bluuebunny/crossref_metadata_2025_split huggingface dataset:
A creeping flow model of a deformable drop approaching a plane interface
Authors: Feuerstein I. A. , Chappelear D. C. 
Published: March 2009

AbstractA new model has been formulated and analyzed which accounts for the deformation of a drop in response to the pressure distribution in the draining film between it and a rigid plane. The rate of approach is related to the pressure distribution and drop shape. When the nonlinear partial differential equations are written in dimensionless form, one dimensionless group, β = Δρgb/σ2, arises which represents the ratio of gravity forces to surface forces. Only β need be specified to solve these equations; viscosity enters only as a scaling factor on time. The equations were simplified to ordinary differential equations by assuming that the rate of change of shape was small relative to the change in position. Numerical soliitions were obtained from β = .15 to 10−3 using an iterative Runge‐Kutta procedure at each separation.
Falling coaxial cylinder viscometry of polymer melts
Authors: Sato Kyosaku , Rudin Alfred , Chee K. K. 
Published: March 2009

AbstractThis article considers possible erxors in experiment or analysis and alternative methods of data treatment for a falling coaxial cylinder viscometer. The viscometer uses a weighted rod falling into a polymer melt contained in a closed end concentric cylinder. Flow relations can be solved for non‐Newtonian fluid response in steady, simple shearing flow. Although the rod fall is found not to be steady, as assumed, this produces negligible error in the computed flow curves. Consistent flow curves which were independent of apparatus geometry were obtained by a method in which instantaneous rod velocities were estimated graphically from raw data and an end correction was taken into account.
Axial pressure profiles in non‐newtonian flow: Part I: Theoretical and experimental considerations
Authors: Blum David B. , Yerushalmi Joseph , Williams David J. 
Published: March 2009

AbstractThe flow behavior of polymeric fluids in tubes can be determined from measurements of the radial stress profile in the flow direction. This subject, the focus of our research, will be examined in Part II of this communication.Part I describes a research designed to test the accuracy of stress measurement with pressure transducers in a variety of recess mount geometries. No mount geometry errors were detected for the fluids used in this work over a shear rate range of 1 to 2000 sec−1. Part I also contains a survey of the literature and theoretical considerations pertinent to the entire work.
Axial pressure profiles in non‐newtonian flow: Part II: Viscometric flow and relaxation phenomena analyses
Authors: Blum David B. , Yerushalmi Joseph , Williams David J. 
Published: March 2009

AbstractExtensive pressure profile data were compiled for a 16.5% polyisobutylene solution in mineral spirits. Values of stored elastic energy obtained from these data compare favorably with those ascertained from die swell and from entrance correction methods. The viscometric normal stress differences were significantly larger than the shear stress and, particularly, the second normal stress rose to a maximum where it was an order of magnitude larger than the first normal stress difference. Time constants calculated from swell decay and entrance‐borne elastic stress relaxation are essentially the same and show an approximate inverse relation to the shear rate.
A new semi‐continuous dilatometer
Authors: Janssens Jean‐Marie , Ruel Maurice 
Published: March 2009

AbstractA new semi‐continuous dilatometer which does not have the major drawbacks of the previous model was designed, constructed and tested, using the systems benzene‐cyclohexane and cyclohexane‐ethanol. The volumes of mixing of five systems made of n‐alcohols and cyclohexanc: were determined at 25°C.
Mechanism of elutriation from fluidised beds
Authors: Guha S. K. , Kumar A. , Gupta P. Sen 
Published: March 2009

AbstractElutriation can be used as a convenient method for classification of particles. However, it has been observed that complete elutriation is not possible. Elutriation stops when the concentration of the elutriating component in the bed reaches an equilibrium value. The rate equation for elutriation has been found to be analogous to that of a first order reversible chemical reaction.In this paper two correlations—one for evaluating the equilibrium bed concentration and the other for the elutriation rate constant have been proposed by relating these quantities with the relevant system parameters.
The influence of design and operating variables on energy consumption and separation efficiency of a hydrocyclonic concentrator
Authors: Hsiang Thomas C. H. , Woods Donald R. 
Published: March 2009

AbstractThe problem of physical separation of solids from liquids in very dilute concentrations by hydrocyclone concentration is considered in two parts. First, the effect of feed concentration, volume split, feed flowrate, cone angle, inlet diameter and vortex finder length on separation efficiency and energy loss are investigated. The relationship between the separation efficiency; and the energy loss is also studied.Secondly, the effect of three different designs of body shape on the separation efficiency and energy loss is investigated.In this study statistical concepts are used extensively in the design of experiments and the analysis of experimental results.
The hydrogenolysis of n‐butane on a nickel on silica catalyst: I A Kinetic model
Authors: Orlickas A. , Hoffman T. W. , Shaw I. D. , Reilly P. M. 
Published: March 2009

AbstractThe catalytic hydrogenolysis of n‐butane was investigated in an integral packed bed reactor (0.70 cm. ID by 25 cm. long). The catalyst was 10% nickel on silica gel. A block factorial set of experiments was performed at hydrogen‐to‐butane feed ratios of 4. to 9., temperatures of 240° to 282°C and feed flowrates of 1.0 to 1.8 ml/sec. The predominant reaction appeared to be the remad of terminal methyl groups.Kinetic rate expressions were developed to predict the product distribution, taking into account a five‐fold change in catalytic activity. A parameter estimation strategy,applying non‐linearregression theory, was used to obtain the ten kinetic parameters. Error analysis of the parameters was performed using likelihood ratios. Models were developed to describe the catalyst activity changes observed during experinrentation. The kinetic model predicts the experimental observations very accurately over all conversions and shows some deviation only at the combination of high temperature and low feed ratio.
Multiproperty analysis of PVT, enthalpy and phase equilibrium data
Authors: Lin Chen‐Jung , Kwok Y. C. , Starling K. E. 
Published: March 2009

AbstractIn the most general application yet made of the method, multiproperty analysis was used to determine methane and propane parameters for a modified BWR state equation. Over 1300 mixture and pure component data points for density, enthalpy, vapor pressure and vapor‐liquid equilibrium, from −290°F to 400°F and up to 9,000 psia, were used in the multiproperty repression calculations. The resultant equation of state predicts thermodynamic properties with low average absolute uncertainties: 0.0055 lb‐mole/cu. ft. (0.77%) for density, 1.01 Btu/lb for enthalpy, 0.0147 Btu/lb‐ °F for entropy, 0.62% and 0.63% respectively for methane and propane vapor pressures and 1.67% and 3.73% respectively for methane and propane K‐values.
Dynamics of cyclic fixed bed ion exchange with counter‐current regeneration: An analysis based on a linear mass transfer model
Authors: Tan K. S. , Spinner I. H. 
Published: March 2009

AbstractSolutions are given for the transient and cyclic steady state performance of fixed bed ion exchange when operated with counter‐current regeneration. A mass transfer model which makes use of linear isotherms and linear driving force rate equations is applied in obtaining the solutions to this boundary value problem. Explicit calculation methods for large time parameter systems and implicit methods for small time parameter systems are illustrated. The model is found to predict adequately the experimental results for a sea water softening process.
Further studies on grid leakage in gas fluidized beds
Authors: Serviant G. A. , Bergougnou M. A. , Baker C. G. J. 
Published: March 2009

AbstractGrid leakage data for single and multiorifice grids of various designs are given. The effect of the wind box volume on grid leakage has been investigated. A grid having long cylindrical nozzles can reduce solids leakage, but there is a critical nozzle length, for a given grid hole velocity, above which instabilities can occur. A method for computing this critical length is given. Implications for the design of commercial grids are discussed.
Bed expansion in a mobile‐bed contactor
Authors: Tichy J. , Douglas W. J. M. 
Published: March 2009

AbstractThe expanded bed height has been investigated in a 0.14‐m diameter mobile‐bed gas‐liquid contactor. The data obtained by two methods of measurement show that the bed height varies linearly with the gas flow rate and is independent of the packing density. The operation of the bed is characterized by the condition of flooding. Correlations are presented for the expanded bed height and the minimum fluidization velocity in terms of the independent system variables.
Average heat transfer coefficient during the direct evaporation of a liquid drop
Authors: Adams A. E. S. , Pinder K. L. 
Published: March 2009

AbstractA dilatometric method was combined with a ciné photographic technique to obtain average heat transfer coefficients for the evaporation of droplets of isopentane and cyclopentane in a continuous phase of 0.0%, 56.02%, 73.07% and 77.06% glycerine‐water solutions. These average heat transfer coefficients and those calculated from the data of Prakash and Sideman were correlated by an equation combining the dispersed phase Nusselt number with the continuous phase Prandtl number, the liquid phase Bond number and a liquid viscosity ratio.The dilatometric method of volume measurement was found to be better than the direct photographic method.
Mass transfer from a single moving spherical bubble in the presence of a complex chemical reaction
Authors: Shah Y. T. 
Published: March 2009

AbstractThis paper analyses the problem of mass transfer from a spherical bubble (Re << 1) in the presence of an (m, n)th order liquid phase reaction. The approximate analytical results for enhancement factor obtained, using a linearization technique of the rate expression which is an extension of the one proposed by Hikita and Asai, are found to agree well with the one obtained from a numerical solution of the problem.The paper also presents numerical calculations of the rise in bubble interface temperature applying Danckwerts method to both the rigorous model as well as the extended penetration model of Ruckenstein et al. for the reaction process.
Effect of complete segregation on the performance of flow tank reactors
Authors: Lo S. N. , Cholette A. 
Published: March 2009

AbstractAn extension is presented to the theory of complete segregation proposed by Danckwerts for second order isothermal reactions in a CSTR. Introducing an integral average rate of reaction, it is now possible to compare the results directly and to show analytically that the conversion obtained under conditions of complete segregation is always larger than, or at least equal to, that for perfect micromixing.The application of the concept of complete segregation of both heat and mass, as considered already by Douglas for adiabatic CSTRés, is extended further to show the influence of the kinetic parameters on reactor performance. Large variations are shown for the relative performance based on the two mixing extremes.
Sequential statistical design strategy in an experimental kinetic study
Authors: Juusola J. A. , Bacon D. W. , Downie J. 
Published: March 2009

AbstractThe value of using a sequential statistical design strategy is illustrated through its use in an experimental kinetic study of the oxidation of o‐xylene over a vanadium oxide catalyst. The rate of oxidation of o‐xylene was determined in a differential reactor over the following ranges of conditions: 270 to 300°C, (0.5 to 3.5) x 10‐4g.mole o‐xylene/1., (1.0 to 10.0) x 10‐3g.mole oxygen/1. The statistical design strategy for precise parameter estimation was found to be effective in increasing the precision of the parameter estimates, in reducing the correlation between parameter estimates and in showing the magnitude of this problem, and in providing a reliable prediction of the value of carrying out additional runs.
Drag force on isolated axisymmetric particles in stokes flow
Authors: Bowen B. D. , Masliyah J. H. 
Published: March 2009

AbstractAn approximate solution to the equation of motion governing Stokes flow past a number of isolated closed bodies of revolution is obtained by the least squares fitting of a truncated series expression for the stream function to known boundary conditions. The solution yields a reasonably accurate (±5%) estimate for the Stokes resistance on body shapes, such as cylinders and cones, for which analytic solutions are exceedingly difficult. The computed drag values were applied in determining the limitations of the various empirical expressions used to predict the drag resistance of these geometrically simple bodies. A new empirical correlation is presented.
Flow maldistribution in two dimensional packed beds: Part II: The behavior of non‐isothermal systems
Authors: Stanek V. , Szekely J. 
Published: March 2009

AbstractA formulation is developed and computed results are presented for flow maldistribution in two‐dimensional packed beds involving non‐isothermal systems. Results are shown for both, systems in cylindrical and rectangular coordinates and the examples discussed include the pasage of a two‐dimensional temperature wave through a packed bed of non‐uniform porosity and the examination of the flow maldistribution that is caused by the radial non‐uniformity of temperature.The results indicate that radial temperature profiles in packed beds may lead to flow maldistribution even under conditions where the porosity is uniform and it is suggested that this phenomenon may play an important role in the formation of hot spots.
Fonction de transfert d'un réservoir agité en système continu: II Variation des constantes de temps avec et sans différence de densité initiate
Authors: Pineault Gilles , Cloutier Leonce 
Published: March 2009

AbstractThe analysis of the dynamic behavior of a continuous stirred tank reactor with a fluorescent tracer has indicated that the short‐circuit of a fraction of the liquid feed constitutes the only non‐ideality in this case. There is no dead space or piston flow in the reactor when the density difference is zero.The variation of the transfer function time constants was also studied as a first approximation, in a reactor with a density difference between the liquid feed and the reactor contents. This had led to the determination of an ideality criterion which includes the main causes of the non‐ideal mixing. The fluorescent tracer technique has permitted the isolation of the effects of physical parameters on the degree of short‐circuit from the effects on other causes of non‐ideal mixing.
Mass flux coupling by confined equilibrium reaction
Authors: Verhoff F. H. , Sundaresan K. R. 
Published: March 2009

AbstractVarious physical systems with either phase boundaries or semi‐permeable membranes can give rise to a confined chemical reaction. An analysis was performed to show the strong and potentially important effect of this confined reaction on chemical species diffusion through the region of reaction. The reaction was treated as one near equilibrium in order to obtain an analytical solution and to illustrate the strong coupling of fluxes caused by the reaction. Some generalities, e. g., facilitated diffusion of a single species transferring, were deduced using the above conditions and assumptions. These generalities are necessarily valid only for a single near equilibrium reaction with constant diffusivity of non‐diffusing species. Three examples were solved to illustrate the strong coupling of mass fluxes.
Continuous blending models for free radical polymerization systems
Authors: Kwon Young D. , Evans Lawrence B. 
Published: March 2009

AbstractThe dynamics of change of molecular weight distribution in free radical polymerization systems was modelled using a continuous blending concept which recognizes that the changes of molecular weight distribution are caused by continuous blending of increments of new polymer formed by the reaction into the already existing polymer, continuous blending of polymer at various parts of reactor by diffusion and convection, and continuous blending of polymer from various parts of reactor into the final product. The models have been applied to the analysis of both lumped and distributed‐parameter systems using either empirical or mechanistic relations for molecular weight of new polymer.
Enthalpies of n‐pentanol and n‐hexanol by flow calorimetry
Authors: Thinh T. P. , Ramalho R. S. , Kaliaguine S. 
Published: March 2009

AbstractEnthalpies of two polar compounds: n‐pentanol and n‐hexanol have been measured by a flow calorimeter at temperatures between 300°F and 650°F and pressures up to 1,500 psia. The measurements covered the liquid, vapor, vapor‐liquid and critical regions. The experimental results were compared with values calculated by three methods for prediction of variation of enthalpy with pressure.
Convergence criteria for relaxation solutions of viscous flow around cylinders
Authors: Griffin F. O. , Meisen A. 
Published: March 2009

AbstractEighteen convergence criteria were studied for monitoring the relaxation solution of equations describing steady, Newtonian fluid flow perpendicular to circular cylinders. The criteria

which represent sums of fractional changes in stream function and vorticity over 100 iterations, are shown to be the most suitable.
Gas absorption with large heat effects in packed columns
Authors: Raal J. D. , Khurana M. K. 
Published: March 2009

AbstractThe system of design equations recently proposed by Treybal for adiabatic packed absorbers has been tested experimentally for ammonia absorption. Examination of temperature profiles and solute recoveries measured in a 6 in. packed column indicated effective interfacial areas for non‐isothermal absorption to be larger than those found by Shulman for isothermal absorption. A modification of Shulman's interfacial area relationship, giving good agreement between measured and predicted recoveries and temperature profiles, is proposed. A convenient algorithm for computer solution of the design equations is described.
On the dynamic modelling of porous catalyst particles
Authors: Elnashaie S. S. E. H. , Cresswell D. L. 
Published: March 2009

AbstractA lumped dynamic model of à porous catalyst pellet is developed on the basis of the active site theory. This model is compared with a previous pseudo‐homogeneous model due to Liu and Amundson and found to differ in two important respects:i) the effective mass capacity is much greaterii) there is an additional heat generation term due to the adsorption‐desorption step.Both differences are shown to have important conflicting effects on the stability and dynamic behavior of the pellet.
The velocity distribution within a hydrocyclone operating without an air core
Authors: Knowles Stephen R. , Woods Donald R. , Feuerstein Irwin A. 
Published: March 2009

AbstractThe three dimensional flow patterns in a 3‐in. diameter hydrocyclone operating without an air cone were studied using tracer particles and cine photography. Analysis of films at 55 locations inside the hydrocyclone yielded data for 18 velocity profiles at six vertical positions. These data were checked for consistency and compared with the results of earlier work in hydrocyclones operating with air cores. The tangential velocity profiles were found to be similar to those produced with an air core although, n. in VAIn = const, is about 0.2 to 0.4 instead of 0.7 to 0.8 for air core operation. In this work the radial velocity component was relatively independent of radius.
Rheological behavior of shear degradable oils: Kinetic and equilibrium properties
Authors: Petrellis N. C. , Flumerfelt R. W. 
Published: March 2009

AbstractAn investigation of the non‐Newtonian, time dependent, flow properties of various crude oils at or below their pour points is reported. Experimental observations of material response under various shear and stress conditions provide a basis for the development of a kinetic and rheological model which quantitatively describes the shear degradation and equilibrium behavior exhibited by these materials. Preliminary data on the effects of thermal history and aging are also reported, showing the relative importance of these factors to the rheological properties.
A mathematical model for cooperative diffusion
Authors: Balcezak W. K. , Stapper C. H. , Veno W. E. , Withers D. H. 
Published: March 2009

AbstractThis model is a mathematical description of the interactive, or cooperative diffusions of boron and phosphorus in silicon. The cooperative diffusions are explained in terms of enhanced diffusion coefficients which are concentration dependent. By using these coefficients, the coupled non‐linear diffusion equations are replaced by two non‐linear uncoupled diffusion equations. The model explains the so‐called emitter push effect found in phosphorus emitter/boron base devices. Results show excellent agreement with experimental profiles.
Comparative performance of packings for gas‐liquid contacting columns
Authors: Furter W. F. , Newstead W. T. 
Published: March 2009

AbstractThe performances of Raschig rings, Pall rings, Intalox saddles, and Berl saddles were compared in respect to pressure drop and mass transfer efficiency, in a 6‐in. I. D. tower having a packed height of 4‐ft., over a matrix of gas and liquid flowrates representing the irrigating and loading flow regimes. The mass transfer experiments were conducted employing a gas absorption system in which both phase films control the overall rate of mass transfer, an improvement in terms of industrial applicability over many previous studies.The Berl saddles were observed to yield the lowest pressure drops of the four. The Intalox saddles yielded the highest overall mass transfer coefficients, followed closely by the Berl saddles and Raschig rings.
Ozonation of wastewater — some technical and economic aspects
Authors: Bowers A. , Netzer A. , Norman J. D. 
Published: March 2009

AbstractThis paper reviews traditional methods of ozone injection for wastewater treatment with special reference to the gas‐liquid contacting system. Operating characteristics and process efficiencies for the different systems described are compared. Recommendations are made about process selection for wastewater treatment by coronation.The cost of ozone generation for wastewater treatment from air, used on a once‐through basis, is compared with recycled oxygen, with special reference to Canadian parameters. Capital investment costs for various plant capacities are presented and operating costs, as a function of oxygen lost during recycling, are calculated.
Regenerative sorption of nitric oxide: A concept for environmental control and kinetics for ferrous sorbents
Authors: Gidaspow Dimitri , Onischak Michael 
Published: March 2009

AbstractA scheme for removing nitric oxide from flue gases and exhaust by regenerative sorption is proposed. Rates of sorption in the parts per million nitric oxide concentration range are presented for two ferrous sulphate‐silica gel sorbents. A kinetic model that correlates all observed room temperature data is derived.