摘要:

AbstractFlooding in countercurrent flow of air and water in inclined tubes has been investigated. Data on flooding inception in the whole range of inclinations have been collected and predictive models for calculating the flooding conditions as a function of the flow rates and pipe inclination were proposed.Special attention is placed on the effect of the liquid injection mode. It has been shown that the porous injection system causes a local disturbance and enhances flooding at relatively shallow inclinations and high liquid flow rates.

ISSN:0008-4034    

DOI:10.1002/cjce.5450640202

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe variation of Taylor‐vortex flow structure with the width of the annulus between concentric cylinders has been studied in combined axial and rotating flow by a direct visualization technique using analytical indicators. The existence of inclined wavy vortex flow with specific transition paths between several wave modes is demonstrated in the low axial Reynolds number range (0

ISSN:0008-4034    

DOI:10.1002/cjce.5450640203

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

年代:1986

数据来源: WILEY

摘要:

AbstractVelocity profiles for the inner and outer flow regions of annuli are proposed for the turbulent flow of drag reducing fluids. Theoretical expressions for friction factors are developed. From the shear stress equations and the velocity profiles, estimates for the entrance lengths are given.

ISSN:0008-4034    

DOI:10.1002/cjce.5450640204

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe choking velocity is the minimum gas velocity required for the vertical dilute phase transport of a given solids flux. Experimental choking velocities obtained from the literature for both monosize and multisize particles were compared to choking velocities predicted with various published correlations. For monosize particles, Yang's correlation (1983) gave the most accurate predictions. For multisize particles, all the literature correlations gave rather poor predictions. Much more accurate predictions were obtained with a new simple physical model which assumes that an annulus forms along the pipe wall at low gas velocities. Choking then occurs when this annulus occupies approximately 25% of the total pipe cross‐sectional are

ISSN:0008-4034    

DOI:10.1002/cjce.5450640205

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

年代:1986

数据来源: WILEY

摘要:

AbstractA method for calculating the collection efficiency of particles by a row of cylinders in a viscous fluid is presented. The Navier‐Stokes equation is solved by the finite element method to determine the carrier gas velocity field. Then, the particle equation of motion is also solved by the finite element method to find the particle velocity of impact. Finally, the collection efficiency is obtained by integration of the intercepted particles on the cylinder surface. Results of this model are compared with other theoretical models as well as with some experimental dat

ISSN:0008-4034    

DOI:10.1002/cjce.5450640206

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

年代:1986

数据来源: WILEY

摘要:

AbstractLes exemples d'utilisation des aérosols générés par voie pneumatique ou ultrasonique dans l'élaboration de couches minces de composés divers (oxydes, semi‐conducteurs etc.) sur des substrats variés sont nombreux. Cependant, si les auteurs rapportent des résultats sur la composition chimique et les propriétés physiques des revêtements, ils ne font pas état d'études sur les conditions hydrodynamiques de l'écoulement de l'aérosol. Le travail présenté ici a pour but de montrer l'importance de ce paramètre et d'en faire ressortir les incidences sur la composition, la morphologie et les pro

ISSN:0008-4034    

DOI:10.1002/cjce.5450640207

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

年代:1986

数据来源: WILEY

摘要:

AbstractA new method which combines analytical and numerical solutions is presented for analyzing coupled transport phenomena between multiple regions. The method was applied to simulate heat transfer from hot laminar forced downward convection in a parallel plate duct to external natural convection through a finite section of one wall. Obtained numerical results showed that the longitudinal wall conduction markedly relaxed the thermal interaction between the two convection systems. Experiments were also performed, using conducting walls made of aluminum, stainless steel and granite. Predicted temperature profiles agreed well with the experimental data.

ISSN:0008-4034    

DOI:10.1002/cjce.5450640208

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

年代:1986

数据来源: WILEY

摘要:

AbstractIt is shown that the presence of a “slotted draft tube” results in reduced air requirements for spouting and improved drying performance. Experimental data are presented on batch as well as continuous spouted bed drying of wheat, paddy, maize and peas. The variables studied are feed moisture content (Qo), inlet air temperature (To), bed mass hold‐up (Mp), inlet superficial air velocity (uo) and bed diameter (Dc) in batch drying, and the above variables and solids feed rate (Fs) in continuous drying. The data on average overall drying rate, ϕm, in kg moisture evaporated per unit time per kg bed solids, is found to be correlatable as ϕm, =k(50Qo+ 0.118To− 12.5) 10−5, and the single parameterkis presented for wheat, paddy, maize and peas for both batch and continuous modes of spouted bed drying. The correlation obtained should be useful in dryer design for the grains studied as well as for other simila

ISSN:0008-4034    

DOI:10.1002/cjce.5450640209

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe absorption of carbon dioxide by aqueous glycerine solutions in a column containing a string of spheres and cylinders has been studied. The Reynolds number was varied between 5 and 560. Using a model based on Higbie's penetration theory, modified to fit the characteristics of this absorber, the number of surface renewals that takes place in the column has been evaluated and correlated with the operating variables that can influence it. The liquid viscosity has no influence on the surface renewal which depends mainly on the liquid rate.

ISSN:0008-4034    

DOI:10.1002/cjce.5450640210

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

年代:1986

数据来源: WILEY

摘要:

AbstractIn searching for solvents that are able to absorb sulfur dioxide and nitric oxide, solvents triethylenetetramine, diethylenetriamine,N‐cyclohexyl‐2‐pyrrolidone andN, N, N',N'‐tetraethylethylenediamine have all been tested. It was found that triethylenetetramine andN, N, N',N'‐tetraethylethylenediamine absorb nitric oxide, while this gas is not absorbed byN‐cyclohexyl‐2‐pyrrolidone and diethylenetriamine. Sulfur dioxide, besides being absorbed by triethylenetetramine, is also absorbed by diethylenetriamine andN‐cyclohexyl‐2‐pyrrolidone.The Henry's law constants and activity coefficients at infinite dilution of the gases in the absorbing solvents were determined by gas

ISSN:0008-4034    

DOI:10.1002/cjce.5450640212

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

年代:1986

数据来源: WILEY