bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical calculation of developing laminar flow in pipes of arbitrary curvature radius
Authors: Humphrey Joseph A. C. 
Published: March 2009

AbstractElliptic forms of the Navier‐Stokes equations in rigorously formulated toroidal coordinates are solved numerically for laminar, incompressible, isothermal flow in curved pipes of small curvature radius and 90° deflection angle. As a special case, the flow through curved annuli is also considered in which the presence of the inner curved wall causes the appearance of two (rather than one) pair of cross‐stream vortices. Recirculation in the main flow direction is observed at the outer curvature wall of a pipe with Rc/d = 1 and Re = 1800 over a deflection angle corresponding to 9° ≤ θ ≤ 21°. Flow reversal is attributed to the large and unfavorable longitudinal pressure gradient prevailing at the outer curvature wall over the first half of the pipe. Calculations show that the cross‐steam flow in a strongly curved pipe can be as large as 80% of the bulk average velocity at θ = 45° but is reduced in magnitude between θ = 45° and 90°.The numerical procedure used for the present calculations is a special case of a more general method which will solve flows in arbitrary curvilinear orthogonal coordinates provided the appropriate scale factors and extra source terms are included. A detailed derivation of the difference equations in curvilinear orthogonal coordinates is, therefore, presented here.
Hydrocracking of bitumen and heavy oils at CANMET
Authors: Pruden B. B. 
Published: March 2009

AbstractA description of pilot‐plant scale investigations of thermal and catalytic hydrocracking of bitumen and heavy oil at the Energy Research Laboratories, Canada Centre for Mineral and Energy Technology, is presented. A summary of division programs in the high pressure hydrogenation area since 1930, and current in‐house and “contract” activities are outlined.
Noncatalytic gas‐solid reaction with changing particle size: Unsteady state heat transfer
Authors: Rehmat A. , Saxena S. C. , Land R. , Jonke A. A. 
Published: March 2009

AbstractA mathematical expression for the unsteady state heat balance is derived for a nonisothermal, noncatalytic, first order gas‐solid reaction. The formulation is based on a shrinking core model and takes into account the changing size of the spherical particle during reaction. Thus, the model has two moving boundaries, viz., the reaction front and the external particle diameter which grows or shrinks due to reaction. This complicates the numerical solution considerably. The calculations indicate that both the conversion‐time relationship and core temperature are significantly influenced by the extent of particle growth. The unsteady state and quasi‐steady state analyses lead to somewhat similar results for conversion‐time relationship except for the case where the solid reactant has a large heat capacity. On the other hand, the core temperatures for the two cases differ significantly.
Isobaric liquid‐vapour equilibrium data correlation for a ternary mixture exhibiting associations: Acetic acid‐acetone‐trichloroethylene
Authors: Francesconi Romolo , Comelli Fabio , Montefusco Laura , Trevissoi Carlo 
Published: March 2009

AbstractLiquid ‐ vapour equilibrium data (temperature and composition in the liquid and vapour phases) of the ternary mixture: acetic acid ‐ acetone ‐ trichloroethylene, which exhibits association of the acid even in the vapour phase, were determined at P = 93.3 kPa (700 mmHg) with the Stage‐Muller apparatus. The thermodynamic consistency of these data was tested by means of the McDermott‐Ellis test, and the activity coefficients of the three components were correlated with Margules' and Wilson's Equations, the parameters of which were evaluated by a least square procedure. The parameters having been thus evaluated, Margules' and Wilson's Equations were then used to recalculate the equilibrium compositions. The value of the standard deviation Δξ between the experimental and calculated composition indicates that Margules' Equation permits a better correlation of the data than Wilson's. Moreover, Margules' Equation with parameter Aij and C* evaluated by the ternary data gives lower values of Δξ than the same Equation, but with parameters Aij evaluated by the binary data and C* by the ternary data with binary Aij, according to the method normally employed.
Une éequation d'éetat de clausius modifiée repréeasentant l'éeatat liquide
Authors: Freze Richard , Chevalier Jean‐Louis 
Published: March 2009

AbstractLes trois paramètres d'une équation d'état de Clausius modifiée ont été généralisés, en ayant pour objectif le calcul des propriétés thermodynamiques des corps purs dans l'état saturé, depuis la température d'ébullition normale jusqu'à la température critique. La méthode décrite, qui nécessite la seule connaissance des propriétés caractéristiques des corps purs (Tc, Pc, Zc, ω) a été testée sur 28 composés divers (hydrocarbures saturés et insaturés, molécules simples et molécules polaires). Les résultats obtenus montrent que l'équation d'état proposée décrit correctement l'équilibre liquide‐vapeur (pression de vapeur saturante et enthalpie de vaporisation) et elle permet de plus une représentation satisfaisante de l'état liquide saturé.
The effect of high magnetic fields on the vapour liquid equilibrium data for nitrogen/oxygen
Authors: Biddulph M. W. , Meachin A. J. 
Published: March 2009

AbstractThis paper describes an experimental study carried out to check the effect of high magnetic fields on the vapour liquid equilibrium of N2/O2. Significant effects were measured on the VLE curves, although these did not correspond to the earlier theory of Atroshchenko and Voronina(1). This theory used a predicted effect on the vapour‐pressures of the pure components. The equilibrium cell is described in detail and the data measured showed increasing non‐ideality with increasing field strength due to an effect mainly on the liquid phase.
Evaluation of capital cost data: Gas moving equipment
Authors: Woods Donald R. , Anderson Susan J. , Norman Suzanne L. 
Published: March 2009

AbstractCapital cost correlations are given for gas moving equipment. Correlations available in the literature and current data are compared on a consistent basis. Forty‐three graphs show the relative magnitude of the different correlations and the recommended correlation for each type of equipment is summarized in a table. Some data on the costs of installing gas moving equipment are given.
Breakage rates of lignite particles during hydraulic transport
Authors: Shook C.A. , Haas D.B. , Husband W.H.W. , Small M. 
Published: March 2009

AbstractExperiments conducted with recirculating test loops show that the rate equations for rod and ball mill grinding can be applied to the changes induced by pumping. Selection rate constants in the range considered were found to be rather insensitive to particle size but strongly time dependent. This time dependence can be attributed to changes in particle shape dominating over fracture as a degradation mechanism. Pump construction and speed appeared to be of considerable importance in determining breakage rates.
A technique for the determination of the concentration distribution in a sedimenting suspension via radioactive solids
Authors: Tory Elmer M. , Mosevich Jack W. , Reddy V. Malla 
Published: March 2009

AbstractIn a slurry of radioactive particles, radiation count and solids concentration are related by a Fredholm equation of the first kind. Two iterative methods are described and conditions for their convergence are given. Two hypothetical examples illustrate computational difficulties and their solution. Experiments with slurries of radioactive praseodymium oxalate demonstrate the feasibility of the method. Solutions are proposed for various practical problems which arise.
Aerodynamic and diluent effects on the emission of nitrogen oxides from hydrocarbon diffusion flames
Authors: Gollahalli Subramanyam R. 
Published: March 2009

AbstractAn experimental study of the quantities of oxides of nitrogen produced in hydrocarbon gas jet flames in concentric and cross‐flow air streams is presented. It is seen that the structure of flames has a strong influence on the quantities of NO and NO2 generated in diffusion flames. Increases in jet velocity result in the increase of NO and NO2 emitted from flames in concentric air streams. However, air stream velocity has opposite effects on the yields of NO and NO2 from flames in cross‐flows. Additions of diluent to jet and air streams decrease NO and NO2 in both concentric and cross‐flow air streams. The implications of scaling these results to fullsize flare stack flames have been discussed.
Gas liquid reactions in a packed bed: Some implications of the extended crossflow model
Authors: Patwardhan V. S. 
Published: March 2009

AbstractThe extended crossflow model was proposed earlier5 to account for the role of the stagnant zones of liquid in a packed trickle bed during absorption with a chemical reaction. Here the model is applied to a second order reaction to investigate the behaviour of the effectiveness f of the interfacial area of the static hold‐up during absorption with a chemical reaction. General criteria are developed which give conditions for the limiting behaviour of f for reaction kinetics of any form. Finally, a possible pitfall is described in detail which must be avoided in conducting kinetic experiments in a packed trickle bed.
Elimination d'anhydride sulfureux par réaction sur l'oxyde de cuivre en couche fluidisée
Authors: Barreteau D. , Angelino H. 
Published: March 2009

AbstractReaction between cupric oxide, oxygen, and sulphur dioxide has been studied in a fluidized bed reactor continuously fed with solid reactant. The effect of bed temperature, solid flow rate, gas flow rate and the hight at minimum fluidization conditions has been investigated.Experimental conversions are between 20 to 60%.Olcutt and Davidson's fluidized bed reactor model slightly modified for our particular reactor has been compared with experimental data. The assumption of plug flow of gas in the dense phase is good for the height of 5 cm, on the contrary, the assumption of perfect mixing of gas in the dense phase is better for the deepest bed.
The kinetics of the primary reactions in cumene cracking on lay catalysts of various mesh sizes
Authors: Best D. A. , Wojciechowski B. W. 
Published: March 2009

AbstractA novel technique of obtaining fundamental kinetic data for complex chemical reactions on a decaying catalyst is described. The technique, based on the use of “Optimum Performance Envelopes” and initial selectivities, it used to determine the initial rate constants for the formation of all known primary prodiicts in the conversion of cnmene on Lay. From these data, the corresponding activation energies and frequency factors are estimated.Using the above procedures to study the effects of diffusion on this reaction it has been shown that the effect of changing particle size is more complex than that predicted by existing theories of catalyst diffusion.
Effects of temperature and charge stock composition on the kinetics of catalyst decay
Authors: Pachovsky Roman A. , Wojciechowski Bohdan W. 
Published: March 2009

AbstractA study of the kinetics of catalyst decay in the presence of a wax‐free and of a waxy feed has shown that the wax‐free feed causes decay by the poisoning of one site at a time whereas the waxy feed shows that wax poisons catalyst activity by competing one and two site mechanisms. In all these mechanism decay proceeds partly and perhaps totally by reactions involving two molecules of poison per deactivation event.
Reservoir depletion calculations for gas condensates using extended analyses in the peng‐robinson equation of state
Authors: Firoozabadi Abbas , Hekim Yusuf , Katz Donald L. 
Published: March 2009

AbstractThe Peng‐Robinson‐AGA computer program was applied to the predicting of liquid yields in flash and stepwise depletion calculations. Prior tests of the validity of the program were based on agreement between bubble and dew point pressures and equilibrium constants. Here, the liquid yields under ietrograde conditions were compared with only a moderate degree of agreement. The need for accurate extended analyses of condensate systems as well as the documentation of an accurate characterization of the cuts is emphasized.
Comparison of effective interfacial areas with the actual contact area for gas absorption in an agitated vessel
Authors: Kon Ngee Siew , Sandall Orville C. 
Published: March 2009

AbstractGas absorption with a pseudo‐first order chemical reaction was carried out in a turbine‐agitated vessel for the case of absorption across an unbroken interface. These experiments were carried out in order to determine the effective interfacial area for mass transfer. Carbon dioxide was absorbed in an aqueous carbonate‐bicarbonate buffer solution in the presence of an arsenite catalyst. The concentrations of arsenite used ranged from 0.05 to 0.2 mol/l. Effective interfacial areas determined from chemical reaction increased from 48.61 cm2 for an agitator speed of 100 r/min to 109.39 cm2 for an agitator speed of 750 r/min. The actual interfacial area was 179.50 cm2.
Quadratic model of the behaviour of a fluidized bed reactor: Catalytic oxidation of benzene to maleic anhydride
Authors: Kizer O. , Chavarie C. , Cassimatis D. , Laguerie C. 
Published: March 2009

AbstractThe behaviour of a fluidized bed reactor for the catalytic oxidation of benzene to maleic anhydride has been studied following a 24 factorial design of experiments. Results stand comparison with those observed in fixed bed reactors. Yields as high as 42% are obtained.Statistical analysis of the data, using the Yates method, to establish the polynomial dependence of conversion, selectivity and yield on the operating variables (temperature, benzene/air ratio, volumetric flow of the feed, height of the catalytic bed of particles) shows that the performance of the system, for each response, can be translated to an incomplete quadratic model with only limited interactions among the variables. Although it is difficult to establish a precise correspondance of the parameters of the models to the fundamentals of fluidized bed reactors, some of the phenomenological principles of the process related to conversion and selectivity have been identified. However, such is not the case for the unusually complex yield response. The analysis of the data suggested a more refined control of the variables to elucidate the behaviour of the yield around the optimal operating conditions.
Traitement du sable bitumineux par micro‐ondes
Authors: Cambon J.L. , Klvana D. , Chavarie C. , Bosisio R.G. 
Published: March 2009

AbstractUn traitement micro‐ondes a été utilisé dans le but de dégager les hydrocarbures présents dans le sable bitumineux, II a été constaté que les micro‐ondes provoquaient une distillation et un craquage du bitume. La dépendance du taux d'extraction du bitume a été évaluée pour les facteurs suivants: temps de traitement, intensité du champ micro‐ondes, débit et nature du gaz de balayage, forme et position de l'échantillon dans le champ micro‐ondes. Les résultats obtenus ont permis de dégager d'une part un mécanisme de chauffage et d'autre part des conditions opératoires pour l'utilisation optimale des micro‐ondes pour le traitement du sable bitumineux.
The thermal conductivity of porous catalyst pellets
Authors: Soomro M. , Hughes R. 
Published: March 2009

AbstractThermal conductivities of γ‐alumina and alumina supported nickel catalysts prepared by impregnation and coprecipitation have been measured by a transient method. Results obtained were compared with predictive models and it was found that a simple modification' of a one parameter model gave good agreement with the results for the support and impregnated catalysts but did not give satisfactory predictions for the coprecipitated catalyst.
Rates of extraction of mercaptan sulfur from pentane by caustic solution
Authors: Carr N. L. , Shah Y. T. 
Published: March 2009

AbstractThe interphase rate process for the extraction of mercaptan sulfur from n‐pentane with a 10% caustic solution is examined. The system represents a case of mass transfer with an equilibrium chemical reaction occurring in one phase. Experimental studies were made with both a continuous flow stirred tank reactor (CFSTR) and an annular flow jet reactor (AFJR). The interphase volumetric mass transfer coefficient (KLa) was derived based on Olander's theory. The KLa data for each contactor was found to be a function of the power input per unit volume. The AFJR exhibited higher KLa values and equilibration of mercaptan sulfur was achieved in about three milliseconds.
Internal mass transfer coefficient within single bubbles. Theory and experiment
Authors: Zaritzky Noemi E. , Calvelo Alfredo 
Published: March 2009

AbstractMass transfer coefficients inside single rising bubbles are measured in the system SO2, N2—H2O by using a photographic technique.The differential equations which govern the phenomena, including internal toroidal circulation inside the bubble, are also presented. Assumptions are incompressible, steady, irrotational outside flow and inviscid, steady, axisymrnetric inside flow.From the mass transport viewpoint, restrictions are: binary dilute mixture and axial symmetry.The theoretical solution is presented as Sh vs. Pe and a comparison with experiments shows good agreement.Theoretical predictions for a stagnant fluid inside the bubble were also compared with the experimental results.
Kinetics of decarburization of molten fe‐c by gaseous hydrogen
Authors: Whiteway S. G. 
Published: March 2009

AbstractHydrogen was directed onto the surface of Fe‐4%C held in an Al2O3 crucible at 1327°C, and the rate of formation of CH4 was measured by mass‐spectrometric analysis of the effluent. The measured rate approached the theoretical limit of mass transfer of CH4 in the gas phase, provided that the concentration of other gases evolved by side‐reactions was small. Deviations from predicted values appeared to be caused by carbon monoxide coming from the reaction of dissolved carbon with the crucible, and water coming from the reaction of hydrogen with the refractories. The gas mass transfer coefficient for the particular geometry used was determined in separate experiments where the carbon was oxidized by CO2.
On the use of residence time distributions for the design of clarifiers
Authors: Silveston P. L. , Stepko W. A. , Sakata N. , Cordoba‐Molina J. F. , Rietema K. , Hudgins R. R. 
Published: March 2009

AbstractUse of residence time distributions (RTD's) for the design of clarifiers proposed by the senior author in 1969 and by others has been found to be based on flow pattern assumptions which are false. Since the residence time distribution depends upon the density of the feed to the clarifier, flow rate and other near‐intangibles, it is not possible to obtain RTD's which pertain to an operating settler from which reliable performance may be predicted. Finally, laboratory studies demonstrate that the combination of RTD's and quiescent settling data do not reliably predict clarifier performance.
An analysis of the viscous behaviour of polymeric solutions
Authors: Carreau P. J. , Kee D. De , Daroux M. 
Published: March 2009

AbstractViscosity data of an aluminum soap solution, a polyisobutylene solution, a polyacrylamide solution, and ten polystyrene solutions have been analysed using two rheological models: the Carreau model A and the Ellis model. The model parameters were obtained by non‐linear regression. The importance of the zero‐shear viscosity for design purposes is illustrated by observing the appearance of a master curve in the representation of the dimensionless viscosity versus the product of the zero‐shear viscosity by the shear rate. A linear relation is shown to exist between the logarithm of the zero‐shear viscosity and the polymer concentration. It is asserted that either model should replace advantageously the commonly used power‐law expression.
Absorption of oxygen by aqueous sodium sulphite solutions
Authors: Sathyamurthy N. , Degaleesan T. E. , Chandrasekharan K. , Laddha G. S. 
Published: March 2009

AbstractNew data have been reported on the absorption of oxygen by aqueous sodium sulphite solutions with cobalt sulphate as catalyst at 30°C. It is observed that the absorption rate increases up to a critical sulphite concentration beyond which the absorption rate becomes constant and this critical concentration varies with the catalyst concentration. The order of reaction with respect to sulphite and oxygen in the constant absorption rate regime was found to be zero and two respectively. The absorption rate is affected by the total ionic strength (sulphite and sulphate) in addition to the effect of pH and catalyst concentraion. The reported data were also analysed to ascertain the effect of temperature and a relationship has been proposed for prediction of the second order reaction rate constant.
Corrosion product transport in water‐cooled nuclear reactors. Part III: Boiling water with indirect cycle operation
Authors: Burrill K. A. 
Published: March 2009

AbstractCorrosion products from out‐core surfaces are made radioactive when deposited in the core of a water‐cooled nuclear power reactor. Their release and deposition on out‐core surfaces causes gamma radiation fields to grow with time around these surfaces.Deposition and release of corrosion products in the reactor core is strongly influenced by the mode of heat transfer and by the water chemistry. Here, the deposition of corrosion products from boiling water onto nuclear fuel sheaths was studied in a water loop and in the CANDU Nuclear Power Demonstration (NPD) reactor as a function of possible water chemistries for indirect cycle operation. Deposits on sheaths in the boiling water region of test sections were very heavy (35 g Fe/m2) when ammonium hydroxide at 10 to 20 mg NH3/kg controlled the pH, or when the pH was controlled with 0.02 mg Li/kg added as LiOD. Deposits were light (∽ 50 mg Fe/m2) if the pH was controlled with at least 1 mg Li/kg. A mathematical model for deposition and release of corrosion products at fuel sheaths in non‐boiling water was modified and found to apply also in boiling water for the high pH test.
Metal recovery from coal ash via chlorination — A thermodynamic study
Authors: Mehrotra Anil K. , Bishnoi P. R. , Svrcek W. Y. 
Published: March 2009

AbstractCoal ash can become an important mineral substitute for the recovery of several metals, especially aluminum and titanium. A plausible route for the recovery could be via high temperature chlorination in the presence of a reducing agent. The thermodynamics of the reaction system for the free energy computations consisted of 135 chemical species containing 12 elements, namely Al, C, Ca, CI, Fe, K, Mg, Na, O, S, Si and Ti. The results indicate that the chlorination route is feasible over a wide temperature range.
Comparison of the product distribution in the catalytic cracking of dewaxed neutral distillate over lanthanum‐exchanged X and Y type zeolites
Authors: Yeh Jer‐Jeng , Wojciechowski B. W. 
Published: March 2009

AbstractA comparison of the selectivity for minor products formed from the same feedstock on LaX and LaY has shown that the two catalysts differ very little in their conversion of the feed. There is, however, a marked difference between the two catalysts in their activity toward short chain product olefins. These are rapidly saturated, cracked or turned to coke by the X catalyst.