摘要:

AbstractThis paper is concerned with the optimization of multistage separation processes using the method of dynamic programming. In particular, optimal (economic) design and operating conditions are determined for binary, multistage mass transfer processes and for solid separation equipment. In the solid separation model, multicomponent feeds are considered. Examples are given in each case to illustrate the computational aspects of dynamic programming.

ISSN:0008-4034    

DOI:10.1002/cjce.5450410502

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

年代:1963

数据来源: WILEY

摘要:

AbstractThis paper reports the results of a theoretical study on mass transfer from solid surfaces to fluids in turbulent flow in circular or rectangular conduits. A combined molecular and eddy diffusion mechanism was assumed; three different cases of eddy‐distribution functions were considered.Analytical results were obtained for concentration profiles, mass transfer coefficients and reaction factors in cases of mass transfer without reaction, with rapid chemical reaction, and with first‐order chemical reaction. Mass transfer coefficients were shown to vary linearly with\documentclass{article}\pagestyle{empty}\begin{document}$ \left({\frac{D}{v}} \right)^n $\end{document}. The exponentnincreased from 0.5 to unity as eddy motion assumed near the wall decreased to zero. The reaction factor was shown to increase with decreasing turbulence near the interface, with the reactant concentration ratio,CBL/CA1and with the Schmidt number ratio,ScA/ScB9to the pow

ISSN:0008-4034    

DOI:10.1002/cjce.5450410503

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

年代:1963

数据来源: WILEY

摘要:

AbstractThe rate of thinning of the liquid film trapped between a fluid drop and a liquid interface and the subsequent coalescence of the drop were investigated using an interferometric method. The rate of film thinning for small drops was in good agreement over a narrow range of film thickness with two previously proposed models. The rate was greater than predicted when the film thickness was less than 0.2 μ presumably because of movement of the interfaces. The minimum thickness in the film at rupture was usually less than 500 Å. for drop diameters up to 2500 μ. The seemingly anomalous behavior of drops previously observed in a partial coalescence series resulted from uneven film thinning with larger drops. Partial coalescence between finite drops was investigated briefly; no secondary drop was produced when the drop diameter ratio was less than about 3

ISSN:0008-4034    

DOI:10.1002/cjce.5450410504

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

年代:1963

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450410505

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

年代:1963

数据来源: WILEY

摘要:

AbstractInvestigations using three experimental scraped surface falling film vertical heat exchanger tubes (6 in., 12 in. and 24 in. by 1 in. D.) have been made. Water and water‐glycerol mixtures have been heated in the tubes by passing them down the heated inside surface which was continuously scraped by rotating blades. Flowrates between 306 lb/hr.ft. and 1070 lb/hr.ft. were used, the rate of rotation was varied from 370 to 1600 rpm whilst the number of blades on the shaft was varied between 1 and 4.As a result of these experiments the following equation accurate within ± 20% is proposed for correlating the heat transfer coefficient in the range of the variables studied:\documentclass{article}\pagestyle{empty}\begin{document}$$ Nu_D = 0.018\left({Re} \right)^{0.46} \left({Re'} \right)^{0.6} \left({Pr} \right)^{0.87} \left({D/L} \right)^{0.48} \left(n \right)^{0.24} $$\end{document}Visual observations of the flow of the liquid down the tube indicate that the liquid is held as a continuous fillet in front of each blade. This fact is used in the Appendix* for the alternative suggestion for the characteristic dimension in the correlati

ISSN:0008-4034    

DOI:10.1002/cjce.5450410506

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

年代:1963

数据来源: WILEY

摘要:

AbstractThe kinetics of the vapor‐phase oxidation of benzene over a sulphate‐promoted vanadium oxide catalyst were studied in a differential flow‐reactor. Rates of oxidation of benzene were measured at temperatures in the range 324° to 400°C., for benzene concentrations from 1 × 10−3to 6 × 10−3moles/l., by analysing the products: p‐benzoquinone and maleic anhydride. Reaction‐rate data were summarized by the following equation based upon a mechanism suggested by Hinshelwood:\documentclass{article}\pagestyle{empty}\begin{document}$$ r = \frac{{k_a k_r C_h C_o }}{{k_a C_o + nk_r C_h }} $$\end{document}Catalyst deactivation was observed during the oxidation of benzene. Benzene, naphthalene, and toluene oxidations over a common vanadium oxide catalyst were compared. Deactivation was observed with benzene and toluene, but not with naphthalene.The rate equation provides a useful empirical description of oxidation rates of individual compounds. However, the deactivation behavior of the systems and the rates observed indicate that the mechanism used in its derivation

ISSN:0008-4034    

DOI:10.1002/cjce.5450410507

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

年代:1963

数据来源: WILEY

摘要:

AbstractThe type of fuel bundle evolved for the various Canadian heavy water moderated power reactors is described. The data necessary for estimating the thermal and hydraulic characteristics of this type of fuel bundle are indicated. The calculations and experimentation undertaken in the general fields of fluid flow, heat transfer and coolant mixing are then described in some detail. The future use of this type of fuel bundle with coolants proposed for more advanced reactor types is also discussed.

ISSN:0008-4034    

DOI:10.1002/cjce.5450410508

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

年代:1963

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450410501

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

年代:1963

数据来源: WILEY