ISSN:0008-4034    

DOI:10.1002/cjce.5450640601

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

年代:1986

数据来源: WILEY

摘要:

AbstractBy recording the drop in dispersion height after stopping the gas supply, the fractions of large and small bubbles, the respective swarm rise velocities, and the contributions to the overall gas flow can be determined. Some problems of the analysis are discussed in detail. The efficiency of the technique is demonstrated for the results obtained with two different gas distributors in a bubble column of 30 cm diameter.

ISSN:0008-4034    

DOI:10.1002/cjce.5450640602

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

年代:1986

数据来源: WILEY

摘要:

AbstractPrevious work on the slow motion of drops in non‐Newtonian liquids has been reviewed. The variational principles have been employed to obtain approximate upper and lower bounds on drag force experienced by a fluid sphere moving slowly in Carreau model fluids. The paper is concluded by presenting a comparison with the appropriate experimental data available in the literatur

ISSN:0008-4034    

DOI:10.1002/cjce.5450640603

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe maximum pressure variation at the bottom of a reciprocating plate column of the Karr type was investigated in single phase liquid and two phase gas–liquid systems. In the gas–liquid system the gas hold‐up was also measured. The power consumption was calculated on the basis of the pressure variation at the bottom of the column.It was shown that the power consumption depends on the vibration intensity, liquid density and geometrical characteristics of the column in a non‐gassed single phase liquid system and on the same factors, as well as gas hold‐up, in gas–liquid systems. Semiempirical correlations were derived for the purpose of predicting power consumption in both single and two phase systems in a reciprocating p

ISSN:0008-4034    

DOI:10.1002/cjce.5450640604

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

年代:1986

数据来源: WILEY

摘要:

AbstractBased on published drop size data in the absence of mass transfer, two equations for the prediction of drop diameter with a break‐point at disc Reynolds number equal to 50 000 are presented which predict the drop diameter to within 14%. The total range of disc Reynolds number covered is 1200 to 282 000. The same equations may be used when mass transfer occurs if only the preconstants are modified. The ranges of disc Reynolds number covered are 28 000 to 434 000 for transfer from the continuous to the dispersed phase and 9300 to 290 000 for transfer from the dispersed to the continuous phase, the average absolute relative deviation being 11% in both case

ISSN:0008-4034    

DOI:10.1002/cjce.5450640605

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe height of the dispersion formed in the separating section of an extraction column is given byH=K/g(σ/Δρg)1/2I/ϕo (Qd/A)2Since calm conditions prevail the height of the sedimentation zone can be neglected and the dispersion is essentially dense‐packed. The effect of physical properties was investigated in a spray column using nine different liquid/liquid systems. A distributor divided into seven equal sectors enabled the effect of drop size and dispersed phase flow rate to be independently investi

ISSN:0008-4034    

DOI:10.1002/cjce.5450640606

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

年代:1986

数据来源: WILEY

摘要:

AbstractNew and long published experimental observations of the onset of aggregate (bubbling) behaviour in liquid fluidised beds are shown to be in agreement with the predictions of a recently published model of the fluidisation process. For a given liquid, the transition from particulate to aggregate fluidisation depends on both the density and size of the suspended particles: the lower the particle density the larger is the size necessary for a transition to occur: thus for fluidisation by ambient water, lead particles larger than 200 μm and soda glass particles larger than 2000 μm will exhibit aggregate behaviour; below a critical particle density no such transition is possibl

ISSN:0008-4034    

DOI:10.1002/cjce.5450640607

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

年代:1986

数据来源: WILEY

摘要:

AbstractA novel means of measuring particle velocities in spouted beds using laser‐doppler anemometry (L.D.A.) is described. L.D.A. is applied mainly in a back‐scatter mode to the spout and fountain of a half‐section bed. The fountain of a three dimensional bed can also be studied. L.D.A. is shown to be a powerful tool for measuring particle velocities in spouted beds. Statistically significant quantities of data are obtained with much higher resolution and in time scales orders of magnitude lower than with previous techniques. Previously unresolved aspects of particle motion, including wall effects in half‐section beds, can be qua

ISSN:0008-4034    

DOI:10.1002/cjce.5450640608

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

年代:1986

数据来源: WILEY

摘要:

AbstractA new experimental technique for measuring particle cycle times, times of occurrence of particles at different levels, and particle velocities in the spout of a spouted bed is described. A magnetized marker particle and search coil or coils are employed together with a microprocessor system for ease of data collection and processing. The magnetic particles have the same diameter, density and similar surface texture to bed particles to ensure proper representation.Data is presented on distributions of cycle time and particle velocity and implied particle mass circulation rates at different levels in a spouted bed. Comparisons are made with photographic and laser–doppler anemometry technique

ISSN:0008-4034    

DOI:10.1002/cjce.5450640609

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

年代:1986

数据来源: WILEY

摘要:

AbstractA γ‐ray technique is described for measuring the distribution of fractional voidage in the fountain of an air spouted bed. What appear to be the first experimental data on fountain voidage are presented. For the relatively shallow, 160 mm diameter, conical spouted bed studied, fountain fractional voidage is quite high, 0.88 and upwards. Generally voidage increases with height up the fountain, apart from a plateau or slight fall part way up. This trend differs from that proposed by Grace and Mathur in a theoretical model for a deeper cylindrical spouted bed. Fountain voidage is shown to depend on air flow rate and on particle size distributi

ISSN:0008-4034    

DOI:10.1002/cjce.5450640610

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

年代:1986

数据来源: WILEY