bluuebunny/crossref_metadata_2025_split huggingface dataset:
A generalized correlation of diffusion coefficients
Authors: Fair J. R. , Lerner B. J. 
Published: June 2004

AbstractGraphical correlations of binary gas diffusion coefficients are developed based on the Hirschfelder‐Bird‐Spotz diffusion equation and the theorem of corresponding states. A critical diffusion coefficient is defined and is used in turn for a definition of a “reduced” coefficient. The reduced diffusion coefficient is correlated graphically in generalized form in terms of the reduced properties of the diffusing gas. Using air as a reference “barrier” gas, the authors compared critical diffusion coefficients for various gases diffusing through a single barrier gas with the critical coefficients for these gases through air. This ratio, termed thebarrier gas ratio, was found to be independent of the properties of the diffusing gas. A graphical correlation of the barrier gas ratio enables rapid estimation of a binary diffusion coefficient with a minimum of information.
Correlation of bubble‐cap fractionating‐column plate efficiencies
Authors: Oliver Earl D. , Watson C. C. 
Published: June 2004

AbstractA method of estimating the true conditions of operation of a bubble‐cap tray is presented. Intermediate between the Murphree and the Lewis methods, which represent the extremes of actual operation, this method involves the use of a correlation to determine the degree of liquid mixing on the tray and the use of new relations between the Murphree vapor efficiency, the Lewis case I efficiency, and the true local efficiency. For the last, partial liquid mixing is taken into account.Data were obtained on an 18‐in. O.D. three‐tray bubble‐cap tower containing ten 3‐in. bubble caps a tray. Partial liquid mixing was correlated for changes in vapor and liquid rates, pressure, temperature, and weir height for the system ethylene dichloride‐toluene.Efficiency data on acetone‐water, ethanol‐water, and ethylene dichloride‐toluene showed the following effects: (1) low concentration of lwo boiler usually, but not always, resulted in low true local efficiencies, always with high Murphree efficiencies; (2) vapor velocity effects are more intimately connected with slot velocity than superficial velocity (and hence entrainment); (3) raising the pressure gives higher efficiencies; (4) an increase in liquid depth increases the true local efficiency but may have no effect on the Murphree efficiency.
Mechanics of steady state single‐phase fluid displacement from porous media
Authors: Von Rosenberg D. U. 
Published: June 2004

AbstractThe physical processes are discussed by which a fluid is displaced from a porous medium during steady state viscous flow by another fluid of the same density and viscosity under conditions of complete miscibility of the two fluids. The displacement occurs on a microscopic scale as a result of combined convective and diffusional mixing. The length of the zone of mixing which comprises the displacement front is predicted to be dependent upon the rate of flow, the diffusion coefficient for the two‐fluid system, the characteristics of the pore geometry, and the distance the front has traversed at the time of its observation.Experimental data are presented for the displacement of benzene by ethyl n‐butyrate at several rates of flow from packed sand columns. These data show that the length of the frontal mixing zone after a prescribed distance of flow is greater at the higher rates of flow. The postulated dependence of the length of the front upon the diffusion coefficient and the pore geometry has not yet been investigated.
Analysis of kinetic data for heterogeneous reactions
Authors: Weller Sol 
Published: June 2004

AbstractThe chemical engineer frequently has to correlate kinetic data for heterogeneous reactions simply and accurately in order to make useful predictions of reaction rates over a range of conditions. The Langmuir‐Hinshelwood approach, which is frequently used for this purpose, does not have the theoretical validity commonly attributed to it, and its use leads to unnecessary mathematical complexity. A simpler method of analysis is suggested which is based on power dependencies of the rate on concetrations, the powers being restricted to integral of half‐integral values. The data for several reactions are shown to be adquately correlated by the suggested procedure, which is simple and convenient.
Kinetics on ideal and real surfaces
Authors: Boudart Michel 
Published: June 2004

AbstractThe wide applicability of the Langmuir‐Hinshelwood classical kinetics to surfaces which are known to depart strongly from ideal Langmuir behavior is a well‐known paradox of surface catalysis. The applicability and limitations of the classical method are illustrated by means of a simple reaction. The generality of the method is demonstrated by its applicability to ammonia synthesis with and without water vapor. The limitations are often more than compensated for by the added insight into reaction mechanism which it can provide without unded complexity. A three‐step approach to surface kinetics is suggested and discussed.
Adsorption phase equilibrium correlations: Light‐hydrocarbon vapors on activated charcoal
Authors: Etherington Lewis D. , Haney Roy E. D. , Herbst Walter A. , Scheeline Harod W. 
Published: June 2004

AbstractData correlations are presented for equilibrium adsorption of pure hydrocarbon vapors and their mixtures. The systems represented are C1 to C4 hydrocarbons (olefins and paraffins) on gas‐adsorbent grades of activated charcoal. The mixture data are limited to binary and ternary gas systems. The adsorption conditions represented among the correlated data cover ranges of 77° to 175°F. temperature and 0 to 100 lb./sq. in. gauge. With the use of empirical adsorption constants, a common correlation of specific adsorption capacity for the various hydrocarbons is presented; it applies for either pure components or their mixtures. A correlation is given also for adsorption relative volatilities. Approximate adsorption heats, a limited amount of high‐temperature steam adsorption data, and sample calculations on applications of the correlations are included. The prediction methods are recommended for adsorption conditions up to 250°F. and 250 lb/sq. in. gauge for the particular systems studied.
Pressure drop through porous media
Authors: Brownell L. E. , Gami D. C. , Miller R. A. , Nekarvis W. F. 
Published: June 2004

AbstractFluid flow data are presnted for beds of uniformly sized spheres consolidated with resin over a porosity range from 36.4 to 12.3%. The data are analyzed in terms of an effective pore volume and equations are given for predicting pressure drop by use of a friction‐factor‐Reynolds‐number plot.
Hydraulic analysis of sudden flow changes in a complex pumping circuit
Authors: Alves George E. 
Published: June 2004

AbstractA problem arose as to what would happen if there were sudden failures of power to one or more pumps of a large‐scale complex pumping circuit composed of several individual pumping systems. This paper describes the application of several published methods of hydraulic transient analysis to the problem. The performance of the system computed under several assumptions is discussed, and a comparison is made with experimentally determined values.
Use of zirconium in liquid‐sodium systems
Authors: Bowman F. E. , Cubicciotti D. D. 
Published: June 2004

AbstractThe attractive nuclear properties of zirconium make it a highly desirable core material for sodium‐cooled reactors. The elevated temperature strength while low is sufficient for certain applications. Development of higher strength alloys is underway. Sodium in itself is completely compatible with zirconium; however, the nonmetallic contaminants, namely oxygen, hydrogen, and nitrogen, can effect serious damage. The primary problem in the use of zirconium in a sodium system, then, lies in controlling these impurities in the sodium.
Mass transfer in liquid metals
Authors: Dunn W. E. , Bonilla C. F. , Ferstenberg C. , Gross B. 
Published: June 2004

AbstractThe rate of mass transfer was measured for solid metal shapes dissolving into mercury at room temperature. Sherwood numbers for horizontal tin, cadmium, zinc, and lead cylinders dissolving by natural convection agreed with Nusselt numbers for heat transfer in nonmetallic liquids at the same Rayleigh (Grashof × Prandtl) numbers. Dissolving of zinc tubes by mercury flowing turbulently within them agreed with heat transfer to nonmetals in tubes. Dissolving of random beds of lead spheres by mercury flowing through the bed agreed with similar nonmetal systems. It is concluded that mass transfer processes in liquid metals follow substantially the correlations for other fluids in heat or mass transfer, which with moderate safey factors may thus be used for at least preliminary design purposes.
Rate of flow and mechanics of bubble formation from single submerged orifices. I. Rate of flow studies
Authors: Leibson Irving , Holcomb Eugene G. , Cacoso Anthony G. , Jacmic John J. 
Published: June 2004

AbstractA study has been made of the rate of flow and mechanics of bubble formation from single submerged orifices 1/64, 1/32, 1/16, and 1/8 in. in diameter installed in an 8‐in. I.D. column operating in the air‐water system. The coefficients of discharge obtained for sharpedged orifices operating with this system indicate that the effective orifice discharge area for this type of operation is greater than that for an orifice of the same size and type operating at the same pressure ratio in the air‐air system. The effective orifice discharge areas for a round‐edged orifice operating in either the air‐water or air‐air systems appear to be identical at the same pressure ratio. The thick‐plate orifice operating in the air‐water system exhibits a constancy of discharge coefficient at ratios of the downstream to upstream pressures less than 0.33. Inasmuch as bubble formation occurring close to the downstream face of a sharp‐edged orifice operating in the air‐water system influences the effective orifice discharge area, liquid physical properties may be expected to be important in determining the rate of flow from this type of orifice for other gas‐liquid systems.In Part II photographic studies of bubble formation reveal that nonuniformity of bubble size is initiated by the onset of turbulence in the air stream flowing through the orifice. In the section of the laminar‐flow range studied in this investigation (200 <NRe< 2,100) the frequency of bubble formation is nearly constant with respect to Reynolds number. The bubble size is relatively uniform at a given Reynolds number and depends markedly upon orifice diameter. Stroboscopic examination reveals that as turbulence is fully developed for the air flow through the orifice, a counterclockwise spiraling, swirling motion of the air jet is initiated. In the turbulent‐flow range the bubblesize–distribution data are fitted reasonably well by a logarithmic‐normal‐probability distribution. More data for bubble formation in other liquids (particularly liquids of low surface tension) are necessary before a general correlation for bubble size in gasliquid systems can be developed.
Ferric ion removal from dilute acidic solutions by fixed‐bed cation exchange
Authors: Mar Brian W. , David M. M. 
Published: June 2004

AbstractThe removal of a trivalent ion (Fe+++) from acidic nitrate solutions by a fixed bed of Dowex‐50 cation‐exchange resin was studied at entering iron concentrations from 14 to 4 meq./liter, flow rates of 0.073 to 1.20 liters/(hr.)(sq. cm.), and bed sizes from 3.7 to 5.4 g. of dry resin/sq. cm. Acid strengths were below 0.45 N. The results were correlated is a relatively simple break‐through equation based on the assumptions of an equilibrium extremely favorable to iron adsorption and liquid‐film diffusion being the rate‐controlling factor. The capacity of the resin for iron was dependent upon the acid concentration of the sulation.The results provide a design equation requiring a minimum of experimental work.
Interpretation and correlation of ion exchange column performance under nonlinear equilibria
Authors: Hiester Nevin K. , Radding Shirley B. , Nelson Richard L. , Vermeulen Theodore 
Published: June 2004

AbstractVarious methods are known for interpreting experimental data for linear‐equilibrium cases or constant‐pattern break‐through curves where either external or internal diffusion alone controls the rate in the ion exchange column. The present paper provides interpretive techniques for nonlinear equilibrium cases where the rate is controlled by a combined diffusion mechanism. The techniques can be applied whether or not the value of the equilibrium constant is known.A completely general correlational method is derived for adding the mass transfer resistances under conditions of nonlinear equilibrium. Published break‐through results from numerous sources and from new measurements, evaluated by the techniques described, are used to determine the numerical constants for the general correlation.
Mass transfer in a horizontal liquid‐liquid extraction tube
Authors: Murphy Nelson F. , Lastovica John E. , Skrzec Adam E. 
Published: June 2004

AbstractA study was made of the effect of physical properties and of geometrical and dynamical characteristics of several liquid‐liquid extraction systems on the mass transfer coefficients. The two‐component systems studied consisted of the following solvents with water: cyclohexanol, methyl ethyl ketone, furfural, normal butanol, and nitromethane. The transfer studies were made in a horizontal glass pipe with the phases flowing counter‐currently at velocities from 1,000 to 15,000 lb./(hr.)(sq. ft.). The transfer of solvents into the water phase and of the water into the solvent phase was measured. The film coefficients of mass transfer for a solvent through the water film and for water through the solvent film were correlated by new dimensionless equations which include interfacial tension and diffusivity.
Mass transfer rates in ion exchange
Authors: Selke W. A. , Bard Y. , Pasternak A. D. , Aditya S. K. 
Published: June 2004

AbstractThe rates of both the liquid‐phase mass transfer and the internal‐diffusion steps in ion exchange were studied by means of shallow‐bed experiments. The mass transfer coeffcients obtained fitted the general correlations for other packed‐bed operations when the Schmidt group was evaluated with experimentally determined ionic counterdiffusivities. An incremental calculation of the diffusion rates within the particles yielded a value of the counterdiffusivity in the resin phase. A general design procedure based on these findings is proposed.
Measurements of bubbles formed in boiling Methanol
Authors: Perkins A. S. , Westwater J. W. 
Published: June 2004

AbstractThe photographic method was used to measure bubble sizes and frequencies for methanol boiling at atmospheric pressure outside a 3/8‐in. O.D., steam‐heated, horizontal copper tube. The average temperature of the tube was measured by use of the tube as a resistance thermometer. For nucleate boiling at heat fluxes up to 80% of the maximum, the product of bubble diameter and frequency was constant at 4 in./sec. In this region both the Rohsenow equation and the Forster‐Zuber equation gave good predictions of the heat transfer. At higher fluxes the productf×Dincreased and the equations were much less suitable. The critical temperature difference for copper to methanol was not a single value but was a region extending from 52° to 62°F. The heat flux was nearly constant throughout this range at a maximum of 115,000 B.t.u./(hr.)(sq. ft.). For film boiling,f×Dwas nearly constant at 11 sec.−1Bromley's equation was unsuitable for ΔTvalues less than 180°F., but it became applicable at this ΔT. The use of Nusselt's equation for steam condensing inside the tube was found to be satisfactory, proof that the slight slope of the tube was sufficient to permit adequate condensate drainage.
Composition change in binary‐component spray vaporization at atmospheric pressure
Authors: Culverwell J. F. , Grounds P. W. , Lamb G. G. , Stevens W. F. 
Published: June 2004

AbstractThis paper describes an investigation of the factors affecting the change in composition with vaporization of a binary‐component spray in heated air at atmospheric pressure. The behavior of the system orthodichlorobenzene‐tetrachloroethylene was studied in air ranging from 400° to 1,000°F. Initial drop diameters in the sprays were in the 20‐ to 400‐µ range. The experimental data obtained indicated that the rate of change of spray composition during vaporization was affected only by the chamber‐air temperature, the initial feed composition, and the nozzle characteristics.Equations are presented which mathematically describe the vaporization process, liquid diffusion being assumed within the drop controls. These equations have been solved by a stepwise procedure for three initial drop sizes. Results of these calculations have been added statistically according to the initial‐drop‐size distribution in order to predict the vaporization behavior of the spray. Details of this process of statistical combination have been summarized by Culverwell (1).The calculations agreed with the experimental data previously obtained during the first 5 in. of nozzle‐to‐tray travel. After 5 in. the deviation was great. Future experimental work to determine more precise values of drop‐size distribution, initial drop velocity, and liquid diffusion coefficient may result in more complete agreement.
Ignition of solid propellants by forced convection
Authors: Churchill S. W. , Kruggel R. W. , Brier J. C. 
Published: June 2004

AbstractExperimental data are reported for the ignition of single grains of solid propellant in a stream of gas at high temperature. The investigation encompassed gas temperatures from 578° to 1,070°K., gas velocities corresponding to free‐stream Reynolds numbers from 156 to 624, a complete range of oxygen‐nitrogen mixtures, and a few oxygen‐carbon dioxide mixtures. Pyrocellulose and double‐base propellants were tested. The grains were approximately 1/8 in. in diameter and extended through the gas stream, so that ignition was forced to take place on the cylindrical surface rather than on the end of the grain. The exposure before ignition was measured for a large number of grains. The data can be represented by an equation that is consistent with the known effect of flow rate on convective heat transfer and the known effect of temperature on chemical reaction rates, an indication that both processes are important in ignition.
Vapor‐liquid equilibria for hydrogen–light‐hydrocarbon systems at low temperatures
Authors: Benham Alvin L. , Katz Donald L. 
Published: June 2004

AbstractExperimental equilibrium vapor and liquid compositions are reported for the hydrogen‐methane system at −150°, −200°, and −250°F. and at pressures of 500 to 4,000 lb./sq. in. The ternary system hydrogen‐methane‐propane was studied at 0°, −100°, and −200°F. at 500 and 1,000 lb./sq. in. Phase compositions were determined for a limited number of similar conditions for the hydrogen‐methane‐propylene and hydrogen‐methane‐ethylene‐ethane‐propylene‐propane systems.
Void fractions in two‐phase steam‐water flow
Authors: Isbin H. S. , Sher Neil C. , Eddy K. C. 
Published: June 2004

AbstractThe pressure‐drop characteristics associated with one liquid and one gaseous phase flowing concurrently in a pipe or tube have yet to be understood. The operation of evaporators, boilers, and condensers has long stimulated interest in the pressure drop of steamwater mixtures, and more recently this specialized case of one‐component, two‐phase flow has received even greater attention from the applications in cooling nuclear reactors. The two‐phase–flow problems have not been amenable to through theoretical analyses, and therefore empirical and semiempirical correlations have attained unusual prominence in practical applications. The present investigation employs a new research tool for the study of two‐phase–flow structure.A variety of geometric flow patterns is possible. Bergelin, Alves, and others have classified these patterns according to visual appearance; whereas the Martinelli classifications were based upon whether the flow in each phase was termedviscousorturbulent. The distinction between viscous and turbulent flow in either phase is rather arbitrary, and if the Reynolds number for one phase, calculated on the basis of the total tube diameter, is greater than 2,000, the flow in the phase is calledturbulent. This investigation is confined to the study of annular flow, in which most of the liquid is found in an annular ring surrounding the central vapor core and the flow in each phase is turbulent.Boiling or flashing occurs when superheated water rises in an insulated vertical tube at atmospheric pressure. For a separated two‐phase flow geometry, the mean linear steam velocity may exceed that of the water. The fraction of the tube occupied by the steam (void fraction) at a given cross section cannot be obtained directly from a determination of the thermodynamic quality. Void fractions, however, must be known for the estimation of the pressure drops due to head and momentum changes.Void fractions and pressure drops for steam‐water flows were measured in an 0.872‐in. I.D. vertical tube at atmospheric pressure over a quality range of 0 to 4%. The test section was the hot leg of a natural‐circulation loop, and the inlet liquid flow rate ranged from 1 to 3 ft./sec. A new technique for measuring void fractions was used, and the method utilizes the difference between the gamma‐ray absorption coefficients of water and steam.
Absorption and stripping‐factor functions for distillation calculation by manual‐ and digital‐computer methods
Authors: Edmister Wayne C. 
Published: June 2004

AbstractNew absorption‐ and stripping‐factor functions have been developed for use in computing multicomponent separations in fractionators, reboiled absorbers, refluxed strippers, and columns with side‐stream strippers. Charts of fraction not absorbed vs. A factor and fraction not stripped vs. S factor are included with the equations for these operations.These functions and procedures are of particular advantage in computing complex columns, i.e., two or more feeds and three or more products, where the proposed A and S factor equations provide a method for converging on a solution.
Phase behavior of hydrogen–light‐hydrocarbon systems
Authors: Benham A. L. , Katz D. L. , Williams R. B. 
Published: June 2004

AbstractThe decreasing solubility of hydrogen in hydrocarbons with decreasing temperature continues down to the freezing point of the hydrocarbons, around −300°F. This behavior is shown to be an enlargement of phenomena exhibited by normal hydrocarbon mixtures. Methods of predicting equilibrium‐phase compositions are presented for hydrogen in ligh‐hydrocarbon systems. The correlations are satisfactory for binary and certain ternary systems, but are not reliable for complex mixtures.
Discharge coefficients through perforated plates
Authors: Kolodzie P. A. , Van Winkle Matthew 
Published: June 2004

AbstractThe design variables that affect the pressure drop across dry perforated plates were determined and correlated. Average orifice coefficients were calculated for the perforated plates by using a modified form of the single‐orifice flow equation.The variables which affected the orifice coefficients were found to be the hole diameter, hole pitch, plate thickness, fraction of the plate covered by the perforated area, and a Reynolds number based on the hole diameter. The orifice coefficients have been correlated with these variables in dimensionless groupings.The correlation presented covers a practicable range of variables for which the pressure drop may be predicted in design.