The solids flow in the CFB-riser quantified by single radioactive particle tracking
Mahmoudi, Shiva, Baeyens, Jan and Seville, J. P. K. (Jonathan P. K.). (2011) The solids flow in the CFB-riser quantified by single radioactive particle tracking. Powder Technology, Vol.211 (No.1). pp. 135-143. ISSN 0032-5910Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/j.powtec.2011.04.011
Single radioactive particle tracking was used to measure the overall solids residence time (and its distribution) in the riser of a CFB, operating at superficial air velocities (U) of 1 to 9 ms− 1 and solids circulation fluxes (G) between 20 to 600 kg m− 2s− 1.
The results demonstrate that the particle motion and mixing differ according to the operating mode of the riser, with a fairly constant velocity throughout the riser achieved in the dilute or dense riser flow, but with a significant amount of back-mixing for intermediate values of U and/or G. This back-mixing is due to the core-annulus mode of particle flow. Whereas experimental results and theoretical predictions are in fair agreement for the dilute and dense riser flow, the core-annulus regime needs to account for a U and G dependent slip factor (φ), in excess of the commonly proposed value φ = 2, especially at U–UTR < 2 ms− 1.
Moreover, the previously published riser operation diagram is confirmed by the experiments, although a further analysis of the core-annulus regime is needed.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics
T Technology > TA Engineering (General). Civil engineering (General)
|Divisions:||Faculty of Science > Engineering|
|Library of Congress Subject Headings (LCSH):||Fluid dynamics, Fluidized-bed combustion , Particle tracks (Nuclear physics), Positrons -- Emission|
|Journal or Publication Title:||Powder Technology|
|Publisher:||Elsevier Science SA|
|Page Range:||pp. 135-143|
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