Numerical and experimental investigation of an 'S-shaped' circulating fluidized bed

K. W. Chu, A. B. Yu

Research output: Contribution to journalArticleResearchpeer-review

12 Citations (Scopus)


It has been widely reported that traditional circulating fluidized beds (CFBs) suffer from core-annulus flow structure which is characterized by severe solid back-mixing and non-uniform distribution of solids in both axial and radial directions. In this work, an S-shaped design of risers is proposed and its performance is examined first by numerical and physical experiments. Both experiments show that the flow pattern in the S-shaped risers is significantly different from that in traditional straight risers. Generally speaking, the uniformity of the distribution of solid concentration is improved in the S-shaped risers and the high solid concentration regions are mainly in the center of the riser instead of the regions near the riser wall, with the core-annulus flow structure of a traditional design almost eliminated. The reason for the improvement is that in an S-shaped riser, the high fluid velocity regions move back and forth along the riser wall, which can prevent the boundary layer of solids from being established. This S-shaped design could be useful to improve the solid-fluid contacting in vertical particle-fluid flow systems.
Original languageEnglish
Pages (from-to)460 - 469
Number of pages10
JournalPowder Technology
Publication statusPublished - 2014
Externally publishedYes

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