ISSN:0001-1541    

DOI:10.1002/aic.690060402

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690060441

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690060442

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690060404

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

摘要:

AbstractA photographic study was made to investigate the boiling phenomena in the neighborhood of the critical heat flux. The system consisted of an electrically heated zirconium ribbon, insulated on its underface, suspended in a pool of water at its saturation temperature. Measurements of bubble diameters, bubble positions relative to the heating surface, local bubble frequencies, and contact angles at known times intervals were obtained from the film. Results indicate that at high heat fluxes the primary forces acting on a bubble leaving the surface are the buoyancy and drag forces. A dimensionless relationship is developed relating bubble velocity, bubble diameter, and contact angle at breakoff. Drag coefficients for freely rising vapor bubbles a saturated liquid are found to be representable by the usual drag coefficient‐Reynolds number curves for solid bodies. Jakob's plot of bubble frequency vs. bubble diameter at breakoff is extended to high heat‐flux values, and a relationship proposed by Deissler at the critical heat flux is found to yield reasonable agreement with the experimental d

ISSN:0001-1541    

DOI:10.1002/aic.690060405

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

摘要:

AbstractThe rate of transfer of a surface‐active solute across an interface may be either greater or less than the rate which would be obtained if the interface had no abnormal properties. Studies of the absorption of methyl chloride, a surface‐active gas, by a laminar water jet show that for contact times of 1 msec. or greater the absorption rate is the same as would be predicted for a system with no abnormal interfacial properties. This is in accord with theory which indicates that an abnormally high rate caused by a positive surface excess could only be observed for contact times considerably shorter than those used h

ISSN:0001-1541    

DOI:10.1002/aic.690060406

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

摘要:

AbstractThe axial effective thermal conductivities of packed beds were determined by measuring the axial temperature gradients at steady state, the heat being conducted in the direction opposite to that of air. The present experiments were carried out with the beds of glass beads, metallic balls, broken pieces of limestone, and Raschig rings, taken in separate experiments.It was found that the axial effective thermal conductivity increases more with the increase of air flow than it does in the case of radial conductivity. The axial effective thermal conductivity coincides with the radial conductivity whenNRe→

ISSN:0001-1541    

DOI:10.1002/aic.690060407

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

摘要:

AbstractA theoretical analysis was made for laminar fluid flow in the annulus of a falling cylinder viscometer. A viscometer calibration constant was defined from the results of this analysis. This constant was expressed in terms of only the physical dimensions of the viscometer. The volues lidity of the theory was demonstrated by the agreement between predicted and experimental values of the viscometer constant.Methods of representing calibration data were compared. Temperature and pressure effects on the viscometer constants were related to the mechanical properties of the viscometer materials.The results of this investigation showed that the practical design of falling cyclinder viscometers is possible.

ISSN:0001-1541    

DOI:10.1002/aic.690060408

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

摘要:

AbstractThe unsteady diffusion‐controlled evaporation of a pure fluid into a multicomponent mixture is studied by a boundary‐layer method. An expression is obtained for the volume of vapor produced by the evaporating species as a function of time. It is shown that the result can be interpreted in terms of an effective diffusivity of the type proposed by Wilke and by Stewart. It is further demonstrated that the boundary‐layer method predicts a sweep‐diffusion

ISSN:0001-1541    

DOI:10.1002/aic.690060409

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY

摘要:

AbstractMixing studies were performed in beds of lead and glass particles fluidized with water. A salt solution was injected from a point source, and electrical conductivity cells were used to determine time average and fluctuating salt concentrations at various points downstream from the point of injection. The frequency distribution of the fluctuations was determined, and correlation coefficients were measured for the fluctuations at two points separated by a known distance.The mixing data for the central portion of the bed yield radial eddy diffusivities and scales and intensities of turbulence. At the same fraction void the eddy diffusivity and scale of turbulence are larger for lead than for glass particles, but the velocity fluctuations appear to be independent of the density of the particles. Minimum Peclet numbers are observed at a fraction void of about 0.7. Scales based on correlation coefficients exceed those calculated from Peclet numbers, indicating that in a fluidized bed there are large‐scale eddies whose size is much larger than a particle diameter. The interpretation of the mixing data is coupled with visual observations of fluidized bed flow pattern

ISSN:0001-1541    

DOI:10.1002/aic.690060410

出版商:American Institute of Chemical Engineers    

年代:1960

数据来源: WILEY