Premium
Comprehensive Study on the Solids Acceleration Length in a Long CFB Riser
Author(s) -
Huang WX.,
Zhu JX.,
Pärssinen J. H.
Publication year - 2006
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.200500218
Subject(s) - acceleration , mechanics , range (aeronautics) , work (physics) , fluidized bed combustion , volumetric flow rate , materials science , flow (mathematics) , degree (music) , thermodynamics , chemistry , fluidized bed , physics , classical mechanics , composite material , acoustics
Systematic experimental work was conducted to investigate the solids acceleration length in a 0.10 m i. d., 16 m long circulating fluidized bed (CFB) riser with fluid catalytic cracking (FCC) particles over a wide range of operating conditions. A more feasible method is proposed to determine the acceleration length from the measured axial profiles of pressure gradient (or apparent solids holdup). With this new method and large amounts of experimental results, a clear picture of the variation of the acceleration length with both solids circulating rate and superficial gas velocity is obtained. It is found that the acceleration length increases generally with increasing solids flow rate and/or decreasing gas velocity. However, the particular variation patterns of the acceleration length with operating conditions are quite different in different operation ranges. Especially under the conditions near or at the accumulative choking, the acceleration length extends rapidly with increasing solids flow rate and/or decreasing gas velocity, and sometimes takes up the whole riser height. Reasonable explanations are provided for the observed variation patterns of the acceleration length.