摘要:

AbstractThe problem of the coating flow of a Newtonian liquid under the influence of a contiguous air flow is considered. The effect of the air flow is simulated by a constant tangential viscous shearing, calculated as the average skin friction per unit area of a boundary layer air flow over a smooth flat plate. Predictions are obtained for the liquid flow characteristics in cases of cocurrent and countercurrent forced air flows. Significant changes in the liquid film thickness start to occur when the absolute value of a dimensionless shearing number, Tn, exceeds 0.01. This value is not sensitive to the other flow parameters. The study is limited to low and moderate liquid Reynolds numbers, when the surface tension forces have considerable to noticeable effect.

ISSN:0008-4034    

DOI:10.1002/cjce.5450600401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractDownward annular two‐phase flow (air‐water) has been examined experimentally. Statistical methods have been applied to calculate the flowrates associated with the hypothetical substrate flow and large wave flow. Agreement with actual Jiquid flowrates under varying gas flows is good. The constant thickness assumption is shown to give significant error. Main characteristics of large waves have also been determi

ISSN:0008-4034    

DOI:10.1002/cjce.5450600402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractExperimental data for the minimum elutriation velocityumeof solids for 134 different systems have been correlated by\documentclass{article}\pagestyle{empty}\begin{document}$$ {\mathop{\rm Re}\nolimits} _{me} = \left( {2.75} \right)\left( {10^4 } \right)\left( {d_p /d_t } \right)^{1.71} \left[ {\left( {\rho _s - \rho _f } \right)} \right]^{0.47} \left( {H/H_s } \right)^{0.19} $$\end{document}The ranges of the different groups investigated were as follows:\documentclass{article}\pagestyle{empty}\begin{document}$$ 0.67 \le \left[ {\left( {\rho _s - \rho _f } \right)/\rho _f } \right] \le 3.33;\,0.00369 \le \left( {d_p /d_t } \right) \le 0.0096\,{\rm and}\,2.74 \le \left( {H/H_s } \right) \le 23.21 $$\end{document}For all of the experiments, the fluidizing liquid was water and the tube had an inside diameter of 4.92 cm. The standard deviation for the above correlation is 21.6 per cent.

ISSN:0008-4034    

DOI:10.1002/cjce.5450600403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractDuring elutriation of binary mixtures of solids differing in size and/or density, it has been found that the rate of decrease in concentration of the finer/lighter component is very fast at the beginning, falls off gradually and assumes an asymptotic value towards the end. The bed at this latter condition seems to have attained a retentive capacity for finer/lighter particles and this concentration has been termed the equilibrium bed concentration,CE. For all practical purposes, this sets the lower limit which the concentration of the elutriating component in the bed can attain, i.e. the maximum degree of removal of the particles from the system under a given set of operating conditions. Based on the experimental values ofCEobtained from concentration versus time plots, an empirical correlation has been proposed as follows:\documentclass{article}\pagestyle{empty}\begin{document}$$ C_E = 16.61\left( {G/G_{me} } \right)^{ - 6.97} \left( {d_1 /d_2 } \right)^{ - 0.29} \left( {\rho _1 /\rho _2 } \right)^{0.36} \cdot \left( {w/W} \right)^{2.01} \left( {H/H_s } \right)^{ - 0.65} $$\end{document}The correlation coefficient and the per cent standard deviation have been calculated to be 0.943 and 20.0, respectively.

ISSN:0008-4034    

DOI:10.1002/cjce.5450600404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThe annular to wavy and intermittent flow pattern transition during condensation inside horizontal tubes was investigated. Eight data sets corresponding to different tube diameters and different test fluids were used to test the predictions of several diabatic and adiabatic correlations. Deficiencies were found in these correlations which prevented consistent agreement with the data base. An improved correlation is proposed and shown to have a good deal of generality and accuracy in predicting this transition.

ISSN:0008-4034    

DOI:10.1002/cjce.5450600405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThe effect of axial conduction was investigated for turbulent heat transfer in a round pipe with uniform wall temperature. Exact solutions were obtained by using the method of separation of variables for the two cases with and without the axial conduction term.The solutions show that the effect of axial conduction is important at low Peclet numbers, say Pe<100, but negligible in the thermally fully‐developed region. Also, the fully developed Nusselt numbers depend only on Reynolds number at low Peclet numbers and the interpolation formula is proposed:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm Nu}_x = 2.77{\mathop{\rm Re}\nolimits} ^{0.0656} $$\end{document}which fits the calculated data well in the liquid metal range 0.001

ISSN:0008-4034    

DOI:10.1002/cjce.5450600406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractThe absorption of pure chlorine into aqueous sodium carbonate solutions accompanied by the desorption of carbon dioxide was studied both theoretically and experimentally. The absorption rates of chlorine and the desorption rates of carbon dioxide were measured at 25°C using a baffled agitated vessel operated batchwise. The experimental results were analyzed with the chemical absorption theory based on the Lévěque model. The measured absorption and desorption rates were in good agreement with the theoretical predictio

ISSN:0008-4034    

DOI:10.1002/cjce.5450600407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractResults of a chromatographic study of diffusion of light hydrocarbons and other permanent gases in 4A and 5A zeolites are reported. The data for CF4and iC4Hm, on 4A sieve (no penetration of the zeolite lattice) suggest that micropore diffusion occurs primarily by a Knudsen mechanism. The majority of the measurements were made with small particles of crushed commercial pelleted zeolites under conditions of intracrystalline diffusion control. The dominance of intracrystalline resistance is shown by the similarity in the time constants obtained with different sizes of particle and the results are generally consistent with earlier gravimetric data. The data for the binary systems containing two adsorbed species are consistent with the simple hypothesis that each species in the mixture diffuses independently with the same intrinsic mobility as for single component diffusion at the same temperature. However, the actual diffusivity of a species in the binary mixture may differ from the pure component diffusivity due to differences in the form of the quilibrium isotherms.

ISSN:0008-4034    

DOI:10.1002/cjce.5450600408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractA thermodynamic description of adsorption from liquid solutions can be used as a basis for a rigorous thermodynamic treatment of ion exchange. Previous treatments were based upon the implicit assumption that the resin phase contains only fixed ionic groups and bound counter‐ions. However, porous ion exchangers can also absorb (or adsorb) the solvent and electrolytes dissolved in it. The observed selectivity of the exchanger depends upon the amount of solvent adsorbed, so that the definition of the boundary (Gibbs dividing surface) between the solid exchanger and the bulk liquid solution becomes important. Instead of the usual counter‐ion selectivity, the variable which describes the uptake of electrolyte is the equivalent of the surface excess. This paper is concerned with the definition and properties of this variable and with the development of an integral thermodynamic consistency test.On peut faire un traitement thermodynamique rigoureux de l'échange d'ions en utilisant une description thermodynamique de l'adsorption à partir de solutions liq

ISSN:0008-4034    

DOI:10.1002/cjce.5450600409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY

摘要:

AbstractA model that takes into account the gas‐phase and liquid‐phase resistance to mass transfer has been developed, where the overall mass transfer coefficient (KOGa) is expressed as a function of the equivalent Sauter‐mean bubble diameter. This parameter was back calculated from mass transfer measurements made at a pilot plant on single pass sieve trays of 0.311 m diameter. Hydraulic parameters were measured for these trays as well. Mean bubble diameters were then correlated as a function of active areaF‐factor and dispersion height for various tray geometries, and these correlations are used to predict point efficiencies on production plant trays up to 8.5 m in d

ISSN:0008-4034    

DOI:10.1002/cjce.5450600410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1982

数据来源: WILEY