scholarly journals Numerical modeling of cold flow and hot gas desulfurization in a circulating fluidized bed

2001 ◽  
Author(s):  
Neeraj N. Pugalia
Keyword(s):  
Numerical Modeling ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Cold Flow ◽  
Hot Gas ◽  
Hot Gas Desulfurization

Cold Flow Model Study on a Dual Circulating Fluidized Bed (DCFB) System for Chemical Looping Processes

2009 ◽  
Vol 32 (3) ◽  
pp. 418-424 ◽  
Author(s):  
T. Pröll ◽  
K. Rupanovits ◽  
P. Kolbitsch ◽  
J. Bolhàr-Nordenkampf ◽  
H. Hofbauer
Keyword(s):  
Fluidized Bed ◽  
Flow Model ◽  
Circulating Fluidized Bed ◽  
Chemical Looping ◽  
Cold Flow ◽  
Model Study

scholarly journals Effects of Riser Diameter on Solids Holdup and Particle Velocity Profiles in Circulating Fluidized Bed Riser Systems

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Ronald W. Breault ◽  
Steven L. Rowan ◽  
Justin M. Weber ◽  
Jingsi Yang
Keyword(s):  
Fluidized Bed ◽  
Particle Velocity ◽  
Circulating Fluidized Bed ◽  
Velocity Profiles ◽  
Small Scale ◽  
Sauter Mean Diameter ◽  
Particle Size Range ◽  
Cold Flow ◽  
Solids Holdup ◽  
Radial Profiles

Abstract Tests were performed in a 0.1-m diameter small circulating fluidized bed (SCFB) and 0.3 m diameter cold flow circulating fluidized bed (CFCFB) riser systems located at the National Energy Technology Laboratory (NETL) to study the effects of riser diameter on the riser hydrodynamics. These tests were performed at solids circulation rates of Gs = 20 and 75 kg/m2 s and superficial gas velocities of Ug = 5.8 and 6.5 m/s using high-density polyethylene (HDPE) pellets with a density of 0.863 g/cm3, particle size range of 600–1400 µm (with a Sauter mean diameter of 871 µm, placing them in the Geldart B classification). Comparisons of riser axial pressure and solids fraction profiles, radial particle velocity profiles, and radial profiles of higher statistical moments and select chaos analysis parameters were considered. The results showed that for a given Ug and Gs, the smaller diameter riser exhibited characteristics associated with more dilute solids flow than that observed in the larger diameter riser. Additionally, the larger diameter riser exhibited a downward flow of solids near the wall under all test conditions, whereas the smaller diameter riser data exhibited little or no indications of solids downflow near the wall. These findings suggest that, from an industrial standpoint, a direct scaleup of small-scale tests cannot readily be accomplished as the solids holdup and the solids velocity profiles in small units (those normally tested in the laboratory) are not similar to those of large units and the performance of large units can therefore not be predicted from small-scale tests.

scholarly journals Systematic Study of Pressure Fluctuation in the Riser of a Dual Inter-Connected Circulating Fluidized Bed: Using Single and Binary Particle Species

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 890 ◽  
Author(s):  
Yusif A. Alghamdi ◽  
Zhengbiao Peng ◽  
Caimao Luo ◽  
Zeyad Almutairi ◽  
Behdad Moghtaderi ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Pressure Fluctuation ◽  
Circulating Fluidized Bed ◽  
Pressure Fluctuations ◽  
Single Species ◽  
Terminal Velocity ◽  
Operating Conditions ◽  
Cold Flow ◽  
Fluidization Regime ◽  
Spectrum Density

This study systematically investigates the pressure fluctuation in the riser of a dual interconnected circulating fluidized bed (CFB) representing a 10 kWth cold-flow model (CFM) of a chemical-looping combustion (CLC) system. Specifically, a single-species system (SSS) and a binary-mixtures system (BMS) of particles with different sizes and densities were utilized. The pressure fluctuation was analyzed using the fast Fourier transform (FFT) method. The effect of introducing a second particle, changing the inventory, composition (i.e., 5, 10 to 20 wt.%), particle size ratio, and fluidization velocity were investigated. For typical SSS experiments, the results were similar to those scarcely reported in the literature, where the pressure fluctuation intensity was influenced by varying the initial operating conditions. The pressure fluctuations of BMS were investigated in detail and compared with those obtained from SSS experiments. BMS exhibited different behaviour; it had intense pressure fluctuation in the air reactor and in the riser when compared to SSS experiments. The standard deviation (SD) of the pressure fluctuation was found to be influenced by the fluidization regime and initial operating conditions, while the power spectrum density (PSD) values were more sensitive to the presence of the particles with the higher terminal velocity in the binary mixture.

Simultaneous experiments of sulfidation and regeneration in two pressurized fluidized-bed reactors for hot gas desulfurization of IGCC

2001 ◽  
Vol 18 (6) ◽  
pp. 1005-1009 ◽  
Author(s):  
Chang-Keun Yi ◽  
Sung-Ho Jo ◽  
Bong-Hee Lee ◽  
Seung-Yong Lee ◽  
Jae-Ek Son ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Reactors ◽  
Hot Gas ◽  
Hot Gas Desulfurization

Hot Gas Desulfurization with Zinc Titanate Sorbents in a Fluidized Bed. 2. Reactor Model

1997 ◽  
Vol 36 (6) ◽  
pp. 2340-2345 ◽  
Author(s):  
J. T. Konttinen ◽  
C. A. P. Zevenhoven ◽  
M. M. Hupa
Keyword(s):  
Fluidized Bed ◽  
Reactor Model ◽  
Zinc Titanate ◽  
Hot Gas ◽  
Hot Gas Desulfurization

The control of bed height and solids circulation rate in the standpipe of a cold flow circulating fluidized bed

2005 ◽  
Vol 150 (3) ◽  
pp. 176-184 ◽  
Author(s):  
Juchirl Park ◽  
Yue Huang ◽  
Richard Turton ◽  
Parviz Famouri ◽  
Edward J. Boyle
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Cold Flow ◽  
Bed Height ◽  
Solids Circulation Rate
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