摘要:

AbstractThe increasing demands for oil, water, and food produced in an environmentally sound manner have placed emphasis on the manner of their production, a major part of which is concerned with flow through porous media.The movement of materials through porous media is of interest in many disciplines: in chemical engineering—adsorption, chromatography, filtration, flow in packed columns, ion exchange, reactor‐engineering; in petroleum engineering—displacement of oil with gas, water and miscible solvents including surface‐active agent solutions and description of reservoirs; in hydrology—movement of trace pollutants in water systems, recovery of water for drinking and irrigation, salt water encorachment into fresh water reservoirs; in soil physics—movement of water, nutrients, and pollutants into plants; in biophysics—life processes such as flow in the lung and the kidney.This paper reviews the fundamentals of steady flow through porous media: it discusses the pseudotransport coefficients permeability, capillary pressure, and dispersion and relates these coefficients to the geometry of porous media. It also discusses single‐fluid flow, multifluid immiscible flow, and multifluid miscible flow including the effects of heterogeneity, nonuniformity, and anis

ISSN:0001-1541    

DOI:10.1002/aic.690270402

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractThe electronic properties of bismuth oxide shed light on the mechanism of its catalytic activity for the oxidative dehydrogenation dimerization of propylene. Variations in the electrical conductivity and thermoelectric power, as the gas phase contacting a pellet of thisp‐type semiconductor was changed, provided information about the nature of species adsorbed at reaction temperatur

ISSN:0001-1541    

DOI:10.1002/aic.690270403

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractA stochastic model is presented for turbulent diffusion of particles or drops in a turbulent field. The model is free of arbitrary adjustable constants and is applicable to realistic situations where the flow is nonhomogeneous such as in boundary layers or in pipe flow. New experimental data is presented for dispersion of glass beads in the boundary layer of the University of Houston Environmental Wind Tunnel. Good agreement with the theoretical model is demonstrated.

ISSN:0001-1541    

DOI:10.1002/aic.690270404

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractAn approximate approach is proposed for the design and analysis of fixed‐bed catalytic reactors in which the intraphase diffusion is important. This approach makes it possible to transform the design and analysis problem of nonisothermal reactors with inter‐ and intraphase mass and heat transfer resistance into one of simply integrating a single equation with respect to concentration. This transformation is applicable to general from of kinetics. Exceptions are reaction rate forms that can exhibit empirical or approximate negative order behavior. The transformation is based on a generalized effectiveness factor or a reactor point effectiveness factor. While the design and analysis of two‐dimensional reactors requires simultaneous solution of conservation equations for mass and heat which are transformed into the equivalents of homogeneous reactors, the problem of one‐dimensional reactors with axial dispersion involves simple integration of a single mass conservation e

ISSN:0001-1541    

DOI:10.1002/aic.690270405

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractMechanical mixing of fluids interpreted as deformation of contact interfaces between materials or originally designated material surfaces, can be described by continuum mechanical arguments. The idea is developed at two levels.Part I: Exact kinematical description of mixing of fluids with negligible interfacial tension.Part II: Description of mixing of fluids with negligible interfacial tension in terms of intermaterial area density.The approach provides a unified mathematical description of the mechanical mixing of fluids.

ISSN:0001-1541    

DOI:10.1002/aic.690270406

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractThis paper deals with the problem of finding, among many alternatives, the sequence of separation units that will isolate desired products from given feed at the minimum cost. Multicomponent products can be specified. An evolutionary procedure is presented. This method consists of two phases. In the first phase, a good initial structure is created by heuristic methods. In the second phase, the initial structure is successively modified by making evolutionary structural changes. This logic has been programmed on a digital computer and has been tested on several problems.

ISSN:0001-1541    

DOI:10.1002/aic.690270407

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractQuantitative measurements of the effect of a third phase of buoyant solid particles on the settling rates of suspensions of heavy particles are reported. It is found that for a wide range of concentration of both buoyant and heavy particles, the settling rates of both solid phases are greatly increased. If the phases are dilute, the settling velocities of both are retarded. The total settling time of heavy particles can be halved, but only under conditions that the light phase is unaccelerated. This suggests that small gas bubbles would form a more satisfactory buoyant phase. The high concentrations of thickened suspensions which result from the acceleration process are also reported.

ISSN:0001-1541    

DOI:10.1002/aic.690270408

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractA dimensionless solids flowrate for discharge from an orifice in the bottom of a containing vessel is shown to be a function of a parameter that measures the importance of fluid drag to particle inertia. The analysis assumes a linear relation between presure gradient and slip velocity and compares favorably to experiment within its supposed region of applicability for three experimental situations: the self‐induced, air‐impeded discharge of fine particles from a conical hopper; the discharge of particles from a sealed egg‐timer‐like vessel; and the air‐assisted discharge of particles through a

ISSN:0001-1541    

DOI:10.1002/aic.690270409

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractTo reduce backmixing in the flow‐type horizontal stirred vessel, a perforated partition plate was attached and the effects of shape of plate on the mixing characteristics were studied under various operating conditions. Results were analyzed in terms of mixing models to evaluate the extent of preventing backmixing. It enabled us to estimate the extent of back flow at the perforated partition plate from power consumptio

ISSN:0001-1541    

DOI:10.1002/aic.690270410

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY

摘要:

AbstractPreviously published data for the six binary combinations that can be formed from CO2, H2S, N2and methanol are used to obtain parameters of the four‐suffix Margules equation describing liquid solution behavior. The vapor phase is described by the Soave modification of the Redlich‐Kwong equation of state. Isothermal binary data are fit well by these equations. The effects of temperature on the Margules parameters are significant and, except for N2‐containing mixtures, the parameters were taken to be inversely proportional to absolute temperature.Experimental data were obtained for multicomponent mixtures of CO2, H2S, N2and methanol. Model predictions were tested against these data. Comparisons of predicted and measured values of bubble point pressure and equilibrium vapor compositions are satisfa

ISSN:0001-1541    

DOI:10.1002/aic.690270411

出版商:American Institute of Chemical Engineers    

年代:1981

数据来源: WILEY