bluuebunny/crossref_metadata_2025_split huggingface dataset:
Equilibrium rations of hydrogen and the critical loci of hydrogen‐paraffin mixtures
Authors: Lenoir J. M. , Hipkin H. G. 
Published: June 2004

AbstractThis paper presentes a correlation to predict the equilibrium ratios of hydrogen in hydrocarbon mixtures by use of the parameters of pressure and convergence pressure. Also a procedure to predict convergence pressures of hydrogen‐containing mixtures was developed from a correlation of critical loci. With the predicted convergence pressure the measured values of hydrogen equilibrium ratios in binary hydrogen‐paraffin mixtures were predicted with a statistical deviation of 8.1% for 237 measurements. Including hydrogen‐olefin and multicomponent mixtures of hydrogen, paraffins, and olefins, the statistical deviation was found to be 11.3% for a total of 375 comparisons with measured values of hydrogen equilibrium ratios.
Graphical solution of turbulent‐flow diffusion equations
Authors: Longwell P. A. 
Published: June 2004

AbstractLinear partial‐differential eqations are often encountered when thermal or material diffusion in flowing systems is considered. Analytic solutions of such equations are known for only the simplest situations. In two examples a graphical method of solution is presented and demonstrated which makes feasible, without excessive labor or special computing facilities, the use of available knowledge concerning turbulent flow in the prediction of thermal or material transfers in complex situations involving linear steady flow.
Studies on effective thermal conductivities in packed beds
Authors: Yagi Sakae , Kunii Daizo 
Published: June 2004

AbstractApplying both their own assumptions and the mechanism of lateral mixing proposed by Ranz (20), the authors obtained theoretical formulas for effective thermal conductivities ke in packed beds. Previously reported experimental data were analyzed with these equations, and the usable data for predicition of ke were shown.In order to see the influence of both packing characteristics and temperature on the effective thermal conductivities, experimental data were obtained with air for beds with various kinds of packing, i.e., iron spheres, porcelain packings, cement clinker, insulating fire brick, and Raschig rings. Correlation of these data with Equation (15) showed that this equation adequately expressed the heat transfer mechanisms in packed beds with motionless gases, especially at hight temperatures.
Thermal and material transfer in turbulent gas streams: Local transport from spheres
Authors: Hsu N. T. , Sage B. H. 
Published: June 2004

AbstractLocal convective thermal transfer is difficult to predict for nonuniform three‐dimensional boundary flows. Direct measurements of local transfer from objects of practical interest are therefore useful in the prediction of thermal transfer and in an understanding of multidimensional boundary flows.Measurements of the gross and local transfer were made upon a silver sphere 0.5 in. in diameter and a ceramic porous sphere of the same size from whichn‐heptane was permitted to evaporate. The air stream had a level of turbulence of approximately 5.4% and only small variation in velocity with position. Temperature distributions in the boundary flows around these spheres were determined, and from these distributions local transfer coefficients were established for the forward hemisphere. The gross transfers were established from the electrical energy added to the silver sphere and from the quantity ofn‐heptane evaporated from the porous sphere.The local thermal transfers were in reasonable agreement with some of the theoretical analyses based upon a three‐dimensional laminar‐boundary layer. Satisfactory agreement was obtained between spatial integration of the local transfer and the simultaneously measured over‐all values. These, in turn, were in fair agreement with correlated values of the gross thermal and material transfer from spheres.
Unsteady state heat transfer in stationary packed beds
Authors: Reilly Park M. 
Published: June 2004

AbstractA new solution is presented of the differential equations describing unsteady state heat transfer in stationary beds of small granular solid particles through which a fluid is flowing. Arbitrary initial solid temperature distribution and arbitrary variation of inlet gas temperature are allowed. The solution presented appears easier to apply in practice than those previously published and affords an example of the versatility of Fourier integrals and series. An application of the solution to the regeneration of Dow type‐B butylene dehydrogenation catalyst is described.
Thermal resistance of an eddy
Authors: Clark L. G. , Hagerty W. W. 
Published: June 2004

AbstractBy experimental means a relation is obtained between the thermal resistance of an eddy and its angular momentum. The eddy is stationary, and no extraneous motion is present. The secondary motion which may develop in the annulus between concentric rotating cylinders is used to obtain the eddies. The fluid motion is well defined at all times and at all points of space. Heat is passed through the eddies, and the Nusselt number is obtained, which varies linearly with the angular momentum. Both Nusselt number and angular momentum vary linearly with the peripheral velocity of the inner rotating cylinder, which can be interpreted in terms of a Reynolds number associated with fluid flow perpendicular to a cylinder.
Heat transfer from superheated vapors to a horizontal tube
Authors: Balekjian Garen , Katz Donald L. 
Published: June 2004

AbstractExperimental data are reported for condensing Freon‐114 (tetrafluorodichloroethane) and steam at several pressures. The condition of the vapors ranged from saturation to 180°F. of superheat. The condensing tube containing embedded thermocouples was 3/4 in. in diameter and 3 ft. long. Visual observation showed that steam condensed by dropwise condensation in part. Increase of superheat in the vapor at constant pressure caused a lowering of the tube‐wall temperature, which was indicative of a lowering of the surface temperature of the condensate. The lowering of the condensate‐surface temperature below the saturation temperature was computed from the experimental tube‐wall temperatures, the heat flux, and Nusselt's equation for the condensate‐film resistance. The lowering of the condensate‐surface temperature is correlated with degree of superheat. An interfacial coefficient of heat transfer between the superheated vapor and the condensate surface is reported based on the computed surface temperatures. Schrage's analysis and equations for relating mass and heat transfer with conditions at an interface were simplified and used to correlated the experimental condensing load with the degree of superheat.
A new electric analogue model for nonsteady state flow problems
Authors: Fatt Irving 
Published: June 2004

AbstractA new, simple electric analogue model is demonstrated which gives solutions, accurate within ten %, to problems in nonsteady state flow of heat, diffusion, and flow of liquids in porous media. The analogue consists essentially of a sandwich of electrical conducting paper, polyethylene or polyester sheeting, and metal foil. One‐ or two‐dimensional problems can be treated. This analogue provides a medium with distributed resistance and capacitance rather than the finite steps of conventional analogues; therefore two‐dimensional problems of complex shape can easily be modeled. The analogue is pulsed by a square wave generator and the transient potential response is displayed on a cathode‐ray oscilloscope.
Effect of superatmospheric pressures on nucleate boiling of organic liquids
Authors: Mesler Russell B. , Banchero J. T. 
Published: June 2004

AbstractSuperatmospheric pressures greatly reduce the temperature differences in nucleate boiling of or ganic liquids. Since nucleate boiling is characterized by bubble formation at the heating surface, it seems logical to investigate the pressure difference that causes bubble formation. It has been found that for organic liquids the difference in vapor pressure corresponding to the temperature difference behaves in a regular manner with pressure but does not vary greatly. This regular behavior permits prediction of temperature differences at higher pressures with a knowledge of only vapor‐pressure and boiling data at one pressure. New boiling data have been obtained in the investigation.
Heat transfer to water in turbulent flow in internally heated annuli
Authors: Stein Ralph P. , Begell William 
Published: June 2004

AbstractNearly 900 values of local heat transfer coefficients were correlated for water flowing through long annuli 1/8, 1/4, and 3/8 in. wide, electrically heated at their inner surfaces and containing three spacer ribs. Both cosine and uniform lengthwise heat‐flux distributions were employed. All heat transfer coefficients were computed for positions corresponding to (L/De) ratios larger than 150. Several methods of correlation were attempted and compared, especially with respect to the method of evaluating physical properties. The proportionality of the Colburnjfactor to the Prandtl and Reynolds numbers with their usual exponents was verified, and the dependence ofjuponD2/D1was analyzed. There was no significant effect of cosine heat‐flux distribution on the heat transfer coefficients. Evaluating physical properties at the usual film temperature gave the best correlation. A simplified dimensional equation for water at moderate temperatures and pressures was also developed.
Estimation of the stage efficiency of simple, agitated vessels used in mixer‐settler extractors
Authors: Treybal Robert E. 
Published: June 2004

AbstractA method of calcuation is presented by which estmates may be made of the stage efficiency of continuously operated, agitated, baffled vessels used in mixer‐settler extractors. The calculations are limited to cases where the agitatiing impeller is a flat‐blade turbine, and do not include estimates of the entrance and exit effects. The method has been tested with all the available experimental data, which include three different sizes of vessels, systems, and impeller sizes, and a variety of operating conditions including speeds of agitation, rates of flow, and ratios of contacted liquids. Because of limitations of the author's knowledge, the calculations are necessarily approximate, but they nevertheless correctly indicate the nature of the variations in stage efficiency to be expected with all of the design and operating variables for which tests could be applied.
Flow of two‐phase carbon dioxide through orifices
Authors: Hesson James C. , Peck Ralph E. 
Published: June 2004

AbstractExperimental flow rate data are presented for saturated liquid, saturated vapor, and two‐phase liquid‐vapor carbon dioxide through a convergent nozzle and a square‐edged orifice. The data cover the range from the triple‐point pressure to the critical pressure. Charts have been prepared for this complete range at critical flow. Results are also presented for subcritical flow.The tests at various back pressures indicate that the saturated liquid behaved as a cold liquid without evaporation ahead of the throat.Saturated vapor became supersaturated in the nozzle, and the vapor behaved as if no condensation occurred.Equations are presented for the flow rates of saturated vapor, and two‐phase mixtures in the critical flow region.A Mollier (pressure‐enthalpy) diagram is used to determine the flow rates of saturated vapor and two‐phase mixtures where supersaturtation takes place. In these cases, the lines of constant specific volume or density are extrapolated from the superheated region into the normal two‐phase region to obtain values corrected for supersaturation.
Freezing points of binary mixtures of methane
Authors: Brewer Jerome , Kurata Fred 
Published: June 2004

AbstractThe experimental freezing‐point data of the methane‐n‐hexane and the methane‐n‐octane binaries are presented and compared with the methane–carbon dioxide system investigated by Donnelly and Katz. A step‐by‐step variation of the freezing point in the paraffin homologous series is exploited to provide reasonably accurate extrapolation of the experimental data on the two binaries and scattered freezing‐point data on the methane‐n‐butane mixture to other paraffin hydrocarbon mixtures of methane in which the heavier constituent ranges from ethane to n‐nonane, inclusive.A composite graph of the freezing points of the various binaries with methane, from ethane to n‐nonane, is presented.
Characteristics of gas pockets in fluidized beds
Authors: Yasui George , Johanson L. N. 
Published: June 2004

AbstractSome characteristics of gas pockets rising through beds of fluidized solids have been measured directly with a light probe technique. The vertical thickness, numerical frequency, and rate of rise of the bubbles were obtained from oscillographs of dual probe signals. Room‐temperature air at 1‐atm. pressure was used in 4‐ and 6‐in. columns. Glass beads, a crushed rock, commerical cracking catalysts, coal, and hollow resin spheres were studied in particle sizes from 12‐µ fluid cracking catalyst to 450‐µ coal.Vertical bubble thickness was found to increase with particle size, distance above the bed support, and gas velocity. Size growth upon rising was mainly the result of coalescence of bubbles. The rise velocity ranged from 1 to 2 ft./sec., relatively unaffected by operating conditions. Bubble frequency decreased with height above the bed support owing to coalescence. Total bed‐depth variation from 1.0 to 2.5 ft. did not significantly influence the results, which should be of interest in studying gas by‐passing in fluidized beds and predicting the slugging behavior and fluidization uniformity.
Fugacities in high‐pressure equilibria and in rate processes
Authors: Prausnitz J. M. 
Published: June 2004

AbstractThis work considers the importance of vapor‐phase nonideal mixing in high‐pressure equilibrium and rate‐process calculations. New techniques are presented for calculating vapor‐phase fugacity coefficients in nonideal mixtures.The equilibrium properties of gaseous mixtures are represented by a virial equation of state which is adequate for the vast majority of chemical engineering problems. Techniques based on an extension of the corresponding‐states theory are given for estimating the various coefficients appearing in the equation of state; these estimates appear to be reliable for a large variety of nonpolar or weakly polar systems. Techniques based on the theory of intermolecular forces are also presented for polar systems and for a limited class of mixtures containing hydrogen‐bonding components. The proposed methods of calculation are illustrated by a large variety of problems occurring in common chemical engineering calculations, and it is shown that failure to correct for vapor‐phase nonideal mixing can, in some cases, lead to very large errors.
Thermodynamic properties of acetylene
Authors: Weber James H. 
Published: June 2004

AbstractThe derived thermodynamic properties of acetylene have been determined over a temperature range of 32 to 500°F. and up to pressures of 2,000 lb./sq. in. abs. The data were calculated from vapor pressure, volumetric, and heat‐capacity data by the use of rigorous thermodynamic relationships. The calculated data were found to be internally consistent. The enthalpy values are believed to be accurate within ±1.0 B.t.u./lb. and the entropy values to ±0.001 B.t.u./(lb.)(°R.).
The study of flow and reaction rates in turbulent flames
Authors: Barbor R. P. , Larkin J. D. , Von Rosenberg H. E. , Shipman C. W. 
Published: June 2004

AbstractIt is proposed that measurements of reaction rate as a function of position within turbulent flames be the basis of an approach to the problem of turbulent‐flame propagation. As a test of the method, measurements of static pressure, impact pressure, and chemical composition were made at several positions within the burning zones of two simulated ramjet combustion chambers. From these measurements a complete mapping of compositions, velocity components, densities, and static pressures could be carried out. By calculation of the appropriate derivatives of the latter quantities, the differential form of the equation of continuity for the species desired could be solved for net reaction rate as a function of position, turbulent diffusion being neglected. By a similar technique the equation of momentum was used to obtain eddy viscosities. The latter results were used to estimate the effect of turbulent diffusion by assuming a turbulent Schmidt number of unity.It is concluded that the method of attack used is a reasonable approach to the problem of turbulent flame propagation, having a special advantage in that it can be used to discover relationships between the rate of reaction and the patterns of the mean flow.
Some effects of baffles on a fluidized system
Authors: Overcashier R. H. , Todd D. B. , Olney R. B. 
Published: June 2004

AbstractSome characteristics are reported for the fluidization of an air‐microspheroidal catalyst system in a 16‐in.‐diameter bed equipped with baffles. The back‐mixing characteristics and retention‐time distributions of gas and solids, allowable gas and solids velocities, entrainment rate, and bed density are studied as functions of baffle design.It is shown that the use of baffles narrows the retention‐time spectrum and permits either concurrent or countercurrent flow while not seriously reducing gas or solids throughput or solids holdup.
Engineering applications of relaxation procedures by digital computation
Authors: Radd M. E. , Tek M. R. 
Published: June 2004

AbstractA generalized computing method is developed to perform mathematical “relaxation” on a Datatron digital computer. The application of the developed relaxation or iteration procedures results in obtaining numerical solutions to several engineering boundary‐value problems expressed by elliptic differential equations. The developed digital relaxation routine is found to be effective, fast, and practical in solving numerous steady‐state heat and mass transfer problems with arbitrary and quite often complex boundary conditions. While the specific speed and accuracy of the developed digital method is found to depend upon the type of differential equation, the grid size, and computational tolerance requirements, a typical problem indicates that 250 iterations/min. speed and 1% accuracy may be achieved in an average case.The examples presented in this paper are chosen from the more classical heat transfer and temperature and pressure distribution problems in order to indicate some other areas where similar engineering problems can be solved however complex the boundary conditions may be.
Reduced density correlation for hydrogen: Liquid and gaseous states
Authors: Schaefer Charles A. , Thodos George 
Published: June 2004

AbstractThe available experimental density data for hydrogen have been complied to produce a reduced density correlation for the liquid and gaseous states. This investigation has utilized fifty‐seven sources of data, extending from the early studies of Amagat (1880) to the recent contributions of Johnston, Keller, and Friedman (1954).Based on the concept of a reduced density, a correlation for hydrogen has been developed ranging in temperature from the melting point (14°K.) to 3,300°K. and in pressure as high as 2,550 atm. This correlation provides continuity between the liquid and gaseous phases; whereas existing equations of state fail to describe the experimental behavior in the transitional region, particularly near the critical point.Four hundred and eighty‐five experimental points covering the entire region were checked to establish the reliability of this correlation, which reproduced the experimental data to within 0.49%.
Characteristics of transition flow between parallel plates
Authors: Whan G. A. , Rothfus R. R. 
Published: June 2004

AbstractMeasurements of pressure drop and mean local fluid velocities have been made in a smooth rectangular duct of large aspect ratio. Data have been taken on the steady, isothermal flow of water at room temperature in the viscous, transition, and lower turbulent ranges of flow. Impact probes were installed in the center of the stream, where flow between infinitely broad parallel plates was closely approximated. The limits of the transition range are discussed, and mean local fluid velocities are correlated. Comparison is made with transitional behavior in smooth tubes.
Flow characteristics in horizontal fluidized solids transport
Authors: Wen Chin‐Yung , Simons H. P. 
Published: June 2004

AbstractThe flow characteristics of dense solid‐gas mixtures transported through horizontal pipes were studied with glass beads and coal powders of various sizes (0.0028 to 0.0297 in.) in 1/2‐, 3/4‐ and 1‐in. glass pipes and a 1/4‐in. steel pipe. Fluidized‐bed feeders were utilized, thus permitting solid‐gas ratios considerably higher (range 80 to 750) than those possible with conventional pneumatic transport. When such high solid‐gas ratios are used, the flow of mixtures in transport lines is characterized by a large amount of slippage between gas and solids. The flow pattern is dicussed on the basis of visual observation through glass pipes.A simple and interesting velocity relationship was noted, namely that the average gas velocity is about twice as large as the average solid‐particle velocity. The solid‐particle velocities and solid loadings in the pipe line were found to be primary factors affecting pressure drops, and the particle sizes and shapes, on the other hand, exerted a very slight effect on the pressure drops. This is apparently due to the fact that the solids move predominantly in the bottom of the pipes as agglomerated masses rather than as individually suspended particles. A pressure‐drop correlation for the dense solid‐gas mixtures is proposed, and applications and limitations of the correlation are shown.
Effective collision diameters and correlation of some thermodynamic properties of solutions
Authors: Prausnitz J. M. , Benson P. R. 
Published: June 2004

AbstractVolumetric data on gas mixtures and vapor‐phase data for gas‐liquid equilibria have been correlated within the framework of the theory of corresponding states. An expression based on the London potential for dispersion forces was used to compute characteristic temperatures for various binary systems, and a correlation was developed relating these temperatures to the polarizabilities, ionization potentials, and critical volumes of the pure components. The correlation shows how the molecular shape of a liquid affects its vapor‐phase solubility. With the help of this correlation it is possible to make very good predictions of such gas‐liquid equilibria as are required in high‐pressure distillation, absorption, and petroleum hydrofining operations.
Particulate fluidization and sedimentation of spheres
Authors: Loeffler A. L. , Ruth B. F. 
Published: June 2004

AbstractParticulate fluidization and sedimentation data were taken over the Reynolds number range of 0.005 to 1,800 by means of glass spheres in both water and ethylene glycol. Porosities for each series of measurements varied from about 0.50 to 0.91 and larger. The closely sized samples of spheres used were obtained by grinding between glass plates. The data for Reynolds numbers up to about 0.5 are in excellent agreement with the laminar theory of Ruth and the porosity function from Ruth's theory gave a satisfactory correlation of all the data, both laminar and turbulent.
Longitudinal laminar flow between cylinders arranged in regular array
Authors: Sparrow E. M. , Loeffler A. L. 
Published: June 2004

AbstractAn analytical solution has been obtained for the longitudinal fully developed laminar flow between cylinders arranged in triangular or square array. Numerical results for the pressure drop and the friction factor are given over a wide range of spacing‐to‐diameter ratios. For large spacings the results can be represented by a single expression independent of the type of array. Plots are also given of velocity distributions and of the variation of the local shear stress around the periphery of a cylinder.