bluuebunny/crossref_metadata_2025 huggingface dataset:
Wetting effects on boiling heat transfer: The copper‐stearic acid system
Authors: Harrison W. B. , Levine Zelvin
Published: June 2004

In order to study effects of wetting on heat transfer in the nucleate boiling regime, stearic acid was boiled in contact with different crystal planes of single crystals of copper. One crystal plane being wetted by the acid more completely than the other, they are called wetted and nonwetted surfaces. In the region of low heat flux, where heat transfer is primarily nonboiling natural convection, the nonwetted crystal required higher values of temperature difference than the wetted crystal for the same flux. At high values of heat flux, though not in the vicinity of the critical temperature difference, the situation was reversed; that is, the nonwetted surface required lower temperature difference than the wetted surface.

In the present studies, stearic acid was boiled at about 465°F., corresponding to a pressure of 17 mm. of mercury. Heat flux ranged from 3,450 to 63,300‐B.t.u./(hr.)(sq. ft.), and temperature difference between the copper crystal and the stearic acid ranged from 38° to 132°F. The corresponding range of heat transfer coefficient was from 91 to 510 B.t.u./(hr.)(sq. ft.)(°F.).
Perforated plate efficiency‐effect of design and operating variables
Authors: Hellums J. D. , Braulick C. J. , Lyda C. D. , Van Winkle Mathew
Published: June 2004

Experimental plate efficiency and pressure drop data were obtained on the n‐octane‐toluene system in a 5 plate, 6 in. diam. column at atmospheric pressure. Hole sizes of 1/16, 1/8, and 3/16 in.; 5.68 and 12.5% free areas; weir heights of 1, 2, and 3 in.; and plate spacings of 6, 12, 18, and 24 in. were studied. Reflux ratios of one, two, four, five, ten, and total were utilized to determine the effect on efficiency.

It was found that hole diameter, free area, plate spacing, and a wide range of reflux ratio had relatively small effect on efficiency and pressure drop; however weir height and lower reflux showed relatively larger effects on both variables.

Efficiencies and pressure drops were lower than those predicted from published correlations particularly at low flow rates.
Equilibria in the hydration of ethylene at elevated pressures and temperatures
Authors: Cope C. S. , Dodge B. F.
Published: June 2004

Values of equilibrium composition for the hydration of ethylene to form ethanol have been calculated for a series of elevated pressures and temperatures by using equilibrium data available from previous low‐pressure studies. To obtain satisfactory agreement between these values and those measured experimentally, it is essential (1) to take into account the formation of ethyl ether and (2) to use available vapor‐liquid equilibrium data for the binary ethanol‐water system at elevated temperatures, instead of the standard “mixture rules” often employed.

Thermochemical data and low‐pressure equilibrium data for both the ethylene hydration and ether formation reactions are critically reviewed. Experimentally measured values for the equilibrium concentrations of ethanol and ether in the liquid phase at 221°C. and 273 atm., with dilute sulfuric acid used as catalyst in a lined rocking‐bomb reactor, are presented.
Mechanics of vertical moving fluidized systems: II. Application to countercurrent operation
Authors: Price B. G. , Lapidus L. , Elgin J. C.
Published: June 2004

Experimental data are presented for two different methods of operating vertical moving fluidized systems of glass spheres and water: free countercurrent fluidization and bottom‐restrained nonfed, or batch, fluidization. Data for a lead‐shot‐and‐water system are also reported. A comparison is made of these data with a generalized theoretical analysis of ideal fluidized systems. The validity of a single characteristic holdup vs. slip‐velocity relationship is illustrated, and consideration is also given to the prediction of flooding in the free countercurrent systems.
Mechanism of drying thick porous bodies during the falling rate period: I. The pseudo‐wet‐bulb temperature
Authors: Nissan A. H. , Kaye W. G. , Bell J. R.
Published: June 2004

The drying of two highly porous thick textiles is studied and compared. Extremes are chosen in that one package is composed of a Terylene (British form of a polyester fiber) net fabric of open structure and the other of a woolen flannel of close structure. The cloths are wound as bobbins and dried by hot air streaming in a wind tunnel, the air flowing parallel to the axis of the cylinder of material. The weight of water as drying progresses is measured by a balance, and thermocouples within the bobbin provide a temperature record.

On investigation of the thermal conductivity of the dry structure, it is found that whereas the coefficient for the wool‐air mixture is constant throughout, the coefficient for the Terylene‐air mixture applies only in the depths, the apparent thermal conductivity growing larger toward the surface and with increasing air speed, as if the heat transfer through the open structure is assisted by some form of air penetration.

As the thick textiles dry, the rate of evaporation falls off, since heat and water vapor have to pass through an increasing layer of dry material. While this is occurring, a constant temperature, the “pseudo‐wet‐bulb temperature,” is established throughout the wet cloth. This state of equilibrium may be expressed as an equation between the rate of heat conduction inward and that required to produce the vapor diffusion outward. From this equation the pseudo‐wet‐bulb temperature can be calculated.
Theoretical explanation of heat transfer in laminar region of bingham fluid
Authors: Hirai E.
Published: June 2004

From time to time, A.I.Ch.E. Journal presents translations of certain technical articles written by our Japanese colleagues in their own language. These translations are made by Kenzi Etani, who received his B.S. in chemical engineering in 1953 at the Tokyo Institute of Technology and his M.S. in 1955 at M.I.T. He is associated with Stone & Webster and is an associate member of American Institute of Chemical Engineers. He is also a member of the Society of Chemical Engineers, Japan, and the Japan Oil Chemists' Society. His offer to help break down the language barrier is acknowledged.

The following article was published in Chemical Engineering (Japan), 21, pages 17–25 (1957).

Abstracts, notation, literature cited, tables, and figure captions not published here appear in English in the original paper. No figures will be reproduced in these translations.
Effect of a volume heat source on free‐convection heat transfer
Authors: Randall I. E. , Sesonske Alexander
Published: June 2004

Heat transfer to a horizontal cylinder from an ordinary fluid containing a volume heat source was studied analytically. The first approach to this problem was to assume that the heat source existed only in the boundary layer surrounding the cylinder. By solving the equations for a vertical flat plate cooling the ambient fluid and applying the results to a horizontal cylinder, one could determine the effect of a volume heat source on the heat transfer coefficient for the cylinder case. The variables studied were volume heat sources from 0 to 300 B.t.u./(sec.)(cu. ft.) and temperature difference across the boundary layer in the range 20° to 100°F.

In the laminar‐flow region a volume heat source was found to increase the heat transfer coefficient for any given temperature difference across the boundary layer. This increase, due to the decrease in boundary‐layer thickness caused by the volume heat source, was moderate, being about 20% for a 1 1/4‐in. O.D. cylinder with a heat source strength of 100 B.t.u./(sec.) (cu. ft.) and a temperature difference across the boundary layer of 20°F.
Mass transfer from a solid sphere to water in highly turbulent flow
Authors: Steele L. R. , Geankoplis C. J.
Published: June 2004

Mass transfer coefficients from 1/2‐in. spheres of benzoic and cinnamic acids and 2‐napthol to water were measured in the high Reynolds number region of 600 to 140,000. Previous data for liquids extended only to a Reynolds number of 11,000. Three separate and approximately parallel lines of JD vs. Reynolds number were found for the different solutes, and the shape of the curves was found to be similar to the total‐drag‐coefficient correlation for spheres.

Experiments with benzoic acid and 2‐napthol showed an effect of driving force and hence flux on the JD values. Mass transfer did occur in saturated solutions having zero driving force. When one subtracted the amount of mass transfer at zero driving force from the values at other driving forces, the corrected JD values at different driving forces were the same for a given solute. Possible explanations may be the effect of extreme turbulence on crystallization or physical attrition.
Chromatographic columns containing a large number of theoretical plates
Authors: Said A. S.
Published: June 2004

To obtain numerical answers for the concentration distribution of solute on a chromatographic column or in the effluent, tables and charts of the Poisson distribution are used. Their use however is limited to a small number of theoretical plates. The transformation of the Poisson to the normal distribution enables the calculations to be performed for any number of theoretical plates through the use of the normal distribution tables.

Equations derived previously for columns containing a large number of plates and employing elaborate mathematical procedures and approximations have been simply deduced by applying a limit property of the Poisson distribution to the exact equations.

A relationship between the Poisson and normal distribution is derived, and charts are drawn which allow the rapid evaluation of the Poisson in terms of the normal values.
Two‐dimensional laminar‐flow analysis, utilizing a doubly refracting liquid
Authors: Prados John W. , Peebles F. N.
Published: June 2004

An experimental technique for the determination of velocity distributions in two‐dimensional laminar flow is described. The method utilizes the optical interference patterns observed in flowing doubly refracting liquids when viewed by transmitted polarized light. The fluid shear‐stress distribution may be determined from these interference patterns by methods similar to those employed in solid photoelasticity. Methods are presented for the calculation of velocity distributions from the observed stress distributions. Experiments are described in which the technique was applied to determine velocity profiles in parallel‐walled, converging and diverging channels and for flow about a cylindrical obstacle. The doubly‐refracting liquids employed were aqueous solutions of an organic dye. Independent experimental checks were obtained in most instances, and these are in satisfactory agreement with the calculated results.
The dynamics of heat removal from a continuous agitated‐tank reactor
Authors: Fanning R. J. , Sliepcevich C. M.
Published: June 2004

The present investigation is concerned with the dynamic characteristics of a 12‐in. diameter continuous agitated‐tank reactor vessel. Response of the vessel effiuent temperature to a change in coolant flow rate through an internal cooling surface is the subject of theoretical and experimental study. Experimental data were obtained through the use of frequency and transient response techniques. Studies were made for the passage of vessel‐charge fluids with widely differing physical properties. Also data were taken for various conditions of fluid turbulence both inside and outside the internal heat transfer coils. Experimental and theoretical results are graphically compared. Recommendations are presented for the development of theoretical dynamic relationships.
Turbulent liquid flow down vertical walls
Authors: Belkin H. H. , Macleod A. A. , Monrad C. C. , Rothfus R. R.
Published: June 2004

Photoggraphic methods have been used to study the behavior of water flowing freely down vertical surfaces under the influence of gravity at Reynolds numbers between 200 and 30,000. The physical appearances of the liquid layers in transitional and fully turbulent flow have been noted. Layer thicknesses have been obtained from high‐speed photographs and correlated with liquid Reynolds numbers, the range of experimental data thus being extended into the fully turbulent region. A simple basis of comparison with flow between parallel plates has been developed.
Rate constants and molecular structure
Authors: Johnston Harold S. , Pitzer Kenneth S.
Published: June 2004

The methods of relating parameters in the Arrhenius rate equation to fundamental molecular properties are briefly reviewed. The limited applicability of purely theoretical methods is noted, the use and limitations of the standard semiemprical method are surveyed, and recent work based on empirical molecular structure and spectroscopy is described in detail. The recent method makes no attempt to calculate activation energy, but within a limited range of cases it does provide a reliable method of estimating the preexponential factor in the Arrhenius equation and calculating the kinetic isotope effect. In this way the method provides a check on the credibility of experimental data and on the assignment of mechanism. If the mechanism is correct, it provides a method of estimating activation energy from rate data taken at only one temperature. Further developments of this method are anticipated.
Performance of packed columns: V. Effect of solute concentration on gas‐phase mass transfer rates
Authors: Shulman H. L. , Delaney L. J.
Published: June 2004

In a determination of the effect of solute concentration on gas‐phase mass transfer rates carbon tetrachloride was vaporized at three different concentration levels in a short 4.0‐in.‐diameter column packed with 0.5‐in. Raschig rings.

The experimental data indicate that previous mass transfer correlations should be modified to include a term (PBM/PT)2/3 and that the Schmidt number should be evaluated at average film conditions.

The correlation found is suitable for predicting gas‐phase mass transfer coefficients which can be combined with effective interfacial areas reported previously to obtain volumetric mass transfer coefficients for any gas‐liquid‐solute system.
Effect of liquid on interparticle forces in gas‐fluidized beds
Authors: Parker Harry W. , Stevens William F.
Published: June 2004

In an investigation of the behavior of an air‐fluidized bed of glass spheres under varying interparticle forces, the results obtained are explained by hypothesizing the coexistence of particulate and aggregative fluidization. As interparticle forces are increased, a greater portion of the particles are in aggregative fluidization, resulting in a decrease in bed height. In this study water added to the fluidizing air increased the interparticle forces. Up to 0.5 mass % water was used, with a fluidized bed of glass spheres 0.013 to 0.035 in. in diameter. The resulting decrease in bed height has been correlated by means of a theoretical equation for the increase in interparticle forces due to the added water.
An experimental study of diffusion‐controlled reactions in a laminar boundary layer
Authors: Litt Mitchell , Friedlander S. K.
Published: June 2004

A brief review is presented of the theoretical solution obtained by the authors to the problem of a rapid second‐order reaction in the incompressible laminar boundary layer on a flat plate. An experimental system is described for investigating reactions of this type, specifically the dissolution of plates and cylinders of benzoic and cinnamic acids in aqueous solutions of sodium and potassium hydroxide. Experimental data are reported in terms of a reaction factor, that is the ratio of the transfer rate with reaction to that in the absence of reaction. The reaction factor is independent of position. The theory closely predicts the reaction factor for cylinders as well as for flat plates. Data obtained by other investigators for packed beds can also be correlated although less successfully.
Radiative and conductive heat transfer in a quiescent gas‐solid bed of particles: Theory and experiment
Authors: Hill F. B. , Wilhelm R. H.
Published: June 2004

This paper concerns a study of radiation as a contributing mechanism in the transfer of heat between discrete solid particles. A theory for transfer in such systems is generalized to include planar‐, spherical‐, and cylindrical‐bed geometries; because of the particulate nature of the system the generalization is given in terms of finite‐difference equations. Transfer experiments were performed in a quiescent cylindrical bed with an axial heat source and a cylinderical containing‐wall sink. Heat fluxes and radial‐temperature profiles were measured. As the experiments were arranged, only modest temprature gradients were established between source and sink, but the ambient sink temperature was taken in steps from 100° to 1,000°C. For a bed of 3.8‐mm.‐diameter alumina spheres the ratio of heat transferred by radiation to that transferred by conduction was estimated to increase with average bed temperature from the order of 0.1 at 100°C., to 1.2 at 1,000°C. The effects of temperature on bed reflectivity and transmissivity and on apparent boundary‐temperature discontinuities are discussed.
The enthalpy of water in the liquid state
Authors: Byrne Robert , Thodos George
Published: June 2004

The enthalpy of water in the liquid state has been calculated from 32°F. to temperatures approaching the critical and pressures ranging from saturated conditions to 160,000 lb./sq. in. abs. (approximately 11,000 atm). The results of this study are presented graphically and show that the influence of pressure on enthalpy is significant, particularly in the lower temperature region. At these conditions pressure is found to increase the enthalpy of liquid water by as much as 360 B.t.u./lb. above the corresponding enthalpy of the saturated liquid state.

A comprehensive literature search disclosed PVT data for water that permitted the construction of a density correlation. This correlation expressed in reduced coordinates extends from the normal freezing point of water to temperatures of 1,870°F. (TR = 2.0) and pressures ranging up to 10,915 atm. (PR = 50). The recent extensive PVT data of Kennedy reported in 1950 supplemented with the earlier data of Amagat and Bridgman allowed the calculation of enthalpies at these elevated temperatures and pressures. For these calculations basic thermodynamic relationships were adapted which utilized this reduced density correlation. This approach has made possible the extension of the thermodynamic properties of liquid water above the highest pressure reported by Keenan and Keys. Below this pressure of 6,000 lb./sq. in abs. good agreement was found to exist between the enthalpy values presented by Keenan and Keyes and those reported in this investigation.
Thermodynamic behavior of hydrogen‐hydrocarbon mixtures
Authors: Motard R. L. , Organick E. I.
Published: June 2004

By use of the Benedict‐Webb‐Rubin (BWR) equation of state an attempt has been made to correlate experimental vapor‐liquid equilibrium data on hydrogen‐methane‐propane mixtures in the temperature range from 0° to −250°F. and pressure range from 500 to 1,500 lb./sq. in. abs. Considerable improvement in hydrogen K values has been obtained by adjusting the coefficient ν in the BWR equation for hydrogen. In the final adjustment it was necessary to specify a new value of ν for hydrogen at each temperature. The root‐mean‐square deviation of calculated from observed K values for hydrogen is 6.6%

As a further check the recommended BWR coefficients for hydrogen have been used to calculate the low‐temperature hydrogen K values in mixtures with ethane and ethylene with good results.

The predicted K values for propane at temperatures below −150°F. have not been altered and are still in error by as much as 2 orders of magnitude.
Thermal conductivity of packed beds
Authors: Schotte William
Published: June 2004

A correlation has been developed to predict the thermal conductivity of packed beds for various conditions of pressure, temperature, and particle size. The correlation takes into account the reduction in thermal conductivity of the gas phase at lower pressures when the mean free path of the gas molecules is of the same order as the distance between particles which are effective in transferring heat. Radiation becomes significant for large particles and high temperatures. A new relationship for the radiation contribution to the thermal conductivity of packed beds has been developed.
Flow patterns in agitated vessels
Authors: Metzner A. B. , Taylor J. S.
Published: June 2004

The flow patterns obtained when viscous fluids are agitated inside baffled cylindrical tanks have been studied in both Newtonian and non‐Newtonian systems. The experimental technique consisted of observing the motions of small tracer particles in highly illuminated, narrow beams of light.

The results may be broken down into two major categories. The first was a qualitative comparison between the flow patterns obtained in non‐Newtonian and Newtonian fluids of the same general viscosity levels. This part of the study included observation of changes in the flow fields as one moves from laminar into turbulent conditions for both fluid systems.

The second portion of the paper deals with quantitative determinations of local flow velocities, shear rates, and power‐dissipation rates in various parts of the vessel. The following conclusions may be drawn from these measurements.

1. Local fluid shear rates were found to be directly proportional to impeller speed, in both Newtonian and non‐Newtonian systems. As would be expected, the shear rates decreased more rapidly with increasing distances from the impeller in pseudoplastic non‐Newtonian fluids than in Newtonian systems.

2. The rates of local power dissipation decreased rapidly with distance from the impeller.

3. The fluid velocities in the horizontal plane of the impeller varied almost linearly with rotational speed in the Newtonian systems, in accordance with prior observations. On the other hand, movement in pseudoplastic systems increased exponentially with impeller speed. This effect, like the dampening of shear rates, is caused by the cumulative effects of local velocity and viscosity changes in these systems. (Increases in velocity decrease the fluid viscosity, which in turn causes further increases in velocity, etc.)

This work serves to define pertinent problems which are of importance in determining mixing rates, on a microscopic scale. Efforts may now perhaps be turned more profitably than before toward macroscopic fluid‐mixing studies.
Chemical process principle, part II, thermodyanamics, 2 ed., O. A. Hougen, K. M. Watson, and R. A. Ragatz. John Wiley and Sons, New york(1959). 537 pages. $9.75
Authors: Butt John B.
Published: June 2004

No abstracts.
A corresponding‐states correlation for higher molecular‐weight liquids
Authors: Bondi A. , Simkin D. J.
Published: June 2004

A corresponding‐states correlation for the liquid‐state properties of higher molecular‐weight substances is presented which contains as reducing parameters the readily measurable (and correlatable) energy vaporization and van der Waals volume instead of the often inaccessible critical constants. One additional parameter characterizing molecular flexibility is introduced.

A single curve of the new reduced density ρ* vs. the new reduced temperatureT* is shown to represent the atmospheric‐pressure‐density‐temperature relations of paraffinic, naphthenic, and aromatic hydrocarbons with 10 or more carbon atoms per molecule to within ±1% between their melting and their atmospheric boiling points. The reduced surface tension is shown to be a unique function of ρ± for many compounds, thus permitting prediction of surface tension over wide ranges of temperature. The heat‐capacity difference between liquid and vapor proved to be easily correlatable with ρ±. Finally the compression of numerous hydrocarbons proved to be well correlated in terms ofT*, ρ±, andP*. Extensive group data forVwandE° have been assembled in the appendix in order to enable others to use the proposed method without effort.
Concurrent gas absorption mass transfer
Authors: Dodds W. S. , Stutzman L. F. , Sollami B. J. , McCarter R. J.
Published: June 2004

Concurrent flow in gas absorption may be used to practical advantage when liquid partial pressure is minor. The higher transfer coefficients of this operation are reported and analyzed in reference to pertinent variables.
Critical temperatures and pressures of organic compounds
Authors: Forman Charles J. , Thodos George
Published: June 2004

The approach presented for the prediction of critical temperatures and pressures for hydrocarbons from the van der Waals' constants a and b (1) has been extended to permit the estimation of these constants for other organic compounds. Analogously, contribution values for a number of functional groups have been established, and the majority were found to depend on the size of the organic molecule. Information presently available in the literature (4) has permitted the establishment of values for functional groups in organic compounds of the following types: alcohols, phenols, ethers, ketones, carboxylic acids and esters, amines, nitriles, and halides. These functional group contributions, in conjunction with the values previously developed for the hydrocarbons, now make possible the calculation of both van der Waals' constants from only structural considerations. Once these van der Waals' constants have been established, the critical temperature and pressure are readily calculated.

With the approach developed in this investigation critical temperatures and pressures for eighty‐one organic compounds have been calculated and when compared with literature values produced average absolute deviations of 1.36% for the critical temperature and 2.32% for the critical pressure.
Heat transfer to liquid streams in a packed tube containing large packings
Authors: Chennakesavan Balapa
Published: June 2004

Wall‐area heat transfer coefficients based on bulk‐mean temperatures of the liquids flowing upward in a steam‐jacketed packed tube (4 ft. long and 2.25‐in. I.D.) were determined. The tube was randomly packed in each of the experiments with spherical glass packings of uniform size (with diameters between 3/4 and 5/32 in.). The liquids used were water, toluene, 45% aqueous glycerine, and nitrobenzene.

Analogous correlations were developed for the heat transfer coefficients and for pressure drop, the dimensionless groups in the above being the same as for open tubes. The two relationships are applicable for the range inDT/DPratio from 14 to 3 and inNRefrom 40,000 to 300. The first is satisfactory within ±15% for heating of liquids in the above packed tube, the second within ±10% for most of the data of packed tubes reported so far.
Natural convection inside a horizontal cylinder
Authors: Martini William R.
Published: June 2004

The two vertical halves of the wall of a 4.3‐in. I.D. cylinder were maintained at different uniform temperatures. The rate of circulation of air inside the cylinder and the local rate of heat transfer between the wall and air were derived from measurements of the velocity and temperature fields in the air for wall‐temperature differences from 3.5° to 367°F. The overall rate of circulation was found to increase quite rapidly and then to decrease slowly as the wall‐temperature difference was increased. The over‐all Nusselt number based on the wall‐temperature difference was found to have an approximately constant value of 7.0.

Numerical solution of the partial differential equations describing the conservation of mass, momentum, and energy for this system was investigated with an IBM‐650 magnetic drum computer. Instabilities in the computational procedure and limitations of this computer prevented solution of the general problem. However specification of the velocity field obtained from experiment yielded a numerical solution for the temperature field in good agreement with the experimental measurements.
The thermal entrance region in fully developed turbulent flow
Authors: Abbrecht Peter H. , Churchill Stuart W.
Published: June 2004

The temperature profile and the local rate of heat transfer from the wall were measured at 0.453, 1.13, 4.12, and 9.97 tube diameters downstream from a step increase in wall temperature for air in fully developed turbulent flow at Reynolds numbers of 15,000 and 65,000 in a 1.52‐in. tube. The velocity profile and the pressure were also measured at these lengths.

Radial and longitudinal temperature gradients, radial heat fluxes, and eddy diffusivities for heat and momentum transfer were computed from the measurements. The longitudinal temperature gradients at all radii were found to differ significantly from the mixed mean temperature gradient. Although the radial heat flux was a maximum at the wall, the radial heat‐flux density, in terms of which the eddy diffusivity for heat transfer is usually defined, was found to go through a maximum near the wall and then to decrease almost linearly across the thermal boundary layer. The eddy diffusivity for heat transfer was found to be independent of length in the thermal entrance region and hence a function only of the fluid motion, as previously hypothesized.
Mass transfer coefficients for solids suspended in agitated liquids
Authors: Barker James J. , Treybal Robert E.
Published: June 2004

The mass transfer coefficient in covered, right‐cylindrical tanks full of liquid, turbulently agitated at various speeds by turbines with six flat blades, was measured by the rate of solution suspended solids in water and in 45% sucrose solutions.

Screened crystals in the following U. S. mesh sizes were used: boric acid: 18/20, 16/18, 16/20, 14/16, 12/14, 10/12, 8/10, 6/8; rock salt: 6/8, 4/6. Pellets were benzoic acid: 0.126 in. long by 0.218‐in. diam.; salt: 0.565‐in. diam. by 0.531‐in. long (over rounded ends). Tanks were 6, 12, 18, and 30 in. Turbines were 2, 3, 4, 6, 9, and 12 in. in diameter, centrally located. Four full‐length baffles 10% of the tank diameter wide were spaced at 90 deg. A few runs were made without baffles.

The coefficient of mass transfer was found to be independent of particle size and Schmidt member (NSc = 735 to 62,000) and could be correlated with turbine Reynolds number in each tank, with larger tanks yielding smaller coefficients at the same NRe. An empirical equation which fits all the data from the baffled tanks within about 4% (in the range 0.1 < k < 2) is

where l2=0.8235−1.544V1/3+0.115V2/3The variance of estimate for this expression i s 0.0383, in units of [ln(10 k)]2.For extrapolation outside the experimental range of vessel sizes it is recommended that l1 = 0.676 − 1.266 V1/3 be used in place of I2. NRe = T2n/v. The results indicate that power per unit volume for a given k goes through a maximum, with the following relative values for the 6‐, 12‐, 18‐ and 30‐in. tanks: 1, 1.73, 1.78, 0.62.A treatment of the data according to dimensionless groups provides another correlation:kd/D=0.02NNt is shown that for the systems used 1/D is essentially proportional to N, and so the effect of diffusivity here is only apparent.
Continuous‐throughput rectification of organic liquid mixtures with thermal‐diffusion columns
Authors: Longmire David R.
Published: June 2004

Experiments were carried out with cylindrical thermal‐diffusion columns in which the separation chambers were sufficiently narrow so that curvature effects might be ignored. For both open and closed operation, results were obtained for the two binary systems benzene‐carbon tetrachloride and n‐heptane–benzene as well as the ternary mixture n‐heptane–methylcyclo‐hexane‐toluene. For the binary systems, correlations are given in terms of dimensionless combinations which arise when the equations of conservation are placed in dimensionless form. The thermal‐diffusion coefficients used in the correlations are literature values determined in steady‐state–cell (no convection) measurements.
Correlating criteria for liquid‐phase adsorption
Authors: Jones Herbert L. , Stuart Edward B.
Published: June 2004

A correlating equation for selective adsorption in the liquid phase has been extended to predict accurately the benzene‐cyclohexane equilibrium data on silica gel. Gel pore diameters range from approximately 25 to 150 Å. and temperatures between the boiling and freezing points of the pure components.
Calculation procedures for binary batch rectification
Authors: Huckaba Charles E. , Danly Donald E.
Published: June 2004

A rigorous mathematical description, consisting of differential‐difference equations, is presented for binary batch rectification in the plate type of column. Two approaches are taken to solving these equations for the condition of constant reflux ratio: an integration by numerical means employing an IBM 650 computer, and a hand calculation procedure that involves trial‐and‐error computation of batch‐rectification curves, which is of interest primarily where high‐speed computing equipment is not available.

Enthalpy balances are used to avoid assumption of equal rate of overflow in the tower; weight units are used instead of mole units; means for accounting for holdup in the condenser‐accumulator system are described. Criteria of convergence and stability of the numerical solution are presented. The validity of the results of the proposed calculation procedures is substantiated by the close agreement of experimental and calculated batch‐rectification curves.
Ion exchange kinetics for systems of linear equilibrium relationships
Authors: Tien Chi , Thodos George
Published: June 2004

The mathematical equations describing the kinetic behavior of ion exchange processes have been solved analytically for systems having linear equilibrium relationships of the type q* = K1 + K2C*. The concentration ratios of the effluent to the influent solution for these cases are found to depend on parameters involving time, position, and relative resistances of the liquid and resin phases. Numerical results have been obtained and are presented in tabular and graphical forms. Furthermore expressions for the constant pattern breakthrough curve for two special cases have also been worked out.
The dual nature of a catalytic reaction: The dehydrogenation of sec‐butyl alcohol to methyl ethyl ketone at elevated pressures
Authors: Thaller Lawrence H. , Thodos George
Published: June 2004

A detailed analysis of initial rate data obtained for the catalytic dehydrogenation of sec‐butyl alcohol to methyl ethyl ketone in the presence of brass reveals that the controlling step of the reaction changes and depends on the operating conditions. To take advantage of the unique characteristics of initial rate equations, the experimental phase of this work has been carried out with a differential reactor and covered the temperature range 550° to 700°F. for pressures up to 15 atm. Feed compositions containing sec‐butyl alcohol and mixtures with methyl ethyl ketone and hydrogen were used.

These studies show that the desorption of molecularly adsorbed hydrogen ceases to be the controlling step in favor of a dual‐site surface reaction depending on the operating variables. In view of these observations it now becomes necessary to calculate reaction rates with both over‐all rate equations and to select the lower rate as representative of the controlling step of the reaction.
A study of sieve‐tray efficiencies
Authors: Hay J. M. , Johnson A. I.
Published: June 2004

The performance of sieve trays in the rectification of the methanol‐water system without entrainment or leakage from the perforations was studied in an 8‐in.–diameter five‐tray column. The trays had a 2‐in. weir height and 4‐in. length of liquid path. Three tray geometries were studied: 1/4‐in. diameter holes on 3/4‐in. triangular spacing, 1/8‐in. holes on 3/8‐in. triangular spacing, and 3/16‐in. on 7/16‐in. triangular spacing. The superficial vapor velocity was varied from 2.2 ft./sec. to the limit of stable operation, which for this apparatus was 4.4 ft./sec. The ratio LM/VM within the column was varied from 1 to 0.5. The Murphree plate efficiency varied greatly from 105% at low concentration to 82% at high concentrations of methanol. Variations of 10 or 12 efficiency % were noted owing to changing velocities and tray geometries. Measurements of concentration gradients, foam heights, and gas pressure drops are also reported. This paper proposes a method of calculating the point efficiency and the number of individual‐phase mass transfer units independent of the actual concentration gradient on the tray.

The method is applied to the methanol‐water data, and calculated point efficiencies range from 50 to 65%. The value of 1/NL for the methanol‐water system is found to be small. The values of NG and the effect of the velocity on NG are believed to be the first in the literature for a tray in distillation operation. The effect of velocity is shown to be in agreement with the theory proposed by Gerster and co‐workers. It is shown that kG' aG decreases for increasing free area and increasing hole size. Finally variation in LM/VM is shown to have little effect on EMV.
Comparison of the specific resistances of cakes formed in filters and centrifuges
Authors: Valleroy V. V. , Maloney J. O.
Published: June 2004

Resistances to the flow of fluids through porous beds were determined in a compression‐permeability cell, a vacuum test filter, and an experimental centrifugal filter. The study was made on nearly incompressible beds composed of Lucite spheres having a given size distribution. The results show that liquid flow through the cakes in all three kinds of equipment can be described by a common basic equation, the terms of which are modified to reflect the type of operation. The centrifugal‐drainage data confirm the form of the centrifugal‐filtration equation. The specific resistances deduced from vacuum‐filtration and centrifugal‐drainage tests agree with permeability‐cell alphas within 16% at the same Δ P and within 2 to 3% at the same porosity.
Rigorous solution of multicomponent, multistage extraction problems
Authors: Smith Buford D. , Brinkley W. K.
Published: June 2004

A new rigorous calculation and convergence method for multicomponent equilibrium stage processes is presented, and the application to multicomponent, multistage extraction problems is described. The application to the vapor‐liquid equilibrium stage processes is discussed briefly.
A boundary‐layer model of fluid‐particle mass transfer in fixed beds
Authors: Carberry James J.
Published: June 2004

The process of fluid‐particle mass transfer in fixed beds at Reynolds numbers less than 1,000 is viewed in terms of transient molecular diffusion within a boundary layer which is developed and destroyed repeatedly as the fluid journeys through the bed. Literature data support the j factor derived from the premises of the model. The theory predicts a Schmidt number exponent of 2/3 for NSc ≧ 1; however this exponent should approach 1/2 for NSc < 1.
Performance of packed columns: VI. Mass transfer rates for dehumidification at high solute concentrations
Authors: Shulman H. L. , Robinson R. G.
Published: June 2004

Air‐carbon tetrachloride gas streams were dehumidified with cold liquid carbon tetrachloride in a short 4.0‐in. diameter column packed with 0.5‐in. Raschig rings in an attempt to explain reported unsuccessful attempts to correlate dehumidification data obtained at high solute concentration.

The data were in satisfactory agreement with a previously presented correlation if the Schmidt number was evaluated at average film conditions and interfacial conditions were employed with regorous calculation methods to evaluate the mass transfer coefficients.
Heat transfer and kinetics in a catalyst bed of rectangular cross section: Air oxidation of nitric oxide with silica gel
Authors: Jaffer J. H. , Bliss Harding
Published: June 2004

The results of an investigation of heat transfer and reaction kinetics in a fixed‐bed catalytic reactor of slab geometry are described. The particular reaction studied is the air oxidation of nitric oxide with silica gel. Conversions and catalyst‐bed temperatures were observed in the experimental, nonisothermal slab reactor, but only a sample of these data are reported and analyzed here.

A mathematical analysis of the processes occurring in a slab reactor has been developed which leads to a design method for such reactors that permits prediction of catalyst‐bed temperatures and conversions from a knowledge of specific reaction rates and the physical properties of the system. The design method involves a step‐by‐step procedure but requires a small number of steps. To evaluate the accuracy of the design method and to illustrate its use, the specific reaction‐rate data together with published thermal‐conductivity data have been used with the method to predict the results of a run on the experimental nonisothermal reactor. Good agreement between calculated and observed temperatures and conversions was obtained.

Specific reaction rates, derived from integral conversions in an experimental, isothermal reactor, are reported.
Multicomponent diffusion problems
Authors: Hsu Hsien‐Wen , Bird R. Byron
Published: June 2004

Analysis of four three‐component diffusion problems by means of the Stefan‐Maxwell equations is presented. In three of these problems heterogeneous chemical reactions are occurring at a catalytic surface. Characteristic curves are presented for the better understanding of the analytical solutions. The results of one of the exact solutions are compared with those by the effective diffusion‐coefficient approach.
The critical temperatures and pressures of binary systems: Hydrocarbons of all types and hydrogen
Authors: Grieves Robert B. , Thodos George
Published: June 2004

A method of the prediction of the critical temperatures and pressures of mixtures has been developed, primarily on the basis of data for binary hydrocarbon systems available in the literature. These mixtures may contain aliphatic (normal paraffinic, isoparaffinic, and olefinic), naphthenic, and aromatic hydrocarbons as well as hydrogen. The mixtures may be of varying complexity, and, although this method has been tested chiefly on binary systems, it has been applied to a limited number of mixtures containing more than two components.

This study introduces two dimensionless temperature parameters, γ and θ, which account for the composition of the mixture and for the nature of the components involved. These parameters are defined by the molar average boiling point, the boiling point, and the dew point, all at atmospheric pressure. For a given composition the ratios of the actual critical values to the pseudocritical values have been found to be functions of γ and θ. These relationships are presented graphically and permit the direct calculation of the critical temperature and pressure of the mixture.

The validity of this method has been checked not only on the binary systems used to obtain these correlations but also on binary and ternary systems which have not been included in this development. Critical values for eighteen systems, consisting primarily of two components, have been calculated for ninety‐six compositions and have been compared with the experimental values presented in the literature. For temperature the average absolute deviation has been found to be 0.76% (based on degrees Rankine) and for pressure, 2.7%. The results for the majority of these systems have been compared with values calculated by the methods of Eilerts et al. (4), Organick and Brown (15), Kurata and Katz (11), Mayfield (12), and Smith and Watson (23).
Vapor pressures: Unsaturated aliphatic hydrocarbons
Authors: Smith Charles H. , Thodos George
Published: June 2004

Vapor‐pressure data available in the literature for olefins, diolefins, and acetylenes have been used to establish the constants of the Frost‐Kalkwarf equation (9). This equation requires the establishment of constants A, B, C, and D and defines accurately the vapor‐pressure function ever the complete range included between the triple point and the critical point. Constant D has been shown to be equal to a/2.303R2. Both van der Waals' constants can be predicted from the molecular structure (33), thus enabling the calculation of the critical temperatures and pressures for these unsaturated hydrocarbons. Constant B has been found also to depend on the molecular structure of these hydrocarbons.

The normal boiling point of an aliphatic hydrocarbon in conjuction with its critical point and the values B and D calculated from structural considerations permit the calculation of constants A and C. All four vapor pressure constants were calculated for twenty‐seven monoolefins, nine diolefine, and five acetylenes for which reliable vapor‐pressure data are presented in the literature. Comparisons between calculated values and values reported in the literature produced an average percentage deviation of 0.63 for the monoolefins, 2.65 for the diolefins, and 1.13 for the acetylenes. For the forty‐one unsaturated aliphatic hydrocarbons considered in this investigation the average deviation was 1.14% for the randomly selected points of comparison.
Extractive reaction: Batch‐ and continuous‐flow chemical‐reaction systems, concentrated case
Authors: Trambouze P. J. , Piret Edgar L.
Published: June 2004

The theory of extractive reaction is extended to concentrated solutions where the distribution coefficients are no longer constant and where important changes in phase volumes may occur. The methods developed are applicable to simple or complex reactions of any order. Two‐ and one‐solvent systems are treated, and convenient graphical methods are developed and illustrated with numerical examples.
The transition from free to forced convection in mass transfer from solid spheres
Authors: Garner F. H. , Hoffman J. M.
Published: June 2004

Mass transfer rates have been measured at 30°C. over a Reynolds number range of 1 to 130 for the solution of 3/8‐in. diameter spheres of benzoic acid for both upflow and downflow streams. These are compared with similar results for 3/4‐in. diameter spheres and show a gradual transition from forced to free convection. The interaction between the two effects is complex but less marked for the smaller spheres. Free convective effects do not disappear entirely until a Reynolds number of about 250 for the 3/8‐in. spheres, compared with a value of 750 given for 3/4‐in. spheres in the previous work (6).
Formation of interfacial area in immiscible liquids by orifice mixers
Authors: McDonough J. A. , Tomme W. J. , Holland C. D.
Published: June 2004

The interfacial areas formed in various immiscible liquid pairs by an orifice mixer were measured by a photoelectric method, which had been calibrated photographically. In addition to the variation of the liquid pair, total flow rate, volume fraction of the dispersed phase, and the orifice diameter, the pipe diameter of the mixing orifice was also varied. It was found that the formation of interfacial area could be correlated as a function of the change in kinetic energy across the mixing orifice, the energy required to overcome the viscous forces within the dispersed phase, and the volume fraction of the dispersed phase.