bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of packed columns. IV. Effect of gas properties, temperature, and pressure on gasphase mass transfer coefficients
Authors: Shulman H. L. , Margolis J. E. 
Published: June 2004

AbstractTo test the applicability, over a wide range of temperatures, pressures, and gas physical properties, of the mass transfer correlation presented earlier, 0.5‐in. naphthalene Berl saddles were vaporized into air, carbon dioxide, and Freon‐12 in a 4.0‐in. column. Temperatures from 15° to 73°C. and pressures from 0.26 to 1 atm. were covered.The correlation was found to represent all the experimental data when the surface temperature of the naphthalene was used to evaluate the correct driving force.This correlation, when combined with effective interfacial areas presented previously, makes it possible to estimate the volumetric mass transfer coefficeint,kGa, for any gas‐liquid‐solute system.
Equilibrium in the system Cu++–Na+–Dowex‐50
Authors: Rao H. C. Subba , David M. M. 
Published: June 2004

AbstractEquilibrium isotherms are presented for the cation exchange of copper and sodium on Dowex‐50 resin in solutions from 0.01 to 4N in chloride content, and the equilibrium data are correlated on the basis of the Donnan equilibrium. Data are also given on the water content of the resin and the diffusible ions present in this water.
Reaction kinetic studies: Catalytic dehydrogenation of sec‐butyl alcohol to methyl ethyl ketone
Authors: Perona Joseph J. , Thodos George 
Published: June 2004

AbstractReaction kinetics for the catalytic dehydrogenation of sec‐butyl alcohol to methyl ethyl ketone has been investigated at atmospheric pressure and temperatures ranging from 650° to 750°F. in the presence of solid brass spheres, 1/8 in. in diameter. The nature of this catalyst permitted a direct evaluation of the surface involved in this reaction and allowed the definition of a surface‐feed ratio to be expressed as S/F in place of the conventional weightfeed ratio W/F commonly used in catalytic studies. Feed compositions ranged from secbutyl alcohol to mixtures containing high percentages of methyl ethyl ketone and hydrogen.In these studies mass transfer effects were found to be significant and, for a proper representation of conditiated at the catalyst surface, must be taken into account. The effect of feed compositions on the initial rates of reaction showed that the rate‐controlling step was the desorption of hydrogen involving a single‐site mechanism.In addition, the results of these studies have been used to produce values of height of reactor unit HRU which have been found to correlate with mass velocity and temperature. The HRU provides a simple means of calculating the depth of catalyst necessary to effect a designated conversion.
Hydraulics of wetted‐wall columns
Authors: Michalik E. R. 
Published: June 2004

AbstractOn the assumption of laminar Newtonian flow, flow profiles are developed for both the vertical plate and cylindrical column by use of classical equations. From the flow profiles the mass transport, vertical pressure gradient, and optimal design parameters are calculated. With the Reynolds‐number criterion used to ascertain the maximum nonturbulent velocity, minimal values for the plate distance and column radius can be calculated. An example is included for each case.
Measured plate efficiencies and values predicted from single‐phase studies
Authors: Rush F. E. , Stirba Clifford 
Published: June 2004

AbstractPlate efficiencies measured on 18‐in.‐diam. sieve plates are reported for the acetic acid‐water system and for the methyl isobutyl ketone‐water system at atmospheric pressure. In the former system the major resistance to mass transfer is in the gas phase; liquid‐phase resistance to mass transfer is controlling in the latter. Efficiencies are also reported for the aniline‐nitrobenzene system (gas‐phase resistance controlling) at 5 mm. Hg absolute on 6‐in.‐diam. sieve plates. Pure gas‐ and liquid‐phase efficiencies for both plate designs were determined by the adiabatic humidification of air and the desorption of oxygen from water into air. Predicted values of plate efficiency for each of the binary systems studied were computed from the pure phase efficiencies according to the procedure outlined by Gerster et al. A comparison between measured and predicted efficiencies is presented as a guide for future research in this field.
Critical constants of the aromatic hydrocarbons
Authors: Thodos George 
Published: June 2004

AbstractFollowing an approach similar to that presented for the aliphatic (6, 7) and naphthenic (8) hydrocarbons, methyl‐group contributions have been developed that now make possible the calculation of van der Waals' constants for aromatic hydrocarbons of considerable size and complexity. These constants are then utilized to calculate the critical temperatures, pressures, and volumes for these aromatic hydrocarbons.In addition, simple relationships have been developed that permit the evaluation of both van der Waals' constants for the unsubstituted linearly fused aromatic hydrocarbons.Comparisons of calculated critical constants with values presented in the literature for over twenty aromatic hydrocarbons produced average absolute deviations of 0.70% for the critical temperature and 2.14% for the critical pressure.
Diffusion coefficients in hydrocarbon systems: Methane in the liquid phase of the methane–n‐heptane system
Authors: Reamer H. H. , Sage B. H. 
Published: June 2004

AbstractThe production and refining of petroleum involve many processes in which conditions deviate markedly from equilibrium. For prediction of the behavior of such nonequilibrium systems, information concerning the molecular‐transport characteristics of the paraffin hydrocarbons is of practical interest.Fick diffusion coefficients for methane were measured in the liquid phase of the methane–n‐heptane system at temperatures between 40° and 340°F. at pressures up to 3,500 lb./sq. in., but the pressure range was limited at the higher temperatures by approach to the critical state of this binary system.The measurements obtained confirmed the fact that the Fick diffusion coefficients for methane decrease with an increase in the concentration of this component and increase rapidly with an increase in temperature for a constant composition. These data together with similar information for other binary paraffin hydrocarbon systems indicate that the Fick diffusion coefficients for methane decrease with an increase in the molecular weight of the less volatile component.
Thermal‐conductivity–reduced‐state correlation for the inert gases
Authors: Owens E. James , Thodos George 
Published: June 2004

AbstractThe fragmentary thermal‐conductivity data for argon available in the literature have been correlated by use of a residual thermal conductivityk–k* vs. density ρ relationship. This correlation produced a unique continuous curve which was found to be singularly independent of temperature and pressure for both gaseous‐ and liquid‐state data. From low‐pressure thermal‐conductivity valuesk* and the relationship given above, it is possible to determine thermal conductivities at any condition of temperature and pressure for which a corresponding density is available. This procedure was used to calculate reliable thermal conductivitieskfor high‐pressure regions where experimental data were lacking.In a similar manner the critical thermal conductivitykcfor argon was established directly from the critical density and the quantityk*. Thekcvalue permitted the calculation of reduced thermal conductivitieskRand made possible the construction of an extensive reduced‐state chart. Although this correlation was developed mainly from data for argon, it was found to apply equally as well to the other inert gases as postulated from the theory of corresponding states.A comparison of thermal conductivities calculated from the reduced‐state plot with over 200 experimental points produced an average deviation of 1.8% for all the inert gases. This chart was also found applicable to the diatomic gases and their mixtures but produced significant deviations for substances having more than two atoms per molecule.
Fluid friction in noncircular ducts
Authors: Walker J. E. , Whan G. A. , Rothfus R. R. 
Published: June 2004

AbstractPressure drop due to fluid friction has been measured in a smooth tube; in six smooth concentric annuli; and between smooth, parallel, flat plates. The data cover the viscous, transition, and lower turbulent ranges of flow. Friction factors are in agreement with theory in the viscous range and can be correlated uniquely in the fully turbulent range by means of a modified hydraulic radius concept. Limits of the transition region in annuli are functions of the ration of inner and outer radii. Correlations in the fully turbulent range permit friction factors for the noncircular ducts to be predicted within the uncertainty of smooth‐tube data. Such factors can be used for the prpose of correlating other variables as well as for direct calculation of pressure drop.
Vapor‐liquid equilibria and heat of mixing: n‐octane–ethylbenzene–cellosolve system
Authors: Murti P. S. , Van Winkle Matthew 
Published: June 2004

AbstractVapor‐liquid equilibria of the systems n–octane–Cellosolve, ethylbenzene‐Cellosolve, and n–octane–ethylbenzene‐Cellosolve were determined at 760 mm. Hg. The activity coefficient data of Yang and Van Winkle (23) for the system n–octane–ethylbenzene and the data of this work on other systems were expressed by Wohl's three‐suffix Margules equations. The ternary data are predicted satisfactorily from the binary constants and no noticeable ternary effects seem to exist for this ternary system.
Diffusion in a moving medium with time‐dependent boundaries
Authors: Forster H. Kurt 
Published: June 2004

AbstractThe problem of diffusion in a moving medium with given motion of the boundaries is considered. The method presented yields the analytical solution to any desired degree of accuracy provided that solutions for certain associated problems of diffusion in a medium at rest with boundaries at rest are known. The method is applied to the analysis of partial and approximate solutions previously presented for the one‐dimensional case of a spherical cavity in a liquid with radial boundary motion induced by evaporation.
Entrapment of gas in the spreading of a liquid over a rough surface
Authors: Bankoff S. G. 
Published: June 2004

AbstractConditions for the incomplete displacement of gas from the valley between two parallel ridges by a liquid‐drop front advancing over the ridges are calculated. The significant parameters are found to be the liquid density, surface tension, contact angle, and geometry of the ridges. The solution may be obtained analytically or, more conveniently, graphically. Surface roughnesses are divided into four classes, one of which can stably switch from liquid—to gas—fill, and another vice versa. This may account for some of the hysteresis effects reported in bubble nucleation. It is pointed out that surfaces consisting predominately of cavities are more likely to follow these considerations than grooved surfaces, owing to displacement of gas by advance of liquid along the grooves. An example important in boiling and cavitation theory is worked out, and qualitative agreement with the literature is shown.
Kinetic studies of carbonation reactions using radioactive tracers
Authors: Himmelblau D. M. , Babb A. L. 
Published: June 2004

AbstractIn this study a radioactive tracer technique was used to determine the kinetic reaction rate constants in the CO2NaHCO3Na2CO3H2O system at temperatures of 32, 50, and 68°F., and at various values of pH ranging from 5.6 to 7.6. By operating with this system at chemical equilibrium but at isotopic disequilibrium, it was possible to divorce the influence of the diffusion of CO2 into and out of the aqueous solution from the kinetic effects of the chemical reaction. Radioactive carbon‐14 in the form of CO2 was analyzed by means of the Bernstein‐Ballentine technique in order to measure the rates of reaction.By this treatment, without using intricate equipment, reaction rate constants were computed from simple, integrated first‐order equations. Results showed that values for the forward rate constant of the reaction CO2 + H2O ⇌ HCO3− + H+ agreed well with the values published by previous investigators. On the other hand, the forward rate constants of the reaction CO2 + OH− ⇌ HCO3− were about 100 times as large as previously reported values. This difference is believed due to the complete elimination of any mass transfer effects in this study. In addition, values for the rate constants of the reverse reactions were measured for the first time, and the calculated values of the equilibrium constants for the two reactions agreed within 6% on the average with those given by Harned and Owen. The technique used, with its variations, is expected to have numerous applications in the study of the kinetics of heterogeneous systems.
Wall effect for the fall of single drops
Authors: Strom J. R. , Kintner R. C. 
Published: June 2004

AbstractMeasurements were made of the rate of fall of drops of five organic liquids through an aqueous phase contained in eight vertical cylinders of various diameters. Newton's equation for the wall proximity effect for rigid spheres or cylinders predicts values somewhat in excess of the observed. A correction factor equation with the more convenient equivalent spherical diameter is presented. Its use is limited to d/D ratios less than one half. The ultimate velocity of a drop of specific size in an infinite medium can be calculated from that measured in a small tube by multiplying the latter by the ratio of the tube cross‐sectional area to the area of the annular space between tube wall and drop.
Viscous flow in multiparticle systems: Slow motion of fluids relative to beds of spherical particles
Authors: Happel John 
Published: June 2004

AbstractA mathematical treatment is developed on the basis that two concentric spheres can serve as the model for a random assemblage of spheres moving relative to a fluid. The inner sphere comprises one of the particles in the assemblage and the outer sphere consists of a fluid envelope with a “free surface.” The appropriate boundary conditions resulting from these assumptions enable a closed solution to be obtained satisfying the Stokes‐Navier equations omitting inertia terms. This solution enables rate of sedimentation or alternatively pressure drop to be predicted as a function of fractional void volume.Comparison of the theory is made with other relationships and data reported in the literature. Of special interest is its close agreement with the well known Carman‐Kozeny equation which has been widely used to correlate data on packed beds as well as sedimenting and fluidized systems of particles. This is remarkable in view of the fact that the force on each particle in a packed bed can be up to several hundred times that exerted on a single particle in an undistrubed medium.
Heterogeneous phase equilibria of the methane—hydrogen sulfide system
Authors: Kohn James P. , Kurata Fred 
Published: June 2004

AbstractThe experimental apparatus and procedures which were developed for the determination of the heterogeneous phase behavior of the methane‐hydrogen sulfide system have been described in a previous paper (2). The apparatus and procedures were tested and employed at temperatures in the range of —300 to 300°F. and at pressures up to 2000 1b./sq. in. abs. The vapor‐liquid, vapor‐solid, liquid‐vapor‐solid, liquid‐liquid‐vapor and liquid‐liquid‐solid phase border curves were determined for six mixtures of methane and hydrogen sulfide. The phase compositions were determined at selected points along the three‐phase univariant equilibrium lines. An invariant point (quadruple point) was found which involves the equilibrium of two liquid phases, a vapor phase, and a solid phase. These data are presented on P‐T and T‐X diagrams.The data contribute to the understanding of phase behavior of light hydrocarbons containing hydrogen sulfide.
Viscosity: Reduced‐state correlation for the inert gases
Authors: Shimotake Hiroshi , Thodos George 
Published: June 2004

AbstractA reduced‐state viscosity correlation has been constructed from the available data of the inert gases. For the development of this correlation, the fragmentary experimental data for argon were utilized along the lines proposed for thermal conductivities by Owens and Thodos (21) in order to determine the effect of pressure on viscosity. In addition, the only available low‐pressure viscosity data for neon and helium have been incorporated in this correlation to produce for the first time the effect of subatmospheric pressures. This correlation covers the range of pressures included betweenPR= 40 andPR= 0.015 × 10−4and extends up to temperatures ofTR= 100. It has been found that the effect of subatmospheric pressures on viscosity does not become significant above pressures of 1 mm. of mercury. However, at lower pressures, viscosity is found to decrease rapidly, particularly in the regions below absolute pressures of 0.01 mm. of mercury.Viscosities calculated with the reduced state correlation produce an average over‐all deviation of 0.93% for neon, argon, krypton, and xenon. In these comparisons the available viscosity data for the gaseous and liquid states of these substances have been included. Deviations of the same order of magnitude are produced for helium in the gaseous state; however, these deviations become excessive for viscosities of helium in the liquid state.The application of the final reduced state correlation has been extended to a number of diatomic and polyatomic gases and found to apply well to the diatomic gases only.
Drop formation in liquid‐liquid systems from single nozzles
Authors: Null Harold R. , Johnson Homer F. 
Published: June 2004

AbstractInterfacial area is an important variable in mass transfer operations. In liquid‐liquid extraction systems, where interfacial area comprises drop surfaces, the area can be computed if drop sizes are known. This work presents a new correlation which predicts volumes of drops formed from single nozzles to within 20% throughout the range of nozzle flow rates for which uniform drop sizes are obtained.
Combined laminar free‐ and forced‐convection heat transfer in external flows
Authors: Acrivos Andreas 
Published: June 2004

AbstractA method is presented for calculating the shear stress and the rate of heat transfer in external flows for combined laminar forced and free convection. The parameterGr/Re2is of fundamental importance in such problems. Numerical results are reported for the heating and cooling of upward flow past a vertical flat for three Prandtl numbers. It is found that the transition from forced to free convection is gradual, especially at high Prandtl numbers. The inflence of free convection on the separation point is also examined.
Some properties of the poisson distribution
Authors: Said A. S. 
Published: June 2004

AbstractThis paper lists various properties of the Poisson distribution and related functions which can be derived from elementary principles without reference to theories of probability or statistics. They are intended for use by persons who may have to deal with Poisson distributed variables but not from a satistical point of view. Limit values and sums of the Poisson distribution, the sums of related functions, and different relations between its sums and integrals are given.Differential and difference equations which lead to solutions in the form of a Poisson distribution are discussed. The general elution equation is derived by setting up the differential‐difference equation for plate n in a chromatographic column and showing that the Poisson distribution is a solution to this equation. The complete solution is then obtained by applying the boundary conditions of the process.
A reactor‐design equation based on a proposed distributed boundary‐layer thickness
Authors: Hoelscher H. E. 
Published: June 2004

AbstractAn empirical equation is developed which seems applicable to the general problem of fixed‐bed catalytic design and relates the reaction rate (in a differential reactor) or conversion (through an integral reactor) to the surface reaction rate, the flow rate through the bed, and the physical properties of the system. The development is based on the assumption that there exists a film of stagnant fluid surrounding each catalyst particle, through which mass is transferred only by molecular motion, and that the thickness of this film varies throughout the bed from zero to some upper limit in a manner which is described by a distribution function. The equation involves two empirical constants: the multiplying constant and the exponent in the usual jd‐factor‐Reynolds‐number relationship.The application of this equation is illustrated. It appears to provide a basis for evaluation of the contribution of diffusional steps in the over‐all mechanism and to provide a means for predicting an expected conversion rate at any flow rate through the bed, provided only that the surface (chemical) reaction rate is known at the operating temperature. It also appears possible to calculate values of the surface‐reaction‐rate constant and the temperature coefficient from data taken from a reactor operating in the diffusion‐controlled range.
Drainage of packed beds in gravitational and centrifugal‐force fields
Authors: Nenniger Emile , Storrow J. Anderson 
Published: June 2004

AbstractThe basic differential equations are developed for the prediction of saturation‐time curves for the drainage of packed beds in either gravitational or centrifugal fields. The only mathematical solution existing at present, a series solution, is provided for these equations. A film drainage function is included to describe the movement of liquid along the surface of the particles when the main liquid level has passed through the pores of the bed. This method of analysis has been used successfully to predict the drainage of packed beds in a 9‐in.–diameter hydroextractor. The important value of capillary suction head is best found from ancillary tests with Haines apparatus, but the value can be found with reasonable accuracy from the change in drainage rate as the liquid surface enters the upper surface of the packed bed. When these two rates are available, the permeability can also be found, and all the major variables are obtained from the drainage test on either the hydroextractor cake or the packed bed under gravity drainage.
Heat transfer in forced convection with internal heat generation
Authors: Toor H. L. 
Published: June 2004

AbstractA solution to the problem of heat transfer with simultaneous heat generation in viscous tubular flow is presented. The temperature profiles and heat transfer coefficients which are obtained apply to compressible as well as incompressible Newtonian and power‐law non‐Newtonian fluids with constant physical properties and to systems in which the heat generation is an arbitrary function of radius. An example of heat transfer with frictional heat generation in a non‐Newtonian fluid is also presented, and the solution to the problem in which a fluid enters a tube in laminar flow with an arbitrary temperature profile is given, with a consideration of a first approximation to the case of heat transfer in a turbulent fluid in which heat is being generated.