摘要:

AbstractA simple empirical model is developed based on two‐dimensional linearized Rayleigh‐Taylor stability theory to describe the break‐up of drops and bubbles in stagnant fluids. Splitting is predicted to occur if the growth of indentations on the leading edge is rapid enough relative to the rate at which the disturbance is carried around the interface to the equator. Experimental data on maximum stable sizes of drops and bubbles in viscous liquids are presented for eighteen different systems, covering a range much larger than in previous studies. Agreement between the model and experimental results is favou

ISSN:0008-4034    

DOI:10.1002/cjce.5450560101

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe available literature data for the drop diameter, hold‐up and backmixing coefficients were tested experimentally in a pilot plant size spray column. For all these parameters correlations were found which gave results in agreement with the experimental data so that reasonable prediction is possible. Different equations were compared and the ones giving the best fit are recommende

ISSN:0008-4034    

DOI:10.1002/cjce.5450560102

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe influence of viscoelasticity and of the shear‐dependent viscosity of ambient liquids on the motion of liquid drops was examined experimentally. In the low Reynolds number region (Re10 irrespective of rheological complex

ISSN:0008-4034    

DOI:10.1002/cjce.5450560103

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

年代:1978

数据来源: WILEY

摘要:

AbstractLa vitesse minimum de mise en fluidisation d'une charge de particules sphériques par un liquide est relié aux variables caractéristiques du système par la relation:\documentclass{article}\pagestyle{empty}\begin{document}$$ Re_{m} = 1.54\,10^{- 2} {\rm Ga}^{0.65} {\rm Mv}^{0.70} $$\end{document}Cette corrélation, contrairement à celles rencontrées dans la biblographie, ne fait pas intervenir le degré de vide de la couche au seuil de fluid

ISSN:0008-4034    

DOI:10.1002/cjce.5450560104

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe Joule‐Thomson effect is known to be important in arctic gas pipelines. The Joule‐Thomson effects on forced convective heat transfer in the thermal entrance region of pipes with uniform wall temperature are studied for steady fully developed turbulent gas flows by the Graetz method. Thermal entrance heat transfer results are presented for Prandtl number 0.72, Reynolds number 105and Brinkman number ± 0.1, ± 1.0 with Joule‐Thomson parameter Jμ ranging from 0 to 1.0 to cover the possible range in practical applications. Bulk temperatures and Nusselt numbers are also presented for fully developed flow with Reynolds numbers from 5 × 103to 106. For given Prandtl and Reynolds numbers, the asymptotic Nusselt number is found to be dependent on the Joule‐Thomson parameter only and is independent of Brinkman number. The fully developed bulk temperature is a linear function of Brinkman number and a linear relationship exists between the bulk temperature parameter (‐θbf/Br) and the Joule‐Thomson parameter Jμ for given Prandtl and

ISSN:0008-4034    

DOI:10.1002/cjce.5450560105

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

年代:1978

数据来源: WILEY

摘要:

AbstractLiquid‐liquid binary mass transfer involving simultaneous transfer of an organic phase component to the aqueous phase and an aqueous phase component to the organic phase in water‐n butanol and water‐methyl ethyl ketone systems has been studied in a vertical ejector system. Correlations have been developed to predict both dispersed and continuous phase film capacity coefficients as function of various physical and dynamic variables of the s

ISSN:0008-4034    

DOI:10.1002/cjce.5450560106

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

年代:1978

数据来源: WILEY

摘要:

AbstractCocurrent and countercurrent absorption and desorption of CO2in water was investigated in tall bubble columns (length 440 and 720 cm, diameter 15 and 20 cm, respectively). Operating conditions were applied which provided for high interphase mass transfer rates. Under these circumstances the relative gas holdup varies considerably with axial position whereas the mean bubble diameter measured at two points was found to be approximately constant. The measured data permit the calculation of local values of interfacial areas, superficial gas velocities, and frequency factors for bubble coalescence and break up.A dispersion model which takes into account the hydrostatic head and a variable gas velocity was applied to describe the measured concentration profiles in both phases. If increased mass transfer coefficients at the column bottom and measured local values of the hold up were used a striking agreement between experimental and predicted profiles could be obtained. The findings lead to a more sophisticated picture of the complex behaviour of gas‐liquid dispersions at high interphase mass transfer rate

ISSN:0008-4034    

DOI:10.1002/cjce.5450560107

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe extended crossflow model is proposed and developed for describing gas absorption with chemical reaction in a packed bed operated in the trickle flow regime. The model involves the division of the total interfacial area into the interfacial area of the static hold‐up and that of the dynamic hold‐up. The concept of the effectiveness of the interfacial area of the static hold‐up is presented. A procedure is developed for calculating the effectiveness, and consequently, the effective interfacial area for various different absorption processes with chemical reaction, both liquid phase controlled and gas phase controlled. The predictions based on the present model agree well with reported experimental data. The present model is shown to be simpler and more accurate than previous m

ISSN:0008-4034    

DOI:10.1002/cjce.5450560108

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

年代:1978

数据来源: WILEY

摘要:

AbstractNiO‐MoO3‐Al2O3based hydrodesulphurization catalysts appear to be of long term interest in the processing of Athabasca bitumen to eliminate organo‐bonded sulphur and nitrogen‐containing groups. This study employs such a catalyst (NALCO NM 502: 2% NiO, 14.0% MoO3, and γ‐Al2O3) in rate measurements of the vapor‐phase reaction of thiophene with hydrogen using an integral fixed‐bed reactor operated at about atmospheric pressure and in the temperature range, 270 to 350°C. Both power‐law and mechanistic models were fitted to the data; discrimination amongst the later being based upon consistency with physicochemical observations and the power‐law behaviour. The kinetic parameters for these models were contrasted with those obtained by a number of other workers for primarily C

ISSN:0008-4034    

DOI:10.1002/cjce.5450560109

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe kinetics of the vapor phase oxidation of benzene has been studied over an industrial catalyst in a continuous stirred tank reactor in the temperature range from 280 to 430°C and at atmospheric pressure. The products obtained are maleic anhydride, carbon oxides and water. The rate of the overall reaction (disappearance of benzene) is represented by the following expression based upon a steady state adsorption model\documentclass{article}\pagestyle{empty}\begin{document}$$ \gamma _B = \frac{{k_B k_o P_B P_O^{1\backslash 2} }}{{k_O P_O^{1/2} + 4k_B P_B }} $$\end{document}The rate of formation of maleic anhydride is correlated by the equation\documentclass{article}\pagestyle{empty}\begin{document}$$ \gamma _M = \frac{{k_B k_O P_B P_O^{1\backslash 2} }}{{k_O P_O^{1/2} + 4k_B P_B }} - k_2 (g)P_M^{0.5} $$\end{document}which allows for a homogeneous depletion of maleic anhydride. The rate constants kB, kO, k2(g)were found to follow Arrhenius behavior.\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{ccl} {\ln k_B } & = & {\frac{{13.40}}{R} - \frac{{24\,576}}{{RT}}} \\ {\ln k_O } & = & {\frac{{67.83}}{R} - \frac{{64\,280}}{{RT}}} \\ {\ln k_2(g)} & = & {\frac{{3.43}}{R} - \frac{{33,427}}{{RT}}} \end{array} $$\end{document

ISSN:0008-4034    

DOI:10.1002/cjce.5450560110

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

年代:1978

数据来源: WILEY