bluuebunny/crossref_metadata_2025_split huggingface dataset:
Joule‐Thomson effects on turbulent graetz problem for gas flows in pipes with uniform wall temperature
Authors: Cheng K. C. , Ou Jenn‐Wuu 
Published: March 2009

AbstractThe Joule‐Thomson effect is known to be important in arctic gas pipelines. The Joule‐Thomson effects on forced convective heat transfer in the thermal entrance region of pipes with uniform wall temperature are studied for steady fully developed turbulent gas flows by the Graetz method. Thermal entrance heat transfer results are presented for Prandtl number 0.72, Reynolds number 105 and Brinkman number ± 0.1, ± 1.0 with Joule‐Thomson parameter Jμ ranging from 0 to 1.0 to cover the possible range in practical applications. Bulk temperatures and Nusselt numbers are also presented for fully developed flow with Reynolds numbers from 5 × 103 to 106. For given Prandtl and Reynolds numbers, the asymptotic Nusselt number is found to be dependent on the Joule‐Thomson parameter only and is independent of Brinkman number. The fully developed bulk temperature is a linear function of Brinkman number and a linear relationship exists between the bulk temperature parameter (‐θbf/Br) and the Joule‐Thomson parameter Jμ for given Prandtl and Reynolds numbers.
Co‐current flow liquid‐liquid binary mass transfer in ejectors
Authors: Acharjee D. K. , Mitra A. K. , Roy A. N. 
Published: March 2009

AbstractLiquid‐liquid binary mass transfer involving simultaneous transfer of an organic phase component to the aqueous phase and an aqueous phase component to the organic phase in water‐n butanol and water‐methyl ethyl ketone systems has been studied in a vertical ejector system. Correlations have been developed to predict both dispersed and continuous phase film capacity coefficients as function of various physical and dynamic variables of the system.
Catalytic oxidation of benzene to maleic anhydride in a continuous stirred tank reactor
Authors: Quach T. Q. Phung , Rouleau D. , Chavarie C. , Laguerie C. 
Published: March 2009

AbstractThe kinetics of the vapor phase oxidation of benzene has been studied over an industrial catalyst in a continuous stirred tank reactor in the temperature range from 280 to 430°C and at atmospheric pressure. The products obtained are maleic anhydride, carbon oxides and water. The rate of the overall reaction (disappearance of benzene) is represented by the following expression based upon a steady state adsorption model

The rate of formation of maleic anhydride is correlated by the equation

which allows for a homogeneous depletion of maleic anhydride. The rate constants kB, kO, k2(g) were found to follow Arrhenius behavior.
Use of waste liquor from bisulfite pulping to produce mixed culture single‐cell protein
Authors: Lo S. N. , Moreau J. R. , St‐Laurent G. 
Published: March 2009

AbstractThe activated sludge process might be used in the very near future to treat the waste liquors from small bisulfite mills in Canada, as a mean of controlling water pollution. These mills produce normally less than 300 t/d of pulp. It was found that the bio‐sludge solids from such a process, when used to treat such waste liquor, contained approximately 38% protein, 47% carbohydrates, some vitamins and sufficient quantities of essential minerals. This bio‐substance, a mixed‐culture in nature, could be considered as a good source of single‐cell protein. The nutritive value in terms of protein efficiency ratio of this substance was tested with rats; good results were obtained when the biomass was slightly supplemented with methionine.Described in this paper is a system used in our laboratory to produce this biomass in a sterile and dried form. The conversion of carbohydrates contained in waste pulping liquor to biomass was carried out in a 400‐l, aerated, continuous‐flow tank reactor. Under the operating conditions studied the sludge yield coefficient was 0.53 g of biomass/g of carbohydrates removed. A cash return study of selling biomass is also presented for two mills producing high‐ and low‐yield pulps respectively.
Hydrodynamics and mass transport in rotary disk contactors
Authors: Laddha G. S. , Degaleesan T. E. , Kannappan R. 
Published: March 2009

AbstractThis paper reports a detailed study of the hydrodynamics involved in the operation of rotary disk contactors (RDC). New information is presented regarding the ‘critical rotor speed’ which divides the two hydrodynamic regimes of near constant and varying characteristic velocity of the dispersed droplet phase. Generalized correlations for prediction of characteristic velocity both above and below the critical rotor speed have been proposed under conditions of no solute transfer as well as solute transfer between the dispersed and continuous phases. Experimental data on mass transfer obtained in the two hydrodynamic regimes of RDC operation have also been correlated by the application of mass transport theory taking into account the factors affecting the interfacial area of contact, drop size, characteristic velocity and dispersed phase holdup.
Two‐phase laminar zero net flow in a circular inclined pipe
Authors: Masliyah Jacob H. , Shook C. A. 
Published: March 2009

AbstractSteady countercurrent zero net flow of two immiscible fluids in an inclined circular tube has been studied under laminar flow conditions. Using appropriate dimensionalization, the interface position and viscosity ratio become the only two parameters that govern the flow. Velocity profiles and shear stresses were determined from numerical solutions of the equations of motion and are compared with the analytical solutions for flow between parallel plates. Such zero net flows are encountered at shutdown of long inclined slurry pipelines. The results of the present investigation are suitable for modelling these flows.
Laminar flow between a circular tube and a cylindrical eccentric capsule
Authors: Garner R. G. , Raithby G. D. 
Published: March 2009

AbstractThe fully‐developed laminar flow between a circular tube and an eccentric moving cylindrical rod is predicted for eccentricities between zero and unity. For eccentricities less than unity, an earlier solution is extended to account for arbitrary rod (capsule) velocities; useful shear force expression in closed form are given. An entirely new solution for the fully eccentric case is presented.
Batch adsorption for pore diffusion with film resistance and an irreversible isotherm
Authors: Weber Thomas W. 
Published: March 2009

AbstractEquations are developed for finite‐batch, irreversible adsorption where both pore diffusion and film resistance are significant. Quasi‐steady state behavior is assumed and comparisons are made for sheets, cylinders, and spheres. The equations for the three shapes are generalized to a single form. For equal volumes of adsorbent, when the external film controls, spheres attain equilibrium more quickly than cylinders, and cylinders more quickly than sheets. When internal diffusion controls and the ratio of the final to the initial solution concentration is high, this ordering of equilibrium times is preserved; however, if the ratio is very low, the ordering is reversed.
Gas separation by permeation Part I. Calculation methods and parametric analysis
Authors: Pan C.‐Y. , Habgood H. W. 
Published: March 2009

AbstractCalculation methods for single‐ and multi‐stage permeation of a multi‐component mixture are presented. The use of the local permeate concentration in the formulation results in a relatively simple form of solution for the binary system in the cross‐flow pattern. A parametric analysis of the permeation cascade is given. For a given permeability of the more permeable component, there exists a membrane selectivity which gives rise to a minimum membrane area requirement in the cascade. It is shown that the compression power requirement is dependent only on the operating pressure ratios, irrespective of actual pressure levels in each stage. A study on the effect of interstage mixing loss shows that the ideal cascade (with no interstage mixing loss) is not necessarily always the thermodynamically most efficient one; some non‐ideal cascades may have higher efficiencies due to more effective permeation steps. Examples given relate to He/CH4 and O2/N2 separations.
Vapor phase oxidation of p‐xylene
Authors: Mathur B. C. , Viswanath D. S. 
Published: March 2009

AbstractThe kinetics of the vapor phase oxidation of p‐xylene over ferric molybdate catalyst were studied in an isothermal, differential, tubular flow reactor in the temperature range of 360 to 420° C. The major product obtained was p‐tolualdehyde with small amounts of maleic anhydride and p‐toluic acid. No terephthalic acid or CO2 were observed.The reaction rate data collected fit the redox model given by Equation 1. The values of activation energies Ex, Eo and frequency factors Ax, Ao obtained are 72, 63 kJ/mol and 0.64, 2.89 m3/kg catalyst s respectively.The reaction mechanism was established by studying the oxidation of p‐tolualdehyde, toluic and terephthalic acids. It is concluded that the reaction follows a parallel‐consecutive scheme.
Cristallisation du trihydrate d'alumine: Un modèle pour l'attrition
Authors: Remillard Michel , Cloutier Leonce , Methot J.‐Claude 
Published: March 2009

AbstractL'attrition des cristaux de trihydrate d'alumine a été étudiée dans un réacteur isotherme parfaitement agité en régime discontinu. Des essais expérimentaux ont été réalisés en utilisant des particules tamisées. La granulométrie des cristaux a été mesurée afin de suivre l'évolution du nombre de particules en fonction du temps d'opération. Les résultats expérimentaux ont servi à développer un modèle mathématique permettant de représenter le phénomène d'attrition. Ces données nouvelles pourront par la suite ětre exploitées dans l'industrie de l'aluminium en vue de simuler les cristalliseurs industriels.
Sodium‐sulphur cells
Authors: Foulkes F. R. , Choi P. T. 
Published: March 2009

AbstractThe sodium‐sulphur battery is reviewed and experimental results are presented. The experimental cells were capable of delivering steady state power densities as high as 50 W.kg−1and energy densities as high as 250 W.h.kg−1. The theoretical open circuit voltage of 2.08 V was observed in all cases. Cell polarization was limited by cell internal resistance, which was attributed largely to the resistance of the β‐alumina electrolyte. The “asymmetry effect” is explained in terms of an electrode blockage mechanism involving polysulphides. The sodium‐sulphur battery appears to be technically feasible as the power source for an all‐electric vehicle.
Deuterium exchange between hydrogen and water in a trickle bed reactor
Authors: Enright J. T. , Chuang T. T. 
Published: March 2009

AbstractThe catalyzed exchange of deuterium between hydrogen and liquid water has been studied as the basis for a heavy water production process. Platinum catalyst which had been waterproofed with Teflon was tested in a 0.2 m diameter trickle bed reactor at pressures and temperatures up to 6 MPa and 440 K. Extensive experimental data were used to test a model of the system which was developed from fundamental principles. It was found that mass transfer plays a very important role in the overall exchange and the conventional theory of vapour/liquid mass transfer does not adequately describe the absorption process. Modelling of the data has resulted in the postulation of a second method of mass transfer whereby HDO transfers directly from the catalyst to the bulk liquid phase.
Phase equilibria calculations with a modified redlich‐kwong equation of state
Authors: Medani M. S. , Hasan M. A. 
Published: March 2009

AbstractA modified Redlich‐Kwong equation of state for pure substances in the liquid‐vapour coexisting phase region is suggested in which the fugacity coefficients of the two phases are equated and the resulting relationship is solved by assuming ωb to be temperature dependent while ωa remains constant. A generalised correlation for ωb is found with the acentric factor as a parameter. This approach is compared with the other two possible modifications, i.e. when ωa is a funtion of temperature while ωb is constant, and when both ωa and ωb are temperature dependent. Comparison revealed the excellent attainment of the equilibrium conditions when the proposed method is applied. Predicted volumetric properties and isothermal enthalpy departures of the liquid and vapour as well as the saturation vapour pressures are also compared which reveal the adequacy of the new modification.With the application of the mixing rules, the proposed modified equation is successfully applied to VLE calculations for binary mixtures of different complexities.
Behaviour of shallow fluidized beds around immersed objects
Authors: Roche G. , Chavarie C. 
Published: March 2009

AbstractImpermeable and permeable objects were immersed in a shallow gas fluidized bed. The pressure distribution on the surface of impermeable cylinders closely follows the principles of classical hydrostatics. The bottom half of larger bodies is nevertheless influenced by the presence of the bottom of the bed; the top half of completely immersed objects is covered by a defluidized zone which prevents reliable surface pressure measurments with the probes devised in this work. A defluidized zone is also readily formed around the surface of partially immersed porous objects. Experimental isobars measured in the bed around these objects were compared to the predictions of a model relying on a uniform potential flow approach. The agreement between the model and the data is generally good but the flow resistance definitely seems to be larger in the defluidized envelope. The defluidized zone seems to be considerably eroded by the brushing of gas bubbles.
Solids separation in a counter‐current fluidized cascade: Jetsam‐rich mixtures at total reflux
Authors: Muzyka D. , Beeckmans J. M. , Jeffs A. 
Published: March 2009

AbstractThe separation of cocoanut charcoal particles (mean size 342 μm) from salt particles (mean size 459 μm) was studied in a counter‐current gas fluidized cascade at total reflux, for a number of bed depths and paddle depths. In each case the experimental separation ratio RE was found to pass through a maximum when plotted against paddle velocity. The fluidized cascade was simulated by a mathematical model, which correctly predicted the general behaviour of the system under the various conditions studied.
Spouted bed collection of solid aerosols in the presence of electrical effects
Authors: Balasubramanian M. , Meisen A. , Mathur K. B. 
Published: March 2009

AbstractA spouted bed of 1.7 mm cement clinker particles was previously found to be an efficient collector of liquid micronsize aerosols introduced into the bed with the spouting gas(1) With solid aerosols, however, collection efficiencies obtained were poor since these failed to adhere permanently to the target particles and were re‐entrained.The present paper describes experimental work to overcome the re‐entrainment problem by making use of electrostatic forces. Solid latex aerosol particles (0.79 μm dia.) were electrified by a negative corona discharge and collected in a 15 cm diameter spouted bed of ABS plastic particles (2.5 mm cubes). The variables studied included corona voltage (0 to 9500 V), bed depth (0.3 to 0.5 m) and superficial gas velocity (0.23 to 0.85 m/s).Spouted bed efficiencies with neutral aerosols ranged from 43 to 65% as against 72‐98% with charged aerosols The experimental results are interpreted using the two‐region model of a spouted bed, and invoking an enhancement factor for aerosol mass transfer due to electrical effects. The values of this factor ranged between 160 to 2300 under the conditions studied.
Solvent extraction of copper in a reciprocating plate column
Authors: Sharma R. N. , Baird M. H. I. 
Published: March 2009

AbstractEquilibrium data for the distribution of copper between an aqueous solution and a 20% solution of di‐(2 ethyl hexyl) phosphoric acid in kerosene has been obtained by shake‐flask experiments. The capacity of the organic phase for copper is greatly improved when the ammonium salt of D2EHPA is used. The performance of a 5 cm diameter Karr reciprocating plate extraction column for continuous counter‐current extraction of copper by ammoniated D2EHPA has been measured. The results, expressed as heights of a transfer unit, have been compared with data for a non‐metallic system (kerosene/acetic acid/water) in the same column. The lowest H.T.U. values measured were 43 cm for copper transfer and 23 cm for acetic acid transfer, with the difference being attributed mainly to the lower molecular diffusivity in the copper/D2EHPA system.
Simulation of cyclic dynamics in isothermal gas‐solid reaction systems effects of the frequency of sinusoidal perturbation in the bulk gas concentration
Authors: Fan L. T. , Fan Liang‐Shih , Miyanami Kei 
Published: March 2009

AbstractThe dynamic responses of a gas‐solid reaction system to a sinusoidal perturbation in the bulk gas concentration are analyzed. Effects of the frequency variations on the gas and solid concentration profiles and the solid conversion are comprehensively examined based on the volume reaction model under the isothermal condition. The results show that the solid conversion can be accelerated as much as 50% and retarded as much as 50% depending on the frequency and the amplitude of the perturbation. The relationships between the reactant concentrations at the surface and the center are elucidated by means of phase‐plane plots.
Substrate‐inhibited microbiological regeneration of granular activated carbon
Authors: Sigurdson S. Paul , Robinson Campbell W. 
Published: March 2009

AbstractA kinetic model of the microbiological regeneration of activated carbon is presented for the case where the adsorbate is inhibitory to the microbial‐growth‐associated bio‐oxidation process. The model is used to predict the regeneration time for specified combinations of microbial species (using growth kinetic constants determined in a carbon‐free system) and carbon type (adsorption isotherm). In addition to the foregoing parameters, computer simulations show that the spent carbon adsorbate loading, the carbon mass‐to‐fermentation broth volume ratio and the inoculum size also have a significant effect on the time required for batch in situ regeneration of a carbon column.Experimental results are given for a granular carbon‐phenol‐bacteria (P. putida) system at several operating conditions; the observed regeneration times are in good agreement with predicted values. Once‐regenerated carbon retained 47 percent of the phenol equilibrium adsorption capacity of fresh carbon. No further loss of adsorption capacity was found for carbon which subsequently was regenerated two more times, i.e., for a total of three sequential microbiological regenerations.
Solubility of ethylene in several polar and non‐polar solvents
Authors: Sahgal A. , La H. M. , Hayduk W. 
Published: March 2009

AbstractSolubilities of ethylene at atmospheric pressure and temperatures ranging from −9°C to 70°C are reported in solvents ranging from the non‐polar ones, heptane, dodecane, carbon tetrachloride, carbon disulfide and chlorobenzene to the highly polar ones, isopropanol, butanol and ethylene glycol. A useful relation was observed between ethylene solubilities in non‐polar solvents and those of methane, ethane and propane, along with the corresponding energy of vaporization at the normal boiling for those gases. In the highly polar solvents on the other hand, hydrogen bonding (H‐bonding) factors were found more useful in relating solubilities in one hydrogen bonding solvent to those in other hydrogen bonding solvents.
Prediction of heats of mixing of liquid mixtures containing alkane, chloroalkane and alcohol by an analytical group solution model
Authors: Lai Tu Tam , Doan‐Nguyen T. Huong , Vera Juan H. , Ratcliff Gerald A. 
Published: March 2009

AbstractAn analytical group solution model (AGSM) previously developed for the prediction of heats of mixing has been applied to ternary group, ternary component mixtures. A simple temperature dependence is proposed for the group interaction parameters. Temperature independent coefficients were obtained in the temperature range 15 to 35°C for mixtures containing CH2, OH and Cl groups. These coefficients allow the prediction of heat of mixing for binary or ternary mixtures containing alcohols, chloroalkanes and alkanes. Heats of mixing for the following systems are reported: 1‐chlorobutane and 2‐chlorobutane with both n‐hexane and n‐octanol at 35°C; n‐octanol — n‐hexane at 25 and 35°C; and three chords of the ternary system 1‐chlorobutane — n‐octanol — n‐hexane at 25 and 35°C.
Solubility and diffusivity of oxygen in aqueous sucrose solutions
Authors: Hikita H. , Asai S. , Azuma Y. 
Published: March 2009

AbstractSolubility and diffusivity of oxygen in aqueous sucrose solutions of various concentrations were measured at temperatures from 15° to 45°C and at atmospheric pressure. The solubility of oxygen could be correlated well by the method of van Krevelen and Hoftijzer. The diffusivity of oxygen was found to be proportional to the −2/3 power of the viscosity of the solution.
Using a statistical multiresponse method of experimental design in a reaction network study
Authors: Boag I. F. , Bacon D. W. , Downie J. 
Published: March 2009

AbstractA statistical design method for multiresponse models was used in an experimental study of a reaction network. The study involved the vanadia‐catalysed oxidation of o‐xylene using a recirculation reactor. Concentrations of reactants and temperature were used as operating variables, and the concentrations of products were the measured responses.The published design procedure was modified by conducting several runs after each design evaluation to reduce computing costs while retaining the benefits of statistical design and analysis. This enabled network analysis to be conducted efficiently to the limits of the equipment, and pointed the way to improved estimates of the parameters.
Waves on thin films of pseudoplastic liquids
Authors: Tekic Miodrag N. , Mitrovic Milan 
Published: March 2009

AbstractWavy flow of a thin pseudoplastic fluid film down a smooth vertical plate has been analytically studied. A boundary layer equation of motion was solved to obtain expressions which permit the prediction of characteristic parameters values of pseudoplastic liquids in wave motion. The presented analysis gives better agreement between predicted and measured values of wavelength and critical regime for wave inception than the existing theories. Also a good agreement was obtained between predicted and measured values of the mean film thickness.
A study of factors affecting the ice nucleation temperature in a domestic water supply
Authors: Gilpin R. R. 
Published: March 2009

AbstractThe ice nuclation temperature in a typical water supply was measured and found in general to be in the range of —4° to —7°C. This amount of supercooling is very significant in a water main in that it will have a major effect on the way in which a pipe freezes. The effects of the temperature‐time history of the water, of the presence of certain nuclating agents and of mechanical vibration on the nucleation temperature were determined and were related to the behaviour of undissolved particulate matter in the water. In addition to determining the nucleation temperature in a water supply under various conditions this study also serves to illustrate some of the phenomena that can be expected in general when hetergeneous nucleation occurs.