New approaches to improve the uniformity of the radial solids concentration distribution in CFB risers

B. Peng, C. Zhang, J. Zhu

Research output: Chapter in Book/Conference proceedingConference contributionpeer-review

1 Citation (Scopus)

Abstract

The so-called core-annulus structure, that is, lower solids concentration in the center region and higher solids concentration in the near wall region along the circulating fluidized beds (CFB) riser, usually has a negative effect on the performance of CFB risers since it may greatly decrease the reactor efficiency and controllability. In order to improve the performance of industrial CFB risers, two potential approaches are proposed in this study: (1) the use of the center-sparse side-dense air jets arrangement for the gas distributor and the side-covered arrangement for the solids distributor and (2) the use of the air jet from the riser circumference. The results show that the patterns of the inlet gas distributor and solids distributor have significant effect on the flow structure in both the entrance region and the fully-developed region in the riser. The gas distributor with center-sparse side-dense air jet arrangement improves the uniformity of the radial solids distribution, while the center-dense side-sparse air jet arrangement steepens the non-uniformity of the solids radial profile. The core-annulus structure can also be greatly flattened by applying a side-covered solids distributor, while it can be heavily steepened by employing the center-covered solids distributor. The results also show that by employing the circumferential air jet approach under appropriate jet velocities, the maximum solids concentration in the near wall region can be greatly reduced, the entrance region can be shortened, and the uniformity of the flow structure can be greatly improved.

Original languageEnglish
Title of host publicationASME 2012 Fluids Engineering Division Summer Meeting Collocated with the ASME 2012 Heat Transfer Summer Conf. and the ASME 2012 10th Int. Conf. on Nanochannels, Microchannels, and M, FEDSM 2012
Pages1351-1357
Number of pages7
EditionPARTS A AND B
DOIs
Publication statusPublished - 2012
Externally publishedYes
EventASME 2012 Fluids Engineering Division Summer Meeting, FEDSM 2012 Collocated with the ASME 2012 Heat Transfer Summer Conf. and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and M, FEDSM 2012 - Rio Grande, Puerto Rico
Duration: 8 Jul 201212 Jul 2012

Publication series

NameAmerican Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM
NumberPARTS A AND B
Volume1
ISSN (Print)0888-8116

Conference

ConferenceASME 2012 Fluids Engineering Division Summer Meeting, FEDSM 2012 Collocated with the ASME 2012 Heat Transfer Summer Conf. and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and M, FEDSM 2012
Country/TerritoryPuerto Rico
CityRio Grande
Period8/07/1212/07/12

ASJC Scopus subject areas

  • Mechanical Engineering

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