrical vessels, 12 and 18 in. in diameter respectively, were used, each fitted with a similar six‐bladed, disk‐turbine impeller.New general correlation curves of power number with Reynolds number are presented which show that elimination of the air‐liquid interface makes it possible to attain dynamic similarity in scale‐up in unbaffled vessels but makes little difference in baffled vessels.
Vapor‐liquid equilibria of Benzene–n‐hexane and benzene‐cyclohexane systems
Authors: Rao V. N. Kumarkrishna , Swami D. R. , Rao M. Narasinga 
Published: June 2004

AbstractVapor‐liquid equilibria of two binary systems, benzene–n‐hexane and benzene‐cyclohexane, were measured at pressures from 4 to 18 atm. The three‐constant Redlich‐Kister equation was found satisfactory for correlation.With the benzene‐n‐hexane system no azeotrope occurred; with the benzene‐cyclohexane system an azeotrope appeared, and the mole fraction of cyclohexane in it diminished with increase in pressure. Lack of correction for fugacity in the vapor phase introduced a maximum error of 4% in activity coefficients at highest pressure.
Diffusion in three‐component gas mixtures
Authors: Toor H. L. 
Published: June 2004

AbstractA solution to the Stefan‐Maxwell diffusion equations for equimolal countercurrent diffusion in a three‐component gas mixture is obtained which is similar in form to Gilliland's equation for diffusion of two gases through a third inert gas. The important features of both types of diffusion are investigated and the conditions under which the following phenomena occur are determined: (1) diffusion barrier (the rate of diffusion of a component is zero even though its concentration gradient is not zero); (2) osmotic diffusion (the rate of diffusion of a component is not zero even though its concentration gradient is zero); (3) reverse diffusion (a component diffuses against the gradient of its concentration).A generalized driving force which describes these phenomena is introduced, and approximate equations are developed which give the individual rates of diffusion directly.
Simplified flow calculations for tubes and parallel plates
Authors: Rothfus R. R. , Archer D. H. , Klimas I. C. , Sikchi K. G. 
Published: June 2004

AbstractThe effective correlations of turbulent velocities and friction losses for tubes and parallel plates recently published have been analyzed further in order to simplify their use and to extend the range of Reynolds number.Working diagrams have been developed from which turbulent friction losses and local velocities for tubes and parallel plates can be calculated without interpolation or trial‐and‐error procedures. Tentative values of parallel‐plate friction factors and average‐to‐maximum velocity ratios in the transition region are also included, and new experimental values of the velocity ratio in smooth tubes are reported. The working diagrams permit more rapid, accurate, and consistent calculations of fluid behavior to be made over a wider range of operating conditions than was previously possible.
Effect of wall roughness on convective heat transfer in commercial pipes
Authors: Smith J. W. , Epstein Norman 
Published: June 2004

AbstractHeat transfer and friction measurements were made for air flow through a smooth copper pipe and six other commercial pipes, with a ratio of diameter to equivalent sand roughness varying from 640 to 64. The Reynolds number range was 10,000 to 80,000. Though some increase in heat transfer coefficients with roughness was found, the heat transmission per unit power loss always decreased.The momentum–heat‐transfer anlogies of Reynolds and Colburn are shown to be inadequate for handling the experimental data. Those of Prandtl and Taylor, von Kármán, and Pinkel fail to show a required Reynolds number dependence ofjhwhen friction factor has become independent of Reynolds number for a rough pipe. Martinelli's equation shows such dependence and, even in approximate form, gives good prediction of the experimental results.
Volumetric and phase behavior in the hydrogen–n‐hexane system
Authors: Nichols W. B. , Reamer H. H. , Sage B. H. 
Published: June 2004

AbstractIn spite of the importance of hydrogenation procesing operations in the refining of petroleum there are only limited experimental volumetric and phase equilibrium data concerning mixtures of hydrocarbons and hydrogen. An investigation of the volumetiric and phase behavior of the hydrogen–n‐hexane system was therefore undertaken.The experimental study involved measurements of the specific volume of four mixtures of hydrogen and n‐hexane at eight temperatures between 40° and 460°F. for pressures up to 10,000 lb./sq. in In addition, the composition of the gas phase in heterogeneous mixtures was determined at six temperatures within the interval mentioned above for pressures as high as 10,000 lb./sq. in.Little about this system was found to be qualitatively unusual except that the critical pressure exceeded 10,000 lb/sq. in. at all temperatures below 340°F. As would be expected, the dew‐point gas was rather lean in n‐hexane for temperatures below 220°F. and at pressures above 100 times the vapor pressure of n‐hexane throughout the pressure range covered by this study.
Some remarks on longitudinal mixing or diffusion in fixed beds
Authors: Aris Rutherford , Amundson Neal R. 
Published: June 2004

AbstractIt has been shown both theoretically and experimentally that the radial Peclet number in a packed bed approaches about 11. If it is assumed that the interstitial volume of the bed forms mixing cells, then a comparison of the solutions obtained from the mixing and turbulent diffusive mechanisms shows that the axial Peclet number for agreement of the two must be about 2, as a limiting case for high Reynolds numbers. This is substantiated by experiment.
Fluidization and sedimentation of spherical particles
Authors: Hanratty Thomas J. , Bandukwala Abdemannan 
Published: June 2004

AbstractData are presented in support of an expression describing the relation between the sedimenting velocity or the fluidizing velocity and the fraction voids. This expression which contains no empirical constants may be obtained by considering a particle in a fluid having the average properties of the suspension. Stokes's law is used to calculate the force on the particle, and an equation derived by Vand is used to describe the viscosity of the suspension. The equation based on this model is valid for particle Reynolds numbers less than 0.07. The model may be used as an approximation of bed behavior at higher Reynolds numbers by application of a correction to Stokes's law.
Nusselt values for estimating turbulent liquid metal heat transfer in noncircular ducts
Authors: Hartnett James P. , Irvine Thomas F. 
Published: June 2004

AbstractA simple expression for estimating the turbulent forced‐convection heat transfer performance of liquid metals flowing through noncircular ducts is presented. This equation requires the knowledge of the slug Nusselt number evaluated for the specific geometry and for the pertinent boundary conditions. Such Nusselt values are presented herein for a number of technically important geometries. One check on the heat transfer prediction given by Equation (4) is in the case of an annular duct with constant heat flow through the outer wall with the inner wall insulated, for which experimental data exist. The prediction agrees within 20% with the experimental data.Several possible boundary conditions that may exist in noncircular cross sections are throughly discussed, and it is hoped that as a result this paper may serve to clarify some of the confusion existing in the literature.
Surface tension of acetone‐water solutions up to their normal boiling points
Authors: Howard Katherine S. , McAllister R. A. 
Published: June 2004

AbstractThe surface tensions against air of acetone‐water solutions have been measured over the entire composition range from 20°C. to generally within 1° to 10°C. of the normal boiling points. The capillary‐height method was employed and the results are thought to be accurate to better than ±0.5%.
Drying of sand on a hot surface
Authors: Ludt R. W. 
Published: June 2004

AbstractConstant layer moisture at the hot surface is found to exist during the constant‐rate period of drying of sand on a hot surface in still air. It accounts not only for the constantrate period of drying itself but also largely for the length of the period.Temperature of the air‐surface interface usually has minor effects on the rate of vaporization because equilibrium between vapor and the bed is not established during periods of rapid vaporization.Numerical relationships have not been established.
Catalyzed gas‐liquid reactions in trickling‐bed reactors
Authors: Babcock B. D. , Mejdell Glør T. , Hougen O. A. 
Published: June 2004

AbstractKinetic studies were made in a differential flow reactor of the hydogenation of α‐methyl‐styrene with the liquid trickling over a bed of catalyst pellets countercurrent to a stream of hydrogen. The catalysts consisted of palladium, platinum, rhodium, ruthenium, and nickel supported on the external surfaces of aluminal pellets.With palladium at pressures above 3 atm. the apparent rate‐controlling step was a surface reaction between dissociated hydrogen and α‐methylstyrene both adsorbed on different type of active sites. Below 3 atm. pressure the reactants competed for similar active sites. With platinum the apparent rate‐controlling step was a surface reaction between dissociated hydrogen and α‐methylstyrene on similar active sites. Rhodium and nickel catalyzed the polymerization α‐methylstyrene together with slow hydrogenation. Ruthenium had negligible activity for catalyzing the hydrogenation under the moderate conditions used in this work.In all cases mass transfer resistances were negligible.
Prediction of cake‐washing results with continuous filtration equipment
Authors: Choudhury A. P. R. , Dahlstrom D. A. 
Published: June 2004

AbstractThis paper proposes a theory of filter‐cake washing on continous filtration equipment based upon the assumption that mixing of the strong liquor and wash fluid is controlling. The theory can be conventiently applied to experimental filtration leaf tests for determining wash efficiency and is easily extrapolated to full‐scale results with the normally experienced uneven cake thickness and wash‐fluid distribution taken into account.To obtain the necessary wash‐fluid volume for proper soluble removal, a correlation method of wash time as a function of wash ratio with parameters of cake‐formation time has been derived from commonly accepted filtration theory. Experimental and plant data indicate a close agreement with the theory, and the method can be employed to predict filtration rate as a function of wash ratio. A typical illustration has been given to determine filtration requirements for recovering soluble uranium after leaching of the ore by continuous filtration. Washing rate was proved to be conrolling, and this design based only on cake‐formation rate would yield insufficient wash ratios and excessive soluble uranium loss. Final filter and flow‐sheet design must be based on uranium recovery which can be predicted by the proposed methods.
Axial mixing in pipes
Authors: Tichacek L. J. , Barkelew C. H. , Baron Thomas 
Published: June 2004

AbstractThe problem of axial mixing in straight pipes is analyzed by a modification of G. I. Taylor's analysis. The treatment presented here includes the effect of both Schmidt and Reynolds numbers throughout the turbulent‐flow range. All applicable data on flow of gases and liquids are found to confirm the validity of the method.The analysis indicates that axial mixing increases rapidly as the flow approaches the laminar region, especially for liquids, and that pipe roughness causes a relatively small increase in axial mixing. Turbulent eddy diffusion in the axial direction has a negligible effect.The results of the analysis are applicable to those systems wherein the kinematic viscosity of the flowing mixture does not vary greatly from one region to another and in which the concentration region of interest is spread out along a sufficient length of pipe. These limitations are broad enough to permit most practical problems to be treated by the method.
Reaction of porous solids
Authors: Petersen E. E. 
Published: June 2004

AbstractA method is presented for the analysis of a reaction between a porous solid and a gaseous reactant where the kinetic expression is linear in the concentration and where appreciable concentration gradients are established in the pore system as a result of diffusive transport rate. Two cases are treated mathematically: a single cylindrical pore initially of uniform diameter and a porous solid initially containing uniform cylindrical pores with random intersections. The mathematical solutions to the latter case are used to interpret the experimental results reported in the literature on the gasification of graphite rods with carbon dioxide. Values of the computed effective diffusivity are an order of magnitude smaller than the bulk diffusivity at the same temperature and pressure.
Vapor‐liquid—equilibrium data for the ternary system cyclohexane‐heptane‐toluene
Authors: Myers H. S. 
Published: June 2004

AbstractPrevious papers have reported equilibrium data for the binary systems cyclohexaneheptane, heptane‐toluene, and cyclohexane‐toluene. This present study gives similar data for the ternary system cyclohexane‐heptane‐toluene and compares the activity coefficients with those predicted from the three limiting binaries.The ternary activity coefficients fall well in line between the limiting‐binary data. Distribution is about as would be predicted by the ternary Margules equations. As an approximation, if the coefficients are plotted as a function of the aromatic concentration only, without consideration of the ratio of naphthenes to paraffins, reasonably good correlation is observed.