摘要:

AbstractIt has been known since 1920 that thing a tube containing a suspension increases the settling rate. The theory of Nakamura and Kuroda is shown to predict both an experimental and theoretical upper limit to this improvement. A small square‐section tube resting on an edge or on a corner is used to study the sculling of suspensions of closely‐sized spherical particles, four concentrations being used at five inclinations to the vertical.The initial settling rate shows no improvement over that obtained in a vertical tube, but a clarified layer is soon formed on the upper inclined face. Hydrodynamic forces then develop which transfer this liquid to the upper surface, thus augmenting the natural settling rate by factors as great as six or seven for the present tube geometry.By introducing a parameter to allow for the resistance to flow within the clarified layer, it is possible to predict the observed behavior on a theoretical basis. In particular, the effect of the concentration of the solid particles on the shape of the settling rate curves is shown to be a logical consequence of the properties of the sys

ISSN:0008-4034    

DOI:10.1002/cjce.5450420502

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

年代:1964

数据来源: WILEY

摘要:

AbstractFlow profiles have been determined experimentally for Newtonian fluids ranging in viscosity from 2,000 to 500,000 cp., flowing over knife‐edged weirs with heights varying from 0.1 to 4.6 in.It has been demonstrated that within the ranges of the variables studied the condition of a flowing system can be defined by specification of four dimensionless groups,\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{h}{{P'}}\frac{x}{{P'}}\frac{Q}{{P^{3/2} \sqrt {g_L } }},\,{\rm and}\,\frac{\mu }{{P^{3/2} \rho \sqrt {g_L } }}. $$\end{document}These groups correspond, respectively, to generalized fluid height, distance upstream, flow rate, and viscosity.The results have been fitted by an empirical equation with a standard error of ± 1

ISSN:0008-4034    

DOI:10.1002/cjce.5450420503

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

年代:1964

数据来源: WILEY

摘要:

AbstractCritical Reynolds numbers were revealed by the study at which the velocity ratio curves typically achieved minimum or maximum values. The pronounced critical condition at Reynolds number about 1,000 is of particular interest, falling as it does in the middle of the Reynolds number range widely regarded as yielding laminar flow in a long circular pipe, but coinciding with the first manifestations of turbulence reported in previous studies.Velocity ratios for both spherical and cylindrical capsules were found to vary from about 1.10 to 1.75 in the laminar flow regime, and from 1.10 to 1.30 at the highest Reynolds numbers.

ISSN:0008-4034    

DOI:10.1002/cjce.5450420504

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

年代:1964

数据来源: WILEY

摘要:

AbstractA systematic experimental study of the minimum spouting velocity of materials with wide and narrow size ranges, mean particle diameters from 0.0134 to 0.104 inches and solids density from 65.8 to 246.3 lb.m/ft.3has been carried out in a 6‐in. column with four inlet sizes at different bed heights. A new correlation is presented in which the standard deviation of experimental from calculated minimum spouting velocity is 6.87%. Some qualitative conclusions on spoutability, segregation, attrition and electrostatic effects have been presente

ISSN:0008-4034    

DOI:10.1002/cjce.5450420505

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

年代:1964

数据来源: WILEY

摘要:

AbstractDiffusional effects on the three general types of catalytic selectivity are studied for complex, isothermal systems. A variable diffusivity evaluated from pore structure‐diffusion models is used to express the influence of mixed modes of diffusion, multicomponent mixtures, and catalytic pore structure on selectivity.Selectivity in complex systems is, in general, lower than that estimated from constant diffusivity analysis, although an optimum particle density may exist for certain cases of parallel reaction. The quantitative estimation of selectivity in complex systems requires some detail on the properties of the reaction and catalyst under stud

ISSN:0008-4034    

DOI:10.1002/cjce.5450420506

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

年代:1964

数据来源: WILEY

摘要:

AbstractEquations are presented for the residence time distribution in multi‐stage systems in which part of the effluent stream is recycled to the inlet of the system. The cases considered include perfect mixing, piston flow and real systems defined by attenuation and time delay factors. Time delay in the recycle stream is also considered. Graphical solutions for several systems are presented. Recycle of part of the effluent stream results in broadening of the residence time distribution and, in addition, produces a discontinuity in the distribution when a time delay is presen

ISSN:0008-4034    

DOI:10.1002/cjce.5450420507

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

年代:1964

数据来源: WILEY

摘要:

AbstractThe vapor‐liquid phase equilibria for the system selenium‐tellurium were determined in the composition range of 40% to 99.999% by weight. Measurements were made by means of a dynamic distillation apparatus at atmospheric pressure and boiling temperatures from 688° to 773°C.Under the above experimental conditions, selenium and tellurium are known to exist in a number of molecular forms, such asSe2,Se4, etc. It was, therefore, necessary to estimate the average molecular weights of the two elements on the basis of published data. An attempt was made to test the thermodynamic consistency of the equilibrium data. The activity coefficient plots were used to extend the experimentalx‐ydata over most of the compositio

ISSN:0008-4034    

DOI:10.1002/cjce.5450420508

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

年代:1964

数据来源: WILEY

摘要:

AbstractAn analytical study of the laminar heat transfer to a power‐law non‐Newtonian fluid in the entrance region of a circular conduit was made. Numerical values of local Nusselt number as well as average Nusselt number were evaluated and shown to be dependent upon Reynolds number, Prandtl number, the parameter z/R and the flow behavior index

ISSN:0008-4034    

DOI:10.1002/cjce.5450420509

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

年代:1964

数据来源: WILEY

摘要:

AbstractThe authors investigate the applicability of the relationshipNsh=A + B NmReNnScto determine over‐all mass transfer rates in forced convection from single solid spheres, where A, B, m and n are presumed to be constants. This expression is shown to be not entirely adequate and, in particular, the changing importance of the wake with increasing Reynolds number and turbulence in the boundary layer will affect these constant

ISSN:0008-4034    

DOI:10.1002/cjce.5450420510

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

年代:1964

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450420511

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

年代:1964

数据来源: WILEY