bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass transfer from fluid and solid spheres at low reynolds numbers
Authors: Bowman C. W. , Ward D. M. , Johnson A. I. , Trass O. 
Published: February 2011

AbstractPredicted continuous phase mass transfer coefficients for fluid and solid spheres in the Stokes region of flow are correlated as Sherwood numbers plotted against Peclet numbers. These correlations permit a study of the effect of internal circulation on the rate of mass transfer from fluid spheres. At a Peclet number of 104, the theory predicts a threefold increase in transfer due to the circulation movements within a gas bubble. At a Peclet number below 10−2, the difference between a circulating and non‐circulating (or solid) sphere is indiscernible.The analysis presented in this paper for fluid spheres is based on a study by Friedlander (1) of mass transfer around solid spheres. A more elaborate concentration profile through the boundary layer has been used in the present investigation and the result reported for solid spheres differs about 8% from that given by Friedlander.The more interesting details of the mathematical treatment and the machine computation of the resulting differential equations are included.
Dynamic analysis of bubble plate performance
Authors: Mickley H. S. , Gould L. A. , Schwartz L. M. 
Published: February 2011

AbstractA frequency response method is examined as a possible experimental method for the simultaneous determination of liquid mixing, plate efficiency, vapor‐liquid equilibrium, and liquid holdup on a single bubble tray. The method depends upon the introduction of sinusoidal fluctuations in the concentration of a species in the liquid and vapor fed to the plate and the measurement of the induced concentration variations of the same species in the effluent liquid. It is applicable to multi‐component systems.The analytical results used to interpret the measurements are based on a linearized model. Despite this idealization, systems exhibiting marked curvature of the liquid‐vapor equilibrium relation are adequately represented. Systems showing very significant enthalpy effects are treated quantitatively when the liquid on the plate is perfectly mixed. This is done with the aid of the “signal flow graph” technique.With incompletely mixed plate liquid, mathematical difficulties have so far prevented the quantitative interpretation of measurements of the frequency response when enthalpy effects are large. At present it appears that the frequency response technique is limited to perfectly mixed plates, i.e., to small laboratory sized plates, or to incompletely mixed systems in which the heat effects are small, i.e., gas absorption plates and distillation systems in which the volatilities and latent heats of all components are of comparable magnitude.
Holdup in liquid‐liquid extraction columns
Authors: Johnson A. I. , Lavergne E. A. L. 
Published: February 2011

AbstractA theoretical study of the countercurrent flow of a dispersed phase in a continuous phase resulted in the following equation relating holdup X to the flow rates of the two phases.

For packed towers this equation has been used in the following form:

Values of A', B', and r for three liquid pairs, and two packing types are reported, using new holdup data determined in this research.Graphical correlations are shown and values of r are reported for some of the data of Gayler and Pratt.For spray towers the equation suggested a correlation of \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{X^3}}{{U_D ^{1.8}}} $\end{document} against the group \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{U_C ^{0.2}}}{{U_D ^{1.8}}}\left({\frac{X}{{1 - X}}} \right)^3 $\end{document} This has been tested using data previously published by one of the authors.
Approximate solutions of conduction of heat through non‐homogeneous medium
Authors: Tien Chi 
Published: February 2011

AbstractBy comparing the respective difference equations of heat conduction through a homogeneous and non‐homogeneous media, an approximate analogy is established. This analogy enables the finding of the solution of conduction through a non‐homogeneous medium in terms of the known solution for homogeneous cases. An illustrative example is given to demonstrate the working details.
The explosive limits and flammability of xanthate dusts in air
Authors: Roxburgh J. M. 
Published: February 2011

AbstractThe minimum concentrations of xanthate dusts in air which will form explosive mixtures have been determined. Comparison with other dusts considered to be hazardous industrially indicates that xanthates of the lower alcohols should be classified as readily explosive. The explosive limit increases rapidly with particle size; dusts coarser than 150 mesh are relatively safe. Xanthate dusts are easily ignited and have very low ignition temperatures. Under conditions such that fine wood flour ignites at 540°C. the xanthates will ignite between 230°C. and 290°C.
A method of measuring the surface area of granular material
Authors: Hedlin C. P. , Collins S. H. 
Published: February 2011

AbstractA method is described which permits measurement of the exterior surface areas of objects down to about 0.1 sq. in. in area. In this method, the object is coated with an adhesive and a single layer of small metal particles. The change in weight gives a measure of the external area of the object.Systematic variations in the density of the metal particle coating are discussed, and appropriate correction factors are given.This method is intended for use in research that involves objects whose exterior surface areas have an effect on the process being investigated. Examples are the drying of agricultural grains and foodstuffs, the comminution of ores and chemicals, and the hydraulic and pneumatic transport of materials.The precision of the method is adequate, the root‐mean‐square error being about 1%.
Solid‐liquid equilibria in wax crystallization
Authors: Butler R. M. , MacLeod D. M. 
Published: February 2011

AbstractThe equilibria obtained during the crystallization of waxes has been studied theoretically and it has been found that the degree of separation between normal paraffins may be predicted, if it is assumed that the solid is an ideal solution. Results predicted from the theoretical equations have been compared with mass spectrometer analyses of recrystallized waxes and surprisingly close agreement has been found.It has also been shown that ketone solvents have essentially the same selectivity for recrystallizing waxes as n‐hexane. The reason for this is that the activity coefficients for various n‐paraffins in a ketone solution are nearly identical even though they are all much higher than in the hydrocarbon solution.The separation between normal paraffins in conventional single stage wax recrystallization is not very sharp. This may be improved by the use of a number of stages in a countercurrent cascade. Experimental results with such a cascade are in agreement with the theoretical predictions.The presence of non n‐paraffinic components in some waxes can cause the formation of eutectic mixtures. This affects the separation in a manner analogous to that of hetero‐azeotropes in some distillation processes.The crystallization of waxes from their, melts has also been studied both theoretically and experimentally. When mixtures of similar molecular weight n‐paraffins, such as n‐C21H44 and n‐C23H48 are cooled, a solid solution is formed. This is also found with mixtures of similar recrystallized waxes. On the other hand, mixtures of n‐paraffins of widely different molecular weight, such as n‐C20H42 and n‐C32H66, or hydrocarbons of different structure, such as n‐paraffins and iso‐paraffins, form separate crystals and a eutectic. Similar results are found with mixtures of commercial waxes of widely different melting point and type.
Optimum process conditions for a completely mixed multistage reactor
Authors: Kubota H. , Namkoong S. , Akehata T. , Shindo M. 
Published: February 2011

AbstractA graphical method for determining the process conditions which give the minimum volume of reactor at a given outlet conversion is described, and illustrated by application to a multistage fluidized bed reactor for the catalytic oxidation of sulphur dioxide.
The application of the copper oxide‐alumina catalyst for air pollution control
Authors: Sourirajan S. , Accomazzo Mauro A. 
Published: February 2011

AbstractThe catalytic combustion of 1‐hexene present in diluent nitrogen in the concentrations of 1170 p.p.m. and 3000 p.p.m. by excess oxygen, has been studied in the presence of the CuO‐Al2O3 (1:1) catalyst in the temperature range 242° to 424°C. and gas space velocity in the range 4000–16,000 hr.−1. The experimental data on the kinetics of the reaction were found to fit an empirical half‐order law with respect to the 1‐hexene concentration. The presence of water vapor in the reactants was found to have no effect on the efficiency of the catalyst at temperatures higher than 400°C. The above results were similar to those obtained for the catalytic oxidation of n‐hexane studied earlier.The possible use of the above copper oxide‐alumina catalyst for the simultaneous removal of hydrocarbons and carbon monoxide present in the auto exhaust gases has been tested, making use of a 1955 six‐cylinder Chevrolet engine run on leaded gasoline fuel. The hydrocarbon and carbon monoxide concentrations encountered in these studies varied in the range 170–16,000 p.p.m. and 1–7% respectively. It was found that the minimum initial temperature of the catalyst bed required for the complete removal of both hydrocarbons and carbon monoxide, simultaneously, was 226°C. under no load condition, 342°C. under an engine load of 2.5 h.p., 400°C. under an engine load of 5.1 h.p. or higher, and 236°C. under deceleration conditions. The catalyst showed no deterioration in performance even after 100 hours of continuous service in conjunction with the above auto exhaust gases.
A design parameter for multicomponent tray design estimates
Authors: Surowiec Alfred J. 
Published: February 2011

AbstractThis, report develops computational techniques that are useful in multicomponent distillation. A design parameter, (∂n/∂N)s is introduced which is numerically equal to the number of theoretical plates required to do the work of one total reflux tray at the bottom of the enriching section. For a minimum sized tower, (∂n/∂N)s is legs than 3.5. Economic conditions may permit values as high as 6.The ratio of the number of theoretical trays, n, to the minimum number, N, for the combined enriching and stripping sections, including reboiler and condenser, and the ratio of the reflux leaving the enriching section, Ls, to the minimum reflux, LMs, can be found from:

A total of 36 sets of minimum reflux data in multi‐component systems were correlated with an average error of −4% in the ratio n/N by these equations.Since (∂n/∂N)s is related to the relative volatility and the compositions of the counterflowing liquid and vapor streams at the bottom of the enriching section, the reflux Ls can be found from a feed tray balance. A procedure is provided for evaluating Ls after a value for the design parameter has been selected.
Factorial design in the study of acid leaching of pegmatitic uranium ores
Authors: Fisher D. G. , Mcintosh R. G. , Eager R. L. , Van Cleave A. B. 
Published: February 2011

AbstractFactorial design of leaching tests done on pegmatitic uranium ores is an efficient method of studying the effects of changes in process variables, as the required information may be obtained with a minimum expenditure of effort.The results of a complete five factor, two level, factorially designed experiment in which an “acid‐cure” technique was used are discussed. The data obtained in two, half replicate, five factor, two level, tests in which a percolation leach technique was used, establish base levels of variables for further economic study of uranium recovery from Higginson Lake pegmatites.
Reactions in a fluidized coke bed with self‐resistive heating
Authors: Johnson H. S. 
Published: February 2011

AbstractWhen electrodes are inserted in a fluidized bed of conductive coke particles, an electric current can be passed with sufficient power to raise the bed to a high temperature. This device becomes a chemical reactor when the fluidizing gas is appropriately chosen. The reaction conditions which obtain in such a reactor are sometimes of especial value in producing favorable yields in chemical reactions.The design and operating characteristics of laboratory scale units are described. These are usually Vycor tubes fitted with rubber stoppers through which electrical and gas connections are made. Even with such simple apparatus, it is possible to operate at 1500°C.Several chemical reactions have been studied in detail using reactors of this type. Among these are some which show commercial promise, such as the high temperature reaction of ammonia and hydrocarbons to form hydrogen cyanide.
Determination of ternary liquid‐liquid systems by use of the lever rule
Authors: Heric E. L. , Williams Kenneth R. 
Published: February 2011

AbstractA method is described for the determination of ternary liquid‐liquid systems. The approach is based upon a combination of the lever rule and the measurement of a physical property which is a function of composition. The method has been tested upon the system toluene‐water‐acetic acid at 25 ± 0.05° and found to yield results in agreement with literature values. A possible modification of the method‐which may be necessary in systems where tie‐lines are essentially parallel when expressed on the usual weight per cent basis‐is described.
Safety of materials of construction used in explosives manufacture
Authors: Van Zeggeren F. 
Published: February 2011

AbstractHazards of materials of construction in machinery used for manufacture of explosives depend on the explosive which is being handled by the machinery. Thus one has to consider the combination material/explosive as well as material and explosive themselves, in assessing hazards. Several types of hazard can occur viz., due to sparks, friction, impact or heat. For a given material the most likely factors that will influence its hazard depend on the type of hazard, e.g. for spark hazards important factors are: static pick‐up of material and explosive, conductive properties and spark confinements; for impact hazards: hardness, surface roughness, elasticity, presence of cavities, confinement offered and area of contact; for frictional hazards: hardness, friction coefficient and thermal conductivity. For purely thermal hazards, only flammability need be considered.In impact and friction the chemical action between material and explosive may play an important role. In all cases the sensitivity of the explosives themselves to the particular type of action, has to be taken into consideration. In accidental mishaps the type of hazard is often a combination of impact and friction, and requires a special test method.In this paper the literature on some aspects of all of the above hazards is reviewed. Experimental results of frictional and frictional impact tests are discussed from a theoretical point of view. A number of results of particular interest, e.g. for aluminum alloys, coated steel and non‐metallic materials are presented.
Speed of sound in a non‐ideal gas
Authors: Squire William 
Published: February 2011

AbstractA method is proposed for computing the speed of sound in a non‐ideal gas based on the approximation

In conjunction with the usual generalized compressibility plot and an analogous reduced enthalpy correction plot, it can be used near the critical point of a non‐dissociating gas. The method is also applicable to highly dissociated and ionized gases.
Kinetics of the vapor‐phase oxidation of toluene over a vanadium catalyst
Authors: Downie J. , Shelstad K. A. , Graydon W. F. 
Published: February 2011

AbstractRates of oxidation of toluene were measured as a function of temperature and reactant concentration. A fixed bed reactor was operated at low conversions over the following range of conditions, 300°C to 350°C., 1 × 10−3 to 15 × 10−3 moles oxygen per litre of gas, and 1 × 10−3 to 6 × 10−3 moles toluene per litre of gas.The rate data for the oxidation of toluene were correlated by the following equation, which is based on a model by Hinshelwood.

The values of k, obtained agree with those reported previously for naphthalene oxidation(1).It is concluded that the Hinshelwood model is a useful one for this type of reaction, and within the limits of available data provides a satisfactory interpretation.
Rail transportation of hydrogen chloride anhydrous
Authors: Drury C. H. 
Published: February 2011

AbstractA railway tank car has been built for Canadian General Transit Co. Limited and is operating in the leased service of Dow Chemical of Canada Limited for the shipment of hydrogen chloride anhydrous shipped at minus 50°F. in single shipments of about 89,000 lb.Necessary safety devices and a liquid CO2 refrigeration system are included which will maintain the car at a safe pressure level for an extended period subject to the supply of liquid CO2.
Photography in bubble and drop research
Authors: Kintner R. C. , Horton T. J. , Graumann R. E. , Amberkar S. 
Published: February 2011

AbstractMethods of photographing bubbles and drops moving in a liquid field are described. Shape, size, terminal velocity, local semi‐vectorial velocities, size distribution and high speed phenomena such as coalescence and breakup can be advantageously investigated by photographic methods. Recommended combinations of lights, reflectors, diffusers, screens, films, and f‐stop values are given. Applications of particle trace and interrupted particle trace photography are described.
Analysis of the radiant heat absorption in the boundary layer surrounding an evaporating drop
Authors: Hoffman T. W. , Gauvin W. H. 
Published: February 2011

AbstractAn approximate analysis is made of the effect of the absorption of thermal radiation on the temperature gradients surrounding an evaporating droplet which is suspended in a high temperature environment. The Hottel‐Cohen method for calculating the radiant heat flux distribution in an enclosure containing an absorbing medium of non‐uniform temperature, has been applied to the spherical symmetrical model of the system. Conduction and radial movement of the cold vapor from the droplet have been included.The analysis shows that, at atmospheric pressure, the absorption of radiant energy in the boundary layer is very small and hence does not affect the temperature gradient nor the rate of heat transfer at the droplet surface.This method of analysis, with the associated solution of the equations describing the reception factors, is quite general and can be applied to any spherical enclosure containing an absorbing medium whether it be one of concentric or hollow spheres.
Sulphur and sulphur dioxide for separating copper from nickel‐cobalt‐copper sulphate solutions
Authors: Kunda W. , Mackiw V. N. 
Published: February 2011

AbstractIn hydro‐metallurgical processes for the production of nickel and cobalt, the leach solutions usually contains salts of nickel, cobalt and copper. To recover high purity nickel and cobalt metals from such solutions, the copper is removed prior to the nickel‐cobalt separation.During the course of extensive investigations to determine the most economical and efficient methods for separating the copper, it was established that copper in solution reacts with elemental sulphur in the presence of sulphur dioxide forming a copper sulphide precipitate. This reaction permits a simple and quantitative separation of copper from nickel and cobalt leach solutions.The variables affecting this reaction were studied and the results are presented in this paper. Studies were conducted on: the sulphur concentration between 0 to 2.0/1 molar ratio of sulphur to copper, the sulphur dioxide concentration 0 to 17 gpl., the temperature in the range from 100°F. to 325°F., the copper concentration from 1 to 30 gpl. and pH from 1.0 to 9.0.The results are correlated and a tentative mechanism for the reaction is discussed.
The design and operation of a high pressure reforming pilot plant
Authors: Bichard J. A. , Bumbulis J. , Butler R. M. 
Published: February 2011

AbstractA pilot plant has been designed and constructed for the exploration of reforming processes at temperatures up to 1200°F. and pressures up to 1500 p.s.i.g. The components of the pilot plant are described, as well as the calculation of material balances and product yields by an IBM 650 computer.
On the mass transport mechanism of leaching processes
Authors: Peters E. , Skrivanek J. 
Published: February 2011

AbstractA model is proposed and tested that yields a theoretical leaching curve for the extraction of values from a finely ground ore. The model assumes that small particles follow the eddy currents in an agitated reactor and behave as if they were surrounded by a rigid medium. The leaching curve is obtained by writing the differential equation for diffusion, determining the extent of dissolution for selected times, and multiplying by a particle size distribution function. The results are consistent with experiment, and some essential conclusions are drawn that bear on the design of leaching circuits.
Binary vapor‐liquid equilibrium data thermodynamic consistency tests
Authors: Lu Benjamin C.‐Y. , James C. K. Ho , Spinner I. H. 
Published: February 2011

AbstractVisual methods for testing thermodynamic consistency of binary vapor‐liquid equilibrium data by means of the Gibbs‐Duhem equation on a log γ vs. x plot at strategic liquid compositions are reviewed. The justifications for these methods and guidance for their applications are presented. Furthermore, these methods have been extended to test the thermodynamic consistency of equilibrium data (t‐P‐x‐y) directly.
Minimum reflux rate for multicomponent distillation systems by rigorous plate calculations
Authors: Erbar Ruth C. , Maddox R. N. 
Published: February 2011

AbstractA procedure for computing the minimum reflux rate for multicomponent distillation systems. The equations developed apply to both distributed and non‐distributed systems. The suggested method of solution is by iteration, beginning with the assumption the system will be distributed. Complete heat and material balances are carried out in the course of each plate calculation. The calculated minimum reflux rates are compared with those of other techniques.
Analysis of the comminution of mixtures
Authors: Fuerstenau D. W. , Sullivan D. A. 
Published: February 2011

AbstractThis investigation has shown that the unit operation of size reduction can be considered to be the result of many individual comminution events and that the distribution modulus of a comminuted solid is a property of the material, independent of whether the material has been ground separately or as part of a mixture. Investigation of the comminution of quartz and limestone in a rod mill has shown that the energy‐size reduction relationships which have been developed for the comminution of homogeneous materials can be used to analyze the comminution of mixtures. Size reduction of mixtures in rod mills has been found to be complex because energy is consumed preferentially by the harder material. Methods are presented to predict the distribution modulus, size modulus, and energy consumption for the size reduction of mixtures.
Mixed models to represent flow of fluids through vessels
Authors: Levenspiel Octave 
Published: February 2011

AbstractModels consisting of interconnected regions (dead‐water, backmix, plug flow, etc.) with various modes of flow through and around these regions (bypass, recycle, cross flow) are used to represent real vessels in which flow deviates greatly from plug flow. This paper deals with some of the problems of choosing and fitting such models, called mixed models, to represent flow in real vessels.The stimulus‐response technique is a useful tool for this purpose, and matching response curves for model and real vessel then serves as the selection method.Some of the simpler mixed models and their corresponding characteristic response curves are presented.