摘要:

AbstractAn experimental study of the rate of evaporation of stationary droplets of water, methanol, cumene, pentane and benzene was carried out in an electrically‐heated 9‐inch stainless steel sphere. The gaseous environment consisted of the superheated vapor of the liquid under investigation and, in all cases, the wall and gas temperatures were the same. Drop diameters ranged from 0.4 to 1.4 mm., and temperatures from 100°C. to 550°C.The evaporation rate of stationary droplets in high temperature surroundings does not appear to be governed by the rate of heat transfer by natural convection, since no dependency of the Nusselt Number on the Grashof Number was found. Attempts to correlate the results on the basis of Godsave's model (conduction across the boundary layer controlling) or Spalding's modified approach to the latter were equally unsuccessful. The experimental evaporation rates could, however, be very satisfactorily correlated in terms of Spalding's Transfer Number B.The correlation obtained indicates that the mechanism of the evaporation process is governed by the effect of the evolved vapors on the boundary layer

ISSN:0008-4034    

DOI:10.1002/cjce.5450380502

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

年代:1960

数据来源: WILEY

摘要:

AbstractThe effects of hole size of the cylindrical tower packing on pressure drop of single phase flow were investigated. It was shown that the hole size had a profound effect on the correlation of pressure drop data. This was attributed to the difference in the characteristics of the spaces inside and outside the packing units and to the interlocking of the packing units in the beds.

ISSN:0008-4034    

DOI:10.1002/cjce.5450380503

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

年代:1960

数据来源: WILEY

摘要:

AbstractThis paper examines the various complicating effects which rotation, surface roughness and shape impose on the motion and drag of single particles entrained in a fluid. In general, rotation appears to have little effect on the drag coefficient at low Reynolds Numbers, but influences the linearity of the motion and may thus play a part in the mechanism of particle entrainment in conveyed solids‐gas systems. Negative lift has been observed in the critical Reynolds Number region as the result of asymmetry in the wake structure. Surface roughness will cause an early transition to a turbulent boundary layer at higherRevalues, which will result in an appreciable decrease in drag coefficient, but it may increase the drag at low Reynolds Numbers.The effect of particle shape is more complex than has been suggested by previously published analyses. The available empirical correlations are discussed and compared, and indicate a dependency on the particle‐to‐fluid density

ISSN:0008-4034    

DOI:10.1002/cjce.5450380504

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

年代:1960

数据来源: WILEY

摘要:

AbstractConsiderable gain in information in characteristics of diffusion coefficient may be obtained if data are analysed for variable diffusion coefficient instead of for a constant value of diffusivity. This paper presents a simple method for graphical analysis of concentration gradients in solids to determine the diffusion coefficient as a function of concentration.Consideration is given to problems encountered in extrapolation of data. It is shown that, if relative values of diffusion coefficient is the objects of consideration, no great need exists for exacting extrapolation. Two extrapolations are employed on any given functional model; the results of one extrapolation are greater, while those of the other arc less than the results predicted by the model.

ISSN:0008-4034    

DOI:10.1002/cjce.5450380505

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

年代:1960

数据来源: WILEY

摘要:

AbstractConcentration distribution of solid particles in two‐phase turbulent pipe flow was studied. Due to the inertia of solid particles, transport of solid particles across the velocity field of the turbulent stream by turbulent diffusion results in deceleration of particles in the region near the wall by the stream and acceleration of particles transported toward the high velocity core. In the core, the particles have lower mean velocity than the stream while near the wall the mean particle velocity is higher. This gives rise to a non‐uniform distribution of solid particles in fully developed turbulent pipe flow. Experimental determination of concentration distribution was made with an impact disk particle counter sys

ISSN:0008-4034    

DOI:10.1002/cjce.5450380506

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

年代:1960

数据来源: WILEY

摘要:

AbstractThis paper reviews the behavior of aluminum in contact with natural waters. The influence of water composition and service factors on corrosivity to aluminum are discussed. Laboratory pitting test methods are described and data are presented to support the existence of a cube root (in time) rate curve for the pitting of aluminum in water. Information on the pitting of aluminum in 17 Canadian waters is given and mention is also made of the pitting of aluminum in seawater and oil field brines. A statistical treatment of pitting data is presented. Finally, measures for extending the life of aluminum equipment subject to pitting by water are suggested.

ISSN:0008-4034    

DOI:10.1002/cjce.5450380507

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

年代:1960

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450380501

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

年代:1960

数据来源: WILEY