ISSN:0008-4034    

DOI:10.1002/cjce.5450610301

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

年代:1983

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450610302

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

年代:1983

数据来源: WILEY

摘要:

AbstractA new general correlation is presented for the minimum spouting velocity based on the annular pressure gradient at the top of the bed at minimum spouting. The correlation fits a wide range of experimental data to 11.6% on average. The normalized minimum spouting velocity ratio.umS/umF, is shown to be a function of three dimensionless parameters.

ISSN:0008-4034    

DOI:10.1002/cjce.5450610303

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

年代:1983

数据来源: WILEY

摘要:

AbstractA theoretical model, describing the equilibrium of forces resulting from gas flow resistance, bed weight and internal solid friction at the point of the minimum spouting velocity, is proposed.An equation for predicting the minium spouting flow rate has been developed and verified by the experimental data obtained in 8 columns with diameters varying from 0.09 m to 0.9 m.

ISSN:0008-4034    

DOI:10.1002/cjce.5450610304

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

年代:1983

数据来源: WILEY

摘要:

AbstractIn a sector spouted bed, fluid is introduced into the bottom at the junction of two vertical walls, the bed forming a sector in horizontal cross‐section. The hydrodynamics of beds of 30° sector angle have been studied in equipment of radius up to 0.78 m. The spout radius is greater than would be predicted from standard correlations on small circular beds. The overall pressure drop can be less than 20% of that found for minimum fluidisation. The vertical pressure distribution is given approximately by a quarter cosine function. Minimum spouting velocity decreases with increasing size of bed, loss of spouting being caused by a decrease in fountain height followed by snuffing of the spout by annular soli

ISSN:0008-4034    

DOI:10.1002/cjce.5450610305

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

年代:1983

数据来源: WILEY

摘要:

AbstractTwo models have been applied to predict the variation of annulus gas velocities in beds of cylindrical geometry with a conical base, and these models have been compared with experimental data obtained in two different columns. Both the cone‐modified Mamuro‐Hattori model and the vector Ergun equation model predict a maximum velocity in the cone region and a minimum at the cone‐cylinder junction, in agreement with experimental measurements. Quantitative differences between the measured and predicted annulus velocities appear to result from the assumption of constant spout diameter, neglect of solids motion, and inadequate knowledge of behaviour at the

ISSN:0008-4034    

DOI:10.1002/cjce.5450610306

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

年代:1983

数据来源: WILEY

摘要:

AbstractSome of the basic concerns in the analysis of spouted‐bed hydrodynamics are the flow pattern and the pressure field of the fluid and the spout shape. These are closely related with other design concerns such as spoutability, minimum spouting velocity and maximum spoutable bed depth. A computer program was developed in order to determine the flow pattern, pressure distribution in the fluid phase and the spout shape for a given operational condition. The computer program relies upon a two region model with a spout and annulus element for an axisymmetric bed. The paper presents some results for grain drying beds and compares them with the existing experimental data qualitativel

ISSN:0008-4034    

DOI:10.1002/cjce.5450610307

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

年代:1983

数据来源: WILEY

摘要:

AbstractMinimum spouting velocity and segregation behaviour of binary mixtures of particles differing in size have been studied. The experiments were carried out in a bed of 20 cm diameter at superficial gas velocities up to 1.3Umsby use of silica sand of four different particle sizes from 0.655 to 2.23 mm.An empirical equation was proposed for the minimum spouting velocity of binary mixtures. The effects of the particle size difference and the superficial gas velocity on segregation were investigated. Results showed that considerable radial segregation as well as axial segregation occurred even for high gas velocity under the condition of large particle size difference.

ISSN:0008-4034    

DOI:10.1002/cjce.5450610308

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

年代:1983

数据来源: WILEY

摘要:

AbstractParticle segregation in spouted beds is shown to result from different trajectories of heavy and light particles in the fountain region, lighter particles tending to scatter more in the radial direction than heavier ones. Some desegregation occurred due to rolling along the inclined annulus surface and due to mixing processes in the spout. Segregation is less severe for overdeveloped fountains, where the particles bounce off the outer wall, and for low bed depths, where the fountain is dilute. Segregation can also be countered by a conical baffle which deflects particles outwards from the core of the fountain.

ISSN:0008-4034    

DOI:10.1002/cjce.5450610309

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe elutriation of fines from a spouted bed of fine and coarse particles has been studied. Equations for correlating elutriation rate coefficients are proposed. Three different regions associated with particle behavior have been identified in a way to permit calculation of elutriation rate at any column height. Measurements of cross‐sectionally averaged holdup of particles and local particle velocity have been used to interpret the decrease in elutriation rate along the freeboard. The known concept of a Transport Disengaging Height (T.D.H.) has been employe

ISSN:0008-4034    

DOI:10.1002/cjce.5450610310

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

年代:1983

数据来源: WILEY