ISSN:0001-1541    

DOI:10.1002/aic.690150402

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractThis study concerns rates of evaporation and mass transfer of water vapor from a heated salt solution through a water repellent porous membrane to a cooled water condensate. This transfer is a result of temperature differences and corresponding vapor pressure differences across the membrane. Three groups of experiments were carried out which indicate that the major factor influencing the rates of transfer is diffusion through a stagnant gas in the membrane pores. However, an equation considering film heat transfer coefficients, membrane thermal conductivity, and an empiricial correction based on temperature driving force appears to be necessary for representing all the data. The empirical correction appears to be related to internal condensation and possibly diffusion along surfaces.

ISSN:0001-1541    

DOI:10.1002/aic.690150404

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractAnalytic equations describing cyclic steady state diffusion in which the diffusivity depends on the direction of transfer, as well as on the system, have been obtained.By imposing the cyclic steady state constraint, of periodically repetitive concentration profiles, simultaneous solution of separate Fick's diffusion equations for the on‐off segments of the cycle results in the desired equatins. The method of solution can be extended to more complex diffusion problems, such as coupled diffusion processes. Shallow bed experiments have been performed on particle‐diffusion controlled, cyclic steady state ion exchange. Agreement between the predicted and experimental transfer was obtained. Variables and parameters affecting cyclic steady state diffusion are discus

ISSN:0001-1541    

DOI:10.1002/aic.690150405

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractThe photodecomposition of acetone vapor was studied in a tubular flow, differential reactor at atmospheric pressure and from 82 to 112°C. The products included significant amounts of biacetyl along with carbon monoxide and ethane. A rate equation was developed from a sequence of elementary reactions believed to explain the photolysis of acetone. The effects of light intensity and acetone concentration, indicated in the derived rate equation, were confirmed by the data.The rate is less than first‐order with respect to acetone, and this is believed to be due to reformation of stable acetone molecules by deactivation of CH3COCH

ISSN:0001-1541    

DOI:10.1002/aic.690150406

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractMetal surfaces of titanium, aluminum, copper, lead, and zinc were irradiated by a 25 joules pulsed laser with an energy flux ranging from 106to 108cal./(sq.cm.) (sec.). The resulted cavities were sectioned, polished and measured to compare with the isotherms computed from several heat conduction models. Reasonable agreement was found between the experimental cavity diameters at the interface and those calculated from the disk source model. Also, a graphical correlation between the cavity depth and its interface diameter is presented.

ISSN:0001-1541    

DOI:10.1002/aic.690150407

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractNumerical solutions of the equations of motion and energy are presented in the form of pressure‐loss, flow‐rate relationships for the laminar, nonisothermal flow of Newtonian and non‐Newtonian fluids being heated and cooled in tubes at constant wall temperature. The flow properties are represented by a temperature‐dependent form of the power law equation. The numerical results are shown to be in good agreement with experimental data for a wide range of fluid properties and flow con

ISSN:0001-1541    

DOI:10.1002/aic.690150408

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractAn expression is derived for the analysis of gas‐phase mass transport in porous media in the presence of gradients in pressure and mole fraction. The behavior of porous media is contrasted with that of capillary tubes. A continuous‐flow diffusion and permeation apparatus was employed for studies of mass transport in a fritted glass diaphragm. Measurements were obtained at varying levels of pressure and cover both isobaric binary diffusion and the permeation of pure gases and gas mixtures. These experimental results and previous data obtained by Hewitt and Sharratt and by Mason,et al.bear out the form of the equation and successfully provide independent checks of the three constants necessary to characterize a given porous med

ISSN:0001-1541    

DOI:10.1002/aic.690150409

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractExperimental results for the adsorption of the binary gas mixtures oxygen‐nitrogen, oxygen‐carbon monoxide and nitrogen‐carbon monoxide on two synthetic zeolites are reported. In all of these experiments the temperature was −200°F. and the total pressure was 1 atm. Also reported are the isotherms for the three pure gases on the two zeolites at −200°F. The results indicate that these zeolites have a surface selectivity which is independent of any sieving effect based on the size of the adsorbed molecules. It does not appear that the strong separations obtained can be explained in terms of the van der Waals forces which are generally believed to be dominant in physical adsorption. The available methods of predicting binary adsorption data from the pure gas isotherms have be

ISSN:0001-1541    

DOI:10.1002/aic.690150410

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractA new theory for convection‐free rinsing of flat plates was developed to include the drop dispersal mechanism as well as the previously considered diffusion mechanism. Cases where carryover is unequal to dragout were also included in the model. Based on film distribution data, the model offers better agreement with rinse data. The effect of drain time on film distribution and bottom drop volume was also investigate

ISSN:0001-1541    

DOI:10.1002/aic.690150411

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY

摘要:

AbstractExperimental values of the wave length and wave velocity have been obtained for dilute solutions of valeric and hexanoic acid for a vertical falling liquid film. The wave length was unaffected by the surfactants for Reynolds numbers in the range 5 to 100; however, the wave velocity was decreased for increased surface concentrations of the two acids. This is in direct contradiction to previous theoretical work, and the explanation for the anomaly is that the free surface velocity is greatly retarded by the adsorption of the surface active agents. In an effort to determine the extent of this retardation, an approximate form of the diffusion equation and the equations of motion were solved subject to boundary conditions describing the effect of the absorbed surfactant on the surface stress. The results indicate that the entrance length can be increased several orders of magnitude by the addition of small amounts of surfactant.

ISSN:0001-1541    

DOI:10.1002/aic.690150412

出版商:American Institute of Chemical Engineers    

年代:1969

数据来源: WILEY