Chemical Engineering Commons^™

The Effect Of Solvents On The Desorption Of Phenol From Carbon, Robert Harold Pahl

Masters Theses

"The desorption of phenol from active carbon was studied using cyclic and continuous flow desorbers. A wide difference in desorption capabilities was shown among nine solvents. The system employed was complex, with water being present in addition to phenol on the carbon. An attempt to correlate the desorption data with the physical properties of the phenol and solvent and Regular Solution theory are presented. A thermodynamic approach using the linear free energy-enthalpy relationship produced an apparently good correlation of the heat of formation of the phenol-solvent hydrogen bond with the desorption data. This indicates that the desorption of the phenol …

The Anodic Dissolution Of Molybdenum In Acidic Nitrate Solutions, Kuan-Hsiung Hoh

Masters Theses

"The anodic dissolution of molybdenum in 1.0 N HNO₃ (pH = 0.3) , 0.1 N HNO₃-0.9 N KNO₃ (pH = 1.2), and 0.01 N HNO₃ -0.99 N KNO₃ (pH = 2.1) was investigated. The following conclusions were possible: 1. Mo is in general electrochemically oxidized to the Mo-VI state during anodic dissolution. 2. The resultant ions in solution are HMOO⁻₄. 3. The Mo surface in aqueous solutions is covered with an oxide whose approximate composition is Mo₂O₅. 4. The polarization curves have a linear Tafel region at potentials slightly above the rest potential. 5. There is no significant effect of …

Anodic Dissolution Of Zinc In Potassium Bromide-Potassium Bromate Solutions, Ying-Cheh Chuang

Masters Theses

"The purpose of this investigation was to study the anodic dissolution of zinc at a temperature of 25°C in Br⁻-BrO₃; solutions. In Br⁻ solutions, it was found that the apparent valences of zinc ions going into solution were approximately the normal value of two. Smaller values were obtained in BrO⁻₃ solutions, with the most pronounced changes occurring in the higher concentrations of BrO⁻₃. An empirical equation was derived relating the apparent valence (z_i) to the current density (amp·cm⁻²) and BrO⁻₃ concentration (gmol/liter): 2- z_i = 3.11 X i⁰̇̇¹³(C_BrO⁻₃)⁰̇⁵⁷ The mechanism for the dissolution of zinc …

The Anodic Oxidation Of Oxalic Acid On Au, Steven C. Mueller

Masters Theses

"The anodic oxidation of oxalic acid on Au has been studied at 80°C in aqueous media. The reaction rate was measured as a function of potential, oxalic acid concentration, pH, and temperature in H₂SO₄-K₂SO₄-KOH solutions of unit ionic strength. The oxalic acid was oxidized only in acidic media. The oxidation to CO₂ was essentially complete. A first order dependence of the rate on both pH and undissociated oxalic acid was found. A mechanism is proposed in which the first decarboxylation is the rate determining step"--Abstract, page 1.

Mass Transfer From Spherical Gas Bubbles And Liquid Droplets Moving Through Power-Law Fluids In The Laminar Flow Regime, Robert M. Wellek, Cheng Chun Huang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Calculated mass transfer coefficients for the continuous phase are presented for internally circulating spheres of a Newtonian fluid traveling through a power-law-type continuous phase in the so-called creeping-flow region. The Nakano and Tien stream functions allow the Sherwood number to be computed as a function of the Peclet number, power-law index, and a viscosity ratio parameter. The Hirose and Moo-Young relation is shown to be a limiting case of this numerical solution. Mass transfer rates increase as the fluids become more pseudoplastic and/or the continuous phase consistency index increases, all other factors held constant. © 1970, American Chemical Society. All …

A Study Of The Anodic Oxidation Of 1, 3-Butadiene On Platinum And Gold Electrodes, Arun Kumar Agrawal

Doctoral Dissertations

"The anodic oxidation of 1,3-butadiene on Pt and Au electrodes was studied at 70°C in solutions of H₂SO₄, K₂SO₄, K₂CO₃, and KOH with pH's ranging from 0.35 to 12.5. Reaction rates (current) were measured as a function of potential, pH, temperature, and butadiene partial pressure. A transition region (apparently a shift in the rate determining step) in case of Pt was observed in the Tafel plots. The coulombic efficiencies of oxidation to CO₂ were 85 percent in 1 N H₂SO₄ on Pt, 93 percent in 1 N KOH on Pt, and 72 percent in 1 N KOH on Au"--Abstract, Page …

Mass Transfer From Spherical Gas Bubbles And Liquid Droplets Moving Through Power-Law Fluids In The Laminar Flow Regime, Cheng-Chun Huang

Doctoral Dissertations

"Continuous phase mass transfer coefficients are presented for internally circulating spheres of a Newtonian fluid traveling through a power-law type continuous phase in to so-called creeping-flow region. The Nakano and Tien stream functions allow the Sherwood number to be determined as a function of the Peclet number, power-law index, and a viscosity ratio parameter. The Hirose and Moo-Young relation is shown to be a limiting case of this solution. Mass transfer rates increase as the fluids become more pseudoplastic and/or the continuous phase consistency index increases, all other factors held constant"--Abstract, page ii.

Numerical Simulation Of Forward Combustion In A Radial System, Tommie C. Wilson

Doctoral Dissertations

"A generalized mathematical model is described for the thermal recovery of oil in a radial system in which there are conductive heat losses to the surrounding formations, three phase fluid flow, conductive-convective heat transfer within the producing formation, combustion, and aqueous-phase changes considered. The mathematical form of the temperature equation requires that numerical solutions be obtained with a digital computer for which the numerical approximations of the partial differential equations are presented and the results discussed. The analysis is applied to field size simulations of a forward combustion project to permit direct field analyses of significant importance for accurate reproductions …

A Liquid Extraction Column With Reciprocated Wire Mesh Packing, Robert M. Wellek, M. Uran Ozsoy, J. J. Carr, Dudley Thompson, Thomas V. Konkle

Chemical and Biochemical Engineering Faculty Research & Creative Works

In a new type of pulsating, liquid extractor, pulsating energy is added to the counter currently flowing liquid streams by a stainless-steel wire mesh packing which is reciprocated vertically in a 3-inch i.d. extraction column. The mass transfer performance and flooding characteristics are studied as a function of the frequency and amplitude of reciprocation, the total solvent and feed throughputs, and choice of phase dispersion. The benzene-HAc-H₂O and MIBK-HAcH₂O systems were used. Extraction data for the benzene system were correlated in terms of a dimensionless pulse velocity group. Operating throughputs are significantly higher than those achieved …

Front Matter, University Of Missouri--Rolla

Symposia on Turbulence in Liquids

No abstract provided.

Ultrasonic Study Of Turbulent Water Flow, W. K. Kramer, R. Grosskreutz, A. Dinkelacker

Symposia on Turbulence in Liquids

The propagation of ultrasonic waves through turbulent water flow has been Investigated experimentally. While passing the turbulent region the sound waves are modulated to some extent. The degree of modulation and the frequency spectra of the modulation are closely related to the properties of the flow. It seems to be possible to use this method for turbulence measurements in liquids, whereby the absence of a probe in the flow region and a possibility to differentiate between velocity and density fluctuations would be special advantages. A disadvantage can be the fact that Information is collected on the whole sound path.

Two-Dimensional Laser-Doppler Velocimetry In Turbulent Flows, N. E. Chatterton, R. D. Lewis, E. W. George

Symposia on Turbulence in Liquids

Localized measurement of the velocity of flow In fluids may be accomplished by detecting the Doppler shift In frequency from coherent, monochromatic light scattered from micrometer sized contaminant particles within the flow. The versatility of applications of this technique, first used several years ago, has been expanded by recent research. The basic geometry of measurement, in which the scattered energy is recombined with light energy at the original frequency on the face of the photocathode of a photomultiplier tube, can be rearranged in many alternative configurations to meet the needs of the experimenter. By using a single laser, additional arrangements …

Diffusion Coefficients Over Rough And Smooth Boundaries, Obtained By Measuring The Concentration-Velocity Covariance, R. S. Mcquivey, T. N. Keefer

Symposia on Turbulence in Liquids

A preliminary investigation of the coefficients of turbulent diffusion in an open channel was conducted by employing: 1) hot-film anemometry to detect the velocity fluctuation, 2) a platinized single-electrode conductivity probe to detect the concentration fluctuations, and 3) a digital computing system to evaluate the covariance and other statistical properties of the two output signals.

Data were collected downstream of a constant-discharge point source of neutrally-bouyant salt solution at stream temperature and velocity. Using current semi-empirical methods diffusion coefficients were obtained in the vertical and lateral directions as well as dispersion coefficients due to convection.

Some Aspects Of Flow Through Rotating Circular Tubes, D. L. Boyer, J. R. Guala

Symposia on Turbulence in Liquids

The flow of water in a circular tube rotating about an axis perpendicular to the axis of the tube is studied. Information about the flow is obtained from coated hot-film probes and a constant temperature anemometer. A maximum Reynold's number of 9,500 is obtained and the Taylor number is varied from 800 to 3,100. Little similarity is found to exist between flows in rotating and in non-rotating systems in this range of parameters.

Optical Statistical Measurements Of Free Convection Flow Patterns, E. F. C. Somerscales

Symposia on Turbulence in Liquids

Measurements have been made of the autocorrelation of photographs of the flow patterns produced at high Rayleigh numbers in a horizontal layer of liquid heated from below and cooled on top. The relation of these measurements to temperature measurements in the fluid are considered. Analogous situations in other physical systems are also discussed.

Turbulence Measurements In Shear Flow Liquid Systems, Robert S. Brodkey, M. F. Cohen, J. S. Knox, G. L. Mckee

Symposia on Turbulence in Liquids

The paper is a composite of a number of years of work on turbulence measurements in a variety of liquid flow systems. The trials and tribulations of such measurements are emphasized. Pipe flow Is considered in some detail, and the consistency between results of various investigators is analyzed. Other systems discussed are a stirred tank unit and a multi-jet reactor configuration. Statistical turbulence measurements such as autocorrelation, spectrum, probability density, flatness factor, and skewness factor are considered in terms of obtaining these from digital signals obtained by conversion of the normal analog signals. Descriptive parameters of statistical turbulence, such as …

Use Of A Constant Temperature Hot-Wire Anemometer To Compensate For The Thermal Lag, Peter Freymuth

Symposia on Turbulence in Liquids

A constant temperature hot-wire anemometer can be used to compensate for the thermal lag of a wire or film resistance thermometer within the useful frequency range of the anemometer. This method may be used as an alternative to the standard method in which a differentiation circuit as employed in constant current anemometers is used for frequency compensation. The new method is useful if a constant temperature anemometer is at hand. The time constant of the resistance thermometer need not be determined.

Measurements Of Turbulence Characteristics In Water And In Dilute Polymer Solutions, Tadeusz Kowalski

Symposia on Turbulence in Liquids

Measurements of turbulence characteristics were made inside a boundary layer in external flow of water and in water with polymer additives of the Polyox type. Flush mounted hot-film sensors and wedge, parabolic, and cylindrical sensors were used to measure the turbulent velocity fluctuations. Graphs are given of energy density, dissipation, turbulence shear correlation spectra, and microscale of turbulence distribution. Tests were run in an open channel flow at one Reynolds number and two rates of polymer injection to give 20 and 40 ppm average concentration in the boundary layer. The results indicate that the advent of the quartz insulated hot-film …

The Response Of A Hot-Wire Anemometer To A Bubble Of Air In Water, S. C. Chuang, V. W. Goldschmidt

Symposia on Turbulence in Liquids

The sensitivity of peak voltage drop and duration of the change In sensor voltages due to the impaction of different size bubbles are confuted and measured. Excellent agreement between these is found for bubbles somewhat larger than the sensor diameter and smaller than Its effective length in water streams in a range of 1.5 to 9 feet per second. The method suggests a reliable method for sizing bubbles in a water stream. The effects due to nondirect hits are not treated.

Frequency Response Studies For A Wedge Probe In Viscoelastic Fluids, J. M. Rodriguez, Gary Kent Patterson, J. L. Zakin

Symposia on Turbulence in Liquids

The response of a hot-film wedge probe in viscoelastic fluids has been investigated by imposing on the probe a sinusoidal vibration of known amplitude and frequency. Root-mean-square (rms) velocities calculated from the displacement of the probe were compared to rms velocities obtained with a constant temperature anemometer. The tests were performed under turbulent flow conditions and also at flow rates where viscoelastic effects (i.e., decrease of heat transfer rates from the probe to the fluid and drag reduction) were observed.

The frequency range covered was narrow ( < 100 cps). This limitation was imposed by the decision to superimpose the sinusoidal vibrations on the turbulence signal, in order to have dynamic conditions similar to those encountered in actual turbulence measurements. Measurements were performed in mineral oil and four solutions of polyisobutylene (Vistanex L-200) In mineral oil.

The experimental technique was established by measuring the response of the probe in …

An Experimental Facility For The Visual Study Of Turbulent Flows, Robert S. Brodkey, Harry C. Hershey, Edward R. Corino

Symposia on Turbulence in Liquids

An experimental technique which allows visual observations of the wall area in turbulent pipe flow is described in detail. It requires neither the introduction of any injection or measuring device into the flow nor the presence of a two-phase flow or of a non-Newtonian fluid. The technique involves suspending solid MgO particles of colloidal size in trichloroethylene and photographing their motions near the wall with a high speed movie camera moving with the flow. Trichloroethylene was chosen in order to eliminate the index of refraction problem in a curved wall.

Evaluation of the technique including a discussion of limitations is …

The Influence Of Ambiguity And Noise On The Measurement Of Turbulent Spectra By Doppler Scattering, J. L. Lumley, W. K. George, Y. Kobashi

Symposia on Turbulence in Liquids

A fundamental uncertainty in velocity measurement by Doppler scattering is caused by the finite residence time of the scattering particles in the observation volume; the arrival of scattering particles at arbitrary times gives rise to fluctuations in phase (and hence frequency) of the observed Doppler frequency. An estimate is obtained for the spectrum of these frequency fluctuations (called ambiguity noise). The frequency at which the spectral levels of a turbulent signal and the ambiguity noise are equal, provides a limit to the temporal resolution of an instantaneous velocity measurement; this limit is obtained, and shown to be quite restrictive. The …

Laser-Doppler Measurements Of The Decay Of Velocity Fluctuations In Dilute Polymer Solutions, Neil S. Berman, Eugene E. Cooper

Symposia on Turbulence in Liquids

Finite disturbances were generated in a pipe containing water or a 20 ppm solution of Separan AP-30 in water by oscillating a sleeve at the wall. The sleeve amplitude in the axial direction varied from 0.5 to 2.0 inches and the frequency from 0.25 to 1.0 Hz. Downstream of the sleeve oscillations in the fluid velocity were measured with a laser Doppler flowmeter at various axial and radial positions to determine behavior at the lower frequency part of the stability curve for water. The response amplitude, phase angle and the mean velocities were measured for both fluids at Reynolds numbers …

The Use Of Electrochemical Techniques To Study Turbulence Close To A Wall, Kamalesh K. Sirkar, Thomas J. Hanratty

Symposia on Turbulence in Liquids

Electrochemical techniques can be used to measure the time averaged velocity gradient and the two components of the fluctuating velocity gradient at a solid surface. A chemical reaction Is carried out at the surface of a small electrode embedded in the wall. The voltage applied to the electrode Is large enough that the current flowing in the circuit is controlled by the mass transfer rate. The probes are the mass transfer analog of the hot wire or hot film anemometer. If the test electrode is part of a large electrode surface, it can be used to measure local time averaged …

Turbulence Measurements In Water, Francois J. Resch

Symposia on Turbulence in Liquids

Turbulence measurements in water have been undertaken using hot film anemometers in a circular conduit. Two different types of film probe were tested and the problem of drift of the calibration curves was carefully studied. A heat transfer law was established for conical hot film probes.

Some turbulence measurements, made at the axis of the pipe, were compared with the corresponding measurements undertaken in air flow. The comparison led to the conclusion that turbulence measurements can be carried out in water with the same degree of accuracy as those carried out in dynamically similar air flow.

Bibliography Of Hot-Wire-Film Anemometry In Liquids, R. L. Humphrey

Symposia on Turbulence in Liquids

It is not a new idea to use heat transfer from a hot sensor in a fluid stream to measure velocity and turbulence. This was done as long ago as 1909 by Mr. Kenelly, but a systematic study was not followed through until 1914 by L. V. King. After this followed a series of dedicated people, some students, some professors, some scientists, who continually advanced the state of the art of anemometry in liquids. This paper deals with their work in the areas of electronics (integrated circuits) and physics (thin film technology), and shows how, in time, these two areas …

Turbulence Measurements In Stably Stratified Fluids, Yih-Ho Pao

Symposia on Turbulence in Liquids

A towing tank system was used to study the structure of turbulence in stably stratified fluids. Turbulence is generated by moving an obstacle (a grid or a cylinder) in a tank of stratified salt water. Recent improved shadowgraph pictures of these laboratory generated stratified flows are shown in this paper. They give further support to Pao's observation that (i) internal waves and turbulence coexist in turbulent stratified flows, with internal waves at the large scales and turbulence at the small scales; (ii) turbulence decays much more rapidly than internal waves; and (iii) the turbulent-nonturbulent interfaces are not necessarily sharp, and …

Some Basic Properties Of Low Quality Two-Phase Turbulent Flow, G. Hetsroni, S. Einav

Symposia on Turbulence in Liquids

This Is an exploratory study dealing with the effect of gas bubbles on the turbulence Intensity of the liquid in a two-phase flow.

Distributions of time-mean and fluctuating velocities were measured in a two - dimensional channel. These were measured for single-phase flow and on the two sides of a bubble layer, which simulated the two-phase flow.

In single-phase flow the distribution of the time-mean velocities agrees well with other data, while the distribution of the Intensity of turbulence Is lower than expected.

The measurements of the time-mean velocity and turbulence Intensity across the bubble layer revealed that they are …

Turbulence Measurements In Dilute Polymer Flows, Joseph M. Wetzel, John A. Almo, John M. Killen

Symposia on Turbulence in Liquids

A hot-film sensor was flush-mounted in the wall of a four-inch pipe and was calibrated as a function of wall shear stress. Flows with water and with homogeneous aqueous solutions of Polyox WSR-301 were utilized. The heat transfer characteristics of the sensor were reduced for polymer flows. Measurements of the number of zeroes and the frequency spectra for the turbulent fluctuations were obtained for a variety of test conditions. The effects of Polyox WSR-301 on surface pressure fluctuations on both smooth and rough surfaces were also measured.

Experimental Investigation Of Polymer Solution Injection On External Boundary Layers, Brian Latto, Chi-Hung Shen

Symposia on Turbulence in Liquids

This paper describes an experimental study of the effects of injecting dilute aqueous polymer solutions into a turbulent boundary layer formed on a flat plate immersed in flowing water.

Hot-film anemometer techniques were employed in the measurement of the velocity profiles, turbulence intensities, and lateral correlation coefficients at a number of locations along the plate. Boundary layer growth parameters and the variation of the local skin friction coefficient were computed from the velocity profile data. The effects of polymer concentration and injection velocity on the local drag reduction are also presented.

It was found that momentum diffusivity was smaller than …