bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical analogies between heat, mass and momentum transfer and modifications for fluids of high prandtl or schmidt numbers
Authors: Metzner A. B. , Friend W. L. 
Published: February 2011

AbstractThe presently‐available analogies for turbulent flow inside smooth round tubes are reviewed in detail; an empirical coefficient in the most promising equation is evaluated experimentally using the first heat transfer data of high accuracy obtained in the region of Prandtl numbers above 100. The final correlation is based on both heat and mass transfer data, and covers Prandtl (or Schmidt) numbers from 0.46 to 3,000. Up to Prandtl or Schmidt numbers of 600 the results are correlated with a standard deviation of 9.4%.
Mass transfer in a bubble column
Authors: Johnson A. I. , Bowman C. W. 
Published: February 2011

AbstractThe effects of gas and liquid flow rates and of seal height on the absorption of carbon dioxide in water have been studied. The gas bubbles were formed from 1/16 in. orifices, with both single and multiple hole arrangements.Bubble frequencies were measured using a high speed motion picture camera and are reported graphically as a function of gas flow rate. At high flow rates, considerable breaking up of the bubbles was observed.Because of the difficulty of estimating interfacial areas, the transfer data were reported using the product of the transfer coefficient and the interfacial area, KLa. For single orifices KLa was found to vary directly with the gas rate, was only slightly dependent on liquid rate and was almost independent of seal height after due allowance for end effects. With multiple hole plates having 5/8 in. spacing, there was no appreciable change in the transfer rate per hole until the hole density exceeded 1.5 per square inch, after which the rate decreased slightly.End effect contributions to transfer are also reported.
Horizontal pipeline flow of mixtures of oil and water
Authors: Russell T. W. F. , Hodgson G. W. , Govier G. W. 
Published: February 2011

AbstractThe flow characteristics of the two‐phase system —white mineral oil and water—were examined in a horizontal, smooth, one‐inch pipe. Flow conditions were investigated over a range of input oil‐water volume ratios from 0.1 to 10 at thirteen superficial water velocities ranging from 0.116 ft./sec. to 3.55 ft./sec. A theoretical analysis of the laminar flow of two immiscible liquids between wide parallel plates yielded a modified parallel plate friction factor based on the water properties and the superficial water velocity. It was evaluated for a number of input oil‐water volume ratios and plotted against the superficial water velocity. The experimental pressure drop data that were obtained were correlated using a modified Fanning friction factor which was evaluated for the range of input ratios studied and correlated with the superfical water velocity. A flow pattern correlation was obtained for visually observed types of flow—bubble, stratified and mixed—and it was shown that these patterns occurred in laminar, transitional or turbulent conditions of flow. The theoretical analysis for flow between wide parallel plates was adapted to obtain hold‐up relationships, and a plot of the hold‐up ratio HR (the input divided by the in situ oil‐water volume ratio) versus the input oil‐water ratio was constructed. This plot indicated that in the laminar region of flow the hold‐up was not dependent on the superficial water velocity but was only a function of liquid viscosity and input ratio. Experimental results for flow in the pipe conformed with this prediction while indicating that in the turbulent region superficial water velocity was also a factor.
Mixing efficiency determinations for continuous flow systems
Authors: Cholette A. , Cloutier Leonce 
Published: February 2011

AbstractModels are defined for various mixing conditions, in continuous flow systems. Differential equations are derived which take into account an effective volume of mixing, possible short‐circuiting, hold‐up time of the system, partial displacement or piston flow.The values of the different factors contained in the integrated equations can he determined experimentally by the particular response of a given system to a sudden change in composition of the feed.A correlation of the effective volume of mixing and the agitator r.p.m. is presented.A design procedure is suggested for tank flow reactors when partial mixing occurs.
Fundamental aspects of solids‐gas flow: Part II. The sphere wake in steady laminar fluids
Authors: Torobin L. B. , Gauvin W. 
Published: February 2011

AbstractA review is made of the experimental evidence and theoretical considerations evolving from studies of the wake formed by an aerodynamically‐smooth sphere moving in steady rectilinear motion through a turbulence‐free stream. The roles of complex fluid dynamic phenomena which include boundary layer separation, vorticity transfer and those characterized by the Strouhal Number, as well as less evident fine scale processes are presented, with reference being made to pertinent two‐dimensional cylinder studies.
Development of design criteria for biological treatment of an industrial effluent containing 2,4‐d waste water
Authors: Mills R. E. 
Published: February 2011

AbstractThe development of design criteria for a waste water treatment plant is described. Operating results for a laboratory activated sludge unit, a Dowpac trickling filter pilot plant, and an aero‐accelator activated sludge pilot plant are given. Studies with the aero‐accelator pilot unit indicated that by observing certain critical nutrient and dilution requirements the industrial effluent, containing toxic 2,4‐D waste water, could be satisfactorily treated by bio‐oxidation. A phenol removal of 99% and a biochemical oxygen demand (B.O.D.) removal of 90% to 95% was obtained. In the full scale treatment plant, the estimated cost of operation was calculated at $0.50 per pound of phenol removed, and $0.08 per pound of B.O.D. removed.
Heat transfer in water spouted beds
Authors: Ghosh B. , Osberg G. L. 
Published: February 2011

AbstractHeat transfer from a column wall to water spouted sand beds was studied in a 9 in. diam. steel column. The heat transfer rate to water flowing through a spouted bed was lower than when the column was empty. The presence of a bed suppressed convection currents, causing a large temperature gradient from the wall to the centre of the bed, and consequently a lowered heat transfer rate. At the same water flow rate, the spouted bed gave a lower rate than a fixed bed, because a large fraction of the water bypassed the wall region and flowed up the spout.
Liquid‐liquid extraction with association effects
Authors: Raal J. D. , Johnson A. I. 
Published: February 2011

AbstractA special case of liquid‐liquid extraction as been considered where the solute on absorption reacts to form a dimer through a rapid second order reversible reaction with the solvent.If dimer and monomer have different diffusivities (in the same solvent) the rate of absorption becomes dependent on the ratio of these diffusivities and the isotherm governing the “association” reaction.The non linear differential equation governing the absorption was solved numerically with the aid of a digital computer for the case of resistance in one phase only.Correlations based on these solutions were then used in formulating a rate equation. Methods were suggested for the determination of the quantities occurring in the “driving force” of the predicted rate equation.
A simplified method for determination of solid diffusion coefficient with non‐linear adsorption isotherm
Authors: Tien Chi 
Published: February 2011

AbstractA simplified method is proposed which enables the determination of solid diffusion coefficient for systems with non‐linear adsorption isotherm. The method involves the approximation of the concentration history of the liquid phase with polynominal functions and consequently the match of the experimental results and calculated values. Experimental work has given rather satisfactory results.
Salt effect in vapor‐liquid equilibrium, part II
Authors: Johnson A. I. , Furter W. F. 
Published: February 2011

AbstractPrevious work in the field of salt effect in vapor‐liquid equilibrium and the theory involved are reviewed briefly. Vapor‐liquid equilibrium data at atmospheric pressure are reported for the systems methanol‐water, ethanol‐water, and n‐propanol‐water, each saturated with a variety of common inorganic salts. A simple equation is proposed for the representation of salt effect. An attempt is made to ascertain the theoretical significance of this equation, and in so doing, to relate salt effect in vapor‐liquid equilibrium to the properties of the system components.
Polymeric self‐sealing distillation and extractor trays
Authors: Kilgallon J. D. , Streight H. R. L. 
Published: February 2011

AbstractA suitable polymeric material offers several advantages over metals and alloys normally used for self‐sealing or friction‐fit trays in distillation and extraction columns, by reducing the capital cost and maintenance charges and by improving the efficiency of small diameter columns. The hydrophobic nature of polymeric materials also increases the plate efficiency of an extractor when the plate is wetted by a continuous organic phase which passes to a dispersed water phase.The plate efficiency and performance of a small column are often reduced by leakage or by passing of vapor and liquor at the periphery of the trays. This problem can be overcome by using self‐sealing polymeric trays arranged in cartridges which are assembled and inserted into the column shell as a unit. The flexible nature of polymers ensures a tight fit between the trays and the shell of the column, notwithstanding normal out‐of‐roundness of the shell.
Concentration distribution in two‐phase pipe flow
Authors: Soo S. L. , Regalbuto J. A. 
Published: February 2011

AbstractConcentration distribution of solid particles in two‐phase turbulent pipe flow was studied. Due to the inertia of solid particles, transport of solid particles across the velocity field of the turbulent stream by turbulent diffusion results in deceleration of particles in the region near the wall by the stream and acceleration of particles transported toward the high velocity core. In the core, the particles have lower mean velocity than the stream while near the wall the mean particle velocity is higher. This gives rise to a non‐uniform distribution of solid particles in fully developed turbulent pipe flow. Experimental determination of concentration distribution was made with an impact disk particle counter system.
A study of aggregative fluidization
Authors: Davies Geoffrey , Robinson Donald B. 
Published: February 2011

AbstractThe effects of size distribution on the expansion of a gas‐solid fluidized system have been studied by the fluidization of glass beads and char particles by air in a 2 1/4 inch diameter column. Log‐probability distributions of 5, 10, 25 and 100‐fold size variation, with an average size of 271 microns, were tested, and changes in the average diameter of the bed due to elutriation were obtained. Systematic tests with beds of closely sized particles ranging in size from 74 to 912 microns were also made. The results show that compared with the effect of particle diameter, size distribution has little influence on the shape of the bed expansion curves.Various correlations, and in particular that suggested by Zenz for particulate fluidization, have been tested using the single size measurements. It is concluded that up to the present time, no really satisfactory correlation for aggregative fluidization has been proposed.
Fundamental aspects of solids‐gas flow: Part VI: Multiparticle behavior in turbulent fluids
Authors: Torobin L. B. , Gauvin W. H. 
Published: February 2011

AbstractAt Reynolds numbers approaching unity the particles in a solids‐gas system acquire a turbulent motion in response to the turbulence of the ambient fluid. This regime is of particular importance and a discussion of recent theoretical and experimental attempts to describe it is presented. The reaction of the fluid phase to the presence of the particles is equally important. The extent to which the mean and turbulent properties of the fluid motion are affected by the presence of the solids phase is governed by the particle concentration and the fluid and solids Reynolds numbers. The experimental evidence is as yet inconclusive owing to the difficulty of obtaining reliable data. The theoretical attack is similarly made difficult by the need to employ mixed Eulerian and Lagrangian coordinates. A discussion of electrostatic charging phenomena has also been included and it shows that in some systems it exerts an over‐riding influence on the particle motion and momentum transfer.
High‐speed photography in the study of two‐phase flow
Authors: Brown R. A. S. , Govier G. W. 
Published: February 2011

AbstractSome of the possible applications of high‐speed motion picture photography in the study of two‐phase, two‐fluid flows are outlined. These include measurements of ripple or wave velocities in annular flow and bubble velocities in bubble and slug flows. Qualitatively, the motion pictures permit better understanding of the interactions between the two phases.The equipment being used in the present photographic study of vertical flow of oil‐water mixtures is described. A 16‐mm. “Fastax” high‐speed motion picture camera having speeds to 8000 frames/sec. is being used in these studies. Auxiliary equipment includes a high intensity light source and a timing pulse generator.In the oil‐water system being studied, bubble groups and bubble clusters are formed which rise at approximately constant velocities. Very little effect of bubble size on the velocity of the bubble was noted except in a few instances where the bubbles appeared to be close to the wall. Preliminary results of the effects of superficial oil and water velocities on the bubble velocity are presented.Some other photographic techniques which might find application in the analysis of two‐phase flows are discussed.
Pelletization and diffusibility studies on silver catalysts
Authors: Amberg C. H. , Echigoya E. 
Published: February 2011

AbstractPowders of silver catalyst of low calcium content and an 8.5% calcium in silver alloy were pelletized at different compacting stresses. The diffusibility of each pellet was measured, using hydrogen, and correlated with internal void volume, The surface area of the powders and of some representative pellets was obtained by nitrogen adsorption. All these parameters were used in an attempt to interpret the changes taking place with decreasing porosity. With the help of two plausible assumptions it was concluded that the tortuosity remained constant over the range examined. The figures obtained have limited usefulness for the prediction of approximate pellet diffusibilities from a knowledge of the compacting stresses applied to similar metal powders.
Chemical engineers and computers
Authors: Williams Theodore J. 
Published: February 2011

AbstractComputers as tools for the chemical engineer have begun to revolutionize his concepts of reaction kinetic analysis, of plant design methods, and of plant control systems. The new field known as systems engineering has arisen to fulfill and exploit the promises which computers offer in these areas. This paper outlines the applications of analog and digital computers to chemical engineering problems, points out the specific advantages of each, and details the numbers and backgrounds of the operating personnel required. The newer field of application of computers to process control is reviewed in the light of progress to date and of present and future trends.
Diffusion coefficients for the liquid system: Ethanol‐water
Authors: Dullien F. A. L. , Shemilt L. W. 
Published: February 2011

AbstractMeasurements of the liquid diffusion coefficients over the complete range of compositions of the ethanol‐water system at 25°C. have been carried out using the porous diaphragm technique with a magnetically‐stirred and modified cell. Both the integral and differential coefficients agree very closely with the values reported by Hammond and Stokes, although an improved method of calculating the differential coefficients has been used. The limiting values at 0 and 100% concentrations differ somewhat from those previously reported. By means of an experimental investigation the work of Smith and Storrow on the same system has been shown to be in error. Analytical errors in calibration have been reduced to a probable error of ± 0.1%, although there is an average deviation of ± 2% for all experimental points relative to the best line drawn through them. The diffusion coefficients based on concentration as a driving force, show a minimum at 25 mole % ethanol, corresponding to the minimum for the relative decrease in volume on mixing and the maximum for the viscosity‐composition curve. For the dimensionless Schmidt number, a very sharp peaking to a value of 7500 occurs at the same composition.
Concurrent two‐phase upward flow of air and water through an open vertical tube and through an annulus
Authors: Carter Cecil O. , Huntington R. L. 
Published: February 2011

AbstractThe concurrent vertical upward flow of air and water has been made at various rates and ratios of air to water in a 2 1/8‐in. × 20 ft. open transparent Tenite tube as well as in a 1 5/16‐in. × 2 1/8‐in. annulus. Pressure drops and in‐place ratios of gas to liquid have also been observed in order to correlate such data with corresponding flow types and patterns. Motion pictures taken at normal and especially those at high‐speed have made it possible to see flow mechanisms indistinguishable to the naked eye.
Surface tension effects on the efficiency of an Oldershaw column
Authors: Ellis S. R. M. , Legg R. J. 
Published: February 2011

AbstractAn Oldershaw column has been operated with two negative systems; ethylene dichloride/toluene, and ethylene dichloride/224 trimethylpentane. The difference in surface tension between ethylene dichloride and toluene at 90°C. is about one‐seventh of the difference between ethylene dichloride and 224 trimethylpentane at the same temperature. It is shown that this surface tension difference does not significantly effect the overall performance of a perforated plate column. Photographs taken show no apparent change in foam structure for the two systems at all boil up rates.Vapor‐liquid equilibrium data has been determined for the system ethylene dichloride/224 trimethylpentane at 750 mm. mercury pressure. There is an azeotrope of composition, 77.0 mole % ethylene dichloride.
Viscous flow around fluid spheres at intermediate reynolds numbers
Authors: Hamielec A. E. , Johnson A. I. 
Published: February 2011

AbstractApproximate velocity profiles and terminal velocities have been predicted for fluid spheres moving in viscous media under the influence of gravity. The equations of motion were satisfied approximately using a numerical method after Kawaguti(1).Predicted terminal velocities are compared with literature data and with data measured by one of the authors(2). The agreement is reasonable for Reynolds numbers up to about 80.The effect of the asymmetry of the exterior flow upon the symmetry of the interior flow is discussed.
The horizontal pipeline flow of air‐water mixtures
Authors: Govier G. W. , Omer M. M. 
Published: February 2011

AbstractA review and comparison of the various methods which have been proposed for the correlation of the pressure drop attending the flow of gas‐liquid mixtures is made. The friction factor and other terms employed in the correlations are related mathematically.The horizontal flow of air‐water mixtures has been investigated in a 41 ft. length of cellulose acetate butyrate tubing of 1.026 in. i. d. The average system pressure was held constant at 36 p.s.i.a. maintaining a constant air density of 0.18 lb./cu. ft. Flow pattern, holdup and pressure drop data were obtained at air‐water volume ratios from 0.1 to 200 (700 in some cases) for 10 superficial water velocities from 0.01 to 5.03 ft./sec. These data overlap and extend the range covered by previous investigators.The flow patterns observed at constant superficial water velocity with increasing air‐water ratio were: bubble, plug, stratified, wave or ripple, slug and film. Bubble, plug and slug flow were encountered only at superficial water velocities above about 0.1 ft./sec. while stratified flow was encountered only at superficial water velocities below about 1 ft./sec. and superficial air velocities below about 5 ft./sec.The holdup ratio, a measure of the relative accumulation of the water in the flow section, increased with air velocity for all superficial water velocities reaching a maximum value of over 50. At constant superficial air velocity the holdup ratio increased rapidly with decrease in superficial water velocity.The pressure drop data were converted to a friction factor based upon the density and the superficial velocity of the water. The friction factors were correlated with the superficial Reynolds number for the water, and the air‐water volume ratio. The data are compared in this form with previous data of Schneider, Thomsen, and Johnson and Abou‐Sabe.
Forced convection transfer around spheres at intermediate reynolds numbers
Authors: Baird M. H. I. , Hamielec A. E. 
Published: February 2011

AbstractApproximate local and overall Sherwood numbers have been predicted theoretically for forced‐convection transfer around solid and fluid spheres for Reynolds numbers up to 100. The diffusion equation was solved analytically for the case of a thin concentration boundary layer (NPo » 1).The predicted overall Sherwood numbers are in fair agreement with published semi‐empirical correlations.
Analog computer solution of the modified rayleigh equation and parameters affecting cavitation
Authors: Marique Lucien A. , Houghton Gerald 
Published: February 2011

AbstractThe modified Rayleigh equation is a non‐linear differential equation governing the growth of bubbles during cavitation. It has been programmed on an analog computer, and the effects on the growth of bubbles of the initial conditions and the physical properties of the system, such as density, viscosity and surface tension, have been made the subject of a detailed parameter study. The observations that the initial growth may be delayed and that the rate of bubble growth may pass through a minimum have been explained by an energy balance. A first order perturbation method has been applied to the case where the effect of viscosity is small.
Axial laminar flow in a circular pipe containing a fixed eccentric core
Authors: Redberger P. J. , Charles M. E. 
Published: February 2011

AbstractVelocity profiles and volumetric rates for the axial, laminar flow of a Newtonian fluid in a circular pipe containing a fixed eccentric core were evaluated numerically using a digital computer. The velocity profiles agree exceptionally well with those evaluated from an analytical expression derived by Heyda(2). The effect of displacing the inner surface from a concentric position is to increase the volumetric flow rate for a given pressure gradient, the maximum increase for a diameter ratio of 0.9 being 240% and for a diameter ratio of 0.1, 60%.The volumetric flow rates are presented graphically in terms of dimensionless ratios which enable the flow rate to be evaluated for any fluid, diameter ratio, relative displacement and pressure gradient.
Optimization study of chemical processes
Authors: Kuo M. T. , Rubin D. I. 
Published: February 2011

AbstractIn a large class of chemical systems, it may be desired to determine the inlet conditions that enables the process to be run in order to meet certain constraints, such as a specified product yield or required temperature. This paper uses Lagrangian Multipliers for solving, numerically, a particular aspect of this problem namely that of determining inlet conditions so as to maximize (or minimize) a characteristic of the reaction and simultaneously meet required constraints.