Scale-up effect of riser reactors (1): Axial and radial solids concentration distribution and flow development

被引:80
作者
Yan, A [1 ]
Zhu, JJ [1 ]
机构
[1] Univ Western Ontario, Power Technol Res Ctr, Dept Chem & Biochem Engn, London, ON N6A 5B9, Canada
关键词
D O I
10.1021/ie049578y
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
The influence of the riser diameter on the axial and radial solids holdup profiles and flow development is studied by measuring local solids holdups with a fiber-optic probe in a 10-m twin-riser system with 0.076- and 0.203-m inner diameters, at solids circulation rates of up to 200 kg/(m(2) s) and superficial gas velocities of up to 8 m/s. It was found that the solids concentration increases with increasing riser diameter. Furthermore, the radial profiles of the solids concentration are steeper with larger-diameter risers. For both risers, the flow development in the riser center is nearly instantaneous, with the solids concentration remaining low under all operating conditions. In the wall region, the flow development slows down. Moreover, the flow development is slower in the larger-diameter riser. Increasing the solids flux also slows the flow development. However, increasing the superficial gas velocity makes the flow development faster while also lengthening the fully developed region.
引用
收藏
页码:5810 / 5819
页数:10
相关论文
共 45 条
[1]  
Arena U., 1988, Circulating Fluidized Bed Technology II, P223, DOI [10.1016/B978-0-08-036225-0.50025-3, DOI 10.1016/B978-0-08-036225-0.50025-3]
[2]  
Arena U., 1991, Circulating Fluidized Bed Technology III, P137
[3]  
Avidan A.A, 1997, CIRC FLUID BEDS, P466
[4]  
BADER R, 1998, CIRCULATING FLUIDIZE, V2, P123
[5]   Analysis of the overall pressure balance around a high-density circulating fluidized bed [J].
Bai, D ;
Issangya, AS ;
Zhu, JX ;
Grace, JR .
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 1997, 36 (09) :3898-3903
[6]   THE AXIAL DISTRIBUTION OF THE CROSS-SECTIONALLY AVERAGED VOIDAGE IN FAST FLUIDIZED-BEDS [J].
BAI, DR ;
JIN, Y ;
YU, ZQ ;
ZHU, JX .
POWDER TECHNOLOGY, 1992, 71 (01) :51-58
[7]   HEAT-TRANSFER IN HIGH-TEMPERATURE FAST FLUIDIZED-BEDS [J].
BASU, P .
CHEMICAL ENGINEERING SCIENCE, 1990, 45 (10) :3123-3136
[8]   Simulation of particles and gas flow behavior in the riser section of a circulating fluidized bed using the kinetic theory approach for the particulate phase [J].
Benyahia, S ;
Arastoopour, H ;
Knowlton, TM ;
Massah, H .
POWDER TECHNOLOGY, 2000, 112 (1-2) :24-33
[9]   HYDRODYNAMICS OF CIRCULATING FLUIDIZED-BED RISERS - A REVIEW [J].
BERRUTI, F ;
CHAOUKI, J ;
GODFROY, L ;
PUGSLEY, TS ;
PATIENCE, GS .
CANADIAN JOURNAL OF CHEMICAL ENGINEERING, 1995, 73 (05) :579-602
[10]   STATIC INSTABILITY ANALYSIS OF CIRCULATING FLUIDIZED-BEDS AND CONCEPT OF HIGH-DENSITY RISERS [J].
BI, HT ;
ZHU, JX .
AICHE JOURNAL, 1993, 39 (08) :1272-1280