bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heats of vaporization of hydrogen‐bonded substances
Authors: Bondi A. , Simkin Donald J. 
Published: June 2004

AbstractA new method is proposed for the calculation of the heat of vaporization of hydroxylated compounds to an accuracy of about ±0.5 kcal./mole from no more data than the molecular structure and a boiling point. The older methods, by comparison, achieved an accuracy of about ±1 kcal./mole with a far greater computational effort, since they required the (usually hypothetical) critical temperature and critical pressure in addition to a boiling point.The method is here applied to aliphatic and aromatic alcohols, to ether‐alcohols (e.g., the cellosolves), and to alcohols conaining keto or aldehyde groups (e.g., salicylaldehyde) and supersedes previous correlations covering the heats of vaporization of these compounds. The method can also be used to assess the quality of vapor‐pressure data of the compounds covered by it.The method is based on the assumption that the heat of vaporization consists of two terms, the dispersion energy and the hydrogen‐bond increment (close but not equal to the hydrogen‐bond strength). The first term is calculated from a knowledge of the heat of vaporization of the equistructural hydrocarbon, now easily available from the Tables of A.P.I. Research Project 44. The hydrogen‐bond term is calculated from a set of rules given in the report.The application of the increment method of this report to other properties and other functional groups is the subject of a continuing investigation.
Viscous flow in multiparticle systems: Motion of spheres and a fluid in a cylindrical tube
Authors: Happel John , Brenner Howard 
Published: June 2004

AbstractAn approximate theory for the behavior of multiparticle systems suspended in a viscous fluid is developed, based on a rigorous treatment for the case of a single sphere occupying any position in a cylindrical tube. The results obtained include estimates of the effect of some of the parameters involved on the particle velocities and spatial distribution of particles in very dilute sedimenting and fluidized beds as well as on the pressure drop resulting from passage of fluid. The conclusions presented are in agreement with such experimental data as are available and suggest a basis for more exact treatment of these systems.
Hydroextraction: Flow in submerged cakes
Authors: Storrow J. Anderson 
Published: June 2004

AbstractFlow equations have been proposed for hydroextractor cakes wherein the pores are filled with moving liquid. These equations have been confirmed for the effect of each variable by use of different experimental techniques. The critical wetting rate has provided the most informative steady state, in which the cake is fed with liquid to maintain the inner surface of the liquid at radius rL coincident with that of the cake at radius rc. Transient techniques have also been used wither with a probe to time the movement of a liquid level between two radii less than rc, or with a photoelectric detector to observe the coincidence of rL = rc. The tests have proved the validity of the hydrodynamic assumptions involved in the equations and have provided both precise methods for research and practical methods for industrial purposes.
Radiant heat exchange in a gas‐filled enclosure: Allowance for nonuniformity of gas temperature
Authors: Hottel H. C. , Cohen E. S. 
Published: June 2004

AbstractA method is presented for predicting the effect of allowance for radiation exchange on the distribution of temperature and heat transfer within a furnace chamber. The system is divided into surface zones and gas zones, the number being dependent on the desired accuracy of the result. Direct‐exchange factors are available for gas‐gas, gas‐surface, and surface‐surface zone interchange. From these factors one can determine the net exchange factor for any zone pair, making due allowance for interaction with all other zones. The resultant factors are then fed into a set of energy balances, one on each zone, which by simultaneous solution permit a determination of the space distribution of gas and surface temperatures and the distribution of heat flux over the surfaces.
Heat transfer between fluidized‐solids beds and boundary surfaces—correlation of data
Authors: Wender Leonard , Cooper George T. 
Published: June 2004

AbstractA broad empirical study of nine independent sets of data on fluidized‐bed heat transfer is presented, with correlation of the data in two groups. A wide range of the many variables is covered, and some data on commercial units are included. Data for external (i.e., walls of the fluidizing vessel) and internal (i.e., tubes in the bed) heat transfer surfaces are correlated graphically. The correlations indicate the importance of heat transport by the mobile particles and of unsteady state conduction in the gas.
Distribution of eddy viscosity and mixing length in smooth tubes
Authors: Rothfus R. R. , Archer D. H. , Sikchi K. G. 
Published: June 2004

AbstractProfiles of eddy viscosity and Prandtl mixing length in fluids flowing steadily and isothermally in smooth tubes have been calculated from the velocity data of several investigators for Reynolds numbers between 1.2 × 103and 3.2 × 106. In the transition range unusually high values of eddy viscosity and mixing length are obtained in some portions of the stream. In the fully turbulent range the effect of Reynolds number is small and the mixing length tends toward zero at the center of the tube. The parameters for turbulent flow between parallel plates have been correlated through the concept of an equivalent tube. The results are of importance in designing equipment for heat and mass transfer and mixing.
Convective heat transfer from hightemperature air inside a tube
Authors: Zellnik Herbert E. , Churchill Stuart W. 
Published: June 2004

AbstractLocal rates of convective heat transfer from air at high temperature to a cold wall were measured in the inlet region of a circular tube. Air entered the tube with a flat velocity and temperature profile at temperatures from 480° to 2,000°F. and flow rates corresponding to Reynolds numbers from 4,500 to 22,500. The inner surface of the 1.0‐in. I.D. tube was maintained at approximately 100°F. by water cooling. Local rates of heat transfer were determined at 1.5, 4, 7, and 10 tube diameters from the entrance by measuring the radial temperature profile in thermally isolated, annular sections of the tube wall.The local rate data for all gas temperatures are well represented by previous correlations for small temperature differences if the gas properties are evaluated at the bulk temperature rather than at the film temperature. The data agree well with the data of previous investigators wherever the experimental ranges overlap.
A graphical method for solution of freezing problems
Authors: Longwell P. A. 
Published: June 2004

AbstractProblems in heat conduction involving a moving boundary are encountered in the freezing of liquids and in other situations. Such problems are difficult to solve, and exact solutions are almost unknown. A graphical method for obtaining numerical solutions to problems of this type which can be described in terms of one space coordinate is derived and is demonstrated in two examples involving the freezing of liquids. The method, which does not require specialized knowledge or equipment, takes into account both sensible heats and latent heat.
Film boiling from vertical tubes
Authors: Hsu Y. Y. , Westwater J. W. 
Published: June 2004

AbstractHeat transfer measurements were made with vertical stainless steel bayonet tubes, 3/8 to 3/4 in. O.D., with lengths from 2.6 to 6.5 in. The heat source was steam. The boiling film ΔT ranged from 154° to 314°F. for three organic liquids and from 547° to 788°F. for nitrogen, all at 1 atm. No forced convection was used. Benzene, carbon tetrachloride, and nitrogen on the longer tubes had h values two or three times greater than predicted by the Bromley equation; however, the Reynolds numbers were found to exceed 2,000. Nitrogen on the 2.6‐in. length obeyed the equation; the Reynolds numbers were less than 2,000, the flow was proved by photography to be turbulent and the h values were much higher than predicted for viscous flow. A correlation is given which fits all the data except for methanol. It shows that a vertical orientation is superior to the horizontal for liquids boiling outside tubes.
Heat and momentum transfer in the flow of gases through packed beds
Authors: Glaser Marvin B. , Thodos George 
Published: June 2004

AbstractHeat and momentum transfer studies have been made for the flow of gases through fixed beds consisting of randomly packed, solid metallic particles. The experimental technique employed in these studies made possible for the first time the procurement of gas‐film heat transfer data under steady state conditions and in the absence of mass transfer effects. Electric current passed through the metallic particles of the bed created within the particles a steady generation of heat, which was continuously removed by gases flowing through the bed. Several direct temperature measurements of both gases and solids within the bed made possible the direct calculation of the heat transfer coefficient for the gas film to produce the Colburn heat transfer factor jh, which has been found to correlate with the modified Reynolds number, Reh = √ ApG/[µ(1 – ∈)φ]. The shape factor φ was established in these studies for cubes and cylinders and was found to be identical to their respective sphericities.Pressure‐drop measurements produced a friction factor fk of the Blake type, which yielded separate curves for each shape when correlated with the modified Reynolds number Rem. No simple relationship was found to exist between the heat transfer and friction factors. A single correlation of the pressure‐drop data was obtained for the modulus fkoφn when correlated with a Reynolds number of the type Rem = √ ApG/[µ(1 – ∈)]. The exponent n varies with the particle shape.Experimental runs have been carried out for 3/16, 1/4, 5/16‐in. spheres, 1/4 and 3/8‐in. cubes, and regular cylinders using hydrogen and carbon dioxide to extend the range of molecular weights beyond that of air, used for the majority of these runs. A particle‐size, column‐diameter effect was found to exist for both heat and momentum transfer. This effect becomes significant in the low Reynolds region.
Fluid‐particle heat transfer in packed beds
Authors: Baumeister Ernest B. , Bennett C. O. 
Published: June 2004

AbstractSteady state heat transfer experiments were carried out in a 4‐in. I.D. transite tube packed with 3/8‐, 1/4‐, and 5/32‐in. steel spheres. Heat was generated in the pellets by means of a high‐frequency induction coil surrounding the test section. Average heat transfer coefficients between the bed of spheres and a stream of air passing through the bed were calculated for Reynolds numbers of from 200 to 10,400. To ensure the reproducibility of the data, the bed was repacked six times for each pellet size.A study of the effect of the tube‐to‐pellet‐diameter ratio indicates that this effect is large for low values of the ratio, but much smaller for higher ratios. The results are presented both graphically and in terms of empirical equations. The analogies among heat, mass, and momentum transfer are discussed, and it was found that no simple relation between the heat transfer coefficient and the friction factor exists for packed beds with a gas as the fluid.An attempt is made to predict the heat transfer rates for packed beds from heat transfer data for single spheres and from pressure‐drop measurements for the packed bed; however, the rates predicted from the pressure‐drop measurements are somewhat lower than the experimental results.
Local boiling coefficients on a horizontal tube
Authors: Lance R. P. , Myers J. E. 
Published: June 2004

AbstractLocal boiling heat transfer coefficients were experimentally determined for nucleate boiling around the outer circumference of horizontal copper tubing. The tubes used were of 16 B.W.G. hard‐temper copper with outside diameters of 1 1/4 and 2 in; the liquids boiled were methanol andn‐hexane. The maximum peripheral variation occurred with the 1 1/4‐in. tube in methanol where an over‐all ΔTof 30.2°F. gave local outside coefficients varying between 249 and 548 B.t.u./(hr.)(sq. ft.)(°F.). The minimum variation was found to occur in the same system, in which an over‐all ΔTof 72.3°F. gave coefficients varying between 856 and 910 B.t.u./(hr.)(sq. ft.)(F.°). The results, plotted in polar coordinates, showed a cardioid configuration for methanol with the maximum coefficients occurring at the bottom of the tube. Then‐hexane results had the general shape of horizontal ellipses with maximum coefficients occurring at the sides of the tube.
Rates of flow through microporous solids
Authors: Gilliland E. R. , Baddour R. F. , Russell J. L. 
Published: June 2004

AbstractRates of flow of pure gases, both those with no adsorption and those with appreciable adsorption, were studied as a function of pressure level, pressure drop, and temperature for flow through 1/2‐in.‐diameter cylindrical plugs of activated carbon and of unsintered Vycor glass. Adsorption isotherms for the pure gases on Vycor glass were measured over the range of variables covered in the flow studies. A few measurements were made for bulk liquid flowing through a Vycor plug.Permeabilities, which are proportional to the rate of flow per unit of pressure drop, were satisfactorily correlated for hydrogen, helium, argon, and nitrogen by employing existing gas‐phase flow theory. Permeabilities considerably larger than the values predicted from the nonadsorbed gas correlation, sometimes more than seventeen times as large, were observed for ethylene, propylene, and isobutane flowing through a Vycor plug. For the hydrocarbon‐Vycor systems, permeabilities for vapor flow are as much as sixty times larger than for bulk liquid flow.The unusual flow phenomena for the hydrocarbon‐Vycor systems are attributed to a rapid transport in the adsorbed layer. The total transport is treated as being the sum of gas‐phase and adsorbed‐layer flow. An equation describing adsorbed‐layer movement is derived by utilizing a force balance together with thermodynamic principles. The resulting equation has just one empirical constant, and its use requires adsorption‐isotherm data. It correlates very well the surface flow rates for the major range of the variables covered in this investigation. Rate measurements were made for adsorbed‐layer concentrations ranging from about one tenth of a monolayer up through the capillary condensation region. Deviations in the one constant form of the equation are observed below one tenth of a monolayer. The available literature data on flow in adsorbed layers are reasonably well correlated by the same equation.
Mass transfer from a soluble solid sphere
Authors: Garner F. H. , Suckling R. D. 
Published: June 2004

AbstractMass transfer from 3/8‐ and 1/2‐in.–diameter spheres of adipic acid and from 3/8‐, 1/2‐, 5/8‐ and 3/4‐in.‐diameter spheres of benzoic acid into a controlled stream of water passing in laminar flow through a 3‐in.‐diameter pipe is found to be correlated by the single equaton NSh = 2 + 0.95 NRe0.5 NSc0.33 for sphere Reynolds numbers between 100 and 700. The limitations on the application of this equation, due to mass transfer by natural convection, are discussed. Correlations are also obtained for transfer from separate regions of the sphere surface.Skin–friction‐drag coefficients for single fixed spheres have been calculated from reported pressure distributions for Reynolds numbers between 100 and 1,000.Good agreement is obtained between the mass transfer j factor and other reported values for heat transfer, but comparison with the calculated frictional forces indicates that the equality proposed by Colburn (3) does not hold, because the distributions of the mass transfer and the skin friction over the surface differ.
Calculation of the diffusion coefficient of dilute gases and of the self‐diffusion coefficient of dense gases
Authors: Slattery John C. , Bird R. Byron 
Published: June 2004

AbstractA corresponding‐states correlation of low‐density binary‐ and self‐diffusion coefficients is presented. The equations are simple to use, are sufficiently accurate for most calculations, and correlate those data used in their derivation somewhat better than calculations based on the Lennard‐Jones potential if potential parameters have to be estimated from the critical properties. The Enskog kinetic theory of dense gases is used in modified form to obtain an expression for the high‐density diffusion coefficient for isotopic mixtures in terms of the viscosity and compressibility of the gas. Generalized viscosity and compressibility charts are then used to construct a graph for predicting a reduced self‐diffusion coefficient as a function of reduced temperatureTr=T/Tcand reduced pressurepr=p/pc. The effect of the pressure on the Schmidt number, Sc = μ/ρ𝒟, is also discussed. Finally the extension of this chart to nonisotopic mixtures is considered.
The role of porosity in filtration part 3: Variable‐pressure—variable‐rate filtration
Authors: Tiller F. M. 
Published: June 2004

AbstractVirtually all filtration literature has been concerned with constant rate or constant pressure with greater emphasis on the latter. In contrast to these types of operations, industrial filtrations involving centrifugal pumps are accomplished under variable‐pressure—variable‐rate conditions. In spite of its importance virtually no work has been reported in connection with variable‐rate—variable‐pressure filtration. Formulas developed for constant pressure and constant‐rate filtration are not in general applicable to operations effected by centrifugal pumps. Methods solving variable‐pressure—variable‐rate filtration problems are presented.A method of determining average filtration resistance as a function of compressive pressure under variable‐pressure—variable‐rate conditions is discussed, and formulas for determining point filtration resistance from data for average resistances are presented.
Prediction of resistance in constant‐pressure cake filtration
Authors: Kottwitz F. A. , Boylan D. R. 
Published: June 2004

AbstractMethods of predicting resistance in constant‐pressure cake filtration have been classified into three groups, (1) basic particle and cake properties, (2) permeability tests, and (3) small‐scale filtration tests. Methods 2 and 3 involve the concept of specific filtration resistance, a property characteristic of each unit mass of deposited cake, and these methods were extensively investigated in the laboratory. Specific resistances for three chemical slurries were determined by laboratory filtrations and filter‐ and compression‐permeability tests. Results of these investigations showed that specific filtration resistance could be predicted from compression‐permeability test data.Filtration tests made on commercial‐scale equipment operating on pearl cornstarch illustrated the correlation between predicted and actual specific resistance values, the resistance predicted from compression‐permeability test data agreeing very well with the actual resistance of the prefilt.
Momentum and mass transfer by eddy diffusioin in a wetted‐wall channel
Authors: Dhanak A. M. 
Published: June 2004

AbstractThe role of eddy diffusion of mass (water vapor) and momentum was investigated in a specially devised wetted‐wall channel in which the rippling of the liquid film was eliminated. The experimental measurements of the turbulent exchange coefficients for mass and momentum transport were carried out in a fully developed turbulent flow of air within the range of Reynolds numbers of 8,00 to 160,000. A correlation with Reynollds number revealed an approximately linear relationship of the eddy diffusivties to Reynolds number revealed an approximately linear relationship of the eddy diffusivities to Reynolds number [Equation (4)]. From the hot‐wire measurements it was found that within the main protion of the turbulent core eddy diffusivities remained fairly constant.
Heat transfer in film condensation
Authors: Baer Eric , McKelvey James M. 
Published: June 2004

AbstractIn this theoretical analysis of heat transfer in film condensation the total vapor‐side resistance to heat transfer is obtained by adding the resistance to conduction through the condensate film to the resistance due to the condensation process at the vapor‐liquid interface.The analysis shows that under ordinary conditions conduction in the condensate film is controlling, provided the condensation coefficient is greater than about 0.10. However, under conditions of low total pressure, low heat flux, or low condensation coefficient, the resistances of both processes must be considered.Experiments carried out on the condensation of methanol are in good agreement with the theory. Furthermore, values of the condensation coefficient for methanol are reported which show that small quantities of air will greatly reduce its magnitude. This is offered as an explantion of the commonly observed phenomenon of reduction of heat transfer rates when noncondensable gases enter a system.
Gas absorption accompanied by a liquid‐phase chemical reaction
Authors: Gilliland E. R. , Baddour R. F. , Brian P. L. T. 
Published: June 2004

AbstractThe rate of absorption of chlorine from chlorine‐nitrogen mixtures into solutions of ferrous chloride in 0.203 N aqueous hydrochloric acid was studied in a short wetted‐wall column. Dimensional analysis and the film and penetration theories were used to infer, from the absorption rate data, that the chemical reaction between chlorine and the ferrous ion is second order. The absorption‐rate results for experiments with a dilute gas phase agreed with theoretical predictions for absorption accompanied by a second order reaction with a reaction rate constant of 188 liters/(g. mole) (sec.). The results for experiments with pure chlorine gas deviated from the rest of the results, and they did not agree with the theoretical equations. It was shown that the assumption of a three‐step mechanism for the chemical reaction, including the formation of a complex ion and the decompositon of this complex ion, explains, at least qualitatively, the deviations observed for the pure chlorine gas runs.
Correlation of local velocities in tubes, annuli, and parallel plates
Authors: Rothfus R. R. , Walker J. E. , Whan G. A. 
Published: June 2004

AbstractA consistent method is presented for predicting local velocities in smooth tubes, concentric annuli, and parallel plates. Consideration is limited to the steady, isothermal, fully turbulent flow of constant‐density fluids. Experimental data show the proposed correlation to be indepdent of Reynolds number and radius ratio. Intermediate quantities, calculated from friction data, permit local velocities to be determined over a wide range of operating conditions.
Discharge coefficients through perforated plates at reynolds numbers of 400 to 3,000
Authors: Smith P. L. , Van Winkle Matthew 
Published: June 2004

AbstractThe correlation of Kolodzie and Van Winkle (3) for predicting dry plate orifice coefficients through perforated plates originally covering a Reynolds number range of 2000 to 20,000 has been extended to apply to Reynolds numbers as low as 400. The correlation applies to column diameters ranging from 3 to 15 in.