摘要:

AbstractAn experimental study of superposed free and forced convection for air in a horizontal tube is reported. The laminar Nusselt number, based on the log mean temperature difference, ranged from 29.9 to 15.2; the laminar flow Graetz number, based on the bulk or average temperature of the air, ranged from 33 to 1,300, the Grashof‐Prandtl modulus based on properties of air at the wall temperature ranged from 1.1 × 106to 2.2 × 106. The Grashof number utilized the log mean temperature difference. An analysis of the system from a macroscopic viewpoint led to the determination of an equation which fits the laminar flow experimental data in the range of Graetz numbers from 60 to 1,300. An equation was also found for the turbulent d

ISSN:0001-1541    

DOI:10.1002/aic.690070111

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractIn recent years there have been quite a few experimental studies on turbulent flow in annuli. In this paper a Prandtl mixing‐length approach is applied to give a friction factor vs. Reynolds number expression for annuli [see Equation (22) and Table 1]; this expression describes tube flow and slit flow as special cases. No new adjustable constants appear in the final result other than those determined earlier for tube flow. The final expression is found to predict friction factors within the accuracy of the existing experimental data. The mixing‐length friction‐factor expression is thus substantially more accurate than the usual hydraulic‐radius procedure and of comparable accuracy to other recent annulus friction‐factor t

ISSN:0001-1541    

DOI:10.1002/aic.690070112

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractIn a previous publication it has been shown that for the case of liquid droplets moving through a second quiescent liquid the holdup vs. slip‐velocity ratio could be predicted on the basis of analogous rigid sphere fluidization data. The present paper extends these results to cover the countercurrent flow of both liquid phases. As long as the system is operated below the flooding point, the behavior of the spray column can be predicted from the corresponding solids fluidized dat

ISSN:0001-1541    

DOI:10.1002/aic.690070113

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractMass transfer coefficients have been measured for air flowing through a bed of naphthalene pellets. Results were obtained for ⅜‐in. spheres and for ½, ⅜, and ¼‐in. cylinders in a bed 4 in. in diameter and packed to heights varying from 5 to 10 in. Radial concentration profiles were obtained for some conditions, from which the radial variation of the mass transfer coefficient was determined. The point‐values ofkgfollow an equation of the formkg=a Gb. From mixed outlet concentrations, values ofkgavandjd, corrected for the effect of axial diffusion, have been obtained for all the pellet sizes as functions of mass velocity and Reynolds number, r

ISSN:0001-1541    

DOI:10.1002/aic.690070114

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractThis paper summarizes an experimental study of turbulent diffusion downstream of a line source of heat. Mean temperature profiles in the core of nearly fully developed pipe flow were measured at four mean velocities, fromUc= 72.6 to 160 ft./sec. Hot‐wire anemometer surveys showed that the turbulence in the axial core was nearly homogeneous and isotropic. The objective was to find empirical relations between the anemometer (Eulerian) specification of the turbulence and the Lagrangian statistical properties which determine diffusion.The diffusion results agreed with predictions of G. I. Taylor's theory of diffusion by continuous movements; the eddy diffusivity increased from zero at the heat source to a constant, asymptotic value far downstream. The Lagrangian correlation coefficients inferred from the diffusion data had shapes similar to the Eulerian correlations over most of the range of time and space. Empirical relations were found to relate the coordinates of the Lagrangian and Eulerian correlation coefficients over the range of this experiment. In addition preliminary measurements are reported for a general Eulerian correlation which is a function of both space and time; the results indicate that a special case of this new Eulerian function may be a fair approximation of the Lagrangian correlatio

ISSN:0001-1541    

DOI:10.1002/aic.690070115

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractA continuous velocity distribution is derived which is based on an arbitrary modification of Prandtl's mixing length expression. The resulting velocity distribution agrees well with experiments for transition and fully developed turbulent flow throughout the entire cross section of the conduit. Furthermore the mixing length expression applies to parallel flow in smooth circular tubes and between infinite parallel plates with the same set of constants.

ISSN:0001-1541    

DOI:10.1002/aic.690070116

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractMiscible displacement as an oil recovery process has received wide interest in the literature recently. Essentially three basic processes have been proposed for attaining miscible displacement in our oil reservoirs: high pressure gas, enriched gas, and miscible slug processes.The present paper relates and compares the phase relations and mass transfer mechanisms of these various basic miscible displacement processes. It also discusses the effects of the various operating variables, such as pressure, temperature, injected gas composition, etc., on the applicability of the process and considers the pertinent conditions that restrict the application of each process. It is to be recognized that at times a miscible displacement may be attempted but not attained, or unforeseen conditions may destroy miscibility once it has been attained. The authors discuss the results of such conditions. The mechanisms of the miscible displacement processes are explained in a conceptual analysis based on the triangular phase diagram. Although the multicomponent reservoir fluid system cannot be represented rigorously from a thermodynamics standpoint by these diagrams, they are useful for cenceptual analysis. Their limitations are presented by the authors along with data supporting the concepts developed.

ISSN:0001-1541    

DOI:10.1002/aic.690070117

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractThe mixing efficiency of simple and pitched paddles, marine propellers, and centrifugal and disk impellers was determined by a heat transfer method in a single stage of a large pump‐mix mixer‐settler. The mixing devices were from 3 to 5 in. in diameter and were tested with a refined kerosene as the organic phase and water as the aqueous phase.A heat conductance was calculated from flow parameters and the efficiency and was correlated against impeller design and speed variables. For centrifugal and disk impellersUAwas proportional ton1.2L3b0.3; for the paddlesUAwas proportional ton1.67L2.5b0.42. At normal operating speeds controlled variation of the internal recirculation of mixed phases through a centrifugal impeller did not change the efficie

ISSN:0001-1541    

DOI:10.1002/aic.690070118

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractThe results obtained by the evaporation of water and nitrobenzene in air from celite spheres in conjunction with the prevailing surface temperature have permitted the simultaneous determination of mass and heat transfer factors. The spheres used were 1.42, 1.88, and 2.00 in. in diameter. The experimental results of this study show that an essentially direct correspondence exists for mass and heat transfer in the flow of fluids past single spheres.

ISSN:0001-1541    

DOI:10.1002/aic.690070119

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY

摘要:

AbstractMethods for expressing, measuring, and correlating drop‐size distribution data for centrifugal spray nozzles are discussed.A method for collecting spray droplets in liquid nitrogen is described which is rapid and efficient for most sprayed liquids which freeze above —20°C. Comprehensive correlations for drop‐size distributions are reported based on 114 runs performed with the liquid nitogen

ISSN:0001-1541    

DOI:10.1002/aic.690070120

出版商:American Institute of Chemical Engineers    

年代:1961

数据来源: WILEY