bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vapor‐liquid equilibria in the argon‐methane system
Authors: Gravelle Denis , Lu Benjamin C. ‐Y. 
Published: March 2009

AbstractVapor‐liquid equilibrium compositions have been measured for the argon‐methane system at 115.2°, 123.4° and 137.1°K, by means of a forced‐recirculation apparatus. A modified Redlich‐Kwong equation of state with the incorporation of a binary interaction constant has been successfully employed to represent the data. Liquid activity coefficients have been evaluated and correlated.
Dense phase vertical pneumatic conveying
Authors: Capes C. E. 
Published: March 2009

AbstractVertical pneumatic conveying was studied in a 3‐in. I.D. line, nineteen feet in length. Experiments were performed in both the empty line and in the line containing screen packing. Whereas in the conventional empty line choking occurs as the gas velocity is decreased, stable operation was possible in the screen packed line from the dilute conveying region down through the dense phase conveying region to the fluidizing region. A theoretical treatment proposed by Leung et al. to describe vertical transport of solids by liquids was used to predict the pressure drop/gas velocity relationship reasonably well for the screen packed line. Indications were obtained that the same equations may also be applied to conventional vertical pneumatic conveying in an empty line.
Two‐phase slug flow in horizontal and inclined tubes
Authors: Vermeulen L. R. , Ryan J. T. 
Published: March 2009

AbstractSlug flow in the air‐water system near atmospheric pressure was studied in a one‐half inch diameter tube. Measurements of flow characteristics, pressure gradient, pressure fluctuations, slug velocity and frequency were made for horizontal and inclined flow.A semi‐empirical theory based on a simple model was developed. Pressure losses calculated from this theory require a priori knowledge of the slugging frequency. A comparison of the prediction of the theory and two published correlations shows that the proposed theory gives better agreement with the data.
Friction factors for a tube rotating about its own axis
Authors: Harvey P. H. , Nandapurkar S. S. , Holland F. A. 
Published: March 2009

AbstractExperiments have been carried out to determine pressure drops and flow patterns for fluids flowing through a tube rotating about its own axis. A newly developed pressure tap enabled the determination of pressure drops between two points in a rotating tube. The effect of rotation is to increase the friction factor in the laminar flow region and to decrease it in the turbulent flow region. Rotation also tends to suppress turbulence and to extend the laminar flow region to higher Reynolds numbers.
Experimental studies of interphase mass transfer with chemical reaction — Saponification of esters
Authors: Seto P. , Johnson A. I. , Hamielec A. E. , Furter W. F. 
Published: March 2009

AbstractThis study concerns the transfer of ethyl acetate from a supernatant still liquid into a lower layer of caustic solution in which a saponification reaction occurs. Apparatus and techniques for measuring the concentration profiles which develop in the turbulent reaction layer in the aqueous phase at the liquid‐liquid interface are described. In particular, the effects of turbulence on the reaction layer propagation, the reaction zone in the turbulent layer, and the concentration distribution of various components of the system were observed and measured. From these data, mass transfer rates and enhancement factors were deduced. The effects of turbulence in the aqueous phase were presented in terms of an eddy diffusivity model.
Laminar‐flow non‐newtonian heat transfer in flattened tubes
Authors: Oliver D. R. , Karim R. B. 
Published: March 2009

AbstractIt is shown experimentally that flattened tubes give higher laminar‐flow heat transfer coefficients than tubes of circular cross‐section. Part of the increase is due to an increase in the tube‐wall shear rate; the magnitude of this effect is predicted and checked by reference to the behaviour of Newtonian liquids. The other part is due to secondary flow patterns which develop in viscoelastic liquids; this effect is at a maximum when the aspect ratio of the tube cross‐section is of the order 1.5:1. The first effect may increase heat transfer coefficient by over 90% and the latter by over 45%.
H2S promoted oxidative dehydrogenation of ethane
Authors: Gaspar N. J. , Pasternak I. S. 
Published: March 2009

AbstractIn the H2S promoted oxidative dehydrogenation of ethane to ethylene, high once through conversions and selectivities (˜ 90%) have been achieved. This is due to the abstraction of hydrogen from ethane by active sulphur produced by the “in situ” reaction between H2S and O2 in the presence of a suitable catalyst. The extensive catalyst screening programme carried out to achieve the above results is described. The effect of processing conditions, e.g. temperature, space velocity and diluent type and amount, using one of the better catalysts found, i.e. cadmium on alundum is discussed.
Cyclic operation of a fixed bed ion exchange process: Experimental and computer simulation studies
Authors: Tan K. S. , Spinner I. H. 
Published: March 2009

AbstractA quantitative study of cyclic fixed bed processes has been applied to binary and ternary ion exchange systems of general forms of isotherms. Mathematical models for simulating the cyclic operation are developed. Experimental results obtained from binary sodium‐calcium and ternary synthetic sea water systems are compared with the calculated results. In general, the agreement is very satisfactory. A significant aspect of this study is that all transport and equilibrium properties used in the column dynamics calculations are determined from independent estimates or measurements, without the use of column data. The good agreement between the experimental and calculated results indicates that a suitable mathematical model can be very useful for the engineering design and application of cyclic fixed bed processes.
Compressibility factor of sour natural gases
Authors: Wichert Edward , Aziz Khalid 
Published: March 2009

AbstractThis paper presents a comparison of twelve selected methods for the prediction of the compressibility factor of natural gases containing H2S and CO2. The methods are compared with experimental data from the published literature and with previously unpublished data made available by oil and gas companies operating in Alberta. The method of Robinson, Macrygeorgos and Govier, and the method of Robinson and Jacoby are found to be most accurate over the range tested here. A brief desription of the twelve methods considered is also presented.Three new methods are also proposed. Two of the proposed methods are modifications of the Pitzer method and the Redlich‐Kwong equation of state. These methods are suitable for digital computer applications. The third method proposed here is developed for hand calculations. The new methods presented here are superior to the twelve methods tested in this study.
Optimal operation of a batch packed distillation column
Authors: Keith F. M. , Brunet J. 
Published: March 2009

AbstractOptimal policies for a batch packed distillation unit are examined for the cases of variable reflux ratio and variable boilup rates. This work was to act as a follow‐up to Converse's work(1) for a batch plate distillation column with variable reflux policy. For the cases studied, it would seem that the boilup rate optimal policy yields better performance for the still than the reflux ratio optimal policy. The results of the present analysis and those of other authors seem to indicate that more effort should in the future be devoted to new modes of operation rather than to various refinements of the model used in the present and past studies. The present exploratory work seems to support the need for further studies using a packed rectifying section with variable boilup policy along with a novel mode of operation such as that considered by Mayur et al,(6).
A vertically oscillating sphere viscometer
Authors: Ray H. S. , Biswas A. K. 
Published: March 2009

AbstractAn apparatus, devised to measure the viscosities of relatively viscous liquids, is described. The device involves the motion of a sphere oscillated forcibly in the liquid with the help of an external driving mechanism. A theoretical analysis shows that the frequency and the amplitude of forced oscillation are independent of the density of the liquid and are solely determined by the viscosity for very viscons liquids. When the viscosity is sufficiently high, a completely developed laminar flow may be assumed at all stages of the motion. Under these conditions, the peak amplitude for resonance is suggested as a direct measure of viscosity.
Coalescence of an emulsion in a fibrous bed: Part I. Theory
Authors: Sherony D. F. , Kintner R. C. 
Published: March 2009

AbstractA model of a fibrous bed coalescer is presented which relates the collision frequency between particles and fibers to the overall coalescence frequency. The model will predict the ratio of outlet to inlet particle number densities (Y) and takes into account the mean inlet particle size, mean fiber size, void fraction of the bed, superficial velocity through the bed, degree of bed saturation, and bed length. The ratio of outlet to inlet particle number density, in terms of these parameters, is given by\documentclass{article}\pagestyle{empty}\begin{document} \[Y = \exp \left\{{- \frac{{3(1 - \in)S(1 + d_{10} /d_f)}} {{4d_f (1 - S)}}\eta _e L} \right\} \] \end{document}where η is defined as the coalescence efficiency and varies between 0 and 1 with the fiber Reynolds number.
Coalescence of an emulsion in a fibrous bed: Part II. Experimental
Authors: Sherony D. F. , Kintner R. C. 
Published: March 2009

AbstractA model of a fibrous bed relating the ratio of the outlet and inlet particle number densities to the various system parameters is tested experimentally. The degree of bed saturation is also determined from single phase and two phase flow data. The inlet and outlet particle number densities are determined by light scattering. It was found that the model does predict the effect of particle size, fiber size, bed length, and degree of saturation consistent with experimental observations. However, the coalescence efficiency based upon aerosol filtration theory is not amenable to the fibrous bed over the widest range of flow velocities.
General mathematical models of transport processes with and without chemical reactions
Authors: Chung Benjamin T. F. , Fan L. T. , Hwang C. L. 
Published: March 2009

AbstractBased on the surface renewal and penetration concept, a number of fairly general mathematical models for transport systems without chemical reaction or heat generation and transport systems with zero and first order reactions have been developed. Solutions of the governing transport equations are presented for cases in which the number of capacitors of the multiple capacitance age distribution is finite or infinite. Some of their limiting solutions are reduced to those proposed by the previous investigators.
Residence time distributions in short tubular vessels
Authors: Veeraraghavan S. , Silveston P. L. 
Published: March 2009

AbstractThe results of an experimental study of the influence of vessel dimensions and fluid velocity on residence time distributions (RTD's) are presented. Length to diameter ratio (L/D) exerts the major influence on the RTD for the range of sizes and velocities studied. At L/D ≤ 2.6, the RTD resembles the response of a well stirred vessel with by‐passing to a pulse signal. Both Reynolds No. (NRe) and nozzle to vessel diameter ratio (d/D) effect the RTD. At L/D ≥ 5.2, the RTD resembles the response of stirred tanks in series to a pulse. NRe and d/D do not effect the RTD and can be neglected for scale‐up. The second and third moments of the RTD's and parameters of a finite stage model fitted to the RTD relate qualitatively to L/D, d/D and NRe, but neither the moments or the particular finite stage model used are satisfactory for quantitative correlations.
A correlation for predicting liquid viscosities of petroleum fractions
Authors: Abbott M. M. , Kaufmann T. G. , Domash L. 
Published: March 2009

AbstractA correlation has been developed for estimating the liquid viscosities of petroleum fractions at 100°F and at 210°F. When used with the ASTM viscosity chart (or its analytical equivalent), the new correlation provides a method for the prediction of viscosity‐temperature behavior of fractions from the Watson characterization factor and specific gravity. Essentially an extension of an API Data Book viscosity nomograph, the proposed correlation substantially improves on the accuracy and increases the range of applicability of this method. Greatest accuracy is achieved for petroleum fractions in the kerosene to heavy gas oil range, although acceptable accuracy for most engineering calculations is also obtained for lube oils and for many complex pure heavy hydrocarbons.
Simulation of the transient behavior of complex chemical plants using a modular approach
Authors: Bobrow S. , Ponton J. W. , Johnson A. I. 
Published: March 2009

AbstractA general computer program for modeling the dynamic behaviour of complex plants is described. Given the name DYNSYS, this program permits computation modules to be written for the various plant units, incorporating the differential equations describing their dynamic behaviour, then uses an Adams‐Moulton‐Shell integrating procedure. Process lags are also handled by the system.Computation modules for control devices, such as a standard three mode controller, can be incorporated into the system. The program has been operated in both a batchwise and interactive mode using the CDC6400 computer.The application of DYNSYS to the modeling of two chemical process units is discussed: a liquid‐liquid extraction unit for recovering butadiene in a synthetic rubber plant; and the modeling of a chlorine compressor system.
An optimal operating policy for a liquid‐liquid extraction column
Authors: Pang K. H. , Johnson A. I. 
Published: March 2009

AbstractThis paper is concerned with the policy to be followed when changing the product produced from a small liquid‐liquid extraction column from one desired composition to another. The grade control policy developed minimizes the production of off‐grade material, or allows the material produced during the change‐over period to have a desired average composition. Such policies are believed important in operating multiproduct plants in Canadian chemical industry, where product changes are frequent.A linear dynamic mathematical model for the extraction column was derived from a previous frequency response study of a laboratory scale unit. The technique used in solving the optimal control problem is based on the minimum principle and a modified Riccati transformation.
The experimental determination of velocity profiles in smooth falling liquid films
Authors: Cook R. A. , Clark R. H. 
Published: March 2009

AbstractA new photographic technique using tracer particles is described for measurement of the fluid velocity distribution in falling liquid films. The distribution for fully‐developed ripple free flow was measured with a precision of 1% for velocity and 4 microns for depth and was found to follow the theoretical Nusselt equation …

over the Reynolds number range 75–250 where the Reynolds number is defined as the ratio of the peripheral mass flow rate to the viscosity.The technique is also applicable to flow close to any smooth reflecting planar boundary.
Gas holdup in a bubble column containing organic liquid mixtures
Authors: Bhaga D. , Pruden B. B. , Weber M. E. 
Published: March 2009

AbstractSome anomolous observations of the gas holdup behaviour in binary organic liquid mixtures in a bubble column are reported in this note, to supplement the recently published data(1). The gas holdup was higher for mixtures of organic liquids than for either pure component. It is shown that none of the existing theories fully explains the data.
Dissolution of copper scrap in hydrochloric acid
Authors: Rigg Tyson , Marflitt William 
Published: March 2009

AbstractThe dissolution of copper scrap has been investigated as a possible approach to the production of copper chloride solutions for certain metallurgical purposes. The principal stages involved in the dissolution have been found to be (1) diffusion‐controlled attack of cupric ions on the surface of the copper, and (2) re‐oxidation of cuprous ions by oxygen. The effects of chloride concentration, acidity, temperature, agitation, metal surface area and oxygen partial pressure are described.
Convergence promotion in the simulation of chemical processes with recycle‐the dominant eigenvalue method
Authors: Orbach O. , Crowe C. M. 
Published: March 2009

AbstractA new method, called the dominant eigenvalue method, is described for promoting the convergence of iterative computations of non‐linear problems, such as chemical processes with recycle. The method is based upon the observation that most iterations eventually approach a geometric progression. In the derivation it is assumed that the iteration can be approximated by a linear matrix difference equation,

The iteration continues until the largest eigenvalue of A dominates the solution. It may be used to extrapolate toward the solution before resuming the iteration.The method is applied to the steady‐state simulation of two chemical processes, an alkylation plant and a distillation column. The computation time was reduced by up to a factor of four.
Stability of chemical reactors in the presence of sustained disturbances
Authors: Seborg Dale E. 
Published: March 2009

AbstractA general method is developed for constructing regions of practical stability for nonlinear lumped‐parameter systems. The region of practical stability serves as a bound on the system response for a general class of magnitude‐constrained disturbances. The construction method is based on a modified Liapunov approach but is not restricted to a particular type of Liapunov function. The method is applicable to higher order systems in which several disturbance variables are present. Numerical results are presented for a CSTR with magnitude‐constrained disturbances in feed composition and feed temperature.
Thermophoretic acceleration of particle deposition from laminar air streams
Authors: Fulford G. D. , Moo‐Young M. , Babu M. 
Published: March 2009

AbstractA preliminary study is reported of the use of temperature gradients to accelerate the deposition of small particles from laminar air streams. It is shown that appreciable effects can be obtained even with small temperature gradients and particles as large as 30 μm. An empirical correlation is proposed for the thermophoretic force based on the present results and those published previously for smaller particles.
Further studies on momentum dissipation of grid jets in a gas fluidized bed
Authors: Behie L. A. , Bergougnou M. A. , Baker C. G. J. , Base T. E. 
Published: March 2009

AbstractFour experimental aspects of momentum dissipation of grid jets in a gas fluidized bed of cracking catalyst are reported. First, an investigation was made into the radial distribution of axial momentum for air jets issuing from vertical long nozzles into a minimally fluidized bed. The theory of Abramovich was compared with these experimental results. Second, data on the distribution of axial momentum along the axis for vertical air jets issuing from single and multi‐hole grids were compared with previous work. Third, the axial dissipation of vertical air jets loaded with fluid cracking catalyst issuing into air and also into a fluid bed was studied. Finally, the shape of the boundary of a jet dissipating into a fluid bed was compared to that given by theory.
Measurement of yield stress of fluid‐like viscoplastic substances
Authors: Vocadlo Jaroslav J. , Charles Michael E. 
Published: March 2009

AbstractThe concept of the yield stress of a fluid is discussed and the principle methods which have been used to evaluate it are critically reviewed. It is shown that many factors can influence the determination of this parameter. Most of the existing methods determine some property near an interface or wall rather than the actual yield stress value which is a physical property of the fluid itself. A procedure and technique for measuring the actual yield stress of a substance is suggested which seems to eliminate most of the shortcomings of other methods.
Withdrawal of cylinders from non‐newtonian fluids
Authors: Roy Subhash C. 
Published: March 2009

AbstractThe cylinder withdrawal theory for power‐law fluids proposed by Tallmadge has been compared with continuous withdrawal data in this work. Calculated withdrawal speeds differ greatly from measured values, although Tallmadge's gravity‐corrected theory for Newtonian fluids is in agreement with the present data on Newtonian fluids.Correlations similar to that of Goucher and Ward have been developed with the experimental data over a 400‐fold range of dimensionless withdrawal speeds. These correlations are applicable for prediction of non‐Newtonian liquid film thicknesses on vertical wires and also apparently for viscoelastic fluids like CMC solutions, but are not applicable for inelastic fluids like Carbopol 934.
Mass transfer in liquid‐liquid (horizontal) pipeline contactors
Authors: Shah A. K. , Sharma M. M. 
Published: March 2009

AbstractThe mass transfer characteristics of liquid‐liquid (horizontal) pipeline contactors were studied for the bubble and plug flow regimes. The contactors were operated co‐currently. The theory of mass transfer with chemical reaction was used to obtain values of physical mass transfer coefficient (kLa) and effective interfacial area (a) for a number of systems. In all the experiments the resistance to mass transfer was confined to the continuous phase. The effect of the flow rates and viscosities of the two phases, interfacial tension, contactor length, pipe diameter, the presence of solids, etc. on both, kLa and a was studied. The values of kLa and a were found to vary from 1 to 50 × 10−3 sec−1, and 0.4 to 25 cm−1, respectively.
Removal of organic sulphur from coal gas
Authors: Bhatia S. P. 
Published: March 2009

AbstractOrganic sulphur compounds present in coal gas containing 15‐20% CO were effectively converted into H2S over a “Nimox” (nickel‐molybdenum) conversion catalyst. H2S was effectively removed by “Luxmasse”, a prepared iron oxide. The overall removal of organic sulphur depended upon the concentration of thiophene present. With only 10 ppm thiophene in the gas, the conversion of organic sulphur was 97% at 350°C after a single treatment. With six‐stage treatment at 350 psig, the final gas contained only 0.2 ppm total organic sulphur in the presence of 4‐5% water vapor.
Effect of temperature on the rates of dissolution of gibbsite and boehmite
Authors: Scotford R. F. , Glastonbury J. R. 
Published: March 2009

AbstractThe effect of temperature on the rate of dissolution of gibbsite and boehmite in caustic soda solutions was studied in the temperature range 25‐100°C. The results fitted the Arrhenius rate equation and the activation energy was found to be 30.6 ± 0.9 k. cal/g‐mole for the gibbsite reaction and 29.4 ± 1.3 k. cal/g‐mole for the boehmite reaction. While the effect of temperature on the boehmite dissolution has not been reported before, the value of the activation energy for gibbsite was higher than previously reported values. Reasons for these differences are given and a consistent value of the activation energy was obtained which agreed both with experimental data for different gibbsite samples and with modified forms of the previously published data.