bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion exchange equilibria in a ternary system
Authors: Pieroni Leonard J. , Dranoff Joshua S. 
Published: June 2004

AbstractA study has been made of the cation exchange equilibria between Dowex 50W‐X8 resin and aqueous solutions of copper nitrate, nitric acid, and sodium nitrate in binary and ternary mixtures. Experiments were carried out at room temperature with solutions having total cation concentrations of approximately 0.1N, 0.05N, and 0.01N. It was found that the equilibria for any two ions were essentially the same in binary and ternary mixtures. Moreover single valued selectivity coefficients were determined which characterize these data quite well for all three concentration levels. This makes possible the complete description, for engineering purposes, of ternary equilibria in terms of the simpler and more accessible binary exchange reactions, as previously suggested (1).
High‐flux heat transfer characteristics of pure ethylene glycol in axial and swirl flow
Authors: Gambill W. R. , Bundy R. D. 
Published: June 2004

AbstractMeasurements were made of heat transfer rates and peak heat flux for atmospheric‐pressure pool boiling, and of adiabatic and diabatic friction factors, nonboiling and local‐boiling heat transfer rates, and burnout heat fluxes for both axial‐ and twisted‐tape swirl‐flow forced convection of pure ethylene glycol. Test sections were electrically heated copper, 347 stainless steel, and A‐nickel tubes.Both axial‐ and swirl‐flow friction factors are in good agreement with available generalized correlations. At the higher Reynolds numbers and heat fluxes axial‐flow nonboiling heat transfer coefficients show a dependence of Nusselt number onNRe0.98rather than the traditionalNRe0.80. Swirl‐flow nonboling heat transfer coefficients from both the glycol data and previously obtained water data are satisfactorily correlated by a single equation. Nucleate‐boiling heat transfer coefficients for both ethylene glycol and water fall approximately 50% above Kutateladze's suggested average line. The atmospheric‐pressure pool‐boiling peak flux is 168,000 Btu/hr. sq. ft. Forced‐convection burnout heat fluxes are correlated in a number of ways, including a new additive method which appears to be generally applicable to a large variety of coolants, geometries, and flow conditions.
High‐pressure phase‐equilibrium studies by gas‐liquid partition chromatography
Authors: Stalkup Fred I. , Kobayashi Riki 
Published: June 2004

AbstractAn elution gas that might be either a single component or a binary mixture, but which in any case was appreciably soluble in the fixed liquid phase on the column matrix material, was used to form a multicomponent liquid phase within the chromatographic column. Vapor‐liquid equilibrium was studied both with the solute of interest at essentially infinite dilution conditions and with the solute present at some finite concentration in both phases. From the elution data vapor‐liquid equilibrium ratios, or K values, were calculated by expressions relating the solute retention volume to the solute K value in the vapor‐liquid system maintained within the chromatographic column.Data were taken for the solutes ethane, propane, and n‐butane at infinite dilution in the methane‐n‐decane system at 160°, 70°, 40°, 0°, and −20°F from 20 to 2,000 lb./sq. in.; for propane at infinite dilution in methane‐n‐hexadecane at 70°F and 20 to 200 lb./sq. in.; and propane in the system methane‐propane‐n‐decane at 40°F from 20 to 460 lb./sq. in. The univariant gas‐liquid‐solid locus was experimentally determined for the methane‐n‐decane binary system.The chromatographically determined K values for n‐butane at infinite dilution in methane‐n‐decane were compared with published static equilibrium values and found to be in substantial agreement. Activity coefficients calculated from the data for all the solute isotherms were compared at atmospheric pressure with the results of the Brönsted and Koefoed relation for estimating activity coefficients of hydrocarbons, and close agreement was again found.
Dynamics of liquid‐solid fluidized bed expansion
Authors: Fan Liang‐Tseng , Schmitz James A. , Miller Eugene N. 
Published: June 2004

AbstractThe dynamic response of height in liquid‐solid fluidized beds to a change in fluidizing valocity was considered. A linearized model was developed such that the time constant for the system could be estimated with the parameters characterizing the system.Spherical particles, with sizes ranging from 6 to 7 to 70 to 80 mesh and densities ranging from 1.08 g./cc. to 2.5 g./cc., were fluidized by water in a 2‐in. diameter glass column. The experimental response to step and rectangular pulse inputs in fluidizing velocity were measured and frequency response data were also obtained.Agreement between the experimental data and the model was quite reasonable in view of the known nonlinearity of fluidization systems. These results show that for control purposes the system behaves as a first order time constant process.
An experimental study of the unsteady nature of the viscous sublayer
Authors: Reiss L. Philip , Hanratty Thomas J. 
Published: June 2004

AbstractMeasurements of the fluctuations in the mass transfer rate to small circular electrodes mounted flush with a pipe wall are used to study the unsteady nature of the viscous sublayer. These fluctuations in the mass transfer rate reflect flow fluctuations at y+ ca 0.5. From these measurements it is concluded that the flow disturbances are elongated in the direction of flow and are characterized by a time scale equal to the diameter of the pipe divided by the bulk average velocity. An attempt is made to relate the mass transfer fluctuations to the fluctuation in velocity gradient at the wall. It is concluded that the ratio of the root‐mean‐square fluctuating velocity gradient at the wall to the average velocity gradient at the wall is at least 0.11.
Eddy transport in liquid‐metal heat transfer
Authors: Dwyer O. E. 
Published: June 2004

AbstractThere are certain semiempirical equations for estimating heat transfer coefficients for liquid metals flowing through regular shapes. These contain the factorψ, which is the average, effective value of the ratio of the eddy diffusivity of heat transfer to that for momentum transfer. The main problem in liquid metal heat transfer has been to evaluate this quantity.
Fluid flow and convective‐radiative energy transfer in a parallel‐plate channel under free‐molecule conditions
Authors: Sparrow E. M. , Jonsson V. K. 
Published: June 2004

AbstractThe flow of a highly rarefied gas in a parallel‐plate channel and the transfer of heat owing to simulataneous thermal radiation and free‐molecule convection has been investigated analytically. The analysis is facilitated by analogies which exist between the processes. The mass throughflow has been determined as a function of the temperatures and pressures of the system and of the channel dimensions. The heat transfer analysis is first carried out in general and then specialized to the boundary conditions of uniform wall temperature, uniform wall heat flux, and the adiabatic wall. It was found that at temperature levels corresponding to room temperature and above, the results for the combined convective‐radiative transport differed little from those for a purely radiative transport.
Mass transfer in the laminar radial wall jet
Authors: Scholtz M. T. , Trass Olev 
Published: June 2004

AbstractData are reported for mass transfer from a flat plate under the influence of a laminar, radial wall jet initiated by a free jet of water.Present theory has been extended to mass transfer for the case of the above wall jet. An exact solution of the mass transport equation was obtained as well as an approximate solution of the integral mass balance equation, using assumed forms of the velocity and concentration profiles.Point mass transfer data were obtained by measuring the thickness decrease of coatings of acetanilide and benzoic acid. In the Reynolds number range of 1,000 to 3,000 (based on the nozzle diameter) data were in good agreement with theory. Boundary‐layer separation and the formation of a toroidal vortex were observed at lower Reynolds numbers. Dye streak photographs of these vortices were obtained and correlated with mass transfer data in this region.
Pulsation in a fixed‐bed reactor
Authors: Biskis E. G. , Smith J. M. 
Published: June 2004

AbstractRates of reaction were measured for the liquid phase hydrogenation of α‐methyl styrene in a pulsed, fixed bed reactor. Data at 80 psia and 55°C., using 0.5 wt. % palladium on ⅛″ Al2O3spheres as a catalyst, indicated that the mass transfer of dissolved hydrogen to the catalyst surface controlled the rate of conversion of styrene to cumene. Hence the data were employed to calculate mass transfer coefficients as a function of pulse frequency and amplitude.Comparison with non‐pulse data at the same Reynolds number showed that pulsation increased the mass transfer rate as much as 80%.
Heat transfer in the critical region—temperature and velocity profiles in turbulent flow
Authors: Wood Rodney D. , Smith J. M. 
Published: June 2004

AbstractUnusual heat transfer phenomena have been observed between solid surfaces and fluids near their thermodynamic critical point. To understand better these phenomena temperature and velocity profiles and local heat transfer coefficients were measured for turbulent flow of carbon dioxide in a tube at 1,075 lb/sq. in. abs. (pc= 1,071). The results indicate a severe flattening of the radial temperature profiles, a maximum in the velocity profile between the wall and the tube axis, and a maximum inh' when the bulk fluid temperature passes through the transposed critical temperature.The results can be explained qualitatively by considering the variation with temperature of thermal conductivity near the tube wall and specific heat in the turbulent core.
Diffusion and reaction in porous glass
Authors: Rao M. Raja , Smith J. M. 
Published: June 2004

AbstractConstant pressure diffusion rates of hydrogen through Vycor porous glass were measured in nitrogen and neon systems. The experimental diffusivities are less than those predicted by the random pore model indicating that this model may not be satisfactory for a low porosity material such as Vycor. Interpreted in terms of an assembly of parallel pores the data suggest a tortuosity factor of approximately 2.4.Rate data for the ortho‐para hydrogen reaction were also measured at −196°C. and 1 atm. The catalyst 2% nickel/Vycor was found to have pore properties (area, mean pore size, pore volume) similar to that of plain Vycor. Predicted effectiveness factors using the experimental diffusion data were in good agreement with values determined experimentally. The latter were evaluated from rate measurements on both pellet and particles (58 μ mean diameter).
Solution of the linearized equations of multicomponent mass transfer: I
Authors: Toor H. L. 
Published: June 2004

AbstractThe linearized equations of diffusion in a multicomponent system with flow and chemical reaction are shown to reduce to a set of equivalent binary diffusion equations.The concentrations and fluxes in a multicomponent system are described by linear combinations of appropriate solutions to the binary diffusion equation for steady and unsteady diffusion and convective mass transfer, laminar or turbulent.The rate of transfer of each component in a nonreacting n component system is a linear combination of the n‐1 independent driving forces with proportionality constants which depend upon the multicomponent diffusion coefficients and appropriate binary mass transfer coefficients, while the concentration profile of each component is a linear combination of appropriate binary concentration profiles with proportionality constants which depend upon the multicomponent diffusion coefficients and the characteristic displacement from equilibrium of each component.The linearized theory is exact for small changes in concentration but needs further testing when the concentration changes and fluxes are large.
Resistance to mass transfer inside droplets
Authors: Skelland A. H. P. , Wellek R. M. 
Published: June 2004

AbstractAn experimental investigation of the effects of various physical properties on the dispersedphase mass transfer coefficient was carried out for both nonoscillating and oscillating liquid droplets falling in a single stream through stationary continuous liquid phases. The Colburn and Welsh two‐component technique was used to isolate and measure the disperesed‐phase resistance to mass transfer. This technique limited the experimental study to systems with low interfacial tensions, between 2.5 and 5.8 dynes/cm. Solute was transferred into the droplets, and the droplet concentration was measured after droplet‐fall heights ranging from about 2 cm. to 103 cm. Precautions were taken to minimize end effects.The experimental mass transfer rates on nonoscillating droplets in general were greater than that predicted by the Kronig and Brink model for nonoscillating circulating droplets. Experimental Sherwood numbers for four liquid systems were correlated in terms of a relationship involving the dispersed‐phase Schmidt number, the Weber number, and the time group, 4DLtc/d2e, which allows for the time dependency of the transfer mechanism. The data were correlated with an average absolute deviation of 34%. The Kronig and Brink and Newman relations fitted the experimental data for nonoscillating droplets with an average absolute deviation of 46 and 54%, respectively. The experimental results for the oscillating droplets were correlated by two relationships with an average absolute deviation of 10.5%. The Handlos and Baron model fitted the experimental results for oscillating droplets with an average absolute deviation of 38%.
Kinetics of hydrogen reduction of ferrous oxide in a batch fluidized bed: Effects of mass velocity and pressure
Authors: Ahner W. D. , Feinman Jerome 
Published: June 2004

AbstractThe kinetics of reduction of ferrous oxide with hydrogen were studied in a 1½‐in. diameter isothermal batch fluidized reactor. The effects of mass velocity and pressure on the reduction path were investigated over the ranges 5.3 to 19.2 moles/sq.ft.hr. and 1.3 to 5.4 atm. at 1,000° and 1,300°F. The results are correlated by means of instantaneous oxygen balances on the assumptions that there are no oxygen concentration gradients in the solid phase, that the distribution of residence times for the gas flow is represented closely by assuming complete mixing, and that the reduction rate is controlled at the oxide‐metal interface. The rate of reduction increased with increasing pressure and mass velocity. An excellent correlation was obtained for the program at 1,000°F. At 1,300°F. sintering and grain growth of the product layer complicated the reduction process, and a correlation was not obtained. Application of the results to the design of commercial fluidized‐reduction processes is discussed qualitatively.
Thermodynamics and interfacial tension of multicomponent liquid‐liquid interfaces
Authors: Shain Stephen A. , Prausnitz J. M. 
Published: June 2004

AbstractSternling and Scriven have shown that the derivative of interfacial tension with respect to solute concentration is an important parameter influencing the hydrodynamic stability at an interface across which mass transfer is taking place. This work is concerned with a molecular thermodynamic study of that derivative.With surface thermodynamics and an extension of the solution theory of Schuchowitzky, an expression is derived which relates the interfacial tension to the solute concentration in terms of physically meaningful parameters. These in turn are related to molecular properties of the solute and solvent species.New experimental data are reported for the interfacial tension of nine ternary systems; these consist of an aqueous phase and an organic phase where both phases are dilute solutions of an alcohol. The organic phases are hexane, benzene, and carbon tetrachloride and the alcohols are methanol, ethanol, and n‐propanol.The theoretical equations predict interfacial tensions which are in good agreement with the new experimental results and with experimental data of Vignes on aqueous‐organic systems which are dilute solutions of organic acids.
Formation of air bubbles at orifices submerged beneath liquids
Authors: Sullivan S. L. , Hardy B. W. , Holland C. D. 
Published: June 2004

AbstractThe results of two investigations are reported. Air bubbles were formed at orifices submerged beneath each of fourteen liquids. The surface tension of the liquids varied from 17.8 to 72.4 dynes/cm., and the viscosities ranged from 0.436 to 713 centipoise. In the first investigation, air bubbles were formed at orifices at various angles of inclihation. Orifice diameters ranging from 0.159 to 0.396 cm. were employed. The air‐flow rate was varied from 0.1 to 100 cc. (at standard conditions)/sec. The results were obtained with two different apparatuses by three independent investigators.In the second investigation, the effect of the velocity of a liquid flowing past a horizontal, submerged orifice on the formation of air bubbles was determined. Liquid velocities ranging from 0.34 to 2.5 cm/sec., which spanned the region of laminar flow, were employed. Orifice diameters ranged from 0.15875 to 0.3175 cm., air‐flow rates from 0.5 to 100 cc/sec. (at standard conditions).It was found that the bubble formation observed in each of these investigations could be correlated with the physical variables of the system by the application of Newton's second law of motion to the bubble at the instant just prior to its release from the orifice.
Tube flow of non‐Newtonian polymer solutions: PART I. Laminar flow and rheological models
Authors: Meter Donald M. , Bird R. Byron 
Published: June 2004

AbstractA correlation of turbulent tube‐flow friction factors for non‐Newtonian polymer solutions, based upon the fluid property τ1/2; defined in Part I, has been found to represent data taken on seven solutions of Natrosol hydroxyethylcellulose in ½‐ and 1‐in, I.D. smooth tubes, with an average accuracy of 10.8%. Also, for these seven solutions, this correlation gives somewhat more accurate predictions of the point of transition into turbulent flow than are made by the Ryan‐Johnson stability theory.The correlation must be considered only provisional, however, because it does not simplify to the limiting case of extremely dilute solutions. Plausible extensions based on models of steady‐flow non‐Newtonian viscosity behavior, and other possible correlation schemes utilizing viscoelastic fluid properties, are briefly discussed.
Effective binary diffusion coefficients in mixed solvents
Authors: Tang Y. P. , Himmelblau D. M. 
Published: June 2004

AbstractThe diffusion of carbon dioxide through ethanol‐water, benzene toluene, and carbon tetrachloride benzene was studied over the entire range of compositions for the solvent pairs. The results were interpreted in terms of an effective binary diffusion coefficient. Two semiempirical correlations were derived with the aid of absolute reaction rate theory to predict the effective binary diffusion coefficient from the binary diffusion coefficients of the solute in the individual pure solvents. These equations, although only crude approximations, reproduced the experimental data for six diffusion systems fairly well, including the highly nonideal solvent mixture ethanol‐water.
Film boiling of nitrogen with suction on an electrically heated porous plate
Authors: Wayner P. C. , Bankoff S. G. 
Published: June 2004

AbstractExperimental equipment to study the film boiling of liquid nitrogen on a porous heat source with vapor suction was developed. The electrically heated element was a 3.69 in. sintered stainless steel screen, which was also used as a resistance thermometer in conjunction with an a.c. potentiometric circuit. In preliminary work, this mode of heat transfer was unstable, but stability was achieved by placing a porous flow control element on the liquid side of the heater. It was found that the Nusselt number was a function of only the Reynolds number; the heat transfer coefficient was increased by a factor of as much as 2.5 over the heat transfer coefficient in normal film boiling; it was possible to vary independently any two of the three variables, heat flux, flow rate through the plate, and temperature difference; and the generated vapor was considerably superheated. Fluctuations in the local surface temperature were measured in film boiling from both porous and nonporous flat plates, indicating that momentary solid‐liquid contacts can occur, for all practical purposes, in film boiling.
Liquid atomization in a high intensity sound field
Authors: Wilcox R. L. , Tate R. W. 
Published: June 2004

AbstractHigh intensity sound was investigates as a means for liquid breakup. Sonic generators provided energy to atomize liquid introduced near the sound source. Droplet size was measured at several conditions of air and liquid flow for sound intensities ranging up to 160 decibels.Atomization was good at low liquid flows but became rahter coarse as flow rate increased. The droplet size distributions were not uniform. No improvement in breakup could be attributed directly to the sonic compressions and rarefactions beyond that normally produced by the tearing action of air in conventional two‐fluid atomizers at comparable air/liquid ratios.
Thermal conductivity of porous catalysts
Authors: Butt John B. 
Published: June 2004

AbstractA random pore model of catalytic pore structure is applied to the determination of the thermal conductivity of porous catalytic solids. The low thermal conductivities reported for such materials are explained by considering the microporous particles to consist of a packed bedlike assembly of smaller particles; heat transfer through the solid fraction occurs by conduction through individual small particles in contact with other particles. An expression for the effective thermal conductivity of a gas in the region between ordinary thermal conduction and free molecule conduction is used in determination of heat conduction through the void volume. Agreement of the theory with experimental data on alumina and silver catalysts over a wide range of conditions is good.
Thermodynamics of mixed‐gas adsorption
Authors: Myers A. L. , Prausnitz J. M. 
Published: June 2004

AbstractA simple technique is described for calculating the adsorption equilibria for components in a gaseous mixture, using only data for the pure‐component adsorption equilibria at the same temperature and on the same adsorbent. The proposed technique is based on the concept of an ideal adsorbed solution and, using classical surface thermodynamics, an expression analogous to Raoult's law is obtained. The essential idea of the calculation lies in the recognition that in an ideal solution the partial pressure of an adsorbed component is given by the product of its mole fraction in the adsorbed phase and the pressure which it would exert as a pure adsorbed component at the same temperature and spreading pressure as those of the mixture. Predicted isotherms give excellent agreement with experimental data for methane‐ethane and ethylene‐carbon dioxide on activated carbon and for carbon monoxide‐oxygen and propane‐propylene on silica gel. The simplicity of the calculation, which requires no data for the mixture, makes it especially useful for engineering applications.
Lateral transport in a fluidized‐packed bed: Part I. Solids mixing
Authors: Gabor John D. 
Published: June 2004

AbstractA theory was developed to relate the average velocity of a fluidized particle to the fluidizing gas velocity and the minimum fluidization velocity. The development of this relationship was based on a model for particle movement caused by gas bubbles rising through the fluidized bed. The diffusivity for lateral solids mixing in a fluidized‐packed bed can then be determined from the average particle velocity and the diameter of the fixed packing by the random walk theory.