bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of plate wetting characteristics on pulse column extraction efficiency
Authors: Sobotik R. H. , Himmelblau D. M.
Published: June 2004

Liquid‐liquid extraction of acetic acid from the methyl isobutyl ketone‐water system was studied as a function of plate wetting characteristics and other variables in a pulsed perforated‐plate extraction column.

Various combinations of stainless steel plates and polyethylene plates were used with different directions of solute transfer at a constant throughput of 82.6 lb. total flow/(min.) (sq. ft. column area) and with other operating variables in the following range:

Frequency — 16 to 117.1 c./min.

Amplitude — 0.492 and 0.973 in.

W/K flow ratio — 0.46 to 2.8 lb. water/lb. ketone

The plate wetting characteristics were found to affect the column extraction efficiency when the solute transfer was from the continuous ketone phase to water. An all polyethylene plate arrangement provided the best efficiency (H. T. U.oc = 4.1 in.) while an all stainless steel plate arrangement was less efficient (H. T. U.oc = 6.1 in.) under the most favorable operating conditions. A combination of these two arrangements in the column produced efficiencies midway between the all‐plastic plate arrangement and the all‐stainless steel plate arrangement.

Within the column flooding limits the extraction efficiency did not seem to be affected by the plate wetting characteristics when the solute transfer was from water to the continuous ketone phase.
Characteristics of the mean flow patterns and structure of turbulence in spiral gas streams
Authors: Schowalter W. R. , Johnstone H. F.
Published: June 2004

Measurements were made of the flow structures in two types of spiral flow fields. The first was a vortex tube in which air entered one end of an 8‐in. pipe through an involute entry and left at the opposite end. The second was a conventional cyclone separator in which the same entry was used.

The experimental results show that the mean and turbulent flow structures are not sensitive to changes in the flow rate, but they are greatly affected by the geometry of the system. In the vortex tube the angular velocity is nearly constant at radial distances less than one‐half of the radius of the pipe. The flow patterns in the vortex tube and in the cyclone are not symmetrical with the pipe axis. The asymmetry can be explained by postulating a dynamic center line with helical shape. The longitudinal intensity of turbulence increases sharply near the center of the vortex tube. This is caused primarily by the abrupt decrease in mean velocity near the center. The radial intensity also increases near the center, but near the wall it decreases rapidly with distance from the center. The longitudinal intensity of turbulence in the cyclone is highest near the center and near the wall. The high intensity near the wall is caused both by the decrease in mean velocity and the increase in root‐mean‐square turbulent velocity.
Measurement of concentration fluctuations with an electrical conductivity probe
Authors: Lamb D. E. , Manning F. S. , Wilhelm R. H.
Published: June 2004

An electrical conductivity probe capable of measuring liquid phase concentration fluctuations occurring at frequencies up to 8 kc. is described. The design permits concentration measurements in volume elements of the order of 3 × 10−5 cc. The probe was applied successfully to the measurement of turbulent concentration fluctuations.
Thermal transfer in turbulent gas streams: Temperature distribution in boundary flows about spheres
Authors: Bathish L. N. , Sage B. H.
Published: June 2004

A knowledge of the temperature distribution about bodies of revolution, and more particularly about spheres, is of interest in connection with many problems associated with thermal and material transport. The present investigation involved measurements of the temperature distribution in the boundary flows about a 0.5‐in. porous sphere and 0.5‐in. and 1.0‐in. silver spheres. The measurements were made in an air stream at velocities between 4 and 32 ft./sec. under conditions of shear flow, as well as at various positions in the wake of a perforated grid. From these measurements the thickness of the thermal boundary layer was established as a function of polar angle and conditions of flow. The experimental data were correlated upon the assumption that the normalized temperature in the boundary flow is a single‐valued function of the position in the thermal boundary layer. It appeared that this simple assumption described the experimental data within the uncertainties of measurement and that the Blasius function provided a reasonable description of the relationship of the normalized temperature to the relative position in the thermal boundary layer.
Diffusion rates in porous catalysts
Authors: Henry J. P. , Chennakesavan Balapa , Smith J. M.
Published: June 2004

Rates of diffusion of helium, nitrogen, and carbon dioxide through alumina pellets were measured at atmospheric pressure and room temperature. The cylindrical pellets, ¾ in. diameter and ⅜ in. in length, were prepared from α‐alumina particles with a mean pore radius of 65 Å. Surface area and pore volume data indicated that the corresponding mean pore radius of the micro and macropores in the whole pellet was 96 Å.

The results showed that Knudsen type of diffusion was the controlling transport process despite the large fraction of void volume in the macropores. Carbon dioxide diffused more rapidly than expected, suggesting the possibility of migration of physically adsorbed molecules along the pore walls.

The diffusion rates were about 16% higher than predicted, with a mean pore radius (Wheeler model) based upon the void volume of both micro and macropores used. However there is no logical basis for using this mean pore radius for a pellet having widely separated, micro and macropore size distributions.
Boundary‐layer behavior on continuous solid surfaces: I. Boundary‐layer equations for two‐dimensional and axisymmetric flow
Authors: Sakiadis B. C.
Published: June 2004

This study deals with boundary‐layer flow on continuous solid surfaces. Flow of this type represents a new class of boundary‐layer problems, with solutions substantially different from those for boundary‐layer flow on surfaces of finite length. In this paper the boundary‐layer behavior on continuous surfaces is examined, and the basic differential and integral momentum equations of boundary‐layer theory are derived for such surfaces. In subsequent papers these equations will be solved for the boundary layer on a moving continuous flat surface and a moving continuous cylindrical surface, for both laminar and turbulent flow in the boundary layer.
Combined free and forced convection in a constant temperature horizontal tube
Authors: Jackson T. W. , Spurlock J. M. , Purdy K. R.
Published: June 2004

An experimental study of superposed free and forced convection for air in a horizontal tube is reported. The laminar Nusselt number, based on the log mean temperature difference, ranged from 29.9 to 15.2; the laminar flow Graetz number, based on the bulk or average temperature of the air, ranged from 33 to 1,300, the Grashof‐Prandtl modulus based on properties of air at the wall temperature ranged from 1.1 × 106to 2.2 × 106. The Grashof number utilized the log mean temperature difference. An analysis of the system from a macroscopic viewpoint led to the determination of an equation which fits the laminar flow experimental data in the range of Graetz numbers from 60 to 1,300. An equation was also found for the turbulent data.
Turbulent newtonian flow in annuli
Authors: Meter Donald M. , Byron Bird R.
Published: June 2004

In recent years there have been quite a few experimental studies on turbulent flow in annuli. In this paper a Prandtl mixing‐length approach is applied to give a friction factor vs. Reynolds number expression for annuli [see Equation (22) and Table 1]; this expression describes tube flow and slit flow as special cases. No new adjustable constants appear in the final result other than those determined earlier for tube flow. The final expression is found to predict friction factors within the accuracy of the existing experimental data. The mixing‐length friction‐factor expression is thus substantially more accurate than the usual hydraulic‐radius procedure and of comparable accuracy to other recent annulus friction‐factor treatments.
A modification of the momentum transport hypothesis
Authors: Gill William N. , Scher Marvin
Published: June 2004

A continuous velocity distribution is derived which is based on an arbitrary modification of Prandtl's mixing length expression. The resulting velocity distribution agrees well with experiments for transition and fully developed turbulent flow throughout the entire cross section of the conduit. Furthermore the mixing length expression applies to parallel flow in smooth circular tubes and between infinite parallel plates with the same set of constants.
Simultaneous mass and heat transfer in the flow of gases past single spheres
Authors: Evnochides Spyros , Thodos George
Published: June 2004

The results obtained by the evaporation of water and nitrobenzene in air from celite spheres in conjunction with the prevailing surface temperature have permitted the simultaneous determination of mass and heat transfer factors. The spheres used were 1.42, 1.88, and 2.00 in. in diameter. The experimental results of this study show that an essentially direct correspondence exists for mass and heat transfer in the flow of fluids past single spheres.
Size distribution of droplets from centrifugal spray nozzles
Authors: Nelson Paul A. , Stevens William F.
Published: June 2004

Methods for expressing, measuring, and correlating drop‐size distribution data for centrifugal spray nozzles are discussed.

A method for collecting spray droplets in liquid nitrogen is described which is rapid and efficient for most sprayed liquids which freeze above —20°C. Comprehensive correlations for drop‐size distributions are reported based on 114 runs performed with the liquid nitogen method.
Tubular reactor sensitivity
Authors: Coste Joseph , Aris Rutherford , Amundson Neal R.
Published: June 2004

The empty lumped constant tubular reactor is considered for an incompressible fluid in which an arbitrary number of chemical reactions is occurring. It is assumed that the reactor influents are steady with time on the average but have superimposed upon them random fluctuations. If the random perturbations are infinitesimally small, the unsteady state equations are linear, the linearity following from the fact that any transient may be considered as a perturbation from the steady state. Thus the effluents are random functions whose mean and variance may be calculated with ease. Reactor sensitivity is defined as the ratio of the standard deviation of an output to the standard deviation of an input. The general theory is developed and two examples are worked to illustrate the method.
Phase and area contributions to mass transfer kinetics
Authors: Teller A. J.
Published: June 2004

A relationship has been developed describing quantitatively the factors affecting packed column performance. The relationship, based on the Colburn equation, is proposed within the limits of a consistent flow regime in the liquid phase.

Via separation of the effects of packing geometry on diffusion rates and the effect of area variation with flow rate, single phase transfer rates can be obtained from over‐all mass transfer data. The appearance of a maximum in the relationship ofHoGvs.Gin the range of 60% of flooding is explained by the large increase of the termHoG/ai(∂ai/∂Gm) relative to the term 1/ai(∂HGai/∂Gm). The ammonia‐air‐system behavior is analyzed via this relationship. It is found that the gas phase resistance varies between 72 and 94% of the over‐all resistance as a function of flow rate.
Design of experiments on the kinetics of the water‐gas shift reaction
Authors: Hulburt Hugh M. , Srini Vasan C. D.
Published: June 2004

Experiments on the continuous catalytic water‐gas shift reaction have been carried out making full use of the principles of statistical design to elucidate the reaction mechanism. Instantaneous reaction rates were determined for sixteen different combinations of the five variables: partial pressures of carbon monoxide, hydrogen, carbon dioxide, and temperature. Nitrogen gas was used as an inert diluent to make up the total pressure to 1 atm. From the analysis of variance of these sixteen runs it can be shown that the Temkin mechanism for the water‐gas shift reaction cannot represent the data within the experimental accuracy. A tentative alternative mechanism which is consistent with the data obtained is presented. The work shows that while it is possible to obtain useful empirical kinetic data from small, well‐planned experiments, both highly precise experimental data and very careful statistical treatment are required. When these are available, a very marked reduction in the amount of experimental work can be effected.
The distribution of nitric acid between water and tributyl phosphate ‐ hexane solvents
Authors: Olander Donald R. , Donadieu Lucien , Benedict Manson
Published: June 2004

The distribution of nitric acid between water and solutions of tributyl phosphate in n‐hexane has been measured over a greater range of acid and tributylphosphate concentrations than have been reported previously.

The partitioning of nitric acid between water and tributylphosphate‐hexane solvents has been satisfactorily explained on the basis of the commonly accepted equilibrium complexing reaction, with this modification: The over‐all aqueous‐to‐organic reaction is subdivided into the distribution of uncomplexed nitric acid and an organic phase complexing reaction. This alteration is found necessary to account for the behavior of the partitioning data of dilute acid over the entire tributylphosphate‐hexane range. The residual discrepancy between the theory and the data can be qualitatively attributed either to modest nonideality of the organic phase or to the effect of the varying water content of the solvent on the distribution coefficient of uncomplexed nitric acid.

The sparse data on water extraction by tributylphosphate‐hexane solvents are not amenable to the same type of analysis, even though a type of complexing similar to that found for nitric acid has been previously proposed. The interaction between water and tributylphosphate appears to be stronger than that normally attributed to nonideality but weaker than a true chemical complex.
Further studies of fluid flow and mass transfer in trickle beds
Authors: Schiesser W. E. , Lapidus Leon
Published: June 2004

Residence‐time studies are reported for water trickling down through a 4‐in. column packed with spheres. The transient response of the column to pulse‐ and step‐function inputs in tracer concentration applied to the water stream was determined for both porous and nonporous packing. Significant radial variations in the distribution of residence times and the volumetric rate of flow were observed. The contribution to the response curves of diffusion into the porous packing and flow in the interparticle voids can be separated. The diffusion rates may then be characterized in terms of an effective pore diffusivity for the packing.
Slow compression crushing of single particles of glass
Authors: Kenny William J. , Piret Edgar L.
Published: June 2004

Glass cylinders and spheres were crushed by slow compression in a hydraulic press. In all experiments the elastic energy stored in the specimen prior to fracture was measured. In some experiments the surface area of the resultant powder was measured by gas adsorption; in others the heat generation upon fracture was measured. The latter experiments show that considerable additional energy is fed into the fracturing specimen from the press. Local stress concentrations, and hence energy level at fracture, varied widely with particle shape. Calorimetric experiments suggest that real differences in crushing effectiveness, that is new surface per unit actual work done on the specimen, do occur. These differences are not due directly to the magnitude of the energy fed in from the press but rather to the effectiveness with which the stored or feed‐in energy is used.
Two‐phase concurrent flow in packed beds
Authors: Larkins R. P. , White R. R. , Jeffrey D. W.
Published: June 2004

Pressure drop and liquid saturation accompanying two‐phase concurrent flow have been studied in a variety of packings and with gas‐liquid systems having a wide range of fluid properties. Two basic flow patterns were observed with nonfoaming systems. Correlations of pressuredrop and liquid‐saturation data were obtained in terms of the single‐phase friction losses for the liquid and the gas when each flows alone in the bed. Deviations from the correlation with foaming systems are discussed and illustrated with sample data.
Effectiveness factors for porous catalysts
Authors: Mingle J. O. , Smith J. M.
Published: June 2004

From the equations expressing mass and energy transfer in the solid and void regions of a catalyst of micropores, conversion and temperature profiles are evaluated as a function of the properties of the particle and the reaction system. The method developed is illustrated with numerical calculations for a first‐order, irreversible reaction. Microeffectiveness factors Ec are derived from these profiles for several distribution functions for the size (radius) of the micropores.

The results indicate that the nature of the pore‐size distribution cannot affect Ec more than about 10%. However effectiveness factors greater than unity are possible for exothermic reactions with high heats of reaction and particles of reasonable size.

To treat pelletted catalysts, equations are also developed for determining conversion and temperature profiles in pellets formed by compressing the microporous particles These results are interpreted in terms of macroeffectiveness factors Es, with values of Ec applicable at various positions in the pellet. To illustrate the method of solution numerical values of Es are determined for a limited range of parameters. The results indicate that in pelletted catalysts large temperature gradients may exist. For an exothermic reaction this can lead to a significant increase in macroeffectiveness factor.
Membrane selectivity
Authors: Wills G. B. , Lightfoot E. N.
Published: June 2004

Previous investigators have developed general integrations of the Nernst‐Planck flux equations to predict the behavior of ion exchange membranes in forced diffusion cells. These results are also applicable to stagnant liquid films, since this latter case can be considered as a membrane with a vanishingly small concentration of fixed charges (1). However these general integrations yield results of considerable complexity, and even the analysis of a specific system becomes a problem of some scope. This paper is based upon a much less general integration which proceeds by a straightforward manipulation of the Nernst‐Planck flux equations for the special case of a single one‐to‐one electrolyte. The results are used to predict the behavior of a system consisting of a membrane with a stagnant film of liquid on either side. To further facilitate understanding the initial results are further simplified by assuming certain specific systems and then constructing plots showing the membrane efficiency in terms of readily interpreted, commonly encountered variables such as thicknesses, currents, and concentrations.
Heat transfer in reacting systems: Heat transfer to nitrogen dioxide gas under turbulent pipe flow conditions
Authors: Krieve Walter F. , Mason David M.
Published: June 2004

Heat transfer rates of both heating and cooling for dissociating nitrogen dioxide gas were experimentally measured under turbulent pipe‐flow conditions. The range of the average Reynolds numbers for which these measurements were made was from 6,700 to 22,000. Thermal flux at the inside surfaces of the tubes ranged from 300 to 8,400 B.t.u./hr.‐sq. ft. for heating and cooling. Wall temperatures of the heater section were varied from 100° to 400°F. and those of the cooler section were varied from 70° to 140°F. Mixed mean bulk gas temperatures for both heating and cooling were in the range 72° to 190°F. Radial velocity and temperature profiles were measured at various longitudinal positions in the heater section.

For this equilibrium gas mixture heat transfer coefficients as high as 14 times those for the gas under frozen equilibrium conditions were obtained. Correlations which should be generally applicable to equilibrium reacting systems have been determined from the experimental data.
Free entrainment behavior in sieve trays
Authors: Cheng S. I. , Teller A. J.
Published: June 2004

Analysis was made of the behavior of entrained particles in the zone between trays in a sieve tray column for the air‐water system. The effects of drop‐size distribution, projection velocity, drag, and gravity were evaluated with respect to the quantity of entrained liquid between trays. The drop‐size distribution was found to be logarithmic in nature.

The entrainment as a function of distance above the froth is estimated in Equation (12) where dH may be calculated from projection velocities and column superficial velocity for particle sizes greater than 400 μ.

Confirmation of the proposed entrainment equation via experimental data was achieved within an average deviation of 28%.

It was anticipated from the relationships developed that a leveling off of entrainment at zones in proximity to the froth and at escape velocity heights would be observed. Confirmation was evident at zones in proximity of the froth and upper zone tendencies were observed.
Diffusion and equilibrium studies for the system acrylonitrile‐styrene‐polyethylene
Authors: Chandler Horace W. , Henley Ernest J.
Published: June 2004

The solubilities of acrylonitrile and styrene in low‐density polyethylene were measured at 0° and 27°C. over the entire range of compositions.

The ternary solubility data were analyzed in terms of the relationships developed by Krigbaum and Carpenter. It is shown that the behavior of the ternary system may be predicted from the Flory‐Huggins interaction constants of the three pairs of binaries.

The rates of desorption of acrylonitrile and styrene from 48 mil thick sheets of polyethylene were measured at 27°C.
Multimolecular adsorption equation
Authors: Rounsley R. R.
Published: June 2004

An equation is derived for the multimolecular adsorption isotherm in the range where capillary adsorption is insignificant. The equation is demonstrated to apply quantitatively to the entire range of relative vapor pressure. It is shown that this equation reduces to the equation of Brunauer, Emmett, and Teller at lower relative vapor pressures.

Application of this equation to data in the literature showed good agreement. The standard deviation of the data from the equation was in the same order of magnitude as the scatter of the data themselves. Although the application of this equation was largely to water vapor adsorption systems, several applications to other systems correlated equally well.
Flow of non‐Newtonian fluids in a magnetic field
Authors: Sarpkaya Turgut
Published: June 2004

The analytical solution to the equation of motion is given for the steady laminar flow of a uniformly conducting incompressible non‐Newtonian fluid between two parallel planes. The fluid is under the influence of a constant pressure gradient and is subjected to a steady magnetic field perpendicular to the direction of motion. Two non‐Newtonian models are considered: the Bingham plastic model and the power‐law model. Flow rates and the velocity profiles for various values of the Hartmann number and the generalized Hartmann number are presented and compared with those corresponding to Newtonian fluids.
The compressibility of carbon dioxide and nitrous oxide at low pressures
Authors: Turlington B. Lynn , McKetta John J.
Published: June 2004

A modified Edwards density balance was used to measure compressibility of carbon dioxide and nitrous oxide at pressures under 2.0 atm. and over a temperature range of −30° to 75°C. Second virial coefficients were calculated for the temperatures covered in this investigation and compared with data presented in the literature for both gases. The compressibility data are estimated to be accurate within ±0.10% of the actual compressibility factor.
Gas dynamic processes involving suspended solids
Authors: Soo S. L.
Published: June 2004

Basic gas dynamic equations involving suspended solid particles were formulated. Considerations include momentum and heat transfer between the gaseous and solid phases. Significance of these contributions was illustrated with the case of expansion through a de Laval nozzle. Duct flow and normal shock problems were also discussed. The extent of earlier methods of approximation was pointed out.
A generalized velocity distribution for non‐Newtonian fluids
Authors: Brodkey R. S. , Lee Jon , Chase R. C.
Published: June 2004

The universal velocity profile equation for turbulent flow is obtained for the power law approximation equation. The profile equation should be valid from wall to the center line, from laminar to turbulent flow, and for Newtonian and non‐Newtonian power law materials. The equation is compared with other theoretical and experimental results. In the center line region, where the other theoretical development is valid, both equations give essentially the same results. The experimental confirmation with literature data is good over the entire flow regime.
Adsorption kinetics of a nonflow system with nonlinear equilibrium relationship
Authors: Tien Chi
Published: June 2004

The kinetics of adsorption in a nonflow system with nonlinear equilibrium relationship and negligible liquid‐phase resistance has been studied, and the numerical solutions corresponding to different initial conditions are presented. The concentration ratio is found to be a function of two dimensionless groups. Consideration is also given to the problem of convergence in connection with the numerical calculation.
Transport characteristics of suspensions: II. Minimum transport velocity for flocculated suspensions in horizontal pipes
Authors: Thomas David G.
Published: June 2004

The minimum transport velocity (defined as the mean stream velocity required to prevent the accumulation of a layer of stationary or sliding particles on the bottom of a horizontal conduit) has been determined for flocculated thorium oxide and kaolin suspensions flowing in glass pipes. The pipes ranged from 1 to 4 in. in diameter, and the concentration was varied from 0.01 to 0.17 volume fraction solids.

Two flow regimes were observed depending on the concentration of the suspension. In the first the suspension was sufficiently concentrated to be in the compaction zone and hence had an extremely low settling rate. The second regime was observed with more dilute suspensions which were in the hindered‐settling zone and settled ten to one‐hundred times faster than slurries which were in compaction. The concentration for transition from one regime to the other was dependent on both the tube diameter and the degree of flocculation. The suspension particles were smaller than the thickness of the laminar sublayer, and they settled according to Stokes' law for the particular conditions of this study. Under these circumstances the relation developed for dilute suspensions is consistent with particle transfer in the radial direction owing to Bernoulli forces on the particle and the action of turbulent fluctuations which penetrate the laminar sublayer. For concentrated suspension in compaction the minimum transport velocity was given by a characteristic critical Reynolds number.
Computer calculation of binary‐drop evaporation
Authors: Rawson Norman E. , Chinn John S. , Stevens William F.
Published: June 2004

A mathematical model has been developed relating the velocity, temperature, composition, radius, and position of an evaporating drop falling through a heated environment. Under the assumption of rapid mixing within the drop a digital computer program has been written and solved for several initial conditions to give the aforementioned variables as a function of time. Details of the computer program are presented, with emphasis on the analysis of and approach to the problem. The computer results are summarized, and their relation to the general problem of spray vaporization is indicated.
An equation for the liquid and vapor states of nitrogen
Authors: Bukacek R. F. , Peck R. E.
Published: June 2004

An equation of state which describes vapor and liquid states of nitrogen in the temperature and density range to three times the critical and the two‐phase boundary is presented. The root mean square error is less than 0.7% in describing the available data for nitrogen. The equation contains thirteen coefficients, only three or four of which are independent, and can be written in virial form.
Extraction of mixed solutes: I. Separation of formic and hydrochloric acids. II. Separation of acetic and sulfuric acids
Authors: McAteer P. J. , Cox R. W. , Geankoplis C. J.
Published: June 2004

In many complex systems in solvent extraction a second solute is often present or is added to promote extraction of the first solute. Previous studies showed that the electrolyte sulfuric acid can be considered as a salting‐out agent for extraction of formic acid from water by methyl isobutyl ketone.

In the present work two systems were studied: (I) hydrochloric acid‐formic acid‐water‐methyl isobutyl ketone and (II) sulfuric acid‐acetic acid‐water‐methyl isobutyl ketone. Selectivities of over 200 were found favoring the extraction of formic over hydrochloric acid, and values of over 6,000 favoring the acetic over the sulfuric acid were found. The data for extraction of formic acid were correlated by the Setschenow equation. A similar type of equation was found for extraction of acetic acid in system II.

The results indicate that the electrolyte hydrochloric acid can also be considered as a salting‐out agent for formic acid. The data show that sulfuric is more effective than hydrochloric acid in salting‐out the formic acid. This is in qualitative agreement with experimental data in other systems employing sulfate and chloride electrolytes and with the theoretical equation derived by Debye and McAuley. About 28% less sulfuric acid is needed to salt‐out a given amount of acetic acid when compared with salting‐out the same amount of formic acid.

The changes in activity coefficient of the acetic acid in the aqueous phase with additions of sulfuric acid were measured in system II. These activity coefficient changes could account for only about 39% of the increase in distribution ratio of the acetic acid. A possible explanation for this is that the molecular species of the acetic acid in the organic and aqueous phases changed when sulfuric acid was added to the water phase.
Liquid flow and gas phase mass transfer in wetted‐wall towers
Authors: Kafesjian Ralph , Plank C. A. , Gerhard E. R.
Published: June 2004

New data have been obtained on vaporization of water from rippling and nonrippling films in a countercurrent wetted‐wall tower. Other similar data in the literature have been analyzed, and an effect of liquid Reynolds number on gas phase mass transfer has been shown to exist. Discrepancies in much of the literature data can be explained on this basis.

The data on vaporization of water from rippling films have been correlated. The data on non‐rippling films were correlated when the gas Reynolds number was calculated relative to the water surface.
Boundary‐layer behavior on continuous solid surfaces: III. The boundary layer on a continuous cylindrical surface
Authors: Sakiadis B. C.
Published: June 2004

The behavior of laminar and turbulent boundary layers on a moving continuous cylindrical surface is investigated by the integral method, based on assumed velocity profiles that satisfy the appropriate boundary conditions. Equations for the characteristic boundary‐layer parameters are presented for both the laminar and turbulent boundary layers, and comparison is made with the boundary‐layer behavior over a cylindrical surface of finite length. The analysis for the laminar boundary layer with a logarithmic velocity profile leads to satisfactory results. The turbulent boundary‐layer behavior on continuous cylindrical surfaces, and cylindrical surfaces of finite length, can best be investigated experimentally.
Taylor instability of an evaporating plane interface
Authors: Bankoff S. G.
Published: June 2004

A new mode of high‐flux heat transfer is proposed, which consists of film boiling from a porous solid plate, the vapor being sucked off through the plate. For horizontal plates the average vapor film thickness is determined by Taylor instability of the vapor‐liquid interface. A theory is presented for predicting the minimum vapor film thickness which takes into account the stabilizing influence of the reactive pressure of the vapor leaving the interface. The predicted heat transfer coefficients are five to ten times greater than observed heat transfer coefficients in film boiling from nonporous surfaces.
Performance of fractional watt ion exchange membrane fuel cells
Authors: Cairns E. J. , Douglas D. L. , Niedrach L. W.
Published: June 2004

The effect of design and operational variables on the performance of one type of hydrogen‐oxygen ion exchange membrane fuel cell has been studied. Only the results of cells based on a phenolsulfonic acid formaldehyde type of ion exchange membrane containing one type of reinforcement are described. Platinum, palladium, iridium, and rhodium are adequate electrode materials for room‐temperature operation. Performance of cells with platinum gauze current collectors bonded to the cell surfaces was only slightly better than that with external contacts about 1 cm. apart.

Open circuit voltages range from 0.9 to 1.1 v. (theoretical 1.23) depending on the catalyst. The typical current at 0.5 v. is 30 ma./sq. cm. Better cells have delivered 80 ma./sq. cm. at 0.5 v. Life tests indicate that these cells can be expected to deliver a minimum of about 40 amp.‐hr./sq. cm., when operated in the load range 8.5 to 230 ohm sq. cm., before failure of the electrolyte owing to pinhole formation. Current efficiency is very nearly 100%. Cell performance vs. temperature in the range 0° to 85°C. shows a maximum at about 55°C.
Heat and mass transfer transients in cylinder drying: Part II. Felted cylinders
Authors: Nissan A. H. , George H. H.
Published: June 2004

An investigation of transient heat transfer and water removal from a sheet on a steam cylinder was made. The sheet was pressed onto the cylinder by the aid of a felt. A theory describing the heat transfer in terms of the Fourier heat equation and appropriate boundary conditions was developed. The differential equation describing fluid flow in a capillary under the capillary potential was also developed. This equation was solved for small values of time.

The experimental work included the measurement of the transient temperatures at internal points in the sheet, the average felt temperature before and after a run, the mass of moisture lost by the sheet, and the mass of water gained by the felt.

It was found that on felted cylinders the majority of the moisture was removed by liquid transport. It was also found that heat was transferred through the sheet by vaporization‐condensation cycles as well as conduction.
Catalytic decomposition of nitric oxide
Authors: Sakaida R. R. , Rinker R. G. , Wang Y. L. , Corcoran W. H.
Published: June 2004

Catalytic decomposition of nitric oxide at a concentration of 0.404 and 0.432% by volume in nitrogen was studied in a tubular flow reactor. The packing consisted of alumina pellets impregnated with 0.1% by weight of platinum oxide and 3.0% by weight of nickel oxide. Tests were conducted at pressures of 1 to 15 atm. and temperatures from 800° to 1,000°F. A rate equation correlating the data as a function of temperature, pressure, and compositions was developed. A reaction mechanism compatible with the rate equation is proposed.
Solid phase transport of glycerol and sodium chloride in resin
Authors: Tayyabkhan M. T. , White R. R.
Published: June 2004

Diffusivities and equilibrium absorption of sodium chloride and glycerol in cation exchange resin Dowex‐50 were determined by making a two‐constant fit of experimental data to a diffusion model. The variables studied were: resin cross linkage—2% to 12% divinylbenzene, temperature—25° to 80°C, concentrations in the equilibrating solution, resin particle size, flow rate of the eluting distilled water. Diffusivities increase with decrease in cross linkage and with increase in temperature. The ratio of the diffusivities of sodium chloride or glycerol in the resin to that in water is between 0.2 and 0.35 for 2% DVB and between 0.025 and 0.1 for 12% DVB. Diffusivities were found to be independent of the third, fourth, and fifth variables. The amounts of solutes absorbed at equilibrium also increased with a decrease in cross linkage and an increase in temperature.
Heat radiation between simply‐arranged surfaces having different temperatures and emissivities
Authors: Sparrow E. M.
Published: June 2004

An analysis of radiant interchange is made which takes account of possible surface variations in incident radiation flux, heat transfer, and leaving radiant flux. This represents a generalization of standard calculation methods which postulate that the radiant fluxes and heat transfer are uniformly distributed on a surface. Consideration is given to pairs of simply‐arranged surfaces having different emissivities, one of which is essentially black. The surface temperatures may be arbitrarily different. The generalized analysis reveals that there may be significant variations in the local heat transfer along a surface, and this stands in contrast to the results of standard (and more approximate) calculation methods. The over‐all heat transfer results are also compared with those predicted by the standard calculation procedure. For the surface which is essentially black the errors arising in the standard procedure are found to be tolerable as long as the net over‐all heat transfer exceeds 20% of the radiant emission. For the nonblack surface the two methods are in agreement.
Skin friction patterns for transitional flow in annuli
Authors: Croop E. J. , Rothfus R. R.
Published: June 2004

Main stream velocity profiles have been obtained by means of impact probes for the steady, isothermal flow of water in three smooth, concentric annuli having widely different diameter ratios. The point of maximum local velocity has been determined, thus permitting the ratio of skin frictions at the inner and outer boundaries to be calculated. Previously published data on pressure drop have been used to obtain separate friction factor correlations for the two surfaces. Attention has been centered on the transition range, where the position of maximum velocity is a function of both the diameter ratio and the Reynolds number.
The separation of ions with permselective membranes
Authors: Dibenedetto A. T. , Lightfoot E. N.
Published: June 2004

This study forms part of a project aimed at obtaining a better understanding of the behavior of nonideal permselective membranes. The object here was to determine the applicability of the Nernst‐Planck equations for studying the behavior of ions in aqueous solutions surrounding such a membrane during electrodialysis.

Attention was confined to stagnant and laminar flow systems. The processes studied were transfer of hydrogen ions, silver ions, and mixtures of the two through the cation exchanging membrane Nepton CR‐61. The bulk solution concentrations on either side of the membrane varied from 0.01 to 0.20 N, and in all cases the only anions present were nitrate ions. Limiting currents for solutions of silver nitrate were predictable within 15%, with much of the uncertainty resulting from the difficulty in defining the limiting current. For mixtures of silver nitrate and nitric acid the limiting currents were predictable within the range of experimental accuracy but were found to be quite sensitive to small changes in the operating conditions. This sensitivity results from the very high relative mobility of the hydrogen ions. The relative transport of the two cations was primarily a function of relative concentration, relative diffusivities, current density, and ion exchange equilibria and was predictable with an accuracy limited only by the uncertainty of the ionic diffusivities and the ion exchange equilibria.

The diffusivities of the cations in the membrane relative to the diffusivity of nitrate ion were estimated to be about ten times lower than in solution. This was explained by assuming that the cations tended to concentrate about the anionic fixed charges of the membrane thereby portially screening their effectiveness and reducing the mobility of the cations. In mixtures, the membrane diffusivity of the silver ions relative to the hydrogen ions was lower (by a factor of 1.4 to 3.6) than the relative diffusivity in solution. This indicated that silver ions were more easily concentrated about the fixed charges and thereby screened them from both the anions and hydrogen ions.
An experimental study of liquid‐phase turbulent diffusion: Part II. Calculation of local turbulent mass transfer coefficients in the turbulent wake of a cylinder
Authors: Sparks Robert E. , Hoelscher H. E.
Published: June 2004

Turbulent mass‐transfer coefficients were calculated from concentration profiles obtained in the wake of a hollow cylinder having a porous wall through which a solution of electrolyte was flowing. These coefficients are presented as functions of the turbulence intensity and the width of the transport region. This paper is a continuation of the previous report on this subject and utilizes the results presented earlier.
Prediction of vapor‐liquid equilibria of binary systems: Part I. Effect of pressure on vapor‐liquid equilibria of binary systems
Authors: Tamura Mikio , Nagata Isamu
Published: June 2004

This paper presents an empirical method for the prediction of vapor‐liquid equilibrium data of a binary system at various pressures on the basis of equilibrium data near atmospheric pressure. The proposed method is tested for six hydrocarbon systems and one aqueous system. The calculated results are in good agreement with the experimental data.
Prediction of vapor‐liquid equilibria of binary systems: Part II. Hydrocarbon systems
Authors: Tamura Mikio , Nagata Isamu
Published: June 2004

This article proposes an empirical method for predicting the vapor‐liquid equilibrium data on binary hydrocarbon systems without any experimental data on the mixtures. The method was tested for twenty‐six systems under atmospheric pressure and three isothermal systems. The predicted results are in excellent agreement with experimental data.
The properties of some new gas hydrates and their use in demineralizing sea water
Authors: Barduhn Allen J. , Towlson Howard E. , Hu Yee Chien
Published: June 2004

The general attributes of the hydrate process for demineralizing sea water are discussed, and it is shown that the economics of the process depend on the properties of the hydrating agent used. Eight new hydrates are reported, and the thermodynamic properties of three hydrate systems are presented in some detail: methyl bromide Freon 21, and Freon 31.
The effect of the hydrolysis reaction upon the rate of absorption of chlorine into water
Authors: Brian P. L. T. , Vivian J. E. , Habib A. G.
Published: June 2004

The rate of absorption of chlorine into water was studied in a short wetted‐wall column. This absorption system is characterized by a liquid phase chemical reaction occurring simultaneously with the absorption process, and thus the absorption coeffiecient is greater than in the case of physical absorption.

The ratio of the absorption coefficient accompanied by the hydrolysis reaction to the physical absorption coefficient varied from 1.3 to 3, depending on the chlorine partial pressure and the liquid flow rate.

Penetration‐theory solutions for absorption accompanied by the hydrolysis reaction were obtained by the use of an IBM‐709 digital computer. Excellent agreement between the experimental and computed results was obtained on the assumption that the forward rate constant for the hydrolysis reaction was 13.7 sec.−1 at 25°C. This value compared favorably with the published results of kinetic studies of the hydrolysis reaction.
The kinetics of ion exclusion
Authors: Vassiliou Basil , Dranoff Joshua S.
Published: June 2004

As a preliminary to detailed kinetic analysis of ion‐exclusion operations a study of the rate of absorption of glycerol from dilute aqueous solution has been made in small fixed beds of ion exchange resin. The resin used was Amberlite IR‐120 (hydrogen form) ranging in size from 0.210 to 1.190 mm., as determined by dry screening. Solution flow rates were varied from 0.45 to 22.20 ml./(sq.cm.min.).

Analysis of this problem has shown that the operation of such a process may be described by a simple linear rate equation and the usual transient column material balance relations. It was found that experimental breakthrough data could be well matched with curves predicted by such analysis. Furthermore, three characteristic regions of operation are apparent in which different rate controlling processes may be operating.
Equilibrium flow of a general fluid through a cylindrical tube
Authors: Sakiadis B. C.
Published: June 2004

Equilibrium flow of a general fluid through a long, straight, cylindrical tube is examined, and equations are derived for determining the three pertinent material functions, the shear stress component, the difference between the radial and angular normal stress components, and the difference between the axial and angular normal stress components. These equations are expressed in terms of quantities which are measurable. Experimental data are obtained for a polymer solution, and the material functions are calculated.
Binary liquid diffusion coefficients
Authors: Kamal Musa R. , Canjar L. N.
Published: June 2004

The present work proposes a new approach for the calculation of the diffusion coefficients in binary liquid systems. The proposed equation is based on the results obtained by statistical mechanics of transport phenomena in dense media. It does not include viscosity explicitly, and the variables required for the calculation are fundamental in nature; these are the free volume of a molecule obtainable from physical measurements such as velocity of sound and the heat of vaporization of the solute. In spite of its theoretical background, the proposed correlation obtains results on fifty‐six different solute‐solvent systems with about 13% deviation from the experimental results. The effect of concentration on the diffusion coefficient is very easy to determine and is more in accord with experimental results than can be predicted by other available correlations.
Spontaneous interfacial cellular convection accompanying mass transfer: Ethylene glycol‐acetic acid‐ethyl acetate
Authors: Orell Aluf , Westwater J. W.
Published: June 2004

Spontaneous interfacial cellular convection accompanying the extraction of acetic acid out of ethylene glycol with ethyl acetate was studied photographically with a Schlieren technique. A flat liquid‐liquid interface at room temperature was photographed straight down with motion‐picture and still cameras. The interface exhibited a dominant pattern of stationary and propagating polygonal cells, accompanied by stripes, cell cluster boundaries, and confined or unconfined ripples. The time‐dependence of the average wave length (size) of the different patterns, their average speed of propagation, and their frequency was determined by means of an initial acetic acid concentration range of 0.1 to 10%, over a time span of 72 hr. The average wave lengths of cells, stripes, and ripples ranged from 0.02 to 0.14, 0.065 to 0.155, and from 0.03 to 0.10 cm., respectively. Cell and ripple velocities ranged from 0.27 to 1.33, and from 0.27 to 1.10 cm./min. respectively.

The relation between the observed interfacial cellular convection and the Sternling‐Scriven theory of interfacial turbulence is discussed.