bluuebunny/crossref_metadata_2025 huggingface dataset:
Vapor pressures: The saturated Aliphatic Hydrocarbons
Authors: Sondak Norman E. , Thodos George
Published: June 2004

A rigorous analysis of the available data presented in the literature for all the saturated aliphatic hydrocarbons from methane through n‐eicosane was conducted to establish the constants A, B, C, and D of the vapor‐pressure equation developed by Frost and Kalkwarf (21). With all the constants determined, vapor pressures can be calculated accurately from the triple to the critical point. The actual constants A, B, C, and D have been calculated from the available reported vapor‐pressure data of eighty‐seven saturated aliphatic hydrocarbons and include all the normal paraffins through eicosane and all the isomeric paraffins through the nonanes.

In order to ascertain the validity of calculated‐vapor‐pressure constants, values of A, B, C, and D were produced from the molecular structure and normal boiling point for all the normal paraffins through eicosane and all the thirty‐four isomeric nonanes. The normal paraffins were selected to cover the range of the saturated aliphatic hydrocarbons; whereas the nonanes were chosen because they represent the most complex structures for which reported vapor pressures are available.

With the calculated constants, vapor pressures were evaluated from the equation at several representative points and were compared with reported values to produce an overall absolute average percentage of deviation of 0.58 for the normal paraffins and 0.73 for the isomeric nonanes, or 0.68 for these fifty‐four saturated aliphatic hydrocarbons.
Fractionation during condensation of vapor mixtures
Authors: Kent Eric R. , Pigford Robert L.
Published: June 2004

Partial condensers of the reflux type are capable of producing substantial fractionation of vapor mixtures. For vapor products having low dew points they may be preferred to conventional equipment for adiabatic distillation plus total condensation.

Experimental studies of a condenser used to fractionate mixtures of ethylene dichloride and toluene show that observed mass transfer effects are in agreement with the Colburn‐Drew film theory, which accounts for the influence of the net mass exchange on the relative mass transfer rates of the components. In an adaptation of the transfer‐unit concept to partial condensation, new equations are derived relating the number of transfer units to liquid‐ and gas‐phase resistances, surface area, and amount of condensation. Observed resistances to mass transfer agree qualitatively with values independently measured; the diffusional resistance of the liquid phase has a pronounced effect on the fractionation, which does not conform to the Rayleigh theory of equilibrium differential condensation.

Partial condensers appear, to require more interracial area than adiabatic distillation equipment in order to produce the same fractionation at the same heat load; for the same interfacial area condensers require more heat removal.

Although only the system ethylene dichloride‐toluene was investigated here, the results of this work are believed pertinent binary liquid mixtures also. Knowledge of the vapor‐liquid equilibrium relationship of the new system and of the liquid and vapor‐phase transfer coefficients is required in order to employ the calculation methods introduced here.
Rate of rise or fall of liquid drops
Authors: Klee Albert J. , Treybal Robert E.
Published: June 2004

Measurements of the terminal velocity of liquid drops immersed in an insoluble liquid were made for eleven liquid systems, covering a wide range of physical properties: continuous‐phase density 0.960 to 1.145 g./cc., viscosity 0.93 to 1.56 centiposes; dispersed‐phase density 0.807 to 1.674 g./cc., viscosity 0.59 to 72.1 centipoises; interfacial tension 0.3 to 42.4 dynes/cm. A correlation of the data was developed for each of the two velocity‐drop‐diameter regions which permits easy computation of the drop velocities. The correlations are shown to reproduce the present data and much of the published data very satisfactorily. Photographs permitted measurement of the drop eccentricities, which are shown to be a function of the drop diameter, density difference, and interfacial tension.
Fractionation of gas mixtures in a moving‐bed adsorber. II. Equilibrium consideration
Authors: Kapfer William H. , Malow Monroe , Happel John , Marsel Charles J.
Published: June 2004

A method for estimating adsorption equilibria based on a modification of the Polanyi adsorption‐potential theory was developed for use in the investigation described in Part I of this article. In addition, the recently published correlation method of Lewis, Gilliland, Chertow, and Cadogan, suitably modified for the present application, was successfully employed in the correlation and extrapolation of the ternary equilibrium data.
Theoretical‐plate concept in chromatography
Authors: Said Abdel Salam
Published: June 2004

The theoretical‐plate concept in chromatography has been treated on the basis of continuous flow of eluent through the plates of the column. A treatment more precise in principle than the previous treatments is presented. General elution and deposition equations have been derived and applied to special cases of practical interest. The derived formulas have the advantage of precision, generality, and simplicity.

The theory was found adaptable to the treatment of gradient elution and also to the calculation of the fraction of solute which has been eluted or still‐adsorbed on the column during the elution process.

A method for the determination of the number of theoretical plates in a chromatographic column is also described.
Diffusion and reaction in viscous‐flow tubular reactor
Authors: Cleland F. A. , Wilhelm R. H.
Published: June 2004

The effect on point and integral average conversion of chemical reaction, coupled with radial diffusion and radial distribution of reaction times in viscous‐flow tubular reactors, is reported. Solutions are given for first‐order reaction over an extensive range of dimensionless rate and time variables. An expression is given for a criterion of the conditions when the contribution of diffusion is so small that it may safely be disregarded as a variable. Another criterion also is given for the situation when diffusivity is so large, in comparison with other system constants, that the simple plug flow solution may be used without incurring more than a specified error.

The hydrolysis of acetic anhydride was studied in 1/4‐ and 1/2‐in.–diam. reactors in 10‐ and 15‐ft. lengths. Reynolds numbers were between 40 and 400 and temperatures between 25° and 35 °C. It was found that the derived equations form a proper description of experiments in the smaller tube. Deviations from theory in the larger tube are explained in terms of free convection arising from nonisothermal conditions and from concentration gradients in the tube. Grashof criteria for initiation of convection in the system are discussed.
Thermodynamic properties of polar‐nonpolar mixtures: Methanol‐benzene‐hexane system
Authors: McCracken P. G. , Smith J. M.
Published: June 2004

Direct enthalpy measurements were carried out for the methanol‐benzene system as a function of composition, temperature (250° to 500°F.), and pressure (30 to 1,400 lb./sq. in. abs.). From these data pressure‐enthalpy diagrams were prepared to show the enthalpy and entropy above a reference state of saturated liquid at 77°F. Similar results were obtained for a single binary system of methanol and n‐hexane and a single ternary mixture.

The conventional generalized correlations were not satisfactory for predicting vapor‐phase enthalpies for mixtures involving methanol. A new method requiring a knowledge of the heat of dimerization, the equilibrium constant for the reaction, and the interaction constant, is proposed for such polar‐nonpolar systems based upon association of the polar component.

The most striking feature of the data for mixtures was the large heat of mixing in the vapor phase for the systems containing methanol. The same type of equation found suitable for the heat of mixing in the vapor phase was applicable to the liquid data.

From the enthalpy data across the two‐phase region, it was possible to predict a limited amount of information on the compositions of the liquid and vapor phases in equilibrium. An azeotrope exists in the methanol‐benzene system, which at 325°F. contains 75 mole % methanol.
Effect of fluidization on catalytic cumene dealkylation
Authors: Mathis J. F. , Watson C. C.
Published: June 2004

This paper reports a direct experimental comparison of the cracking of cumene in a fluidized bed of silica‐alumina catalyst with the same reaction in a fixed bed. The effects of fluidization on the kinetics of this reaction are interpreted in terms of an empirical approach using effectiveness factors and by a simplified mathematical model.
Thermodynamic properties of tertiary butyl alcohol
Authors: Krone Lester H. , Johnson R. Curtis
Published: June 2004

By use of Cp values from the literature and experimentally determined vapor‐pressure‐temperature and pressure‐volume‐temperature relationships, a thermodynamic network has been established for tertiary butyl alcohol in the range of 78° to 500°F. and 14.7 to 700 lb./sq. in. abs. The results include tabulated values of p, v, T, H, S, f, and Z, as well as the vapor‐pressure‐temperature curve, the critical properties, and constants for the Beattie‐Bridgeman equation.

The original pressure data were accurate to within 0.14% in the high range and to within 4% in the low range. The limits on the experimental volume data were 0.07% for large vapor volumes and 2% for liquid volumes. The temperature was determined to within 0.1 °F., or less than 0.02% of the absolute temperature.

Experimentally determined vapor pressures were found to be lower than those reported in the literature in the range above 1 atm. Values previously reported were obtained by extrapolation of a vapor‐pressure‐temperature relation developed for use at subatmospheric pressures. For pressures below 1 atm. the experimental values agreed with the reported values.
Evolution of gas from liquids flowing through porous media
Authors: Hunt E. B. , Berry V. J.
Published: June 2004

The production of oil and gas by pressure depletion involves both the formation of bubbles and the diffusion of gas from the liquid phase into these bubbles. Studies were undertaken to outline in detail the process of bubble formation when the driving force is small. This work shows that the formation of bubbles is a random process which can, however, be described by a simple probability distribution function. Also, calculations have been made to determine how fast gas will diffuse into uniformly distributed gas bubbles.

These results make it possible to describe the manner in which a gas phase is established during the pressure depletion process. In this process the rate of pressure decline is the most important factor influencing the total number of bubbles produced. Laboratory tests have substantiated the finding that in certain types of porous media the amount of oil recovered is sensitive to the number of bubbles formed.
Correlating kinetic data in reactors: Application to tertiary Butanol dehydration
Authors: Black J. H. , Wright J. H. , Coull James
Published: June 2004

The reactor‐unit concept proposed by Hurt is extended in this paper to include fractional‐order reactions and to show the effect of volume change on the system. Equations defining the reactor unit for homogeneous and heterogeneous reactions are derived.

The catalytic dehydration of tertiary butanol was chosen as a means of studying the validity of the extended reactor‐unit concept. The experimental investigation was conducted over a wide range of flow rates, catalyst bed heights, and temperatures. The result of the application of this modified reactor‐unit expression to the correlation of the data was excellent.
Material transport in turbulent gas streams: Radial diffusion in a circular conduit
Authors: Lynn Scott , Corcoran W. H. , Sage B. H.
Published: June 2004

Experimental studies of the mixing of coaxial streams of a natural gas and air at atmospheric pressure were made at Reynolds numbers of 44,000 and 79,000 under conditions where the turbulent‐velocity profile of nearly uniform flow was altered as little as feasible by the blending of the two streams.

Total diffusivities of natural gas in air for the region near the center of the conduit were computed from the data for turbulent, steady, nonuniform flow. The total diffusivities were found to be rather complicated functions of the conditions of flow. Limitations in the configuration of the apparatus did not permit a study of the behavior of the total diffusivities to be made over as wide a range of flow rates as would be necessary to investigate the large‐scale trends indicated by this study.
Liquid‐liquid extraction in a pulsed perforated‐plate column
Authors: Li W. H. , Newton W. M.
Published: June 2004

Liquid extractions of benzoic acid–toluene solutions by means of water were studied under varying flow rates of both solvents in a 2‐in. perforated‐plate column to which pulsations of different frequencies and amplitudes were applied. Studies on reversal of the phase of the dispersion were made. With fixed flow rates of both solvents, the rate of extraction increased much more rapidly when the flow through the perforation became turbulent. The results are correlated by means of Reynolds number based on the flow through the perforations and are calculated from the product of the frequency and amplitude of the pulsations.
Effect of concentration level on mass transfer rates
Authors: Westkaemper L. E. , White Robert R.
Published: June 2004

Carbon tetrachloride was evaporated into a stream of air over ranges of gas concentration from 0 to 0.70 mole fraction carbon tetrachloride, Reynolds number from 600 to 15,000, and Schmidt number from 0.23 to 1.17. The data were correlated by an equation and also by a computer solution to the differential equation describing mass transfer from values of eddy viscosity and eddy diffusivity obtained from the literature.
Vapor‐liquid equilibria of nitrogenargon‐oxygen mixtures
Authors: Latimer R. E.
Published: June 2004

The equations and graphs presented here for the vapor‐liquid equilibrium of the nitrogen‐argon‐oxygen low‐temperature system are based on published binary and ternary experimental data involving mixtures of nitrogen, argon, and oxygen, and on careful thermodynamic study over a period of years of accurate plant‐performance data on tall, large air‐rectifying columns operating near the minimum reflux ratios. The plants have achieved separations that are impossible according to some of the published equilibrium data, and thus the plant data have made a major contribution toward the preparation of this paper.
Axial mixing of binary gas mixtures flowing in a random bed of spheres
Authors: McHenry K. W. , Wilhelm R. H.
Published: June 2004

Measurements are reported on axial mixing of binary gas mixtures at room temperature and atmospheric pressure in a random bed of spherical particles. By means of the Fick's Law equation for diffusion an axial Peclet number, dp U/Ez (where dp is particle diameter, U is interstitial velocity, and Ez is axial eddy diffusivity), was computed in terms of the ratio of the amplitudes of a sinusoidal concentration wave at the inlet and outlet of the bed. An experimental method was devised to eliminate end effects in the system. For the gas systems H2N2 and C2H4N2 and for Reynolds numbers between 100 and 400 the mean of twenty‐one determinations of axial Peclet number was 1.88 ± 0.15. This value is in excellent agreement with a value of 2.0 predicted theoretically on the assumption that the bed acts as a series of n perfect mixers, where n is the number of particles traversed between inlet and outlet.

Axial diffusivity for turbulent flow of gases among particles is about sixfold larger than radial diffusivity, previously determined. It is suggested that axial diffusivity may not, perhaps, be neglected in contacting devices, such as adsorbers and catalytic reactors.
Heats of mixing of liquids
Authors: Schnaible H. W. , Van Ness H. C. , Smith J. M.
Published: June 2004

Experimental data are presented for the heats of mixing of liquids at 25°C. and 1 atm. pressure for ten binary and five ternary systems. For nonpolar binary systems a two‐constant equation has been developed which correlates the data within experimental accuracy. Several equations which have been proposed for the calculation of ternary heats of mixing from binary data are tested for the systems studied. The method of Jost and Röck (4) for determining the constants in power‐series functions from experimental data is considered.
Densities of liquid‐acetone‐water solutions up to their normal boiling points
Authors: Thomas K. T. , McAllister R. A.
Published: June 2004

The densities of acetone‐water liquid solutions have been measured over the entire composition range from 20°C. to within 3° to 7°C. of the normal boiling point of the mixture. The density was measured with a Robertson pycnometer (13), which was modified slightly. The density values are thought to be accurate to within ±0.00005 density units. The technique for determining density values of the volatile mixture near the boiling temperature is given in some detail. The refractive index (nD25) of pure acetone has been redetermined and equals 1.35596 ± 0.00003.
A study of laminar‐flow heat transfer in tubes
Authors: Gross Joseph F. , Van Ness H. C.
Published: June 2004

The general problem of heat transfer to fluids in laminar flow in tubes is discussed, a new procedure for the measurement of local laminar‐flow heat transfer coefficients is described, and an empirical equation is presented for the correlation of data for local heat transfer rates to liquids flowing upward in laminar flow in vertical tubes under conditions of constant heat flux at the tube wall.
Ion exclusion equilibria in the system glycerol–sodium chloride–water–Dowex‐50
Authors: Shurts Edward L. , White Robert R.
Published: June 2004

Ion exclusion is an operation in which an ion exchange resin is used to separate an electrolyte from a nonelectrolyte in a polar solvent. An ion exchange resin tends to absorb a nonelectrolyte and to exclude an electrolyte. This is described quantitatively by the equilibrium distribution of the electrolyte, the nonelectrolyte, and the solvent between the resin phase and the liquid phase surrounding the resin.

As no ternary distribution data applicable to ion exclusion are available, and only a few binary data have been published, a principal purpose of this investigation was to determine the distribution data for a typical system: glycerol‐sodium chloride‐water‐Dowex‐50.
Separation of liquids by thermal diffusion
Authors: Powers John E. , Wilke C. R.
Published: June 2004

Data were obtained in flat‐plate continuous‐flow thermogravitational columns to check the theory developed by Furry, Jones, and Onsaer and a modification of this theory proposed by the authors. Separations of ethyl alcohol–water and benzene–n‐heptane mixtures were measured, flow rate, column length, temperature difference, spacing between plates, and inclination of the plates being varied in the experiments. Theory and data are in qualitative agreement for the range of variables studied. Quantitative agreement exists between theory and experiment in the region of practical design for liquid‐thermal‐diffusion plants.

Equations to aid in the design of thermal‐diffusion plants are developed, and a plant to treat 1,000 bbl./day of a liquid aromatic‐aliphatic mixture is designed and costs are estimated.
Radioisotope technique for the determination of flow characteristics in liquid‐liquid extraction columns
Authors: Markas S. E. , Beckmann R. B.
Published: June 2004

A radioisotope technique has been utilized to study the point holdup of the dispersed phase and some operational flow characteristics in a packed countercurrent liquid‐liquid extraction tower. The system used was toluene‐water and the packing was Raschig rings. The toluene dispersed phase was tagged with gamma‐radiating iodine‐131.

The study revealed that holdup experiences a hysteresis cycle with variations of the continuous‐phase flow rate. Correlating equations are presented for “total” and permanent holdup, below loading, to account for this hysteresis. Entrance effects and flow maldistribution effects are readily determined by the method utilized. Displacement studies demonstrated that no simple “operational” dispersed‐phase flow holdup exists, but rather a complex dispersed‐phase movement, which involves all the “nonhysteresis” permanent holdup.
Flow of steam‐water mixutures in a heated annulus and through orifices
Authors: Hoopes John W.
Published: June 2004

Values of total pressure drop are presented for the flow of vaporizing water in an internally heated 1‐in. I.D. by 1½‐in. O.D. annulus at mass velocities of 270 to 1,440, lb./(sec.)(sq.ft.), pressures of 9 to 180 lb./sq. in., and up to 0.34 fraction by weight vaporized. The total heated length over which boiling took place was as large as 6 ft. There is no evidence of “sonic” pressure jumps at the outlet. The results for the annulus mentioned lie within +30 to −11% of the Lockhart‐Martinelli curve at higher qualities and with ±45% of the correlation at lower qualities where the actual quality is more uncertain. A simplified correlation in terms of quality and volume fraction of liquid predicted the two‐phase frictional pressure drops with an average error of 41%.

It was found that the ratio of the two‐phase pressure drop through a 0.3‐in. orifice to the drop with no vaporization was approximately a linear function of the quality in thevena contractabut was only one tenth to one third as great as would be predicted if the mixture were to expand as a homogeneous fluid. Prediction of orifice presure drops is improved if slip between vapor and liquid is considered.
Mass transfer in a continuous‐flow mixing vessel
Authors: Humphrey D. W. , Van Ness H. C.
Published: June 2004

Mass transfer coefficients have been determined for the dissolution of Na2S2O3·5H2O crystals in water under conditions of turbulent agitation in a mixing vessel. The dissolution was carried out in a steady‐flow process in which the area of selt crystals and the concentration of the solution in the mixing vessel were constant during each run. A comparison is made with previously unpublished results for batch runs in a similar system, and a method is developed for calculating the surface area of salt particles suspended in the mixing vessel under steady‐flow conditions.
Ion exchange separation of gram quantities of americium from a kilogram of lanthanum
Authors: Armstrong D. E. , Asprey L. B. , Coleman J. S. , Keenan T. K. , LaMar L. E. , Penneman R. A.
Published: June 2004

The separation of 4.5 g. of americium from approximately a kilogram of light rare earths (primarily lanthanum) was achieved on a pilot plant scale by chromatographic displacement of the mixture from Dowex‐50 resin with 0.1% ammonium citrate at pH 8 into hydrogen‐form Dowex‐50. The americium collected into a narrow band and was eluted free from lanthanum but contained an equal weight of cerium. A 6‐ and a 2‐in.‐diam. column were used in tandem. Use of a final column with a much smaller diameter would have permitted a cleaner separation from cerium, but this was left for a laboratory‐scale separation by a different process. Precipitation, which was observed in the columns during the first runs, was later avoided entriely by use of high flow rates both initially and during the transfer between columns. No adverse effects were noted from ∼15 curies of alpha activity.
Effect of water vapor on the catalytic oxidation of nitric oxide
Authors: Kircher Omer , Hougen O. A.
Published: June 2004

Extension of the kinetics of the catalytic oxidation of nitric oxide on activated carbon and silica gel confirms the rate‐controlling step postulated by previous workers. The effect of variables including water vapor on the reaction rate is expressed by an equation containing the constants a, b, c, and w, which have been evaluated for both catalysts at 30°, 45°, and 60°C. The effect of water vapor is to reduce the reaction by reversible adsorption on the active sites of the catalyst. The value of w is dependent on temperature but independent of water‐vapor concentration up to a relative humidity of 20%. Above 20% the value of w for activated carbon increases greatly with relative humidity, in agreement with the effect of capillary adsorption at high water contents.
Heat transfer coefficients for condensing organic vapors of pure components and binary mixtures
Authors: Pressburg Bernard S. , Todd James B.
Published: June 2004

The behavior of the film coefficient of heat transfer for the condensation of organic vapor mixtures was investigated experimentally to establish a satisfactory basis for applying the Nusselt equation to binary systems. Five ideal and nonideal pairs, all of which gave miscible condensates, were studied; the work was carried out under conditions of almost total condensation on a horizontal condensing surface designed to comply as rigidly as possible with the conditions for which Nusselt's equation is valid.

The same behavior was observed for all systems and all concentrations studied: the experimental coefficients fell between those for the pure components and followed the behavior pattern for pure components when the temperature difference was taken as that between the bubble point of the condensate and the surface temperature, rather than between the dew point or the measured vapor temperature and the surface temperature, Correlation of the film coefficient showed it to vary approximately linearly with composition if the coefficients were compared at a constant value of the temperature difference, defined as above. This permits determination of the coefficient for a mixture by interpolation between the coefficients for the pure components, which are easily obtained, in preference to making the calculations with the properties of the mixture obtained by laborious and uncertain weighting of the corresponding properties of the pure components.

When results are interpreted in the light of the theories of Colburn and Drew, the presence of a vapor‐phase resistance to heat and mass transfer, as postulated by them, is indicated.
Two‐phase, steam‐water critical flow
Authors: Isbin H. S. , Moy J. E. , Da Cruz A. J. R.
Published: June 2004

Two‐phase critical flow of steam‐water mixtures has been investigated over a pressure range from 4 to 43 1b./sq.in. abs. and a quality range from saturated vapor to 1% (weight) vapor. Discharges were measured from 1/4‐,1/2‐, 3/4‐, and 1‐in. pipes and from annuli of intermediate cross‐sectional areas. The experimental mass flow rates are always grteater than the values calculated on the basis of a homogeneous flow model. Several empirical methods for correlating the data were determined, and comparisons are presented of the predictions of several analytical flow models.
Behavior of suspended particles in a turbulent fluid
Authors: Friedlander S. K.
Published: June 2004

Heat and mass transfer and coagulation are considered as related to the mean‐square relative velocity between particle and fluid uR2 and eddy diffusion as described by the mean‐square particle displacement, Xp2. The mathematical methods used are similar to those employed in the early calculations of the Brownian motion.

The mean‐square relative velocity is obtained as a function of particle characteristics, intensity of turbulence, and a fluid correlation coefficient. In the limiting case of equal particle and fluid density uR2 = 0, and for very heavy particles uR2 → uF2.

A general expression for the eddy diffusivity is obtained is obtained which reduces to the same form as that of the fluid for the stationary state. However, the correlation coefficient to be used in the calculations depends on uR2. As a first approximation, it can be assumed that at a sufficiently long time from the introduction of the particles, fluid and particle diffusivities are equal.

For short times after injection, the particle spread may be much less than that of the fluid. An illustrative calculation for the initial spreading of a jet of suspended particles is offered. In all cases an effort is made to organize the available experimental data within the framework of the theory.
Determination of the chemical properties of an oxide catalyst in a closed system
Authors: Holland C. D. , Murdoch P. G.
Published: June 2004

The bulk chemical properties of an impregnated chromia‐alumina catalyst with respect to several gases, CO, CO2, C3H6, were determined as a function of the degree of oxidation of the surface of the catalyst. The importance of the results lies in the demonstration that a simple method described herein can be used to obtain significant data on catalytic surfaces. Briefly, the prior adsorption of oxygen by the catalyst tended to promote the adsorption of carbon monoxide and to prohibit the adsorption of carbon dioxide. Far more carbon monoxide was adsorbed by the highly oxidized surface than could be accounted for on the basis of adsorbed carbon dioxide. The quantity of propylene adsorbed also increased with an increase in the oxidation of the surface. The results are explained on the basis of two types of adsorbed oxygen atoms.
Effects of bubbling and stirring on mass transfer coefficients in liquids
Authors: Johnson D. L. , Saito Hirotaro , Polejes J. D. , Hougen O. A.
Published: June 2004

In the hydrogenation of α‐methylstyrene by means of a suspended palladium‐alumina catalyst in a stirred reactor the mass transfer of hydrogen through the liquid is the rate‐controlling step and the resistance to chemical reaction at the catalyst surface is negligible except at extremely rapid rates of stirring. This system therefore provides an excellent means of establishing the effects of operating variables and mechanical construction on mass transfer coefficients in liquids in stirred reactors. It is convenient to consider the total resistance to mass transfer as consisting of two separate resistaces: in the liquid adjoining the bubbles and in the liquid adjoining the suspended solid particles; thus R = Rb + Rs.

A general equation was evaluated from experimental data based upon unit volume of liquid.
Effect of liquid physical properties and flow rates on the surface area of sprays from a pressure atomizer
Authors: Consiglio J. A. , Sliepcevich C. M.
Published: June 2004

The effects of the physical properties and volume flow rate of liquids on the surface area of sprays produced by a pressure type of atomizing nozzle were determined experimentally. the specific surface area of the sprays is correlated by an equation of two dimensionless groups in terms of the variables surface tension to the −1.0 power, kinematic viscosity to the −0.4 power, and volume flow rate to the 2.4 power. The volume flow rate is correlated by an equation of two dimensionless groups containing the variables viscosity to the 0.17 power, density to the −0.58 power, and spray pressure to the 0.42 power. The conversion of compression energy to surface‐area energy appears to be constant at approximately 0.1%.
Kinetics of aldehyde hydrogenation: Vapor‐phase flow system and supported nickel catalyst
Authors: Oldenburg C. C. , Rase Howard F.
Published: June 2004

A kinetic study of the catalytic vapor‐phase hydrogenation of three aldehydes (acetaldehyde, propionaldehyde, and n‐butyraldehyde) was made at low conversions with a commercial supported nickel catalyst. A simple initial rate equation was determined and found to agree with a mechanism suggested by the ideal kinetics of Hougen and known experimental evidence. By means of this equation the relative reactivities of the aldehydes were compared and found to agree with the predictions of organic theory. An improved reactor designed to ensure isothermal operation is described.
Continuous‐flow stirred tank reactors: Solid‐liquid systems
Authors: Mattern R. V. , Bilous Olegh , Piret Edgar L.
Published: June 2004

The theory and design of continuous stirred tank reactors are extended to the complex but industrially important field of continuous‐heterogeneous‐reaction systems. The present investigation is concerned with the elementary process occurring when solid particles and a liquid flow into and from a single reactor or a chain of these reactors. The equations are developed for dissolution processes, and the theoretical size distributions and specific areas are confirmed experimentally. Performance is also related to operating conditions and reactor design.
Control of flow distribution by mixing headers
Authors: Hyman Seymour C. , Gruber Alan R. , Joseph Leon
Published: June 2004

The coolant flow distribution among parallel passages in a nuclear reactor (or boiler or heat exchanger) can be very sensitive to variations in heat input, channel dimensions, etc. In a previous paper this flow sensitivity was defined in terms of certain partial derivatives, which were related by analytical expressions to fluid properties and operating characteristics. Flow sensitivity contributes largely to potential malfunction, reduced efficiency, or failures. The use of valves and orifices was quantitatively evaluated for supercritical water in the earlier paper. The scope of this paper is to consider the utility of mixing headers. These mixing chambers are located along the flow passage as a common receiver for parallel flow from many channels. The headers, in turn, supply subsequent lengths of heated passages in parallel. Analytical expressions are derived for the effect of headers on flow, outlet‐fluid enthalpy, and channel‐wall temperatures. The limiting cases of minimum and complete mixing in the headers are considered and numerical results for water at supercritical pressures are given to show the marked increase in stability obtained by use of intermediate mixing headers.
Natural‐convection heat transfer in regions of maximum fluid density
Authors: Schechter R. S. , Isbin H. S.
Published: June 2004

One of the important factors affecting the rate of heat transfer by natural convection is the temperature‐density relationship of the convecting fluid. The importance of this factor is amplified when the heat is being transferred to a medium which has a maximum density.

This investigation consisted of measuring the heat transfer rates, velocity gradients, and temperature profiles when heat is transferred from a flat vertical plate to water in the region of 4°C. In some experiments the flow in the boundary layer was observed to be downward while at other conditions of plate and fluid temperature a dual motion (both up and down) was noted, thus establishing a basic difference in the heat transfer mechanism and precluding a unified theory. Theoretical consideration is given to each mechanism and a criterion is derived to predict the flow regime which will prevail at fixed conditions of plate and bulk temperatures.

An analogue computer was used to establish theoretical velocity and temperature profiles. The theoretical values agree reasonably well with the measured values; however, the experimental temperrature gradients near the wall were not sufficiently accurate to be extrapolated to determine a point heat transfer coefficent.
Velocity profile for fully developed turbulent flow in a pipe
Authors: Hanratty Thomas J. , Flint Duane L.
Published: June 2004

An equivalent Poiseuille's Law is derived for a homogeneous isotropic turbulent field. The derivation is based on an analogy between momentum transfer and heat and mass transfer, three coefficients being used to characterize the exchange process: (1) the molecular viscosity µ, (2) an intensity parameter to characterize the magnitude of the turbulent velocity fluctuations ν2, and (3) a scale parameter to characterize the scale of the turbulence T.
Mathematical development of tube loading in horizontal condensers
Authors: Kern Donald Q.
Published: June 2004

Equations were derived by Nusselt for condensation on a vertical bank of horizontal tubes employing several questionable assumptions. His theoretical results indicate that the average condensing coefficient for a tube in ann‐tube vertical bank should ben−1/4times the single‐tube coefficient. An empirical modification for turbulence previously suggested by the present author changed the factor ton−1/6. To facilitate further experimental studies and design calculations, precise equations are developed for condensate loading for the different common tube layouts bounded by a circle. These equations use a generalized factorn−1/swhere a value of s/4 > 1.0 becomes an index of turbulence.
Individual film coefficients of mass transfer in liquid‐liquid extraction
Authors: Smith G. C. , Beckmann R. B.
Published: June 2004

A study has been made of the individual film coefficients of mass transfer for two binary liquid‐liquid systems of differing physical properties, namely methyl isobutyl carbinol‐water and methylethyl ketone‐water, in a 4‐in. diam. extraction column operated as a spray column and with 1/2‐in. Raschig ring packing. The value of Ht for the dispersed phase was found to be a constant, C1 for a given system in a given column. The Ht values for the continuous phase could be correlated by the equation,

Values of the constants C1, C2, and n are tabulated along with the values found by earlier investigators for other systems and column packings. The Ht values have been reduced to area base coefficients by the expression for droplet surface area proposed by Gaylor and Pratt (3).

Presaturation of either phase was found to have no effect on mass transfer rates. There appears to be relatively little difference in the efficiency of spray and packed columns for systems of low interfacial tension, but for high interfacial‐tension systems packed columns are considerably more efficient than spray columns.

While no definitive correlations for the effect of physical properties are proposed, there are some indications that n is a function of the viscosity ratio of the two liquid phases and that C2 is a function of the 1/4 power of the groups (dΔργ/μ2c)(μc/μa) and (NS c)c. No correlation was found for the effect of physical properties on (Ht)d.
Kinetics of nitrogen tetroxide absorption in water
Authors: Wendel M. M. , Pigford R. L.
Published: June 2004

The rate of absorption of nitrogen peroxide into water at 25° and 40°C. has been found to be a linear function of the concentration of nitrogen tetroxide in the gas phase and directly proportional to the interfacial partial pressure of the same species.

The rate of absorption is independent of gas velocity over a range of ReG from 170 to 350. The results plotted as absorption rate divided by interfacial partial pressure of nitrogen tetroxide show no effect of liquid rate or contact time between gas and liquid over a tenfold range of contact time from 0.03 to 0.3 sec. This indicates that the rate‐controlling step during nitrogen dioxide absorption into water is the rate of hydrolysis of nitrogen tetroxide.

The absorption rate decreases with increasing temperature from 25° to 40°C., owing to the shift of the equilibrium in the gas phase away from the reacting species nitrogen tetroxide toward nitrogen dioxide and owing to the the decreased solubility of nitrogen tetroxide in water. The effect of these factors on absorption more than offsets the effect of the increase in reaction rate and higher diffusivity on absorption at 40°C.

The reaction rate constant for the hydrolysis of nitrogen tetroxide has been determined and the solubility of dissolved but unreacted nitrogen tetroxide in equilibrium with gaseous nitrogen tetroxide has been found.
Convergence pressures for close‐boiling nonideal systems
Authors: Lenoir J. M.
Published: June 2004

The unconventional behavior of equilibrium ratios and convergence pressures is illustrated for close‐boiling systems with activity coefficients exceeding 1 throughout the two‐phase region. Also presented is a correlation to predict convergence pressure, or the critical locus, of nonideal binary systems.
Pulsations in sieve‐tray and bubble‐cap distillation towers
Authors: McAllister R. A. , Plank C. A.
Published: June 2004

A periodic pulsation of the frothing mass of liquid and vapor on a sieve tray and a bubblecap tray is reported. An equation is proposed which relates the frequency of the oscillation to the velocity of sound, the physical dimensions of the systems, and the flow rates of the gas and liquid. The equation is a modification of the acoustical analogy to the classical Helmholtz resonance in electrical circuits having both capacitance and inductance. The oscillation is shown to decrease back‐mixing on the tray, and thus to result in an increase in the Murphree vapor efficiency.
II. The ammonia—isooctane system
Authors: Kay Webster B. , Warzel F. Morgan
Published: June 2004

Because of the paucity of data on the phase behavior of binary systems that form azeotropes, the P‐V‐T‐x relations of the ammonia‐isooctane system were determined at the liquid‐vapor boundaries from room temperature to the critical temperature of issoctane. Evidence of an azeotrope existing over a very limited pressure and temperature range was obtained. The sistem is unique in that the critical locus contains a minimum temperature point as well as a minimum and a maximum pressure point. These relations are shown to fit a general pattern of phase relations characteristic of binary systems that form azeotropes in the critical region. This pattern serves as an aid for the qualitative prediction of the P‐T‐x relations of such systems.
Local shell‐side heat transfer coefficients in baffled tubular heat exchangers
Authors: Ambrose T. W. , Knudsen J. G.
Published: June 2004

An experimental study of local heat transfer coefficients in a baffled tubular heat exchanger for five baffle spacings and two tube spacings (23/16‐in.‐pitch, four‐tube bundle, and 11/4‐in.‐pitch, fourteen‐tube bundle) is reported. Shell‐side air‐flow rate was constant for all runs. The variation of the local heat transfer coefficient around the tubes and along the length of the tubes for each tube spacing and baffle spacing was investigated. Average shell‐side heat transfer coefficients were evaluated from local values and were found to agree with average values reported in the literature. These average values varied with the six‐tenths power of the mass velocity in the heat exchanger. The average Nusselt number and the pressure drop across the exchanger each increased at about the same rate as the number of baffles was increased from two to ten. The average heat transfer rate decreased with decreased tube spacing. This effect was evident from the local heat transfer coefficients, and it is explained on the basis of the mechanism of flow around tubes. An eddy flow zone was detected between the baffles. Average heat transfer rates in the eddy and crossflow zones were almost equal and were about 15% below the average rate in the longitudinal‐flow zone. The variation of the average heat transfer coefficient along a tube definitely showed the effects of baffles. High coefficients occurred in the baffle holes and in the baffle windows.
Electrolytic methods for measuring water velocities
Authors: Ranz William E.
Published: June 2004

A convection‐controlled mass transfer process in which the rate of mass transfer results in an electrical signal should have certain advantages as the working principle for a velocity‐and turbulence‐measuring device. The velocity can be read at a remote place as a calibrated electrical signal. Compensation for phase shift and amplitude attenuation of a fluctuating signal should be small because the measuring probe would have no capacity for the transferred quantity. In water, such processes are possible whenever electrolysis occurs under conditions ofconcentration polarization, and they exist in relatively uncomplicated from as thelimiting currentsof polarographic analysis. The investigation reported here was intended as a survey and evaluation of electrolytic methods for measuring water velocities.

The series of experiments that was performed showed that a working instrument could be designed on the principle of convection‐controlled electrolysis, but that the chemical reactions involved were unreliable for consistent trouble‐free results. Practical instruments appear to be possible only after long development and considerable study of chemical mechanisms.
The formation of interfacial area in immiscible liquids by orifice mixers
Authors: Scott L. S. , Hayes W. B. , Holland C. D.
Published: June 2004

This paper deals with the dispersion of one immiscible liquid in another (water in kerosene) by means of an orifice mixer. The degree of mixing was determined by measuring the area per unit volume of the dispersed phase. The area was measured with a photoelectric device, which had been calibrated photographically. The interfacial area formed at high Reynolds numbers (10,000 to 45,000, based on the diameter of the orifice) was found to increase with increases in both the volume fraction of water in the water‐kerosene mixture and the change in kinetic energy across the orifice. In addition, other aspects such as the rate of coalescence of the dispersed phase downstream from the orifice are treated.
An improved experimental reactor for applied kinetic studies
Authors: Perkins Thomas K. , Rase Howard F.
Published: June 2004

A recirculation type of reactor has been designed and tested on a rapid reaction which characteristically causes difficult temperature‐control problems and high diffusional resistances (hydrogenation of propylene on nickel catalyst). Descriptions of the reactor and its operation are given, together with an assessment of errors and the advantages and disadvantages of the recirculation technique. A rate equation and rate constants are determined so that the data will be more readily comparable with the work of other investigators.
Liquid‐phase adsorption equilibria
Authors: Stuart Edward B. , Coull James
Published: June 2004

A correlating equation for liquid‐phase adsorption equilibria, including the effects of temperature and pore diameter, is presented, together with a derivation of the equation ascribing the equilibration process of physical adsorption to van der Waal's forces. The derivation is based on the effect of temperature and surface configuration on the concentration of adsorbate at the surface. The correlating equation was tested with experimental data for the benzene‐cyclohexane‐silica‐gel system and the toluene‐isooctane–silica‐gel system. Temperatures ranged between 23.9° and 99°C. and the pore diameters between 20.7 and 149.5 Å.
On phase equilibrium at the gas‐liquid interface during absorption
Authors: Scriven L. E. , Pigford R. L.
Published: June 2004

That phase equilibrium exists at the gas‐liquid interface during gas absorption is usually assumed in the analysis and design of absorption equipment, but the validity of this assumption has been in doubt since Higbie's pioneering gas‐absorption studies. Accurate measurements are reported herein of the absorption rates at 25°C. of carbon dioxide into short water jets in which the liquid was in laminar flow. The jets issued from circular nozzles of about 1.5‐mm. diam., flowed intact downward through an atmosphere of carbon dioxide at average velocities of from 75 to 550 cm./sec. over distances of 1 to 15 cm., and were collected in a receiver slightly larger in diameter than the nozzles. The measured absorption rates are in excellent agreement with predictions based on unsteady state diffusion theory, when one assumes interfacial equilibrium. It is concluded from these results and those of other investigators that equilibrium prevails at a freshly formed, relatively clean, carbon dioxide–water interface and that the same statement probably applies to the absorption of other slightly soluble gases in water.

Evidence is discussed which indicates that an accumulation of minute quantitities of surface‐active materials may seriously reduce the rate of gas absorption, either by affecting the hydrodynamic characteristics of the system or perhaps by offering resistance to the transfer of solute molecules across the interface.