bluuebunny/crossref_metadata_2025 huggingface dataset:
Factorial design in the study of acid leaching of pegmatitic uranium ores
Authors: Fisher D. G. , Mcintosh R. G. , Eager R. L. , Van Cleave A. B.
Published: February 2011

Factorial design of leaching tests done on pegmatitic uranium ores is an efficient method of studying the effects of changes in process variables, as the required information may be obtained with a minimum expenditure of effort.

The results of a complete five factor, two level, factorially designed experiment in which an “acid‐cure” technique was used are discussed. The data obtained in two, half replicate, five factor, two level, tests in which a percolation leach technique was used, establish base levels of variables for further economic study of uranium recovery from Higginson Lake pegmatites.
Reactions in a fluidized coke bed with self‐resistive heating
Authors: Johnson H. S.
Published: February 2011

When electrodes are inserted in a fluidized bed of conductive coke particles, an electric current can be passed with sufficient power to raise the bed to a high temperature. This device becomes a chemical reactor when the fluidizing gas is appropriately chosen. The reaction conditions which obtain in such a reactor are sometimes of especial value in producing favorable yields in chemical reactions.

The design and operating characteristics of laboratory scale units are described. These are usually Vycor tubes fitted with rubber stoppers through which electrical and gas connections are made. Even with such simple apparatus, it is possible to operate at 1500°C.

Several chemical reactions have been studied in detail using reactors of this type. Among these are some which show commercial promise, such as the high temperature reaction of ammonia and hydrocarbons to form hydrogen cyanide.
Determination of ternary liquid‐liquid systems by use of the lever rule
Authors: Heric E. L. , Williams Kenneth R.
Published: February 2011

A method is described for the determination of ternary liquid‐liquid systems. The approach is based upon a combination of the lever rule and the measurement of a physical property which is a function of composition. The method has been tested upon the system toluene‐water‐acetic acid at 25 ± 0.05° and found to yield results in agreement with literature values. A possible modification of the method‐which may be necessary in systems where tie‐lines are essentially parallel when expressed on the usual weight per cent basis‐is described.
Safety of materials of construction used in explosives manufacture
Authors: Van Zeggeren F.
Published: February 2011

Hazards of materials of construction in machinery used for manufacture of explosives depend on the explosive which is being handled by the machinery. Thus one has to consider the combination material/explosive as well as material and explosive themselves, in assessing hazards. Several types of hazard can occur viz., due to sparks, friction, impact or heat. For a given material the most likely factors that will influence its hazard depend on the type of hazard, e.g. for spark hazards important factors are: static pick‐up of material and explosive, conductive properties and spark confinements; for impact hazards: hardness, surface roughness, elasticity, presence of cavities, confinement offered and area of contact; for frictional hazards: hardness, friction coefficient and thermal conductivity. For purely thermal hazards, only flammability need be considered.

In impact and friction the chemical action between material and explosive may play an important role. In all cases the sensitivity of the explosives themselves to the particular type of action, has to be taken into consideration. In accidental mishaps the type of hazard is often a combination of impact and friction, and requires a special test method.

In this paper the literature on some aspects of all of the above hazards is reviewed. Experimental results of frictional and frictional impact tests are discussed from a theoretical point of view. A number of results of particular interest, e.g. for aluminum alloys, coated steel and non‐metallic materials are presented.
Speed of sound in a non‐ideal gas
Authors: Squire William
Published: February 2011

A method is proposed for computing the speed of sound in a non‐ideal gas based on the approximation

In conjunction with the usual generalized compressibility plot and an analogous reduced enthalpy correction plot, it can be used near the critical point of a non‐dissociating gas. The method is also applicable to highly dissociated and ionized gases.
Kinetics of the vapor‐phase oxidation of toluene over a vanadium catalyst
Authors: Downie J. , Shelstad K. A. , Graydon W. F.
Published: February 2011

Rates of oxidation of toluene were measured as a function of temperature and reactant concentration. A fixed bed reactor was operated at low conversions over the following range of conditions, 300°C to 350°C., 1 × 10−3 to 15 × 10−3 moles oxygen per litre of gas, and 1 × 10−3 to 6 × 10−3 moles toluene per litre of gas.

The rate data for the oxidation of toluene were correlated by the following equation, which is based on a model by Hinshelwood.

The values of k, obtained agree with those reported previously for naphthalene oxidation(1).

It is concluded that the Hinshelwood model is a useful one for this type of reaction, and within the limits of available data provides a satisfactory interpretation.
Rail transportation of hydrogen chloride anhydrous
Authors: Drury C. H.
Published: February 2011

A railway tank car has been built for Canadian General Transit Co. Limited and is operating in the leased service of Dow Chemical of Canada Limited for the shipment of hydrogen chloride anhydrous shipped at minus 50°F. in single shipments of about 89,000 lb.

Necessary safety devices and a liquid CO2 refrigeration system are included which will maintain the car at a safe pressure level for an extended period subject to the supply of liquid CO2.
Photography in bubble and drop research
Authors: Kintner R. C. , Horton T. J. , Graumann R. E. , Amberkar S.
Published: February 2011

Methods of photographing bubbles and drops moving in a liquid field are described. Shape, size, terminal velocity, local semi‐vectorial velocities, size distribution and high speed phenomena such as coalescence and breakup can be advantageously investigated by photographic methods. Recommended combinations of lights, reflectors, diffusers, screens, films, and f‐stop values are given. Applications of particle trace and interrupted particle trace photography are described.
Analysis of the radiant heat absorption in the boundary layer surrounding an evaporating drop
Authors: Hoffman T. W. , Gauvin W. H.
Published: February 2011

An approximate analysis is made of the effect of the absorption of thermal radiation on the temperature gradients surrounding an evaporating droplet which is suspended in a high temperature environment. The Hottel‐Cohen method for calculating the radiant heat flux distribution in an enclosure containing an absorbing medium of non‐uniform temperature, has been applied to the spherical symmetrical model of the system. Conduction and radial movement of the cold vapor from the droplet have been included.

The analysis shows that, at atmospheric pressure, the absorption of radiant energy in the boundary layer is very small and hence does not affect the temperature gradient nor the rate of heat transfer at the droplet surface.

This method of analysis, with the associated solution of the equations describing the reception factors, is quite general and can be applied to any spherical enclosure containing an absorbing medium whether it be one of concentric or hollow spheres.
Sulphur and sulphur dioxide for separating copper from nickel‐cobalt‐copper sulphate solutions
Authors: Kunda W. , Mackiw V. N.
Published: February 2011

In hydro‐metallurgical processes for the production of nickel and cobalt, the leach solutions usually contains salts of nickel, cobalt and copper. To recover high purity nickel and cobalt metals from such solutions, the copper is removed prior to the nickel‐cobalt separation.

During the course of extensive investigations to determine the most economical and efficient methods for separating the copper, it was established that copper in solution reacts with elemental sulphur in the presence of sulphur dioxide forming a copper sulphide precipitate. This reaction permits a simple and quantitative separation of copper from nickel and cobalt leach solutions.

The variables affecting this reaction were studied and the results are presented in this paper. Studies were conducted on: the sulphur concentration between 0 to 2.0/1 molar ratio of sulphur to copper, the sulphur dioxide concentration 0 to 17 gpl., the temperature in the range from 100°F. to 325°F., the copper concentration from 1 to 30 gpl. and pH from 1.0 to 9.0.

The results are correlated and a tentative mechanism for the reaction is discussed.
The design and operation of a high pressure reforming pilot plant
Authors: Bichard J. A. , Bumbulis J. , Butler R. M.
Published: February 2011

A pilot plant has been designed and constructed for the exploration of reforming processes at temperatures up to 1200°F. and pressures up to 1500 p.s.i.g. The components of the pilot plant are described, as well as the calculation of material balances and product yields by an IBM 650 computer.
On the mass transport mechanism of leaching processes
Authors: Peters E. , Skrivanek J.
Published: February 2011

A model is proposed and tested that yields a theoretical leaching curve for the extraction of values from a finely ground ore. The model assumes that small particles follow the eddy currents in an agitated reactor and behave as if they were surrounded by a rigid medium. The leaching curve is obtained by writing the differential equation for diffusion, determining the extent of dissolution for selected times, and multiplying by a particle size distribution function. The results are consistent with experiment, and some essential conclusions are drawn that bear on the design of leaching circuits.
Binary vapor‐liquid equilibrium data thermodynamic consistency tests
Authors: Lu Benjamin C.‐Y. , James C. K. Ho , Spinner I. H.
Published: February 2011

Visual methods for testing thermodynamic consistency of binary vapor‐liquid equilibrium data by means of the Gibbs‐Duhem equation on a log γ vs. x plot at strategic liquid compositions are reviewed. The justifications for these methods and guidance for their applications are presented. Furthermore, these methods have been extended to test the thermodynamic consistency of equilibrium data (t‐P‐x‐y) directly.
Minimum reflux rate for multicomponent distillation systems by rigorous plate calculations
Authors: Erbar Ruth C. , Maddox R. N.
Published: February 2011

A procedure for computing the minimum reflux rate for multicomponent distillation systems. The equations developed apply to both distributed and non‐distributed systems. The suggested method of solution is by iteration, beginning with the assumption the system will be distributed. Complete heat and material balances are carried out in the course of each plate calculation. The calculated minimum reflux rates are compared with those of other techniques.
Analysis of the comminution of mixtures
Authors: Fuerstenau D. W. , Sullivan D. A.
Published: February 2011

This investigation has shown that the unit operation of size reduction can be considered to be the result of many individual comminution events and that the distribution modulus of a comminuted solid is a property of the material, independent of whether the material has been ground separately or as part of a mixture. Investigation of the comminution of quartz and limestone in a rod mill has shown that the energy‐size reduction relationships which have been developed for the comminution of homogeneous materials can be used to analyze the comminution of mixtures. Size reduction of mixtures in rod mills has been found to be complex because energy is consumed preferentially by the harder material. Methods are presented to predict the distribution modulus, size modulus, and energy consumption for the size reduction of mixtures.
Mixed models to represent flow of fluids through vessels
Authors: Levenspiel Octave
Published: February 2011

Models consisting of interconnected regions (dead‐water, backmix, plug flow, etc.) with various modes of flow through and around these regions (bypass, recycle, cross flow) are used to represent real vessels in which flow deviates greatly from plug flow. This paper deals with some of the problems of choosing and fitting such models, called mixed models, to represent flow in real vessels.

The stimulus‐response technique is a useful tool for this purpose, and matching response curves for model and real vessel then serves as the selection method.

Some of the simpler mixed models and their corresponding characteristic response curves are presented.
Mass transfer from carbon dioxide bubbles rising in water
Authors: Bowman C. W. , Johnson A. I.
Published: February 2011

Continuous phase mass transfer coefficients have been measured for carbon dioxide bubbles rising in water. A procedure was developed for systematically studying the effect of the three variables: bubble volume, formation frequency, and seal height.

The mass transfer coefficient was independent of bubble volume, increased 35% with a ten‐fold increase in frequency and varied only 8% over a 30 cm. range in seal height. The data, extrapolated to zero frequency, agreed well with the single bubble study of Hammerton and Garner. The Higbie equation predicted results very close to those obtained here but was not too successful in explaining the effect of bubble size or frequency.

The average mass transfer coefficient is about four times that for a solid particle as reported by Akselrud; this enhancement is attributed to internal circulation. Surface absorption rates were determined as a function of bubble frequency. New data has also been presented on the factors which control frequency, velocity of rise, and bubble shape. A partial correlation was developed relating bubble frequency to chamber volume.
Axial thermal conductivities in packed beds
Authors: Bischoff Kenneth B.
Published: February 2011

Radial thermal conductivities in packed beds have been extensively studied and correlated, but there is little published work on axial conductivities. The data on axial conductivities that is available is limited to low flow rates because of measurement difficulties at high flow rates. In this paper, a method is presented for estimating the values of axial thermal conductivities at high flow rates from the existing data on radial thermal conductivities. The necessity for considering packed bed axial conduction in design work can be determined from these results.
Resolution of the operating variables of a small hydrocyclone
Authors: Pilgrim R. F. , Ingraham T. R.
Published: February 2011

Application of dimensional analysis and experiment to the operation of a hydrocyclone yielded an equation of the form: magnified image

This equation shows that the volume throughput Q is a function of the pressure differential P, the density δ and the viscosity μ of the medium. The constant K1 and the coefficients of the pressure differential, density and viscosity were shown by statistical analysis to be relatively simple functions of the dimensions of the body and orifices of small glass hydrocyclones used with liquid media.
Gas diffusion with chemical reaction in porous solids
Authors: Scott D. S.
Published: February 2011

The nature of the diffusive mechanisms in the pore spaces of catalytic solids is briefly reviewed, and the effective diffusion coefficient is discussed. Binary diffusion equations, including a general expression covering all modes of diffusion, are given. Using the general diffusion equation together with first order reaction, a solution for isothermal conditions and slab type geometry is found, applicable to all modes of diffusion, with or without volume change on reaction. The extension of this solution to other pellet shapes and to second order reactions is discussed.

The measurement of diffusion rates in porous solids is considered, and the interpretation of such measurements in terms of effective diffusion coefficients is clarified by means of the general diffusion equation. Methods of determining effective diffusion coefficients other than by direct diffusion measurements are discussed, and, in particular, a forced flow technique is reviewed.
Batch processing plants
Authors: Thomas L. R.
Published: February 2011

The profitability of small‐scale chemical operations is a subject of wide interest in Canada because of the problems arising from a small and spread out domestic market. In this paper the author discusses the place of “Batch Processing Plants” within this context, emphasizing those features having a bearing on the flexibility of operation and economics of batch plants, viz:‐reaction yields, flow interruptions, plant complexity, ease of plant expansion and multipurpose applications. Since this paper is of a general review nature, discussion of the more detailed aspects of batch versus continuous processing, such as reaction kinetics, tubular reactors, process control, etc., are not included since each is a subject in itself.

The author concludes that, in the circumstances applying to the Canadian chemical industry today, greater consideration should be given to the use of batch processing plants at the appropriate production levels because of their flexibility for development and multi‐purpose applications and relatively low capital cost.
The vapor phase hydration of acetylene
Authors: Szonyi A. J. , Graydon W. F.
Published: February 2011

A study has been made of the kinetics of the vapor‐phase hydration of acetylene over a zinc phosphate‐phosphoric acid‐activated carbon catalyst. Rates of acetylene hydration were measured in a fixed bed flow reactor operated at low conversions. The majority of the data was obtained at 350°C. The amounts of acetylene hydrated were determined by analyzing the products for acetaldehyde, crotonaldehyde and acetic acid. The catalyst activity diminished with increasing process time.

The reaction rate data obtained at low conversions of acetylene were correlated by an empirical equation and a tentative mechanism suggested which is consistent with this equation.

The data obtained in the low conversion (differential) reactor have been compared to the data obtained using a fixed bed flow reactor operated at high conversions, using the integrated form of the rate equation.
Optimum process design for a heat exchanger type of reactor: Application of a Bi‐variant function generator to an analog solution
Authors: Kubota Hiroshi
Published: February 2011

The optimum process design for a heat exchanger type of reactor is derived through a selection of process conditions which give the minimum volume of reactor for a fixed conversion of a particular reactant. The method is illustrated by calculations on an ammonia synthesis reactor using an analog computer equipped with a bi‐variant function generator.
Simultaneous gas absorption and liquid phase chemical reaction in an agitated vessel
Authors: Vassilatos G. , Trass O. , Johnson A. I.
Published: February 2011

Absorption rates of pure carbon dioxide by aqueous ammonia and sodium hydroxide solutions were measured using a small agitated vessel. The interfacial area was known and the stirring rate was kept constant.

The rates were compared with those predicted by the film, the penetration, and the Kishinevsky models for intraphase mass transfer. The film theory showed the best agreement.
Numerical analysis of stratified laminar flow of two immiscible Newtonian liquids in a circular pipe
Authors: Gemmell Alan R. , Epstein Norman
Published: February 2011

Complete numerical solutions were determined in dimensionless form, of the velocity profiles for cocurrent laminar stratified flow of two immiscible Newtonian liquids in a circular pipe, for viscosity ratios of 1, 10, 100 and 1000, at eight positions of the horizontal liquid‐liquid interface, which was incorporated into the relaxation procedure by a twodimensional finite difference method described by D. N. de G. Allen. The velocity profiles were used to compute the theoretical hold‐up ratios, pressure gradient reduction (or volumetric flow rate enhancement) factors and power reduction factors for the various viscosity ratios and interface positions; the maximum reduction factors for each viscosity ratio; and the input volume fractions of the two liquids corresponding to each of the above.

The theoretical results for laminar flow were compared with experimental data in the literature, in particular those of Russell, Hodgson and Govier for the horizontal flow of a mineral oil and water (viscosity ratio = 20.1) in a circular pipe. Good agreement was obtained for both hold‐up and pressure drop data when both water and oil were in laminar flow. As the water entered the transitional and turbulent regions, however, a deviation between the experimental and the computed results developed, the deviation increasing in the anticipated direction as the Reynolds number of the water increased.
Spouted bed drier
Authors: Peterson W. S.
Published: February 2011

The first commercial spouted bed driers have been installed in Canada and one has been used to dry three types of peas, lentils and flax. The data obtained from this drier have been compared and correlated with previous drying studies in various laboratory spouted bed driers. An empirical relationship between solids temperature and other variables has been obtained:

where TK and TA are respectively the particle and inlet air temperature, dgm the particle diameter, Do the column diameter, F the feed rate and Mf the feed moisture content.

High drying capacity was achieved through the use of high air temperatures with the result that a two foot diameter spouted bed heater (plus cooler) dried almost two tons per hour of peas through 8.8% moisture range. No damage was evident in materials dried.
Performance characteristics of a 12 in. Diameter sieve plate
Authors: Harris I. J. , Roper G. H.
Published: February 2011

The hydraulic characteristics of a 12 in. diameter sieve plate have been studied and data are presented for plate pressure drop, clear liquid head on the plate and foam height, measured over a range of gas and liquid phase rates and outlet weir heights.

The mass transfer performance of the plate, as expressed in terms of an equivalent number of transfer units, was measured for conditions of both gas and liquid film control over a similar range of operating variables. The number of transfer units are shown to be directly related to the appropriate phase contact time on the plate.

The equations developed by A.I.Ch.E., to correct for back mixing effects on the plate efficiency, have been found to under‐estimate the degree of mixing on the plate used, and hence predict lower liquid efficiencies than might be expected from a comparison with literature values.
Critical temperatures and pressures of substances from vapor pressure data
Authors: Stiel Leonard I. , Thodos George
Published: February 2011

A method has been developed for the prediction of the critical temperature and pressure of any pure substance from its reliable vapor pressure data. These data are used to determine the constants A, B, C, and D of the substance for the Frost‐Kalwarf equation. The critical temperature of the substance is then calculated from the constants B and C. The critical pressure is calculated by substituting the values of A, B, C, and the calculated critical temperature into the Frost‐Kalwarf equation applied at the critical point.

This approach was used to calculate critical constants for 64 non‐hydrogen bonding substances of all types which were primarily hydrocarbons. An average deviation of 0.59% resulted for the critical temperature and 3.18% for the critical pressure.
Radioactive factors in water pollution
Authors: Guthrie J. E.
Published: February 2011

This paper is primarily concerned with the introduction of radionuclides into bodies of water as a result of nuclear reactor operations. When radioactive materials are dispersed in surface waters, several factors such as water usage and biological concentration in human food chains must be considered. Individual radiochemical determinations of the potentially hazardous nuclides in the water, particularly Sr‐90 are desirable.

The off‐site water monitoring program at the Chalk River Plant of Atomic Energy of Canada is outlined.
Heat transfer to clouds of particles
Authors: Themelis N. J. , Gauvin W. H.
Published: February 2011

An analysis was made of the rate of heat transfer by convection, radiation, and chemical reaction to a dispersion of particles in a non‐absorbing gas. The gas‐solids suspension was subjected to co‐gravitational flow at low Reynolds Numbers (50–500) through a cylindrical reactor, the wall of which was maintained at a uniform temperature (400–900°C). The rate of heat transfer by convection from the wall to the gas was determined experimentally. The differential equations were solved on an IBM‐650 digital computer, for the reduction of iron oxide particles (40 to 100 microns) by hydrogen. The program output recorded the particle residence time and corresponding values of gas and particle temperatures, length of reactor travelled, percent reduction, and individual rates of heat transfer to the particle by convection, radiation and chemical reaction. Experimental measurements in an electrically‐heated, 4.4‐in. i.d. × 8.5 ft. long stainless steel reactor verified the calculated prediction that the particle temperature should at all time be nearly equal to that of the gas.
Isobaric vapor‐liquid equilibrium data for binary systems
Authors: Nagata Isamu
Published: February 2011

Vapor‐liquid equilibrium data at atmospheric pressure are reported for the systems: 2‐butanone‐2‐propanol, chloroform‐2‐propanol, ethyl acetate‐2‐butanone, and methyl acetate‐2‐propanol. The experimental results are correlated by two typical methods in the literature.
Sedimentation in inclined vessels
Authors: Graham W. , Lama R.
Published: February 2011

The rate of sedimentation of precipitated calcium carbonate in water was measured as a function of the solid concentration and the shape and angle of inclination of the container. It was found that an experimentally determined coefficient had to be included in the settling equation proposed by Nakamura to make it fit the data.
Fluorescence effects in ion exchange resins
Authors: Flint T. R. , Eichholz G. G.
Published: February 2011

Fluorescence under ultraviolet illumination has been observed in anion and cation exchange resins when in the unloaded state. This fluorescence decreases rapidly in intensity as the resin is loaded and this process has been shown to offer a practical method for controlling the loading and elution cycles in ion exchange operations.

The relative effectiveness of different resins and various ions on this fluorescence quenching process has been determined and some correlation has been found between quenching efficiency and ionization potential of the elements. The measurements have shown adequate stability and reproducibility for industrial control applications.
A theoretical and experimental investigation of fiber suspension drainage in the turbulent regime: Part 2. An experimental study of turbulent drainage using model nylon fibers with application to practical papermaking suspensions
Authors: Meadley C. K.
Published: February 2011

Results of drainage experiments using a laboratory hand sheet machine and model nylon fiber suspensions are presented and discussed. The discussion is concerned with the measurement of two general parameters of the turbulent drainage theory, previously published as Part I of this study, and the ability of the theory using these measured values to predict nylon suspension drainage characteristics over a wide range of conditions. In addition, results of drainage tests with groundwood and sulphite fractionated stocks are discussed in terms of the application of this theory to natural fiber suspensions.

In general, it was found that, in the realm of practical papermaking represented by high machine speeds, drainage resistance is proportional to the square of the filtration rate and the turbulent pressure drop concept applies.
Settling velocities of coal particles
Authors: Moreland C.
Published: February 2011

Settling velocities of coal particles falling by gravity in a mineral oil have been measured for particle sizes ranging from 80 to 2,000 microns, at slurry porosities of between 0.6 and 1.0. Velocities for the latter figure correspond to the terminal velocities of single particles.

The terminal velocities were found to be within 25% of the predicted values for spheres and could, for Reynolds numbers less than 0.2, be related to the particle size (d) by the equation V = Kd2,15.

The settling velocities of the slurries, which were all in the laminar region, are shown to be related to the slurry porosity (ε) by the theoretical equation of Maude and Whitmore, namely V = V, where Vo is the terminal velocity. Values of n between 6.5 and 7.5 were found.
Channels and chains of bubbles in gas fluidized beds
Authors: Botterill J. S. M. , Bloore P. D.
Published: February 2011

The disturbance caused by the development of channels and chains of bubbles through gas fluidized beds has been studied using a local gas injection technique. The average disturbance formed was measured using a γ‐radiation absorption technique supplemented by pressure drop and bed expansion measurements.

The channels or close chains of bubbles were found to persist through the bed to a height dependent on bed conditions and the energy of the gas flow through the disturbance. The disturbance then degenerated into larger bubbles which tended to coalesce, grow and become more widely separated. The rate of increase of disturbance diameter was inversely proportional to the square of the estimated gas flow velocity through the disturbance. Bubble spacing increased through the upper elements of the disturbance. It was concluded that the resistance to flow of escape gas through this part of the chain was increased and that this caused an increase in gas residence time corresponding to the observed increase in resident void volume in the upper elements of the disturbance.

The channel or close chain of bubbles provided a low resistance path by which gas readily escaped. In shallow beds at incipient fluidization the path readily reached through to the bed surface and reactant gasses may largely bypass the bed under these conditions and the bed cease to be fluidized.
The pipeline flow of coal‐in‐oil suspensions
Authors: Berkowitz N. , Moreland C. , Round G. F.
Published: February 2011

The flow behavior of coal‐in‐oil suspensions at velocities up to ca. 20 ft./sec. has been investigated in a one‐inch d. experimental pipeline. Detailed data are presented for a bituminous and a subbituminous coal (effective size < 700 microns) entrained in two oils (μ = 5.6 and 46.7 ep. at 25°C. respectively); coal concentrations in the suspensions ranged > 70% w/w.

At flow velocities greater than 2 ft./sec. and coal concentrations below 50% w/w, the suspensions were found to move as relatively homogeneous (or quasi‐homogeneous) fluids, and pressure gradients followed the usual friction factor/Reynolds number relationship. But no satisfactory correlations could be established for flow at < 2 ft./sec., which is influenced by significant settling, or for the behavior of suspensions containing > 50% w/w coal. In the latter case, laminar flow obtained at all velocities and the suspended particles tended to concentrate near the pipe axis (and to move along it as a definite ‘core'’. One effect of this phenomenon is a substantial reduction in the apparent viscosity of the suspension.
Experimental investigation of natural convection heat transfer in confined space for non‐Newtonian fluid
Authors: Pierre Carl St. , Tien Chi
Published: February 2011

Experimental work was carried out for the study of convection heat transfer of fluid confined between two horizontal plates. The rheological properties of the fluid can be described by Ostwald ‐ de Wael model. The results as expressed in terms of dimensionless groups were successfully correlated by the following expression:

The Rayleigh and Prandtl numbers are defined in the generalized sense with the flow behavior index, N, being considered as a correcting factor for the deviation from Newtonian behavior.
Optimal design of a continuous stirred‐tank reactor by a gradient method
Authors: Reed Lawrence A. , Stevens William F.
Published: February 2011

The design of a continuous stirred‐tank reactor, used in the formation of allyl chloride from chlorine and propylene, was optimized by a gradient method. Four process variables were considered: Reaction temperature, pressure, feed composition, and “pseudo” residence time (ratio of reactor volume to molar feed rate). In addition to the primary reaction, a secondary and a consecutive reaction were included in the process model.

Sensitivity analyses revealed that 5% errors in the reaction rate constants produced only very slight changes in the optimal design. In addition, it was found that the profit from the operating reactor was a strong function of feed composition and reaction temperature and a relatively weak function of pressure and “pseudo” residence time.

A program was developed for the IBM 709 computer by which the machine made all appropriate decisions and calculations in finding the optimal design and carrying out the sensitivity analyses.
Studies of the critical heat‐flux for some binary mixtures and their components
Authors: Carne M.
Published: February 2011

A pool boiler and a forced convection loop used for studying critical heat fluxes in binary mixtures are described. The geometry of the test element is shown to be an important variable in pool boiling experiments, affecting both absolute flux values and the variation with composition. Data given for AC and DC power supplies show that the critical heat flux is relatively unaffected by the power supply source.

Empirical equations of the form (Q/A) c = const. Va ΔTbsub are given for benzene, toluene and acetone, which correlate the forced convection subcooled data with average deviations of 3.1%, 5.0% and 5.1% respectively.

Forced convection subcooled data are given for the systems benzene‐toluene and acetone‐toluene showing the effect of composition on critical heat flux.

It is concluded that, at forced convection subcooled conditions in certain concentration ranges, binary mixtures may exhibit critical heat fluxes which are higher than for either of the pure components. In this respect loop experiments are analogous to pool boiling ones. However, extrapolation from pool boiling experiments to loop conditions does not appear to be feasible under the present test conditions.
Viscous flow around fluid spheres at intermediate reynolds numbers (II)
Authors: Hamielec A. E. , Storey S. H. , Whitehead J. M.
Published: February 2011

Approximate velocity profiles have been predicted for laminar, incompressible flow around solid and fluid spheres for Reynolds numbers up to several thousand. The accuracy of the predicted profiles for solid spheres has been tested in three ways. Drag coefficients, flow‐separation angles and forced‐convection transfer rates calculated from these profiles have been compared with experimental data for solid or rigid spheres. The predicted quantities oscillate about the experimental data as the Reynolds number is increased. Cross‐over points occur at Reynolds numbers of about 20, 100 and 500. The velocity profiles for fluid spheres are of little practical value above Reynolds numbers of several hundred as drop or bubble deformation is significant.

Drag coefficient data for solid spheres, liquid drops and gas bubbles showing the effect of dispersed‐phase viscosity on total drag are presented. These data are correlated over the Reynolds number range, 10–100 with a viscosity‐ratio correction factor which was derived theoretically.
Exploratory studies on batch and continuous foam separation
Authors: Grieves R. B. , Kelman S. , Obermann W. R. , Wood R. K.
Published: February 2011

Foam fractionation has been employed for inorganic and organic chemical separations, for the treatment of radioactive wastes, and as a tertiary treatment method for secondary sewage effluents. Although the general effect of the basic variables of foam separation has been established, a quantitative approach to the process has not been made. In this study, a fundamental analysis of foam separation as a mass transfer operation is presented, utilizing both equilibrium and rate concepts of mass transfer.

Foam separations have been carried out employing aqueous solutions of dodecyl sodium sulphate and alkyl benzene sulphonate at concentrations ranging from 0.005 to 0.14% weight. The range of surfactant concentrations which can be handled under a given set of operating conditions is established. In the batch experiments, volumes and concentrations of the foam and residual bulk phases are presented for nitrogen rates of 200 and 320 cc./min. Flow experiments were carried out using gas rates of 320, 440 and 580 cc./min. and liquid feed rates of about 70 and 100 cc./min. In general, the concentration of the drain stream was relatively insensitive to both gas and feed rates, but the total removal rate was found to be a strong function of gas rate.
Coefficient of thermal expansion: Reduced state correlation for water in the gaseous and liquid states
Authors: De WITT K. J. , Thodos George
Published: February 2011

A reduced state correlation for the coefficient of thermal expansion of water has been developed from PVT data available in the literature for the substance. The coefficient of thermal expansion was expressed in terms of reduced variables and a reduced state density correlation was developed for water. This density correlation was then utilized to develop plots of the dimensionless variable, βTc, againstTRandPafor reduced temperatures up toTR= 3.0 and reduced pressures up toPR= 20.
Some physical and chemical properties of sprayed silver alloy catalysts
Authors: Osberg G. L. , Tweddle A. , Brennan W. C.
Published: February 2011

Spraying of silver alloy catalysts by powder flame spray and by molten alloy spray techniques is briefly described. Some of the physical properties such as density, porosity, thermal conductivity and diffusibility are listed for catalysts prepared from 8.5% calcium in silver alloy, as well as a few data on pure silver, copper and nickel. Initial rate data from the oxidation of ethylene have been compiled to show a diffusion effect within the catalyst layer, and these data have been used to calculate a diffusibility factor which is lower than a similar factor estimated from oxygen‐helium diffusion experiments. The kinetic data were obtained from catalyst strips immersed in an inert mullite powder bed fluidized with reacting air‐ethylene mixture. Heat transfer coefficients from strip to bed were estimated from the kinetic data, exothermic heats of reaction and recorded temperature differences.
Yield studies in packed tubular reactors: Part 1 ‐ Mathematical model for design and analysis
Authors: Mickley H. S. , Letts K. W. M.
Published: February 2011

The prediction of chemical yield and productivity for packed tubular reactors is examined in two articles. A mathematical model and digital computing scheme are presented for reactors with several reactions, large heat effects, and heat exchange at the wall. Case studies show that yield loss depends strongly on the dimensions and flow rate adopted in reactor design.

Part 1 presents a steady state reactor model based on material and energy balances formulated in partial differential equations on radial and axial space coordinates. The model allows for multiple reactions with arbitrary rate expressions and stoichiometry, axial bulk flow, radial effective diffusion and conduction, and a heat transfer resistance at the wall. Problems of scale‐up and similitude are discussed in terms of the model.

Part 2 presents the numerical computing scheme and case studies.*
Yield studies in packed tubular reactors: Part 2 ‐ results of computed cases
Authors: Mickley H. S. , Letts R. W. M.
Published: February 2011

Part 2, of two articles, outlines a finite‐difference computing scheme for the reactor model of Part 1, based on implicit backward differences for linear terms and explicit evaluation of non‐linear terms. The chemical system, vAA → B → vCC, with B the desired product, is examined through case studies to find sources of chemical yield loss. The system is gas phase, with exothermic reactions and Arrhenius temperature activation.

Under moderate reaction conditions: 1. Activation energy differences cause yield losses of 4–8%. 2. Radial mixing causes yield losses up to 6%. 3. Failure to withdraw the stream where local yields are maximum causes yield losses larger than 1%.

A technique for reactor design by simulation is outlined.
Reciprocating flow fixed bed contactor: Part 1 ‐ development, ion exchange
Authors: Spinner I. H. , Hunter R. F.
Published: February 2011

The development of a new semi‐continuous method for operation of a fixed bed contactor is described. The technique, termed reciprocating flow, utilizes density differences to achieve the shunting of solutions in alternating directions through a fixed bed.

One of the possible flow arrangements was investigated using a strong acid ion exchanger and the calcium/sodium system. It was found that the technique was feasible for the partial removal (80–60%) of calcium from solutions having concentrations ranging from 400 to 2000 ppm. of calcium carbonate.

Regenerant consumption and water requirements compare favourably with present commercial practice. However, a small regenerant leak of 1–14 meq./l. into the solution is unavoidable. Resin bed and column heights can be made a small fraction of those presently used in commercial installations.

Analyses of some of the important factors limiting efficiency indicate that highly concentrated solutions may be effectively treated by the reciprocating flow technique.
Determination of chemical kinetics for multiple reaction systems
Authors: Letts R. W. M. , Mickley H. S.
Published: February 2011

A technique is presented for the determination of chemical kinetics of multiple reaction systems from differential reaction rate data. All rate constants, activation energies, and reaction orders of the system are simultaneously fitted to all the data, using the methods of linear and nonlinear least squares. A desk calculator is practicable for systems involving ten or fewer unknown kinetic parameters. The method is especially useful for reversible reactions, since there has been no simple technique for the joint measurement of parameters of the forward and reverse reactions. The calculation is illustrated with a numerical example.
Vapor‐liquid equilibrium data for the benzene‐cyclohexane‐2‐propanol system at 760 mm. of Hg
Authors: Nagata Isamu
Published: February 2011

Vapor‐liquid equilibrium data are presented for the binary benzene‐2‐propanol and the ternary benzene‐cyclohexane‐2‐propanol systems at 760 mm. of Hg. The equilibrium data are correlated with the van Laar and three‐suffix Margules equations and a small ternary constant was found to be necessary for the satisfactory description of the ternary data. A ternary minimum azeotrope was found to be 14.2 mole % of benzene, 47.4 mole % of cyclohexane, and 38.4 mole % of 2‐propanol at 69.1°C.
Venting of high pressure fixed‐bed catalytic reactors
Authors: Basmadjian D.
Published: February 2011

A semi‐quanlitative analysis is presented of the pressures arising in catalyst pellets during the rapid venting of a typical high pressure fixed‐bed reactor. It is shown, for both macroporous pellets and the microporous powder particles within them, that the pressures will not exceed those of the surroundings by more than a few atmosphers. It is concluded that a rapid release of pressure may be effected without risking damage to the catalyst pellets.
Analytical solutions of the equation of heat conduction for a non‐homogeneous medium
Authors: Heaps H. S. , Srivastava R. D.
Published: February 2011

Consideration is given to the equation of heat conduction when the parameters are functions of position. A solution is obtained in the form of an infinite series in which the first term represents the solution for homogeneous material. The further terms of the series represent correction terms caused by the departure from homogeneity. Two illustrative examples are described.
The application of a modified conditional probability computer to chemical process optimization
Authors: Tinker E. B. , Nikiforuk P. N.
Published: February 2011

The application of a conditional probability computer to the steady‐state optimization of a simple chemical process has been investigated. On the basis of the work of previous investigators, the memory structure of the conditional probability computer was modified in a way designed to accelerate the learning process and improve the predictive capabilities of the computer. The proposed modifications were studied by optimizing an analog simulation of a simple chemical process subjected to a variety of uncontrolled disturbances. The investigations served to delineate some of the special problems encountered in the application of a binary pattern recognition device such as the conditional probability computer to process optimization. The proposed modifications were successful in achieving significant acceleration in the learning process and improvement in predictive capabilities over that offered by a conventional conditional probability computer.
Time dependent rheology of the tetrahydrofuran‐hydrogen sulphide gas hydrate slurry
Authors: Pinder Kenneth L.
Published: February 2011

The tetrahydrofuran‐hydrogen sulphide hydrate slurry was shown to have a gel structure at very low concentrations and to display thixotropic or false body behavior depending on the shape of the slurry particles. The crystals were allowed to grow and readings of viscosity, particle size and particle shape were made at regular intervals during the period of growth.

The observations were calculated by a new technique to give a yield value, a rate of decrease of viscosity and an equilibrium apparent viscosity. A correlation was found between the yield value, the square root of the Sauter mean diameter and the shape of the particles in the slurry.

A second order‐zero order reversible reaction mechanism was found to yield an equation which fits the viscosity data for this slurry. A simplified technique for determining the constants in the equation makes it possible to predict the apparent viscosity‐time curves from a few readings taken at short time interval after initiation of shear.
On the pumping of wood chips through a four‐inch aluminum pipe‐line
Authors: Brebner Arthur
Published: February 2011

This paper summarizes an investigation into the behavior of a wood‐chip suspension in a 4‐inch diameter aluminum pipe, 400 feet in length, when pumped under differing flow rates and concentrations, and evaluates the modes of conveyance and the friction losses therein.

The following points are brought out by the investigation.

The mode of conveyance is essentially one of a sliding bed, the depth of which is related directly to the concentration. There is little evidence of any homogeneity of flow, despite the fact that the solids conveyed have a specific gravity very close to the conveying medium, water.

The friction losses are considerably higher than those of water alone, again despite the fact that the mixture specific gravity is very close to that of water. These relatively high losses are attributed to the size, shape and interlocking properties peculiar to wood‐chips.

The wood chips are easiest to handle when they are almost fully saturated.

If suitable precautions are taken the possibilities of blockages can be minimized or completely eliminated.

A rough estimate of pumping costs indicates that conveyance by pipe‐line can be competitive with other means of over‐land transport.