bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of surface active agents on fall velocities of drops
Authors: Skelland A. H. P. , Huang Y‐F 
Published: March 2009

AbstractTerminal velocities of drops undergoing mass transfer were measured in nine systems containing anionic, cationic, or nonionic surfactants. Variables included drop size, formation time, number of parallel droplet‐streams, and surfactant concentration. Results were interpreted in terms of visually observed internal circulation and oscillation of the drops and some success was achieved in correlating the data obtained.
Experimental analysis of particle deposition on single collectors
Authors: Rajagopalan R. , Tien Chi 
Published: March 2009

AbstractExperimental studies of particle deposition from liquid suspensions of monodispersed particles flowing past single spherical collectors were carried out and compared with theoretical results based on trajectory calculations. The experimental observations indicate the significant effect of particle flocculation and thus suggest the importance of sedimentation as a collection mechanism. The agreement between the theoretical results and the experimental data is good when the surface force interactions are favorable for collection. However, when the electrokinetic repulsion dominates in the neighborhood of the collector, the rate of collection drops rapidly, although not to zero as predicted by theory.
Solving multicolumn equilibrium stage operations by total linearization
Authors: Browne Denis W. , Ishii Yoshikazu , Otto Fred D. 
Published: March 2009

AbstractAn efficient, reliable and easily programmed method for solving systems of equilibrium stage separation devices is described. The method is an extension of an algorithm developed by Ishii and Otto(9) for single columns. It solves all equations simultaneously, takes advantage of the basic tridiagonal matrix form form of the linearized steady state equations and can handle configurations which include distillation columns, absorbers and reboiled absorbers. The solution for a thermally coupled distillation system is presented.
The history and status of research in fouling of heat exchangers in cooling water service
Authors: Suitor J. W. , Marner W. J. , Ritter R. B. 
Published: March 2009

AbstractA review of research in fouling by cooling water is presented. The literature survey covers the period from 1924 to the present. Both theoretical and experimental papers are reviewed, and the more important of these studies are categorized in table form. Significant contributions are discussed with respect to theoretical developments and experimental apparatus as well as operating variables such as velocity, temperature, water chemistry, and material effects. An assessment of the current status of cooling water fouling is made, and several areas for future research are suggested.
Measurements of flow characteristics in a confined vortex flow
Authors: Bank Nader , Gauvin W. H. 
Published: March 2009

AbstractA study of air flow patterns by hot‐wire anemometry is reported for a vortex chamber consisting of an upper cylindrical section 122 cm in diameter and 61 cm high and a conical bottom section 122 cm high. Quantitative data are presented for flow angles, profiles of mean tangential and axial velocities, and radial distributions of tangential and axial intensities of turbulence as a function of air entrance velocities of 1.6, 2.4 and 3.2 m/s, and axial distance from the top of the chamber.In general, the quantitative results confirm the theoretical predictions and the experimental trends reported in the literature. In particular, they fully support the conclusion that the flow pattern is relatively insensitive to the entrance volumetric flow rate.A generalized correlation is presented for the axial velocity distribution. Preliminary correlations are also presented for the tangential velocity distributions in the core and in the annular region of the vortex near the wall. These were found to be functions of the axial location and of the air entrance velocity.
Wall to liquid mass transfer in fluidized beds
Authors: Storck A. , Coeuret F. 
Published: March 2009

AbstractThe paper reports a study of the influence of particle motion on wall to liquid mass transfer in liquid fluidized beds. Results obtained in classical fluidized beds are compared with those observed with expanded fixed beds of the same particles and having the same mean porosity. It is shown that the particle motion has no measurable influence. The particles only act as obstacles to the fluid flow in the same way as if they were fixed in their mean statistical positions.
Generalized treatment for the vapor pressure behavior of polar and hydrogen‐bonding compounds
Authors: Gomez‐Nieto Mateo , Thodos George 
Published: March 2009

AbstractThe vapor pressure behavior of 25 polar compounds, including water and a number of alcohols, has been analyzed and subjected to a generalized treatment using the relationship,

for a total of 1343 experimental measurements presented in the literature and covering the range included between their respective triple points and critical points. For each of these compounds, the parameters of this equation were established using a nonlinear regression numerical technique. The parameters resulting from this regression reproduce vapor pressures for all these polar compounds with an average deviation of 0.44 percent (1343 points).To extend the application of this vapor pressure relationship, the original parameters of these polar substances were correlated with their respective basic physical properties M, Tc, Pc and Tb. The resulting generalized parameters reproduce vapor pressures with an average deviation of 1.44 percent (1343 points) for all these polar and hydrogen‐bonding compounds. This generalized correlation can be applied for the reliable prediction of vapor pressures for polar substances for which inadequate information is available.
Spherical agglomeration in a conical drum
Authors: Sparks B. D. , Meadus F. W. 
Published: March 2009

AbstractThe spherical agglomeration process is a means of size enlargement in which agitated particles, suspended in a liquid, are bonded together by a second liquid, which will wet the solid surfaces and be immiscible with the suspending medium. A process is described in which agglomeration takes place in a cone shaped vessel, rotating horizontally about its symmetric axis. The cone configuration of the agglomerator imparts a longitudinal impulse to the charge, which is most effective on the largest particles. This causes a size classification within the cone, with the largest agglomerates congregating at the base. The result is the continuous production of uniformly sized, highly spherical pellets. The factors affecting agglomerate growth and size are outlined and discussed.
Diffusion in tabletted catalysts
Authors: Jury Stanley H. 
Published: March 2009

AbstractA two pore size model is proposed with random arrangement of the dispersed phase (s) and the transient solution and steady state equivalent diffusivity are presented for three new cases. These involve “open micropores,” “blind microprocess” and a combination of the two kinds.The results reveal modeling inconsistencies in the recent literature. The quasi‐steady state is discussed in relation to this phenomenon.A new technique of data analysis involving a combination of transient and steady state methods is proposed. This subjects the transient solution to a much more strenuous test.The results also apply to “barrier” materials.
Contraction de bulles de vapeur non sphériques
Authors: Delmas H. , Angelino H. 
Published: March 2009

AbstractAn experimental study of steam vapour bubble collapse in water suddenly pressurized is performed by use of high speed cinematography. Bubbles with initial radii ranging from 0.14 cm to 1 cm are presented. The pressure difference ranges from 21.7 to 80.8 kPa and the corresponding degrees of subcooling are 6.6°C to 40.9°C.The experimental data are compared with various theories. Heat transfer between the bubble and the surrounding liquid is underestimated while liquid inertia is more accurately evaluated. This underestimation apparently caused by the distortion of rising bubbles has a great effect on the large bubbles and on low subcooled cases.
Étude des régimes d'évolution thermique de couches fluidisées gaz‐solide mécaniquement agitées
Authors: Rios G. , Gibert H. 
Published: March 2009

AbstractIn the present paper the authors propose a pattern of calculation permitting to predict the thermal evolution of a gas‐fluidized system, which is mechanically stirred and subjected to abrupt fluctuations of the speed of the agitator. The two following cases are studied:
a full‐fluidized system.
a partly‐fluidized system involving a dense portion of wall layer.
The present work permits to confirm the results obtained from the mechanical and thermal studies performed in a steady state(1,2); it also gives a valuable tool for designing automatic control systems intended for regulating the temperature of heterogeneous layers.
Mass transfer and hydrodynamic characteristics of gas inducing type of agitated contactors
Authors: Joshi J. B. , Sharma M. M. 
Published: March 2009

AbstractPower consumption, rate of gas induction (Q), fractional gas hold‐up and mass transfer characteristics of 0.41, 0.57 and 1.0 m i.d. gas inducing type of agitated contactors were studied. The power consumption was measured by a torque table. The values of effective interfacial area (a), and liquid side mass transfer coefficient (kLa) were obtained by using chemical methods. Two types of impellers (pipe and flattened cylindrical) were employed. The impeller speed was varied from 3 to 11.7 r/s.The effects of impeller diameter, baffle position, orifice area on the impeller, number of impeller blades, position of impeller from the bottom and liquid submergence on the values of Q and a were investigated. Further, the effect of liquid viscosity and surface tension on the values of Q was studied.A satisfactory agreement was found between the observed and the predicted value of the minimum impeller speed at which gas induction occurs. The performance of the gas inducing type of agitated contactor has been compared with the conventional mechanically agitated contactor.
Prediction of drop diameter, hold‐up and backmixing coefficients in liquid‐liquid spray columns
Authors: Horvath M. , Steiner L. , Hartland S. 
Published: March 2009

AbstractThe available literature data for the drop diameter, hold‐up and backmixing coefficients were tested experimentally in a pilot plant size spray column. For all these parameters correlations were found which gave results in agreement with the experimental data so that reasonable prediction is possible. Different equations were compared and the ones giving the best fit are recommended.
Hydrodesulphurization of thiophene over a NiO‐MoO3‐Al2O3 catalyst
Authors: Kawaguchi Y. , Lana I. G. Dalla , Otto F. D. 
Published: March 2009

AbstractNiO‐MoO3‐Al2O3 based hydrodesulphurization catalysts appear to be of long term interest in the processing of Athabasca bitumen to eliminate organo‐bonded sulphur and nitrogen‐containing groups. This study employs such a catalyst (NALCO NM 502: 2% NiO, 14.0% MoO3, and γ‐Al2O3) in rate measurements of the vapor‐phase reaction of thiophene with hydrogen using an integral fixed‐bed reactor operated at about atmospheric pressure and in the temperature range, 270 to 350°C. Both power‐law and mechanistic models were fitted to the data; discrimination amongst the later being based upon consistency with physicochemical observations and the power‐law behaviour. The kinetic parameters for these models were contrasted with those obtained by a number of other workers for primarily Co‐Mo‐Al2O3 catalysts.
Colour removal from kraft mill caustic extraction effluent using aluminum and iron
Authors: Nasr M. S. , Macdonald D. G. 
Published: March 2009

AbstractThe highly coloured compounds found in the caustic extraction effluents of kraft mill bleach plants can be removed by chemical reaction with trivalent metal ions (Me3+). At pH 2.8, these ions react stoichiometrically with carboxylic acid groups (A−) on the lignin compounds to form moderately soluble MeA3 salts. Above pH 2.8, hydroxyl ions compete with the A− groups to form highly insoluble hydroxy metal salts. Maximum colour removals of 99.6 and 98.8% were obtained for an effluent containing 12000 APHA colour units treated with 7 mol/m3 of Al3+ at pH 5.0 and Fe3+ at pH 3.3, respectively.
Cryogenic recovery of tar from athabasca tar sands
Authors: Welmers A. , Bergougnou M. A. , Baker C. G. J. 
Published: March 2009

AbstractCryogenic recovery of tar from Athabasca tar sand could be an attractive alternative to the conventional hot water separation process. It is based on the fact that when frozen tar sand is ground, distinct particles of tar and sand are obtained and can be separated by elutriation. A specially designed fluidized bed grinder was developed for operation at temperatures in the range −30 to −130°C. Preliminary experiments have shown that 88% of the tar can be removed from the sand. Improved results can be expected after further optimization of the unit.
Bulk and interfacial physical properties of aqueous solutions of sodium lauryl sulphate and lauryl alcohol with air and benzene systems: Part II — mixed aqueous solutions of sodium lauryl sulphate and lauryl alcohol
Authors: Vijayan S. , Woods Donald R. , Vaya Helene 
Published: March 2009

AbstractThe pH, density, bulk viscosity and electrical conductivity of aqueous solutions of mixtures of sodium lauryl sulphate and lauryl alcohol were measured for a range of concentrations at 25°C. The influence of interface age on the interfacial tension of mutually saturated benzene/aqueous solution surfaces is also reported. The effect of impurities on various physical properties was illustrated using an impure lauryl sulphate system. A detailed comparison of these data with those reported in the literature shows satisfactory agreement above the critical micelle concentration of the sodium lauryl sulphate in water. Current data in the premicellar concentration range reveal anomalous behavior.Data reported in the literature are summarized for the pH, density, bulk viscosity, electrical conductivity, surface tension, interfacial tension with benzene, surface excess concentration, surface shear viscosity, critical micelle concentration and molecular complex formation of the sodium lauryl sulphate/lauryl alcohol aqueous solutions. The interactions of the anionic‐nonionic surfactants at fluid/fluid surfaces and their influence on the physical properties are examined. The use of such systems in the stabilization of dispersions is also discussed. Eighty‐five references are cited.
Minimum fluidization velocities in beds of mixed solids
Authors: Vaid R.P. , Gupta P. Sen 
Published: March 2009

AbstractThe fluidization behaviour of a bed of solids of mixed sizes and/or densities indicates that for a range of velocities between ubf (the velocity of beginning of fluidization) and utf (the velocity of complete fluidization), such a bed is only partially fluidized. The phase diagrams of these systems show that the phenomenon is analogous to the fractional crystallization of a multicomponent solution and it can find use in selective classification of solids.In the present work, data on ubf and utf for liquid fluidized beds of two, three, four and five component mixtures have been processed along with those reported earlier on gas‐solid systems, to yield useful correlations for their prediction.
Data and models for flow distribution and pressure drop in spouted beds
Authors: Epstein N. , Lim C. J. , Mathur K. B. 
Published: March 2009

AbstractA critical examination is made of the approaches used by recent investigators to the prediction of fluid flow distribution and pressure drop in spouted beds. Mathematical models are assessed both with respect to their theoretical validity and their agreement with experiment. Some of the models are rationally modified in order to increase their theoretical acceptability and their conformity to experimental observation. New experimental data on both flow and pressure distribution are presented. Desirable directions for future research are indicated.
Sub‐optimal control of a multivariable non‐linear chemical reactor using quasilinearization
Authors: Litchfield R. , Locke A. 
Published: March 2009

AbstractThe performance of a multivariable non‐linear stirred tank chemical reactor has been used to compare the practicability of an optimal controller and two types of suboptimal controller. The optimal controller, which by its nature required lengthy calculations, was suitable for open‐loop control only and therefore sensitive to modelling errors. By contrast a suboptimal controller, which used the method of quasilinearization to solve the two point boundary value problem, needed only a small amount of computation time and was capable of online implementation. This controller was much less sensitive to modelling errors, and also had the advantage of decoupling the control variables. An extension of this controller incorporated a feedback feature which compensated further for modelling errors and, in addition, unmeasured disturbances. This controller, which is expected to be of interest to the process industries facing inaccurate‐model problems, produced responses close to the true optimal response even when the actual model used was in gross error.
Vortex formation in stirred draining vessels
Authors: Hayduk Walter , Neale Graham 
Published: March 2009

AbstractWhen water was rotated by means of a “horse‐shoe” stirrer in a vertical, cylindrical tank and a stream was withdrawn from the bottom through a central exit pipe, a pronounced filament‐like vortex was formed under certain conditions. Experiments were performed to determine the factors which influenced the height of the vortex. The effects of vessel sue, stirrer geometry, rotational speed, exit flow rate and exit pipe diameter on vortex depth were studied. It was found that the vortex depth was highly dependent on the rotational speed, exit flow rate and exit pipe diameter. It was also found that under certain flow conditions the vortex penetrated the exit pipe. A relationship between the vortex depth and the pertinent variables was developed using dimensional analysis. The relationship resulting from a regression analysis of the dimensionless groups affecting the vortex depth was found to be:

Motion picutes were taken showing the flow characteristics in the vicinity of the vortex by using a dye tracer technique. Ways of inhibiting vortex formation were also examined.
Gas‐liquid equilibria in mixtures of hydrogen and thianaphthene
Authors: Sebastian H. M. , Simnick J. J. , Lin H. M. , Chao K. C. 
Published: March 2009

AbstractGas‐liquid equilibrium conditions in binary mixtures of hydrogen and thianaphthene were experimentally determined at temperatures of 190 to 430°C and pressures to 250 atm in a flow apparatus. The same apparatus was also employed to measure the vapor pressure of thianaphthene. Comparisons of the new mixture data with Chao‐Seader and Grayson‐Streed correlations show that both correlations predict the thianaphthene equilibrium ratios well but are in error by up to about 45 and 35% respectively for K‐values of hydrogen.
Influence of operating parameters on selectivity in a separation process by liquid membrane permeation for the system styrene‐ethylbenzene
Authors: Alessi P. , Canepa B. , Kikic I. 
Published: March 2009

AbstractAn experimental comparative analysis of various factors involved in the separation of styrene‐ethylbenzene mixtures by liquid membrane permeation was performed.The choice of the proper surfactant and the influence of the ratio surfactant/solvent/feed and of the operating parameters were investigated.An attempt is made to interpret the experimentally determined characteristics of the system on the basis of a diffusive model adapted to this kind of separation.
Kinetics of adsorption in bi‐porous molecular sieves. Part II: Comparison of theory and experiment for batch systems
Authors: Lee Lap‐Keung , Yucel H. , Ruthven D. M. 
Published: March 2009

AbstractExperimental kinetic uptake curves for two sorbates (cis‐2‐butene from the gas phase and n‐heptane from the liquid phase) have been measured in a variety of 5A molecular sieve pellets. Conditions were selected to fulfil either the linear isotherm approximation of the Ruckenstein(3) model or the rectangular isotherm approximation of the preceding paper. For these systems both macropore and micropore diffusional resistances are significant and it is shown that the theoretical models provide a satisfactory interpretation of the experimental uptake curves. Time constants for both macropore and micropore diffusion, calculated by matching experimental and theoretical uptake curves, are consistent with independently measured values.
Extension of the pitzer correlation for compressibility factor calculations
Authors: Hsiao Yuh‐Jen , Lu Benjamin C. Y. 
Published: March 2009

AbstractThe three‐parameter generalized correlation of Pitzer et al (1955) for calculating the compressibility factor Z of normal fluids in the Tr and Pr regions of 0.8 ≦ Tr ≦ 4.0 and 0 ≦ Pr ≦ 9.0 has been extended to wider ranges, using the P‐V‐T data available in the literature for 53 compounds with a total number of data points about 15,000. The linear equation in ω proposed by Pitzer et al is found to be adequate. Values of Z(0) and Z(1) of the linear equation are presented in tabular forms at regular intervals of Tr and Pr in the region of 0.2 ≦ Tr ≦ 5.0 and 0 ≦ pr ≦ 12.0. Quantum gases and highly polar compounds are not included in the correlation.In comparison, volumetric data for 15 compounds were used as the basis for the correlation of Pitzer et al, while 4 compounds were used by Lee and Kesler. The ω values covered in this work (–0.002 to 0.9065) is also wider than those used by Pitzer et al. (–0.002 to 0.352) and Lee and Kesler (0.0072 to 0.4902). The overall average absolute deviation between the calculated Z values obtained from the proposed correlation and the literature values for the 12 compounds tested by Lee and Kesler is 1.38%, which reduces to 1.07% if 1‐pentene is excluded in the comparison. The corresponding deviations obtained from the correlation of Lee and Kesler are 1.41% and 1.35% respectively. The proposed correlation also yields better results at ω = 0 than those obtained from earlier correlations.
Time‐dependent shear flow of artificial slurries in coaxial cylinder viscometer with a wide gap
Authors: Horie Michihiko , Pinder Kenneth L. 
Published: March 2009

AbstractAn experimental method was developed for characterizing time‐dependent slurries of elongated particles in a coaxial cylinder viscometer which has a wide gap between the inner rotating cylinder and the stationary cup. A model slurry system was studied; it consisted of a dispersed phase of regularly sized nylon fibres and a dispersing medium of an aqueous solution of polyethylene glycol with dextrose and sodium chloride, each of whose effects on the time‐dependent nature of the slurry could be examined.It was found that only a part of the gap between the cylinders of the viscometer flows under shear, and that the thickness of the flowing layer increases with time and approaches an equilibrium value.An empirical reaction‐rate type model was constructed for the time‐variation of the thickness of the flowing layer. A second order‐zero order reversible reaction model fitted the experimental data well. The fitting parameters of the model were correlated with slurry variables.
Prediction of mean drop size in batch agitated vessels
Authors: Gnanasundaram S. , Degaleesan T. E. , Laddha G. S. 
Published: March 2009

AbstractA correlation is proposed for prediction of mean drop size in agitated vessels in the two major hydrodynamic regimes of importance as observed in this study covering a wide range of holdup from 0.01 to 0.5 and impeller Weber numbers from 35–200,000.