摘要:

AbstractThis paper shows how the rigorous critical state criterion enunciated by Willard Gibbs can be used with a recently formulated two‐parameter equation of state to obtain an analytical solution to the problem of predicting the critical properties of defined multicomponent mixtures. Comparisons are made between predicted and experimental values for several systems containing paraffin hydrocarbons and related material

ISSN:0001-1541    

DOI:10.1002/aic.690230202

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

摘要:

AbstractA group contribution molecular model is developed for the thermodynamic properties of polar and nonpolar liquids and their solutions, including energy of vaporization, ρVT relations, excess properties, and activity coefficients. The model is based on the cell theory in which the repulsive forces of molecules are expressed with a modified cell partition function derived from the Carnahan‐Starling equation of state for hard spheres. The attractive forces are made up of group pair interaction contributions. Group and interaction properties have been determined for methyl, methylene, hydroxyl, and carbonyl. Extensive comparisons are made of predictions of the model with data for pure liquids and their solutio

ISSN:0001-1541    

DOI:10.1002/aic.690230203

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

摘要:

AbstractMeasurements are presented on the influence of Schmidt number on the frequency of the mass transfer fluctuations at a solid boundary. The shape of the spectral function is similar at all Schmidt numbers. A relation between the mass transfer fluctuations and the fluctuating velocity field can be obtained only at high frequencies. A comparison of the scale and the frequency of the mass transfer fluctuations and the velocity fluctuations suggests that the rate of mass transfer is controlled by convective motions in the flow oriented eddies described by a number of previous investigators. However, the concentration fluctuations caused by these convective motions are greatly dampened close to the wall by molecular diffusion. Thus the mass transfer fluctuations reflect only the scale and not the frequency of the convective motions in the flow oriented eddies.

ISSN:0001-1541    

DOI:10.1002/aic.690230204

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

摘要:

AbstractA compartmental dispersion model of longitudinal mixing in tube networks has been developed. The ability of this model to predict the impulse response of helium, benzene vapor, and sulfur hexafluride tracer gases in two and in five generation symmetric network models of the large airway system of the lung has been tested over an air flow range of 1 to 400 ml/s.The results imply that velocity profile distortion and secondary flows in branching regions have only a small effect upon the overall longitudinal mixing when flow is directed toward the higher‐order generations. On the other hand, accurate prediction of the data requires adequate treatment of the finite rate of evolution of the Taylor dispersion occurring in these tube network

ISSN:0001-1541    

DOI:10.1002/aic.690230205

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

摘要:

AbstractDiffusional mass transfer across membranes with uniform but low pore densities was studied experimentally as a function of stirring rate and pore area fraction. The results were analyzed in terms of a stagnant film boundary‐layer model specially formulated for a heterogeneous membrane containing discrete pores. The overall membrane diffusional resistance is linearly related to the inverse of the pore area fraction of the membranes for a constant stirring rate. An equivalent boundary‐layer thickness can be defined which is independent of membrane properties but a unique function of stirrer speed. These experimental boundary‐layer thicknesses are greater by a factor of 3 than those predicted by a published Sherwood number correlation determined for homogeneous surfaces, but the stirring rate dependence is in excellent agreement with this same correl

ISSN:0001-1541    

DOI:10.1002/aic.690230206

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

摘要:

AbstractThe geometrical parameters of injection devices are shown to have almost no effect on the resulting two‐phase flow, while they influence the pressure drop owing to its formation. The predominant hydrodynamic parameter is the ratio of the mean superficial velocities. A simplified analysis leads to good agreement with experimental results. The different causes of pressure drops are quantifie

ISSN:0001-1541    

DOI:10.1002/aic.690230207

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

摘要:

AbstractWhen a suspension of fine solid particles in a gaseous medium flows through a fibrous filter, particles deposit on the fibers forming chainlike agglomerates known as dendrites. This deposition pattern is responsible for the intrinsically transient behavior of the filter, leading to drastic increases of the filtration efficiency and of the pressure drop. Related phenomena are observed when aerosols flow through other types of porous media (for example, granular beds), or next to duct walls, around immersed objects, etc. A theoretical model of the particle dendrite growth was proposed recently by Payatakes and Tien. Here a revised and generalized version of that model is developed. The following major revisions are made: allowance is made for collisions with a particle in a given dendrite layer that lead to retension in the same layer, radial as well as angular contributions to deposition are considered, and the dendrite layer adjacent to the collector is allowed to contain more than one particle. These changes lead to a substantially more realistic theoretical model. Expressions for the transient behavior of a filter of differential thickness are obtained, based entirely on first principles. These, as it has been shown in a previous publication, can be used to predict the dynamic behavior of a macroscopic fibrous filter. The use and behavior of this model is demonstrated in the simple case of deposition by pure interception. The present treatment of deposition by pure interception is more rigorous than and supersedes that adopted in previous works.

ISSN:0001-1541    

DOI:10.1002/aic.690230208

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690230209

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690230210

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690230211

出版商:American Institute of Chemical Engineers    

年代:1977

数据来源: WILEY