bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generalized correlation for loading in packed towers with countercurrent gas‐liquid flow
Authors: Howkins J. E. , Davidson J. F. 
Published: June 2004

AbstractExperiments in which a liquid film runs over a vertical string of spheres surrounded by a concentric tube through which air is blown upward have shown that loading in a packed tower is due to the formation of standing waves on the liquid film. In the ball‐and‐tube system a wave is formed just below the equator of each ball, owing to the pressure gradient within the air stream as it accelerates through the narrowing gap between the ball and the tube. Interfacial shear and surface tension are of secondary importance. The similarity between the characteristics of the ball‐and‐tube system and those of the randomly packed tower suggests that loading in the latter system is also due to wave formation. With this concept of loading, a correlation has been dérived.
Critical temperatures and pressures of hydrocarbons
Authors: Forman J. Charles , Thodos George 
Published: June 2004

AbstractA method has been developed for the calculation of van der Waals' constants both a and b for hydrocarbons usually encountered, including the aliphatic, naphthenic, and aromatic types. With these constants critical temperatures and pressures can be calculated directly.Methods recently made available (12, 13, 14, 15) allow the calculation of these constants through the use of substitution values involving the replacement of hydrogen atoms by methyl groups in a definitely prescribed pattern. In this study van der Waals' constants are directly calculated from a consideration only of the molecular structure of the hydrocarbon. This approach has become possible through the assignment of group contributions to different types of carbon atoms, which can be combined in any manner to produce the van der Waals' constants representative of the molecular structure of the hydrocarbon.
Heat transfer to a liquid fluidized bed
Authors: Lemlich Robert , Caldas Isidoro 
Published: June 2004

AbstractAn experimental study of the rate of heat transfer from the retaining wall to a fluidized bed of solids was carried out for liquid water and glass spheres. The independent variables included mass velocity, particle size, bulk temperature, and wall temperature. Significant increases in heat transfer were observed, owing to the presence of the suspended solids, even to the extent of tripling the coefficient. For each of several particle sizes, the coefficient passed through a maximum corresponding to a particular mass velocity. The behavior of the bed at velocities below and above those for maximum coefficient was studied and categorized. Tentative correlations for both regions are offered.
Wetting effects on boiling heat transfer: The copper‐stearic acid system
Authors: Harrison W. B. , Levine Zelvin 
Published: June 2004

AbstractIn order to study effects of wetting on heat transfer in the nucleate boiling regime, stearic acid was boiled in contact with different crystal planes of single crystals of copper. One crystal plane being wetted by the acid more completely than the other, they are called wetted and nonwetted surfaces. In the region of low heat flux, where heat transfer is primarily nonboiling natural convection, the nonwetted crystal required higher values of temperature difference than the wetted crystal for the same flux. At high values of heat flux, though not in the vicinity of the critical temperature difference, the situation was reversed; that is, the nonwetted surface required lower temperature difference than the wetted surface.In the present studies, stearic acid was boiled at about 465°F., corresponding to a pressure of 17 mm. of mercury. Heat flux ranged from 3,450 to 63,300‐B.t.u./(hr.)(sq. ft.), and temperature difference between the copper crystal and the stearic acid ranged from 38° to 132°F. The corresponding range of heat transfer coefficient was from 91 to 510 B.t.u./(hr.)(sq. ft.)(°F.).
Perforated plate efficiency‐effect of design and operating variables
Authors: Hellums J. D. , Braulick C. J. , Lyda C. D. , Van Winkle Mathew 
Published: June 2004

AbstractExperimental plate efficiency and pressure drop data were obtained on the n‐octane‐toluene system in a 5 plate, 6 in. diam. column at atmospheric pressure. Hole sizes of 1/16, 1/8, and 3/16 in.; 5.68 and 12.5% free areas; weir heights of 1, 2, and 3 in.; and plate spacings of 6, 12, 18, and 24 in. were studied. Reflux ratios of one, two, four, five, ten, and total were utilized to determine the effect on efficiency.It was found that hole diameter, free area, plate spacing, and a wide range of reflux ratio had relatively small effect on efficiency and pressure drop; however weir height and lower reflux showed relatively larger effects on both variables.Efficiencies and pressure drops were lower than those predicted from published correlations particularly at low flow rates.
Equilibria in the hydration of ethylene at elevated pressures and temperatures
Authors: Cope C. S. , Dodge B. F. 
Published: June 2004

AbstractValues of equilibrium composition for the hydration of ethylene to form ethanol have been calculated for a series of elevated pressures and temperatures by using equilibrium data available from previous low‐pressure studies. To obtain satisfactory agreement between these values and those measured experimentally, it is essential (1) to take into account the formation of ethyl ether and (2) to use available vapor‐liquid equilibrium data for the binary ethanol‐water system at elevated temperatures, instead of the standard “mixture rules” often employed.Thermochemical data and low‐pressure equilibrium data for both the ethylene hydration and ether formation reactions are critically reviewed. Experimentally measured values for the equilibrium concentrations of ethanol and ether in the liquid phase at 221°C. and 273 atm., with dilute sulfuric acid used as catalyst in a lined rocking‐bomb reactor, are presented.
Mechanics of vertical moving fluidized systems: II. Application to countercurrent operation
Authors: Price B. G. , Lapidus L. , Elgin J. C. 
Published: June 2004

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

AbstractThe drying of two highly porous thick textiles is studied and compared. Extremes are chosen in that one package is composed of a Terylene (British form of a polyester fiber) net fabric of open structure and the other of a woolen flannel of close structure. The cloths are wound as bobbins and dried by hot air streaming in a wind tunnel, the air flowing parallel to the axis of the cylinder of material. The weight of water as drying progresses is measured by a balance, and thermocouples within the bobbin provide a temperature record.On investigation of the thermal conductivity of the dry structure, it is found that whereas the coefficient for the wool‐air mixture is constant throughout, the coefficient for the Terylene‐air mixture applies only in the depths, the apparent thermal conductivity growing larger toward the surface and with increasing air speed, as if the heat transfer through the open structure is assisted by some form of air penetration.As the thick textiles dry, the rate of evaporation falls off, since heat and water vapor have to pass through an increasing layer of dry material. While this is occurring, a constant temperature, the “pseudo‐wet‐bulb temperature,” is established throughout the wet cloth. This state of equilibrium may be expressed as an equation between the rate of heat conduction inward and that required to produce the vapor diffusion outward. From this equation the pseudo‐wet‐bulb temperature can be calculated.
Theoretical explanation of heat transfer in laminar region of bingham fluid
Authors: Hirai E. 
Published: June 2004

AbstractFrom time to time, A.I.Ch.E. Journal presents translations of certain technical articles written by our Japanese colleagues in their own language. These translations are made by Kenzi Etani, who received his B.S. in chemical engineering in 1953 at the Tokyo Institute of Technology and his M.S. in 1955 at M.I.T. He is associated with Stone & Webster and is an associate member of American Institute of Chemical Engineers. He is also a member of the Society of Chemical Engineers, Japan, and the Japan Oil Chemists' Society. His offer to help break down the language barrier is acknowledged.The following article was published in Chemical Engineering (Japan), 21, pages 17–25 (1957).Abstracts, notation, literature cited, tables, and figure captions not published here appear in English in the original paper. No figures will be reproduced in these translations.
Effect of a volume heat source on free‐convection heat transfer
Authors: Randall I. E. , Sesonske Alexander 
Published: June 2004

AbstractHeat transfer to a horizontal cylinder from an ordinary fluid containing a volume heat source was studied analytically. The first approach to this problem was to assume that the heat source existed only in the boundary layer surrounding the cylinder. By solving the equations for a vertical flat plate cooling the ambient fluid and applying the results to a horizontal cylinder, one could determine the effect of a volume heat source on the heat transfer coefficient for the cylinder case. The variables studied were volume heat sources from 0 to 300 B.t.u./(sec.)(cu. ft.) and temperature difference across the boundary layer in the range 20° to 100°F.In the laminar‐flow region a volume heat source was found to increase the heat transfer coefficient for any given temperature difference across the boundary layer. This increase, due to the decrease in boundary‐layer thickness caused by the volume heat source, was moderate, being about 20% for a 1 1/4‐in. O.D. cylinder with a heat source strength of 100 B.t.u./(sec.) (cu. ft.) and a temperature difference across the boundary layer of 20°F.
Mass transfer from a solid sphere to water in highly turbulent flow
Authors: Steele L. R. , Geankoplis C. J. 
Published: June 2004

AbstractMass transfer coefficients from 1/2‐in. spheres of benzoic and cinnamic acids and 2‐napthol to water were measured in the high Reynolds number region of 600 to 140,000. Previous data for liquids extended only to a Reynolds number of 11,000. Three separate and approximately parallel lines of JD vs. Reynolds number were found for the different solutes, and the shape of the curves was found to be similar to the total‐drag‐coefficient correlation for spheres.Experiments with benzoic acid and 2‐napthol showed an effect of driving force and hence flux on the JD values. Mass transfer did occur in saturated solutions having zero driving force. When one subtracted the amount of mass transfer at zero driving force from the values at other driving forces, the corrected JD values at different driving forces were the same for a given solute. Possible explanations may be the effect of extreme turbulence on crystallization or physical attrition.
Chromatographic columns containing a large number of theoretical plates
Authors: Said A. S. 
Published: June 2004

AbstractTo obtain numerical answers for the concentration distribution of solute on a chromatographic column or in the effluent, tables and charts of the Poisson distribution are used. Their use however is limited to a small number of theoretical plates. The transformation of the Poisson to the normal distribution enables the calculations to be performed for any number of theoretical plates through the use of the normal distribution tables.Equations derived previously for columns containing a large number of plates and employing elaborate mathematical procedures and approximations have been simply deduced by applying a limit property of the Poisson distribution to the exact equations.A relationship between the Poisson and normal distribution is derived, and charts are drawn which allow the rapid evaluation of the Poisson in terms of the normal values.
Two‐dimensional laminar‐flow analysis, utilizing a doubly refracting liquid
Authors: Prados John W. , Peebles F. N. 
Published: June 2004

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

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

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

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

AbstractIn a determination of the effect of solute concentration on gas‐phase mass transfer rates carbon tetrachloride was vaporized at three different concentration levels in a short 4.0‐in.‐diameter column packed with 0.5‐in. Raschig rings.The experimental data indicate that previous mass transfer correlations should be modified to include a term (PBM/PT)2/3 and that the Schmidt number should be evaluated at average film conditions.The correlation found is suitable for predicting gas‐phase mass transfer coefficients which can be combined with effective interfacial areas reported previously to obtain volumetric mass transfer coefficients for any gas‐liquid‐solute system.
Effect of liquid on interparticle forces in gas‐fluidized beds
Authors: Parker Harry W. , Stevens William F. 
Published: June 2004

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

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

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

AbstractThe enthalpy of water in the liquid state has been calculated from 32°F. to temperatures approaching the critical and pressures ranging from saturated conditions to 160,000 lb./sq. in. abs. (approximately 11,000 atm). The results of this study are presented graphically and show that the influence of pressure on enthalpy is significant, particularly in the lower temperature region. At these conditions pressure is found to increase the enthalpy of liquid water by as much as 360 B.t.u./lb. above the corresponding enthalpy of the saturated liquid state.A comprehensive literature search disclosed PVT data for water that permitted the construction of a density correlation. This correlation expressed in reduced coordinates extends from the normal freezing point of water to temperatures of 1,870°F. (TR = 2.0) and pressures ranging up to 10,915 atm. (PR = 50). The recent extensive PVT data of Kennedy reported in 1950 supplemented with the earlier data of Amagat and Bridgman allowed the calculation of enthalpies at these elevated temperatures and pressures. For these calculations basic thermodynamic relationships were adapted which utilized this reduced density correlation. This approach has made possible the extension of the thermodynamic properties of liquid water above the highest pressure reported by Keenan and Keys. Below this pressure of 6,000 lb./sq. in abs. good agreement was found to exist between the enthalpy values presented by Keenan and Keyes and those reported in this investigation.
Thermodynamic behavior of hydrogen‐hydrocarbon mixtures
Authors: Motard R. L. , Organick E. I. 
Published: June 2004

AbstractBy use of the Benedict‐Webb‐Rubin (BWR) equation of state an attempt has been made to correlate experimental vapor‐liquid equilibrium data on hydrogen‐methane‐propane mixtures in the temperature range from 0° to −250°F. and pressure range from 500 to 1,500 lb./sq. in. abs. Considerable improvement in hydrogen K values has been obtained by adjusting the coefficient ν in the BWR equation for hydrogen. In the final adjustment it was necessary to specify a new value of ν for hydrogen at each temperature. The root‐mean‐square deviation of calculated from observed K values for hydrogen is 6.6%As a further check the recommended BWR coefficients for hydrogen have been used to calculate the low‐temperature hydrogen K values in mixtures with ethane and ethylene with good results.The predicted K values for propane at temperatures below −150°F. have not been altered and are still in error by as much as 2 orders of magnitude.
Thermal conductivity of packed beds
Authors: Schotte William 
Published: June 2004

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