Acceleration Length (acceleration + length)

Distribution by Scientific Domains


Selected Abstracts


Comprehensive Study on the Solids Acceleration Length in a Long CFB Riser

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2006
W-X. Huang
Abstract 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. [source]


A critical analysis of the acceleration length and pressure profile of single-particle systems in a circulating fluidized bed

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2008
Mitali Das
Abstract A study was conducted to explore the hydrodynamic behaviors using both Geldart group A and B materials in a circulating fluidized bed unit consisting of fast column (riser) of 0.1016 m i.d. and 5.62 m height. The materials tested were 120 µm of the fluid catalytic cracking (FCC) catalyst, 166 µm of iron ore, 215 µm of coal and five types of sand particles, ranging in size from 300 to 622 µm. The superficial air velocity ranged between 2.01 and 4.681 m/s and solid fluxes of 12.5,50 kg/m2s. Riser static pressure profiles were measured for the FCC catalyst, coal, iron ore and sand particles. Acceleration lengths were determined from the data, and using these and other data from the literature two correlations for the acceleration length were established for Geldart's group A and B particles. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source]


Comprehensive Study on the Solids Acceleration Length in a Long CFB Riser

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2006
W-X. Huang
Abstract 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. [source]