摘要:

AbstractFlooding rates, dispersed phase hold‐up, hold‐up profile and drop‐size distribution were investigated in rotating disc and Oldshue Rushton 0.10 m diameter, 18 compartment columns with toluene‐water as the liquid‐liquid system. The axial dispersed phase hold‐up and the mean drop size in both contactors varied significantly with column height. The hold‐up profiles were correlated by semi‐the

ISSN:0008-4034    

DOI:10.1002/cjce.5450630501

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe sequential form of the axial displacement of inclined Taylor vortices and their progressive degeneration to horizontal streaks due to the increasing dominance of axial flow is demonstrated via an analytical indicator‐based direct flow visualization technique applied to a concentric cylinder cell with the inner cylinder rotatin

ISSN:0008-4034    

DOI:10.1002/cjce.5450630502

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe shapes of liquid jets issuing from tubes into a second immiscible liquid are examined experimentally. Previous theoretical work is seen to be based on boundary layer theory and therefore not applicable to low Reynolds number jets as presented here. However, these works have provided insight into dimensionless parameters which could be important in governing this process. The experimental data is presented in the form of these dimensionless groups so that their significance can be explored.The results clearly show that the dispersed phase Reynolds number and the viscosity ratio of the two liquid jets are the most important parameters affecting jet shape. Non‐Newtonian elasticity is seen to contribute to jet expansion but not as much as in the case of inviscid jet swelling. The continuous phase is seen to have a component of velocity far from the jet surface unlike the assumption used in boundary layer theory.The boundary layer theory of Schlichting was extended to predict jet shapes for a viscosity ratio of one. It is seen that the theory does not apply within 15 dimensionless distances from the tube exit. Accurate predictions will require more precise evaluation of the equations of motio

ISSN:0008-4034    

DOI:10.1002/cjce.5450630503

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe local variation of droplet diameter in a stirred tank was measured in the vicinity of the impeller and at another region. The degree of difference in droplet diameter between regions increases with the impeller speed.A correlation equation between the local difference in droplet diameter and the frequencies of coalescence and circulation of the droplet was derived according to the circulation interaction model. The degree of local difference in droplet diameter was found to be controlled strongly by the ratio of coalescence to circulation frequency.

ISSN:0008-4034    

DOI:10.1002/cjce.5450630504

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe polynomial vvelocity profile due to Pai (1953), applicable to transition and turbulent conditions in single phase flow, has been used to solve the equations of two‐phase annular flow with appropriate matching conditions at the interface and at the boundaries. The results obtained enable one to predict the pressure drop and the void‐fraction, when the interfacial friction factor is specified. Entrainment of the liquid in the core of the flowing gas has been taken into account by using the empirical relation of Hutchinson and Whalley (1973). It has been shown that the theory provides results in agreement with horizontal tube and vertical tube adiabatic flow data, in addition to predicting the liquid film thickness accurat

ISSN:0008-4034    

DOI:10.1002/cjce.5450630505

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

年代:1985

数据来源: WILEY

摘要:

AbstractWe present a first order stability analysis of a steam‐water front moving through a porous medium. The interplay between gravity, mobility and phase change are investigated. Several new phasical effects are observed in this dynamic study (e.g. oscillatory solutions, multiple solutions, etc.) and a number of specific limiting solutions are also considere

ISSN:0008-4034    

DOI:10.1002/cjce.5450630506

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

年代:1985

数据来源: WILEY

摘要:

AbstractAn experimental study of the errors arising in side wall sampling has been conducted. A two‐dimensional model provides qualitative explanation of these errors but, unlike probe sampling, quantitative prediction of sampling efficiency is not possible because the flow to the sampler is more complex. The experiments show that serious errors in concentration or particle size distribution can arise unless the particles are fine, the concentration is high and a very high sampling velocity is used. A projection extending from the pipe wall was found to improve sampling efficiency. However this improvement was of marginal value because the complex nature of the flow precluded a simple theoretical predictio

ISSN:0008-4034    

DOI:10.1002/cjce.5450630507

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

年代:1985

数据来源: WILEY

摘要:

AbstractA three dimensional column was used to study the hydrodynamics of a three phase system: air, water and 3 mm glass beads. Various effects of the grid jets on bed hydrodynamics were investigated for both increasing and decreasing liquid superficial velocities. Three regimes were observed: spouted bed, spouted fluidized bed and three phase fluidized bed.The hydrodynamics of the two phase region above the bed was also studied. The gas holdup increased when the gas superficial velocity was increased but decreased when the liquid superficial velocity was increased. A correlation for the estimation of the gas holdup as a function of gas and liquid superficial velocities was established.

ISSN:0008-4034    

DOI:10.1002/cjce.5450630508

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe primary chemical step in the recovery of uranium oxide (U3O8) from ore in South Africa's uranium plants is thesulphuric acid teaching of slurries of the ore in water. The reaction is promoted by live steam injection to elevate temperatures to about 70°C. Up to 50 per cent of this heat can be recycled by slurry‐to‐slurry heat excange. However conventional equipment relying on conduction has proved inadequate in this duty owing to problems of solids settling. The evaporator/condenser exchanger is more appropriate. Its thermodynamics are explained and design equations devel

ISSN:0008-4034    

DOI:10.1002/cjce.5450630509

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe use of classic interferometry to study liquid diffusion has been well known since the 1940's. Much more recently holographic interfereometry was introduced in this field of study. In this paper a description of the general characteristics of holographic interferometry is presented. The evolution as well as the improvements of the technique are describged.

ISSN:0008-4034    

DOI:10.1002/cjce.5450630510

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

年代:1985

数据来源: WILEY