bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical solution of two‐dimensional heat‐flow problems
Authors: Douglas Jim , Peaceman D. W. 
Published: June 2004

AbstractTwo‐dimensional heat flow frequently leads to problems not amenable to the methods of classical mathematical physics; thus, procedures for obtaining approximate solutions are desirable. A recently introduced finite‐difference method, known to be applicable to problems in a rectangular region and involving much less calculation than previous methods, is extended by example to cases of more practical interest. Although all three examples given are steady state, unsteady state problems may also be attacked successfully by the method. The first example is that of flow around a corner and indicates that a more complicated region than a rectangle can be treated. Then a problem involving a radiation‐boundray condition is given; as this condition is nonlinear, the method is extended to more general equations. The last example involves point heat sources and sinks in an elliptical region and so extends the method to treat curved boundaries (as distinguished from polygonal domains) and singular points. It is believed that materially less calculation is necessary by this method than for previous procedures.
Plant performance of a 13‐ft.‐diameter extractive‐distillation column
Authors: Gerster J. A. , Mizushina Tokuro , Marks T. N. , Catanach A. W. 
Published: June 2004

AbstractPlant performance data are presented for a 13‐ft.‐diam., 100‐tray furfural extractive‐distillation column separating iso‐ and n‐butane from 1‐ and 2‐butene. In addition to composition, temperature, pressure, and flow rate of the external streams, values are presented for vapor and liquid compositions and flow rates at a number of different locations within the tower. With the exception of the vapor compositions, which were determined experimentally, the internal conditions were determined by heat and material balances. These data permitted calculation of plate efficiency over various small sections of the column. In the 50‐tray rectifying section, plate efficiency for the isobutane—1‐butene separation was constant at 20%, and in the stripping section the plate efficiency varied from 25 to 45%. The average for the entire column was 25%.The furfural‐column plate efficiencies compare favorably with those predicted from laboratory tests made before the construction of the column to evaluate the performance of the tray design to be employed. The laboratory plate efficiencies were obtained for the desorption of oxygen from oxygen‐rich water with air at the same conditions of volumetric gas and liquid rates to be encountered in the furfural column. When these values were suitably corrected for physical property differences between the two systems, the point efficiencies predicted from the laboratory data for the furfural column ranged from 35% near the top of the column to 25% near the bottom of the column, the average value being 29%.
An algebraic approach to calculating the solvent extraction of complex mixtures
Authors: Hopp Harry F. , Smith R. B. 
Published: June 2004

AbstractIn the usual method of calculating the solvent extraction of complex mixtures it is assumed that the complex mixture behaves like a binary mixture. However, the hypothetical binary composition of the mixture is never explicitly used; rather, an additive property of the mixture is used as an indication of its composition. The calculation must be done graphically on a triangular diagram or its equivalent.On the assumption that the complex mixture consists of only two hypothetical components, empirical equations have been arrived at relating the distribution coefficients of these two components and of the solvent to the phase compositions. These equations contain three arbitrary constants. By use of the data from a minimum of three simple laboratory batch extractions of a given complex mixture, the three constants, plus the hypothetical binary composition of the original complex mixture, can be determined.With the equations for the distribution coefficients, the equilibrium curve and tie lines for the system can be calculated. Properties of the raffinates and extracts can be measured and related to the hypothetical binary compositions of these mixtures.The use of the method is demonstrated by comparing calculated results with laboratory yields and properties. The calculated results show good agreement with the experimental results. Calculations can be carried out not only on the triangular diagram, but by any of the other graphical methods that have been developed for the solvent extraction of binary mixtures. Equally important, calculations can be done analytically, and therefore the use of automatic computers is feasible.
Determination of relative permeability under simulated reservoir conditions
Authors: Wilson J. W. 
Published: June 2004

AbstractAn apparatus for the determination of relative permeability under simulated reservoir conditions has been designed, constructed, and operated successfully. Complete water‐oil relative‐permeability data, with kerosene and simulated reservoir brine have been taken on four natural‐sandstone cores at fluid pressures to 5,000 1b./sq. in. and overburden pressures to 10,000 1b./sq. in. One run was made at low pressure at a temperature of 160°F. for comparison with the results at low temperature. The apparatus is now being expanded so that gas‐oil relative‐permeability data may be taken, and crude oil containing gas in solution may be employed as the oil phase.The results indicate that essentially the same water‐oil relative‐permeability data are obtained at fluid pressures of 5,000 1b./sq. in. as at 30 1b./sq. in. gauge. The application of overburden pressure causes a reduction in both water and oil effective permeability in about the same proportion as it affects the single‐phase permeability. Consequently the calculated relative permeabilities are affected to only a moderate extent. The results of the one run at 160°F. were in good agreement with the values obtained at room temperature.
Properties of evaporated metal films related to their use for surface temperature measurements
Authors: Simpson Theodore B. , Winding Charles C. 
Published: June 2004

AbstractExtension of the understanding of properties of films of metals produced on glass surfaces by vacuum evaporation has permitted the fabrication of film‐resistance thermometers that with simple instrumentation accurately measure surface or average surface temperatures without altering the geography of that surface. Formerly unknown and unstabled related properties of such films have been classified and may be anticipated or eliminated by recommended experimental procedures. Films of several of the most chemically inert and refractory metals 300 to 3,000 Å. thick have been shown to attain accuracies as high as 0.01°C. for practical periods of time. Their use, which is described, is developing satisfactorily, and the technique and equipment for their preparation are relatively simple.
Effect of gamma radiation on aqueous ethylene‐oxygen solutions
Authors: Henley Ernest J. , Schiffries Wesley P. , Barr Nathaniel F. 
Published: June 2004

AbstractMixtures of ethylene and oxygen dissolved in water under pressures ranging from 200 to 700 lb./sq. in. were irradiated with Co60 gamma rays at a dose rate of 180,000 r./hr. G values (molecules/100 ev.) for aldehyde production as high as 200 were observed. Increasing total pressure and dose were found to decrease these G values. Alcohol, acids, hydrogen peroxide, and organic peroxide are also products of the reaction; however, the yields are much smaller.
Heat transfer to water flowing parallel to a rod bundle
Authors: Miller Philip , Byrnes James J. , Benforado David M. 
Published: June 2004

AbstractHeat transfer was measured for water flowing parallel to 5/8‐in. rods in a triangular lattice (0.914‐in. spacing). Velocity was varied from 5 to 20 ft./sec., temperature from 150° to 325°F., and heat flux from 50,000 to 200,000 B.t.u./(hr.)(sq. ft.). Reynolds numbers ranged from 70,000 to 700,000. Coefficients were 40% higher than predicted from the Colburn equation for flow in pipes by use of the equivalent diameter. The effect of heated length was studied. No variation in local coefficient around the rod periphery was found. Pressure drops were 65% higher than predicted by the Fanning equation (by use of De).
Factorial experiments in sequence: The attainment of optimum conditions for a decontamination process
Authors: Barnett M. K. , Hamilton P. M. , Mead F. C. 
Published: June 2004

AbstractThe advantages of factorial design are first illustrated by a simple experiment devoted to the effect of two pH factors and an iron‐concentration factor on the efficiency of a decontamination process employing iron sulfide as a scavenging agent. The broadening of the base of an investigation by the expansion of a factorial is illustrated by addition of the sulfide concentration as a factor. Finally the principle of expanded factorials is further utilized in the later phases of the study, in which additional levels are assigned to the pH factors in order to arrive at a closer estimate of the optimum conditions for the process.
A common basis for the correlation of forced and natural convection to horizontal cylinders
Authors: Lemlich Robert , Hoke Ronald 
Published: June 2004

AbstractNatual and forced convection have always been correlated on different bases although the two phenomena have much in common. Accordingly, a method for correlating both types of convection on the same basis, at least for heat transfer outside horizontal cylinders, would be of interest.A tentative method of accomplishing this for transverse convection is presented, involving certain simplifying assumptions relating to drag and buoyancy, from which an “effective velocity” for natural convection is calculated (by means of the well‐known drag correlation) and incorporated in a Reynolds number. The Nusselt number for natural convection is then correlated in terms of the Prandtl number and this Reynolds number in much the same manner as that for McAdams's well‐known correlation for forced convection. For 150 different combinations of independent variables covering seven different fluids and wide ranges of diameter, surface temperature, and bulk fluid temperature, the transformed natural‐convection data agree with Douglas and Churchill's recent refinement of McAdams's relationship for forced convection with an average deviation of about ±10%.
A semiempirical solution for local heat transfer coefficients for flow in nonparallel passageways
Authors: Stevens P. N. , Obert E. F. 
Published: June 2004

AbstractA method, based upon the pertinent flat‐plate heat transfer equation, is presented for computing the local heat transfer coefficients for a boundary layer subjected to streamwise velocity and pressure gradients. No extensive mathematical background is required as the complexity of a rigorous solution for this type of problem is avoided. The validity of the method for gases is demonstrated by comparison of the predicted coeffcients with the experimental data for two widely different problems.
Application of Bernoulli's equation to buoyant systems
Authors: Ruth B. F. , Boylan D. R. 
Published: June 2004

AbstractThe various forms of Bernoulli's equation as customarily written express static pressure energy in terms of absolute pressure, thereby restricting their direct application to systems situated in vacuo. It is shown here that recognition (1) of the universal presence of a fluid outside all systems over which Bernoulli's equation is written, and (2) of the practical necessity of measuring pressure within such systems as gauge pressures relative to the pressure of the exterior fluid leads to a more general set of equations and to a concept of buoyant static pressure and potential energies, as opposed to strictly abslute values.Failure properly to distinguish between these two types of energy quantities may result in error and confusion in the application of the various forms of Bernoulli's equation.
Operating characteristics of a centrifugal extractor
Authors: Jacobsen F. M. , Beyer G. H. 
Published: June 2004

AbstractThe operating characteristics of a Podbielniak model 5,000 centrifugal extractor, having a combined‐stream capacity of 450 cc./min. at 5,000 rev./min. and a rotor holdup of 529 cc., were investigated. Variables studied were density difference, rotor speed, light‐liquid‐out pressure, flow rates, holdup, and number of stages.A technique for holdup determination that comprises displacing either phase in the extractor with the other phase is described and experimentally demonstrated. An equation useful in predicting flooding limits is verified. It is suggested that the effective values of the rotor dimensions in this equation be determined by the behavior of the extractor.A relationship among number of stages, light‐liquid‐out pressure, and flow‐rate ratio is demonstrated by extracting boric acid from isoamyl alcohol with water. With only a few runs this relationship should permit one to map in a family of curves for a particular system and thus rapidly to estimate optimum operating conditions.A procedure is outlined for applying the methods to other systems using similar extractors. First the constants in an equation are estimated from holdup measurements in order to predict flooding limits. Then a few extraction runs are made to estimate optimum operating conditions.
Vapor pressures: The saturated Aliphatic Hydrocarbons
Authors: Sondak Norman E. , Thodos George 
Published: June 2004

AbstractA 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

AbstractPartial 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

AbstractMeasurements 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

AbstractA 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

AbstractThe 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

AbstractThe 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

AbstractDirect 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

AbstractThis 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

AbstractBy 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.