bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass transfer in liquid‐lithium systems
Authors: Gill William N. , Vanek Richard P. , Jelinek Robert V. , Grove C. S. 
Published: June 2004

AbstractThe behavior of type‐304 stainless steel in a forced‐convection closed‐loop lithium system was investigated over a wide range of temperatures and velocities. Fundamental information concerning the mechanism for mass transport has been obtained by examining solution and deposition effects along flat plates. The rate‐determining process for solution is transport from the solid to the interface, whereas deposition rates are liquid‐phase controlled.Liquid‐phase mass transfer coefficients were correlated with a maximum deviation of approximately 15% by the use of von Kàrmàn's analysis of the turbulent boundary layer along a flat plate, combined with the Chilton‐Colburn empirical modification of the Schmidt group. In contrast no adequate model is available for the prediction of solution rate constants which must be determined experimentally. Mean values of the solution rate constants ranged from 0.154 to 0.750 × 10−5 cm./sec. at temperatures from 510° to 612°C. These values are on the order of 103 smaller than corresponding liquid‐phase mass transfer coefficients.
Plate efficiencies in multicomponent distillation
Authors: Toor H. L. , Burchard John K. 
Published: June 2004

AbstractA first approximation to the multicomponent plate‐efficiency problem has been carried out with a film model combined with equations for steady state diffusion in a ternary gas mixture. Numerical integration of the equations through a plate yields the ternary efficiencies as functions of the binary efficiency.The effects of diffusional interactions in a distillation column were studied by computing the efficiencies on each plate when a column is designed to separate a ternary mixture. In the example studied, the average column efficiency was 39% less than the binary efficiency.Some criteria are suggested for comparing other multicomponent systems to the one studied in order to estimate the uncertainty in the use of binary correlations for these systems.
Correlating vapor pressures and heats of solution for the ammonium nitrate—water system: An enthalpy–concentration diagram
Authors: Othmer Donald F. , Frohlich Gerhard J. 
Published: June 2004

AbstractThe usual tedious method of construction of enthalpy‐concentration charts for solutions of solids requires data seldom available. A new, simple method is therefore presented that utilizes more readily available data, that is vapor pressures of the solutions. These plot as straight lines on a logarithmic‐reference substance plot. Differences from unity of the slopes of these lines represent heats of solution, and when this difference function is integrated between concentration limits the integral heat of solution is obtained. The enthalpy chart is then readily constructed by use of the specific heats of liquid and solid.Ammonium nitrate is the solid used in this example, and water is the liquid because of the industrial importance of aqueous solutions. Vapor pressures were carefully determined experimentally, and the enthalpy chart was developed from the straight lines of the logarithmic plot and available heat data. Constants for the vapor‐pressure curves for ammonium nitrate solutions and equations for enthalpies of solid ammonium nitrate are given for the temperature range 0° to 170°C.
Hydrocarbon vapor‐liquid equilibria and solubility parameter
Authors: Prausnitz J. M. , Edmister W. C. , Chao K. C. 
Published: June 2004

AbstractHydrocarbon vapor‐liquid equilibria are expressed in terms of K values, which are functions of composition, as well as pressure and temperature. The composition effect in the liquid phase is calculated by the Hildebrand‐Scatchard equation for regular solutions. The parameters in this equation, called solubility parameters, can be calculated simply from heat of vaporization for the heavier hydrocarbons, but an indirect method of calculation must be used for the lighter components. Solubility parameters for hydrogen, methane, ethane, and propane were computed from gas‐solubility data in several hydrocarbon solvents at various temperatures and pressures. This computation also yielded simultaneously the fugacities of the hypothetical liquid‐standard states.The results presented are not complete for practical applications, owing to the scarcity of suitable solubility data, especially at high temperatures and pressures. However solubility parameters appear to give the right liquid‐phase corrections in the correlation and prediction of hydrocarbon phase equilibria. Calculated K values for light hydrocarbons in paraffinic, naphthenic, and aromatic absorption oils are compared with experimental results. The average deviation for the forty‐two values tested is 13%.
Mass transfer from a solid soluble sphere to a flowing liquid stream
Authors: Steinberger Robert L. , Treybal Robert E. 
Published: June 2004

AbstractSolution rates of 1/2‐, 3/4‐, and 1‐in. cast benzoic acid spheres were measured under natural‐and forced‐convection conditions. Upward‐flowing streams of water and aqueous propylene glycol, in laminar and turbulent flow, were used to contact single spheres in either a 1.50‐ or 4.00‐in.‐ diameter column. Sphere Reynolds numbers ranged from 10 to 16,920; Schmidt numbers from 987 to 69,680; sphere‐ to column‐diameter ratios, ds/dc, from 0.123 to 0.497; and Grashof numbers from 5,130 to 125,200.The Sherwood number was found independent of the laminar‐turbulent transition for pipe flow and the sphere‐ to column‐diameter ratio when the Reynolds number is based on the average fluid velocity and sphere diameter.A correlation of the data based on the additivity of the natural and forced convection processes is proposed, and statistical analyses of the new experimental data result in equations which correlate other heat and mass transfer data for single spheres immersed in bounded and free‐jet streams of gases and liquids for NRe, S from 1 to 30,000 and NSe from 0.6 to 3,000, within an average deviation of about 20%.
Modified law of corresponding states for gases
Authors: Bloomer Oscar T. , Peck Ralph E. 
Published: June 2004

AbstractA new correlation is presented for predicting the pressure‐volume temperature relations of nonpolar (and slightly polar) gases. The correlation modifies the law of corresponding states in which a third parameter, the slope of the pseudocritical isometric in dimensionless form, is introduced. This parameter is introduced in a simple manner by multiplying the reduced pressure and temperature of the gas by a factor which can be easily calculated or read from a graphs. This gives the corrected reduced pressure and temperature which can then be used with a generalized compressibility factor chart in place of the true values. The correlation is accurate for densities up to about 1.2 times the critical density.A detailed comparison of the method with data on twelve pure gases showed that by introducing this parameter into the law of corresponding states the average error was decreased from 1.598 to 0.320%. The parameter S can readily be determined from experimental PVT data, and only one isotherm is required. S is related to the vapor‐pressure curve for a substance as characterized by the critical pressure and the ratio of the critical temperature to the normal boiling temperature, and a simple method is proposed for predicting S when no experimental data are available.A new set of generalized compressibility factor and fugacity to pressure ratio charts is presented for use with the proposed correlation. A method is also presented for determining the thermodynamics functions.
Miniature hydroclones as slurry concentrators
Authors: Engel F. C. , Weisman Joel 
Published: June 2004

AbstractMiniature hydroclones were evaluated for use with thoria‐urania slurries being considered as fuels for one type of homogeneous nuclear reactor. In addition to extensive room temperature data on concentrating performance, the results of tests with thoria slurries at a pressure of 2,000 lb./sq. in. and temperatures up to 550°F. are given. The data correlation presented allows prediction of the concentrating performance of a given clone provided that the properties and particle size distribution of the slurry feed are known.
Burning rates of solid propellants
Authors: Smith J. M. 
Published: June 2004

AbstractA model is proposed for the burning of solid propellants which takes into account heat transfer, diffusion, and chemical reaction processes. The chemical step influencing the rate is postulated to be a reaction between a gaseous molecule and a solid component occurring at the solid‐gas interface. The combination of expressions for the rates of the heat transfer, diffusion, and reaction steps leads to relatively simple equations for the burning rate in terms of (1) the physical properties of the propellant; (2) the transport coefficients; (3) the operating conditions of the burning process, temperatures, and pressure; and (4) chemical characteristics of the gas‐solid reaction, activation energy, frequency factor, and heat of reaction.The well‐established facts concerning burning rates, the effect of pressure and initial temperature, and the phenomenon of erosive burning are predicted by the proposed theory. Also specific experimental data for burning potassium and ammonium perchlorate composite propellants can be predicted from the theory. The values of the variables necessary to obtain agreement between observed and predicted results are generally realistic. However it should be emphasized that conclusions regarding the detailed mechanism of the burning process cannot be obtained from comparison with burning‐rate data. Elucidation of the kinetic steps in the process will require experimental investigation of the intermediate products of combustion and a detailed study of the burning surface and gaseous flame zone.
The mechanics of vertical moving fluidized systems: IV. Application to batch‐fluidized systems with mixed particle sizes
Authors: Hoffman Robert F. , Lapidus Leon , Elgin J. C. 
Published: June 2004

AbstractThe present paper extends the previous investigations from this laboratory on ideal fluidized systems to a system which is somewhat nonideal. Mixtures of different but well‐defined glass spheres are fluidized by water to ascertain whether the principles developed for a single particle size still hold. The analysis indicates that the ideal prediction method gives a reasonable representation of the batch‐expansion curves for mixed sizes.
Radiological study of liquid holdup and flow distribution in packed gas‐absorption columns
Authors: Hwa C. S. , Beckmann R. B. 
Published: June 2004

AbstractA radiological method has been developed to study the local flow characteristics in two‐phase contacting equipment. The method presented permits the evaluation of both the vertical and horizontal components of the liquid holdup and flow distribution and can also be used to study the performance of a wide variety of two‐phase contacting apparatus. An external source of radiation is used, and hence neither phase is contaminated by the radioactive material.The application of this method is illustrated in the specific case of air‐water contact in a countercurrent packed column.
Extractive reaction: Batch and continuous‐flow chemical reaction systems dilute case
Authors: Piret Edgar L. , Penney W. H. , Trambouze P. J. 
Published: June 2004

AbstractA reaction process occurring simultaneously with an extraction by an immiscible phase is referred to herein as extractive reaction.Quantitative relations are developed which show how the rate of reaction, volumetric efficiency, and reactant conversion of a single‐phase batch reaction can be enhanced by deliberately adding to the batch a second phase such as an immiscible solvent or an inert gas.Analytical solutions are also obtained for continuous‐flow extractive reactions of first order and of simple or complex stoichiometry occurring in single‐ or multistage stirred‐tank reactors. The effect of recirculated or side streams is included.Dilute systems and several types of reactions are considered. The equations are applicable, for instance, to liquid‐liquid systems and solid‐liquid or gas‐liquid processes wherein reaction occurs in either the vapor or condensed phase.
Liquid, gas, and dense‐fluid viscosity of propane
Authors: Starling Kenneth E. , Eakin Bert E. , Ellington Rex T. 
Published: June 2004

AbstractExperimental data, believed accurate within ±0.5%, are presented for pressures of 100 to 8,000 Ib./sq. in. abs. for nine temperatures from 77° to 280°F. One isotherm, within 1° of the critical, indicates the detail required in further investigation of the critical region. These data were combined with the available literature values to prepare a table of recommended viscosity values with maximum uncertainty of ±2% for temperatures from 70° to 460°F. Two generalized correlations and the Enskog viscosity theory for dense gases exhibit significant errors in predicting the data. Methods are suggested for extrapolation of the values to higher temperatures and pressures.
Effect of radial temperature variation on axial mixing in pipes
Authors: Hawthorn R. D. 
Published: June 2004

AbstractIn a pipe reactor axial mixing results in a distribution of residence times of fluid elements in the reactor. Taylor and others have discussed methods of predicting the extent of axial mixing for isothermal flow in pipes; however, in a reactor the heat of reaction and its supply or removal at the wall can cause significant radial variation of temperature and temperature‐dependent physical properties. Thus the velocity profile in a reactor may differ from that in a pipe through which fluid flows at constant temperature.This paper presents an analysis of the effects of radial temperature variations on effective axial diffusion coefficients. In laminar flow it is found that radial temperature variation may increase or decrease the effective diffusivity two‐ to threefold from that calculated for isothermal flow. At Reynolds numbers greater than 10,000 the diffusivity calculated for constant temperature flow does not differ significantly from that for flow through a reactor tube (with radial temperature variation) at the same Reynolds number, calculated with the viscosity evaluated at the wall temperature. In turbulent flow at Reynolds numbers less than 10,000, the effect of radial temperature variation is important but can be estimated only roughly.
Effect of uniformity of fluidization on catalytic cracking of cumene
Authors: Gomezplata Albert , Shuster W. W. 
Published: June 2004

AbstractThe effect of uniformity of fluidization on the catalytic cracking of cumene, with a silicaalumina catalyst, was studied in a 3‐in.–diameter reactor operated at 800°F. Superficial gas velocities were varied from 0.06 to 0.24 ft./sec. for bed heights of 1.5, 3, 5, and 8 in. The percentage conversion in a fluidized bed was found to be lower than in a fixed bed and to be dependent on the type of catalyst support used. A porous plate support was up to 30% more efficient than a screen support, which is attributed to its better gas‐distribution characteristics and to its ability to introduce the discontinuous phase as smaller gas bubbles. Indications are that the first few inches of bed are very effective in bringing in contact the continuous and discontinuous phase, and therefore most of the conversion due to the interaction of the two phases takes place here. This can be explained in terms of the rapid growth of gas bubbles as they proceed through the bed.
A scintillation method for determining liquid ‐ liquid interfacial areas
Authors: Mitsis George J. , Plebuch Richard R. , Gordon Kenneth F. 
Published: June 2004

AbstractIn stirred beakers the interfacial area between xylene containing a scintillator and tritiated water was measured as a function of stirrer speed by a scintillation counting technique. Because of the 6 μ average range of the tritium betas the rate at which flashes are detected by a phototube is a function of the interfacial area. A calibration curve of count rate against known interfacial area for unstirred phases in containers of various diameters gave a numerical estimate of the interfacial area for ten configurations.
Mass transfer with interfacial adsorption methyl chloride into water
Authors: Chiang S. H. , Toor H. L. 
Published: June 2004

AbstractThe rate of transfer of a surface‐active solute across an interface may be either greater or less than the rate which would be obtained if the interface had no abnormal properties. Studies of the absorption of methyl chloride, a surface‐active gas, by a laminar water jet show that for contact times of 1 msec. or greater the absorption rate is the same as would be predicted for a system with no abnormal interfacial properties. This is in accord with theory which indicates that an abnormally high rate caused by a positive surface excess could only be observed for contact times considerably shorter than those used here.
Unsteady multicomponent diffusional evaporation
Authors: Hsu Hsien‐Wen , Bird R. Byron 
Published: June 2004

AbstractThe unsteady diffusion‐controlled evaporation of a pure fluid into a multicomponent mixture is studied by a boundary‐layer method. An expression is obtained for the volume of vapor produced by the evaporating species as a function of time. It is shown that the result can be interpreted in terms of an effective diffusivity of the type proposed by Wilke and by Stewart. It is further demonstrated that the boundary‐layer method predicts a sweep‐diffusion effect.
Macroscopic mixing in fluidization
Authors: Cairns E. J. , Prausnitz J. M. 
Published: June 2004

AbstractMixing studies were performed in beds of lead and glass particles fluidized with water. A salt solution was injected from a point source, and electrical conductivity cells were used to determine time average and fluctuating salt concentrations at various points downstream from the point of injection. The frequency distribution of the fluctuations was determined, and correlation coefficients were measured for the fluctuations at two points separated by a known distance.The mixing data for the central portion of the bed yield radial eddy diffusivities and scales and intensities of turbulence. At the same fraction void the eddy diffusivity and scale of turbulence are larger for lead than for glass particles, but the velocity fluctuations appear to be independent of the density of the particles. Minimum Peclet numbers are observed at a fraction void of about 0.7. Scales based on correlation coefficients exceed those calculated from Peclet numbers, indicating that in a fluidized bed there are large‐scale eddies whose size is much larger than a particle diameter. The interpretation of the mixing data is coupled with visual observations of fluidized bed flow patterns.
Second virial coefficients of the acetonitrile‐acetaldehyde system
Authors: Prausnitz J. M. , Carter W. B. 
Published: June 2004

AbstractThe low‐pressure compressibilities of acetonitrile, acetaldehyde, and their mixtures were measured in the temperature range 40° to 100°C. From these data second virial coefficients were determined for the pure components and for the mixture. The absolute value of the coefficient B12, characteristic of interaction between dissimilar molecules, was considerably larger than that for B11 or B22, which are characteristic of interactions between similar molecules. As a result it was not possible to predict the properties of the mixture with only data for the pure components. Calculations based on the Stockmayer potential and with conventional mixing rules gave seriously incorrect results for the second virial coefficient B12.The data were interpreted with the aid of an association theory. Dimerization equilibrium constants and enthalpies and entropies of formation were computed for the pure‐component dimers and for the complex. The heat of formation for the complex was significantly larger than that for the dimers; comparison with energy terms calculated from electrostatic theory suggest that the structure of the complex is different from that of the pure‐component dimers.
Kinetics of mixed‐bed deionization: I
Authors: Frisch Norman W. , Kunin Robert 
Published: June 2004

AbstractMixed‐bed deionization of 0.0002 to 0.01N sodium chloride solutions at flow rates in the range of 3 to 70 gal./(min.) (sq. ft.) with bed depths of 0.25 to 3.2 ft. was investigated. The rate of ion exchange was found to be limited by a liquid‐film mass transfer mechanism in the high purity water range (< 1 μ micromho/cm. effluent conductivity).The magnitude of the temperature effect in the range 15° to 45°C. is given. Methods for prediction of effect of both changes in particle size distribution and incomplete regeneration of the component ion exchange resins are presented. A tentative correlation is given which estimates the effect of solute and solvent species.
Local shell‐side heat transfer coefficients and pressure drop in a tubular heat exchanger with orifice baffles
Authors: Lee K. S. , Knudsen J. G. 
Published: June 2004

AbstractBy means of a moveable sensing probe previously described2 local shell‐side heat transfer coefficients and friction losses were measured on a model tubular heat exchanger containing orifice baffles. The heat exchanger shell was 6‐in. nominal I.D. and 45 in. in length and contained four tubes in triangular arrangement passing through orifice baffles. Baffle hole diameters of 1‐/16, 1–2/16, 1–3/16, and 1–5/16 in. and baffle spacings of 4.0 and 9.0 in. were studied. Data were taken at several air flow rates for each of the four baffle hole diameters.The average heat transfer coefficient for the region between two central baffles was correlated with an empirical equation based on only two baffle spacings.An increase in the baffle‐to‐tube clearance caused a decrease in heat transfer. An increase in the baffle spacing also resulted in a decrease in heat transfer. Four flow zones in the baffle space are postulated from the analysis of Nusselt number distribution along the tube. The heat transfer characteristics in each of the four flow zones were analyzed in terms of the mechanism of the fluid flow.The pressure‐drop data were correlated in terms of an annular orifice coefficient of discharge and an orifice‐pressure‐drop function. As a result of this study a method was developed by which one can predict the average of the local coefficients at the baffle position from the knowledge of pressure drop across a single baffle.
Thermal conductivity: Reduced state correlation for ethylene and its application to gaseous aliphatic hydrocarbons and their derivatives at moderate pressures
Authors: Owens E. James , Thodos George 
Published: June 2004

AbstractBy means of a procedure similar to that used for the inert gases (19) and methane (20) a reduced thermal conductivity correlation was developed for ethylene from experimental data available in the literature (2, 3, 4, 9, 13). The resulting correlation permits the prediction of thermal conductivities for gaseous and liquid ethylene in the temperature rangeTR= 0.4 toTR= 6.0 and for pressures up toPR= 50. For pressures belowPR= 0.5 this correlation was found to apply to gaseous aliphatic hydrocarbons and their derivatives but not to cyclic compounds. For these aliphatic hydrocarbons and their derivatives the relation between thermal conductivity at atmospheric pressure and temperature isk*/k= 0.364T.Experimental thermal conductivities of ethylene in the liquid state and dense‐phase region were compared with values predicted by the reduced‐state correlation. The average deviation for thirty‐six experimental points was 1.8%. Gaseous‐state data at atmospheric pressure of alkanes, alkenes, alkynes, alcohols, ethers, halogenated derivatives, esters, aldehydes, ketones, amines, nitriles, and other aliphatic compounds were also compared with values predicted by this correlation. For 414 experimental points the average deviation was 1.63%.