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

作者：Chu K W^*; Yu A B

来源：Powder Technology, 2014, 254: 460-469.

DOI：10.1016/j.powtec.2014.01.052

• Solid-fluid contacting
• Circulating fluidized bed
• Riser reactor
• Core-annulus
• Back-mixing

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.

• 出版日期2014-3