bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of lead in chemical and metallurgical plant construction
Authors: Turner A. , Wellington J. R. , Williams L. 
Published: February 2011

AbstractThe use of lead in the chemical and metallurgical operations at Trail, B.C. is described.A wide variety of corrosive environments are encountered, including phosphoric and sulphuric acids, sulphur dioxide, fluorides, and ammonium sulphate. It is found that except in the presence of fluorine compounds, 6% antimonial lead is more resistant to corrosion than is soft lead.The mechanical properties of lead are reviewed with particular reference to its high specific gravity, low mechanical strength, creep and fatigue properties. Principles of plant design to give adequate support, to provide for thermal expansion and contraction, and to minimize the effects of creep and fatigue are enunciated, and illustrated by proven designs that have given long periods of satisfactory service.
The pyrolysis of a heavy crude oil in a fluidized bed
Authors: Madgwick G. G. , Amberg C. H. , Peterson W. S. 
Published: February 2011

AbstractThe pyrolysis of a heavy high sulphur crude oil in an inert fluidized bed at temperatures between 550 and 800°C. has resulted in the production of an olefin rich gas and a liquid product containing increasing amounts of aromatic material with increasing temperature.Analysis of the process gas has shown that for average reactor residence times of more than one second, equilibrium is approximated for the system ethane‐ethylene‐hydrogen. There is considerable scatter in the data for the analogous system propane‐propylene‐hydrogen but for most conditions a significant deviation from equilibrium exists.The sulphur compounds in the light oil were of thiophenic character. The ratio of 2‐ to 3‐methylthiophene in the toluene fractions was examined.
The effects of shape and reynolds number on drag in the motion of a freely oriented body in an infinite fluid
Authors: Becker H. A. 
Published: February 2011

AbstractThe drag on freely oriented bodies in motion relative to an infinite fluid is related to the Reynolds number, ReS, by the formulaK = 24ReS + CIRes2where Res = DsuOρ/μ is formed from the diameter, Ds, of a sphere with the same surface area as the body, and K = 8ρFD/πμ2 is defined as the drag number. The inertial drag coefficient, Cl, is related to shape, orientation, and the Reynolds number. At Reynolds numbers above 2000 the relation is expressed by the formula,Cl = 2.53 − 0.283e2Ψwhere Ψ, the surface sphericity, is the ratio of the surface area of a sphere with the same volume to the gurface area of the body. Correlations are also developed for predicting Cl at Reynolds numbers below 2000.
Sodium hydroxide‐sodium sulphate stripping of uranium from amine extracts
Authors: Bellingham A. I. , Simard R. 
Published: February 2011

AbstractBatch shake‐out tests on two tertiary amines and one secondary amine to determine the effects of sodium sulphate concentration and pH on the distribution of uranium between 0.1N amine in kerosene and aqueous sodium sulphate solution showed that transfer of uranium from the solvent to the aqueous phase was favored by increasing pH values up to 5.5 and by increasing the aqueous sodium sulphate concentration up to 20% w/v Na2SO4.Continuous counter‐current stripping of tri‐isooctylamine (TIOA) extracts with 20% w/v Na2SO4 was also carried out in a three‐stage mixer‐settler arrangement in which the pH was controlled by the addition of 10% NaOH to the three stages. Further addition of caustic to the separated aqueous strip solution to raise the pH to 7.0–7.2 yielded a high grade uranium precipitate (88% U3O8). The continuous testing confirmed the results of the shake‐out tests and showed that the procedure gave results comparing favorably with other stripping methods accompanied by a lower overall reagent cost.
Performance of flow reactors at various levels of mixing
Authors: Cholette A. , Blanchet J. , Cloutier Léonce 
Published: February 2011

AbstractChemical flow reactors studied include models in which partial mixing and piston flow are present and others which involve partial mixing and short‐circuit. Mixing levels considered extend all the way between the extreme cases of tubular and continuous‐stirred tank reactors. Various orders of reaction are taken into account.The curves presented, obtained through analytical methods, show either the variation of conversion with mixing level at given values of residence time, or relative residence times for a given conversion. Graphical methods of solution are proposed. They involve, in part, a means of computation whereby the overall conversion for a number of reactors in series is obtained from the individual conversions.While isothermal conditions only have been considered, more interesting results are expected when other conditions are applicable, whether isothermal or not.
Evaporation of stationary droplets in high temperature surroundings
Authors: Hoffman T. W. , Gauvin W. H. 
Published: February 2011

AbstractAn experimental study of the rate of evaporation of stationary droplets of water, methanol, cumene, pentane and benzene was carried out in an electrically‐heated 9‐inch stainless steel sphere. The gaseous environment consisted of the superheated vapor of the liquid under investigation and, in all cases, the wall and gas temperatures were the same. Drop diameters ranged from 0.4 to 1.4 mm., and temperatures from 100°C. to 550°C.The evaporation rate of stationary droplets in high temperature surroundings does not appear to be governed by the rate of heat transfer by natural convection, since no dependency of the Nusselt Number on the Grashof Number was found. Attempts to correlate the results on the basis of Godsave's model (conduction across the boundary layer controlling) or Spalding's modified approach to the latter were equally unsuccessful. The experimental evaporation rates could, however, be very satisfactorily correlated in terms of Spalding's Transfer Number B.The correlation obtained indicates that the mechanism of the evaporation process is governed by the effect of the evolved vapors on the boundary layer flow.
The horizontal pipeline flow of equal density oil‐water mixtures
Authors: Charles M. E. , Govier G. W. , Hodgson G. W. 
Published: February 2011

AbstractThe horizontal flow of equal density oil‐water mixtures was investigated in a 1‐inch diameter laboratory pipeline. Oils of viscosities 6.29, 16.8 and 65.0 centipoise were used in the experiments. Flow patterns, holdup ratios and pressure gradients were investigated for a range of superficial oil velocity from 0.05 to 3.0 ft./sec. and a range of superficial water velocity from 0.1 to 3.5 ft./sec, with input oil‐water ratios ranging from 0.1 to 10.0.Similar series of flow patterns were observed for each oil and were found to be largely independent of the oil viscosity. At high oil‐water ratios oil formed the continuous phase and a water‐drops‐in‐oil regime was noted. As the oil‐water ratio was decreased the flow patterns concentric oil‐in‐water, oil‐slugs‐in‐water, oil‐bubbles‐in‐water and oil‐drops‐in‐water in which water was the continuous phase were observed. The most viscous oil did, however, exhibit anomalous behavior at low superficial water velocities and this is attributed to different interfacial properties.The pressure drops measured indicated that for a given oil flow rate the pressure gradient was reduced to a minimum by the addition of water provided that the oil was not in turbulent flow. Maximum pressure gradient reduction factors varied from 1.7 for the 6.29 centipoise viscosity oil to 10 for the 65.0 centipoise viscosity oil at input oil‐water ratios of 4.5 and 1.0 respectively.
The upward vertical flow of oil‐water mixtures
Authors: Govier G. W. , Sullivan G. A. , Wood R. K. 
Published: February 2011

AbstractThe upward vertical flow of oil‐water mixtures has been investigated in a 37‐ft. length of cellulose acetate butyrate tubing of inside diameter 1.038‐in. Flow pattern, holdup and pressure drop data were obtained for water mixtures with 0.936, 20.1 and 150 centipoise oils at superficial water velocities ranging from 0.10 to 10.0 ft./sec.The oil‐water mixtures exhibited a behavior similar to that of air‐water mixtures studied previously. The flow patterns observed at constant superficial water velocity with increasing oil‐water ratio were: drops of oil in water, slugs of oil in water, froth, and drops of water in oil. Holdup of the phase forming the continuous medium was observed but to a much lesser extent than with the air‐water system. Curves of pressure drop versus oil‐water ratio exhibited a minimum, a maximum and a second minimum at low water velocities; a single minimum at intermediate water velocities; and a steady increase at superficial water velocities above about 5 ft./sec.A friction factor based upon the properties and the superficial velocity of the water is correlated with the superficial velocity of the oil and a Reynolds number based on the properties and superficial velocity of the water. This shows that the pressure drop due to friction and other irreversibilities is essentially independent of the viscosity of the oil except under conditions where the oil is the continuous phase.
Dynamic behavior of a continuous stirred‐tank reactor
Authors: Kermode Richard I. , Stevens William F. 
Published: February 2011

AbstractSolution of the non‐linear differential equations of a continuous flow stirred‐tank reactor, with a first‐order reacting system, has been accomplished by the use of the analog computer. The three common modes of control have been programmed on the computer and, while controlling temperature or composition by means of the adjustment of cooling water flow rate, the regions of stability have been determined for various values of the controller constants. These results have been compared to those obtained by applying the root‐locus method to the linearized forms of the differential equations previously derived.
Spherical agglomeration of solids in liquid suspension
Authors: Farnand J. R. , Smith H. M. , Puddington I. E. 
Published: February 2011

AbstractThe process of spherical agglomeration provides a method for making rapid and efficient separations of solids from liquid suspensions. Because preferential wetting of the solid surface by a second liquid, which acts as a bridging agent between the particles, is a basic requirement of the operation, a novel method for the separation of multi‐component solids becomes available. The procedure is also useful in the breaking of emulsions through the addition of a finely divided solid, the surface of which is repellent to the continuous phase and wetted by the emulsified phase. The process operates equally well in aqueous or in organic media. A number of illustrative examples are given.
Heat‐transfer to high‐quality steam‐water mixtures flowing in a horizontal rectangular duct
Authors: Davis E. J. , David M. M. 
Published: February 2011

AbstractHeat transfer and pressure drop were investigated for steam‐water mixtures flowing in an electrically heated horizontal duct of rectangular cross‐section. The investigation was primarily concerned with the region of high vapor fractions and mass flow rates, where two‐phase convention‐controlled heat transfer predominated.The experimental data were found to be in good agreement with those of other studies in which circular tubes were used. The data in the convection‐controlled region were correlated by equations developed from two flow models, a separated‐annular model and a homogeneous model.Two phase pressure drop data were correlated satisfactorily by the Lockhart‐Martinelli correlation.
Fluid friction and heat transfer in cylindrical pipes: Relationship between lumped and distributed parameters
Authors: Smith Julian C. 
Published: February 2011

AbstractPhysical phenomena may be described from the “microscopic” point of view, in terms of distributed parameters, or from the “macroscopic” viewpoint, using lumped parameters. Engineering correlations almost always involve lumped parameters. A lumped parameter is equal or proportional to some average value of the corresponding distributed parameter. Like any average quantity it gives no information regarding the form of the distribution. The use of lumped parameters therefore requires some assumptions, expressed or implied, regarding the form of the distribution within the system.The characteristic lumped parameters used in problems of heat transfer and fluid friction are overall or average fluxes of heat energy or momentum, arbitrarily defined as described in this paper. Common dimensionless groups, such as f, NBe, NSt and others are ratios of these energy or momentum fluxes. Such dimensionless groups, since they are ratios of lumped parameters, are themselves lumped parameters. In their definition, therefore, several assumptions regarding the distributions of velocity and temperature are implicit. When these assumptions are not valid, correction factors such as diffusivity ratios or length‐to‐length ratios are needed to allow for deviations from the distributions used for reference.Using this approach the form of empirical equations becomes easy to predict. Dimensional analysis is not needed. In addition, this approach suggests that some accepted correlations may contain weaknesses not predicted by other methods.
Mass transfer with and without chemical reaction
Authors: Marangozis J. , Johnson A. I. 
Published: February 2011

AbstractRates of dissolution of cast solids in a baffled agitated vessel were obtained for the systems: Benzoic acid‐water, o‐salicylic acid‐water, benzoic acid‐22.5% acqueous glycerol and benzoic acid‐41% aqueous glycerol. A new continuous technique was developed for the measurements, and the data were empirically correlated by the method of least squares with the equationwith a mean deviation of ± 5.8%.The present data agreed qualitatively with the predictions of the turbulent boundary layer theory.Reaction factors,kL/kL°, were also measured in the agitated vessels for the systems: Benzoic acid‐aqueous sodium hydroxide solutions, benzoic acid‐aqueous potassium hydroxide solutions, and o‐salicylic acid‐aqueous sodium hydroxide solutions. The data were found to depend strongly on the ratio of the reactant concentrations,CB/CA6, in a manner quantitatively predicted by the boundary layer theory corrected for ion‐diffusion effects.Reaction factors were also measured in diaphragm‐type diffusion cells for the system benzoic acid‐sodium hydroxide. The results provided quantitative support for the ion‐diffusion theory in a stagnant film.
An analysis of spray evaporation in a high‐temperature environment: I. Radiant heat transfer to clouds of droplets and particles
Authors: Hoffman T. W. , Gauvin W. H. 
Published: February 2011

AbstractThis series of papers presents an analysis of the rate of evaporation of a spray which is injected into a cylindrical column, the walls of which are maintained at a high temperature. The method is an extension of the Hottel‐Cohen analysis of the radiant heat transfer to an absorbing gas of non‐uniform temperature1 and permits the calculation of the magnitude and distribution of the heat flux at the wall.The present paper discusses the difficulties inherent in the calculation of the absorption of thermal radiation by clouds of particles suspended in an absorbing gas medium. Approximations to the intractable exact solution are made to permit the calculation of the absorption strength of spray from operating conditions and the properties of the atomized liquid.The various reception factors for the cylindrical system have been accurately determined as a function of the combined absorption strength of spray and medium. The use of these factors in the present system is discussed.
Prefabricated plastic piping
Authors: Nenniger E. 
Published: February 2011

AbstractThis paper describes some procedures used to design and develop prefabricated plastic pipe for a chemical plant installation. Two aspects of this design are: (a) Stresses in mitred elbows; (b) Flange reinforcing. It has been found that the only stress resulting from internal static pressure on a mitred pipe joint is that of pure tension. The most satisfactory method of flange reinforcing involves the use of a steel backing ring. The ring tends to reduce the bending stresses on the flange to a minimum and facilitates the working at higher static pressures.
On optimal adiabatic reactors of combined types
Authors: Aris Rutherford 
Published: February 2011

AbstractSome fairly general considerations arising out of the work of Cholette and Blanchet on combined stirred tank and tubular reactors are here presented. General analytical and graphical conditions for the optimality of the MT combination are given and it is shown that, save for autocatalytic reactions, the combination is only optimal for sufficiently exothermic reactions. The proportions of the optimal combined reactor can be readily calculated and it is shown that the stirred tank design is always stable. A circumstance under which the TM combination is optimal is also suggested but it is thought to be of rare occurrence.
Laminar heat transfer of power‐law non‐Newtonian fluid—the extension of Graet‐Nusselt problem
Authors: Tien Chi 
Published: February 2011

AbstractThe asymptotic solutions of the classical Graetz‐Nusselt Problem is extended to the case of power‐law non‐Newtonian fluid flowing between parallel plates. Expressions are given for the eigen value, eigen functions and its related expressions, average temperature and Nusselt modulus.
Approximation methods to evaluate the effect of axial dispersion in isothermal flow reactors
Authors: Houghton Gerald 
Published: February 2011

AbstractTwo quasi‐analytical methods are given for the approximate solution of the nonlinear differential equation governing the effect of longitudinal dispersion on the concentration profile in an isothermal flow reactor with reaction orders other than zero or first. The first method converts the nonlinear differential equation and its boundary conditions into a nonlinear integral equation which is solved by iteration, while the second method generates approximate solutions by considering axial dispersion as a perturbation on the reaction kinetics. By using the perturbation method a dimensionless group has been generated that is characteristic of the interaction between axial diffusion and reaction kinetics. It is also demonstrated that an axial dispersion coefficient characteristic of Taylor diffusion can be applied in the presence of a reaction of any order and that the effect of depletion of concentration by chemical reaction is to aid in the reduction of radial concentration gradients.
The dynamics of the expanding vapor bubble in a boiling liquid
Authors: Savic P. , Gosnell J. W. 
Published: February 2011

AbstractThe theory of a constant pressure vapor bubble growing in a liquid with both superheat and sub‐cooling is presented. In the case where the initial temperature profile is purely radial, bubble radius‐time curves and temperature profile near the bubble are calculated. For the case of the hemispherical bubble growing on a plane heater surface with initially plane parallel temperature distribution, it is shown that the problem may be reduced to that of radial temperature profile if the inverse thickness of the superheated layer measured along the radius vector is averaged over the surface of the bubble. It is further shown that in the latter case vaporization is always present at the foot of the bubble, but condensation may occur near the top where the bubble penetrates furthest into the subcooled liquid.
A study of the condensation of binary vapors of miscible liquids: Part I: The equilibrium relations
Authors: Tenn F. G. , Missen R. W. 
Published: February 2011

AbstractLiquid‐vapor equilibrium data at 750 mm. Hg are given for the four binary systems CH3OH + CH2Cl2, n‐C5H12 + CH2Cl2, n‐C5H12 + CH3OH and n‐C5H12 + n‐C6H14. The second and third of these systems have been shown previously to exhibit the phenomenon of non‐filmwise condensation, and the equilibrium data are used in the following paper to calculate (condensing) film coefficients for the liquid and vapor films. The first three systems are azeotropic, and the compositions and boiling points (at 750 mm. Hg) of the minimum‐boiling azeotropes are given.Densities have also been measured for the system n‐C5H12 + CH3OH at 25°C. and refractive indices at 25°C. for the other three systems. The calculated volume of mixing for n‐C5H12 + CH3OH is positive at all compositions. A geometrical interpretation of this is discussed in comparison with results previously obtained for solutions of alcohols and carbon tetrachloride.
Viscosity of suspensions of coal in mineral oil
Authors: Moreland C. 
Published: February 2011

AbstractViscosity data for slurries of five solid particle systems suspended in a mineral oil are presented for solid concentrations up to 50% by volume. At volume concentrations of less than 30% the results are well represented by the Einstein equation in its fluidity form, the constant varying with the system between 2.65 and 3.15, (as compared with 2.5 in the theoretical equation). At higher concentrations the slurries are non‐Newtonian, and no satisfactory correlation is available in this region, very little complete data for the high concentration region have been published.Slurry viscosities are greater for smaller particles, and are greater for irregular particles than for spherical particles. Slurry viscosities in regions of high concentration can be considerably reduced by careful selection of particle size distribution.Pressure gradients measured in an experimental pipeline carrying a suspension of coal in oil in laminar flow could not have been predicted using the viscosities determined in the laboratory.
An economic study of propane propylene splitter operation
Authors: Smy K. G. , Hay J. M. 
Published: February 2011

AbstractDetailed economic studies were prepared for the distillation of a propane‐propylene mixture to make 99% propylene: (a) low pressure operation with vapor recompression (b) high pressure with water condensation.The equipment required was calculated for various reflux ratios at both pressures. The relative economics are compared.These calculations allow a study by inference of the relative cost of the two methods of recovering propylene from a cracked gas stream. One method is to distill the individual components overhead in a series of columns. The alternative is to take a cut of C3's from the main stream and recover the propylene from this cut. It was found that the latter case was the most economic.In calculating the column requirements various methods were used for estimating the number of trays required. These methods are compared.
Continuous thickening in an inclined thickener
Authors: Graham W. , Lama R. 
Published: February 2011

AbstractA continuous thickener inclined at 50° to the horizontal was compared with a conventional vertical thickener. When used to thicken a pulp of precipitated calcium carbonate in water the capacity of the inclined thickener was at least twice that of a similar vertical unit.A method for obtaining an approximate estimate of the capacity of the inclined thickener from batch settling data is suggested.