摘要:

AbstractHeat transfer coefficients were measured experimentally for carbon dioxide in turbulent flow in an 0.18‐in. I.D. pipe. The pressure was 1,200 lb./sq. in. abs. and the bulk temperature varied from 70° to 120°F. In this critical region the coefficients between fluid and tube wall ranged from 300 to 2,600 B.t.u./(hr.)(sq. ft./°F.) over a Reynolds number interval of 30,000 to 300,000.Existing empirical and semitheoretical correlations were found inadequate in this region, where the thermal conductivity, viscosity, density, and specific heat are all varying rapidly and nonuniformly with temperature. A method of integrating the heat and momentum transfer equations with variable physical properties, recently proposed by Deissler, was applied to the experimental data and found to fit well. The application required extensive calculations, which were carried out with an Electrodata digital computer.A simplified procedure was proposed for estimating heat transfer coefficients in the critical region by using a semitheoretical equation developed for zero heat flow. Simple rules were suggested for estimating the temperature at which to evaluate the physical properties when this equation is applied to the realt case of finite heat transfer. The method worked well when compared with the computed heat transfer coefficients of Deissler for supercritical wate but showed about 30% deviation when compared with the carbon dioxide results. This discrepancy is believed due to the fact that the carbon dioxide was very close to the critical point (reduced pressure = 1.1) but the water was somewhat further removed (reduced pressure =

ISSN:0001-1541    

DOI:10.1002/aic.690030110

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractLiquid extractions of benzoic acid–toluene solutions by means of water were studied under varying flow rates of both solvents in a 2‐in. perforated‐plate column to which pulsations of different frequencies and amplitudes were applied. Studies on reversal of the phase of the dispersion were made. With fixed flow rates of both solvents, the rate of extraction increased much more rapidly when the flow through the perforation became turbulent. The results are correlated by means of Reynolds number based on the flow through the perforations and are calculated from the product of the frequency and amplitude of the pulsa

ISSN:0001-1541    

DOI:10.1002/aic.690030111

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690030112

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractCarbon tetrachloride was evaporated into a stream of air over ranges of gas concentration from 0 to 0.70 mole fraction carbon tetrachloride, Reynolds number from 600 to 15,000, and Schmidt number from 0.23 to 1.17. The data were correlated by an equation and also by a computer solution to the differential equation describing mass transfer from values of eddy viscosity and eddy diffusivity obtained from the literature.

ISSN:0001-1541    

DOI:10.1002/aic.690030113

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractThe equations and graphs presented here for the vapor‐liquid equilibrium of the nitrogen‐argon‐oxygen low‐temperature system are based on published binary and ternary experimental data involving mixtures of nitrogen, argon, and oxygen, and on careful thermodynamic study over a period of years of accurate plant‐performance data on tall, large air‐rectifying columns operating near the minimum reflux ratios. The plants have achieved separations that are impossible according to some of the published equilibrium data, and thus the plant data have made a major contribution toward the preparation of

ISSN:0001-1541    

DOI:10.1002/aic.690030114

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractMeasurements are reported on axial mixing of binary gas mixtures at room temperature and atmospheric pressure in a random bed of spherical particles. By means of the Fick's Law equation for diffusion an axial Peclet number,dpU/Ez(wheredpis particle diameter,Uis interstitial velocity, andEzis axial eddy diffusivity), was computed in terms of the ratio of the amplitudes of a sinusoidal concentration wave at the inlet and outlet of the bed. An experimental method was devised to eliminate end effects in the system. For the gas systems H2N2and C2H4N2and for Reynolds numbers between 100 and 400 the mean of twenty‐one determinations of axial Peclet number was 1.88 ± 0.15. This value is in excellent agreement with a value of 2.0 predicted theoretically on the assumption that the bed acts as a series ofnperfect mixers, wherenis the number of particles traversed between inlet and outlet.Axial diffusivity for turbulent flow of gases among particles is about sixfold larger than radial diffusivity, previously determined. It is suggested that axial diffusivity may not, perhaps, be neglected in contacting devices, such as adsorbers and catalytic re

ISSN:0001-1541    

DOI:10.1002/aic.690030115

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractThis paper presents the first theoretical analyses combined with an experimental study of the variables controlling heat transfer rates to non‐Newtonian fluids in the streamline‐flow region. The theoretical analyses, for the limiting types of non‐Newtonian materials, were related to the intermediate case of Newtonian behavior to form a coherent theory applicable to Newtonian and non‐Newtonian fluids alike.The experimental data covered Graetz numbers between 100 and 2,000 and were correlated with a mean deviation of 13.5%. The flow‐behavior indexes of the three non‐Newtonian fluids used varied form 0.18 to 0.70.Some preliminary non‐Newtonian results are presented on the problems of nonisothermal fluid‐flow pressure losses and heat transfer outside the laminar‐flow region. Further theoretical work is recommended in both these areas. Additional experimental data would be of value in all of the p

ISSN:0001-1541    

DOI:10.1002/aic.690030116

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractThis paper describes further research on a 4‐in. I.D. by 8‐ft. spray tower of Elgin design. Previous work concerned limiting flow and holdup in this tower. Owing to its high capacity and low cost, the spray tower would have much greater commercial application in liquid‐liquid extraction if its conditions of transient operation could be predicted and if it could be operated to yield lowHtvalues. This research attempts to show that transient conditions can be predicted and that lowHtvalues for both mass and heat transfer can be realized near the limiting flow conditions.Theroretical equations for rate of approach to steady state derived and tested for the systems ethylene dichloride–water–propionic acid and ethylene dichloride–water–acetic acid show that the approach depends on the ratio of the phase flow rates. This study is important for the prediction of start‐up time for industrial towers.With the same systems the extraction capacity of the spray tower was investigated up to the condition of rejection. The results were correlated asKEaandHt,OEvs. a function of the ratio of the phase flow rates. The dispersed‐phase flow rate was found to have primary significance.The heat transfer rates between water as continuous phase and solvents of various denisties were correlated asHt′ values plotted against a function of the ratio of the phase flow rates. The advantages of operation near rejection were demonstrated, and the effect of direction of heat transfer was foun

ISSN:0001-1541    

DOI:10.1002/aic.690030117

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

摘要:

AbstractThe viscosity of a suspension is related to the properties of the suspending liquid and the suspended particles by measuring the viscosity of suspensions made up of closely sized materials such as glass spheres, plastic Zeolite spheres, blasting sand, and salt cubes in a wide range of concentrations in liquids of varying properties made up of castor oil, tetrabromoethane and carbon tetrachloride, or corn syrup and water. The measurements were made under carefully controlled conditions by means of a Brookfield viscometer, and the reproducibility of results was demonstrated by repetitive runs.Equations are derived to describe the viscosities of these various suspensions in terms of the viscosity and density of the suspending liquid and of the shape, size distribution, density, and concentration of solid particles. The range of concentration covered is from infinite dilution to near infinite viscosity.The results obtained can best be explained by postulating nonuniform distribution of particles in a suspension in a network of tetrahedral and simple cubical packings.

ISSN:0001-1541    

DOI:10.1002/aic.690030118

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690030119

出版商:American Institute of Chemical Engineers    

年代:1957

数据来源: WILEY