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

Solids circulation rate and static bed height in a riser of a circulating fluidized bed

2014 ◽  
Vol 32 (2) ◽  
pp. 284-291 ◽  
Author(s):  
Daebum Cho ◽  
Jeong-Hoo Choi ◽  
Muhammad Shahzad Khurram ◽  
Sung-Ho Jo ◽  
Ho-Jung Ryu ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Bed Height ◽  
Solids Circulation Rate

A method for estimating the solids circulation rate in a closed-loop circulating fluidized bed

2001 ◽  
Vol 121 (2-3) ◽  
pp. 213-222 ◽  
Author(s):  
Shantanu Roy ◽  
Abdenour Kemoun ◽  
Muthanna Al-Dahhan ◽  
M.P Dudukovic
Keyword(s):  
Fluidized Bed ◽  
Closed Loop ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Solids Circulation Rate

An Experimental Comparison of a Sliding Mode Estimator to an Extended Kalman Filter Applied to a Cold Flow Circulating Fluidized Bed

2004 ◽  
Author(s):  
Juchirl Park ◽  
Edward J. Boyle ◽  
Richard Turton ◽  
Parviz Famouri
Keyword(s):  
Kalman Filter ◽  
Fluidized Bed ◽  
Extended Kalman Filter ◽  
Circulating Fluidized Bed ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Department Of Energy ◽  
Experimental Comparison ◽  
Cold Flow ◽  
Bed Height

Circulating fluidized beds (CFB) have been applied to a wide variety of chemical industry processes to reduce pollution and increase efficiency. Identifying the void fractions and the bed-height in the standpipe of the CFB is required for designing a controller to improve the overall system operation. An extended Kalman filter (EKF) algorithm has been applied in order to successfully estimate the states and the bed-height of the standpipe in the cold flow circulating fluidized bed (CFCFB) at the Department of Energy, National Energy Technology Laboratory. However, for some oscillating input cases, this method does not perform well. In addition, covariance matrices Q and R need to be assumed initially and depending upon initial conditions, for some cases, the EKF behaves unstably. In this research, a sliding mode estimator (SME) is applied in order to estimate the state, and the bed-height of the standpipe in the CFCFB. The sliding mode estimator requires the proper gain for tuning in order to have proper estimations. Test results show improvement in state estimation performance of SME over EKF.

scholarly journals OPERATIONAL INFLUENCE OF THE MONO-CHAMBER AERATION MODE IN THE LOOP SEAL OF A CIRCULATING FLUIDIZED BED

2020 ◽  
Vol 51 (1) ◽  
pp. 15-20
Author(s):  
Fernanda De Oliveira ◽  
Guilherme Santos Furquim ◽  
Vitor Otávio Ochoski Machado ◽  
Maria Regina Parise ◽  
Jhon Jairo Ramírez Behainne
Keyword(s):  
Pressure Drop ◽  
Fluidized Bed ◽  
Energy Demand ◽  
Static Pressure ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Sauter Mean Diameter ◽  
Solids Circulation Rate ◽  
Fluidization Regime ◽  
Superficial Gas Velocity

Fluidization numbers varying from 0.84 to 1.68 were used in the loop seal valve of a bench-scale circulating fluidized bed (CFB) system to analyze the influence of the mono-chamber aeration mode on both the solids circulation rate and the static pressure drop inside the solids recycle device. Runs were carried out using 4 kg of overall solids inventory and particles of 183 µm in Sauter mean diameter, which were kept under fast fluidization regime at superficial gas velocity of 4 m/s. Results showed that the choice of the chamber to be aerated can noticeably affect the gas-solid hydrodynamics. In this sense, the analysis of variance applied on the experimental data indicated that the aeration into the recycle chamber of the loop seal offers lower levels of solids circulation rate but also allows to control it within a wider range of fluidization numbers and with less pressure drop or energy demand.

Radial Distribution of Liquid Velocity in a Liquid-Solids Circulating Fluidized Bed

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Ying Zheng ◽  
Jesse Zhu
Keyword(s):  
Fluidized Bed ◽  
Radial Distribution ◽  
Circulating Fluidized Bed ◽  
Liquid Velocity ◽  
Circulation Rate ◽  
Liquid Transport ◽  
Solids Circulation Rate ◽  
Fluidization Regime ◽  
Radial Profiles ◽  
Radial Nonuniformity

Local liquid velocity was measured in a liquid-solid circulating fluidized bed, with a Plexiglas riser column of 7.62 cm ID and 3.0 m in height, by a dual conductivity probe, with 508 micron glass beads. The results show that radial distribution of local liquid velocity in the LSCFB is nonuniform with higher liquid velocity at the axis and lower near the wall, compared to the more uniform radial profiles in both the conventional fluidization and the dilute liquid transport regimes. The radial nonuniformity increases with increasing liquid velocity and solids circulation rate in the LSCFB. A radial nonuniformity index, proposed by Zhu and Manyele (2001), was used to quantify the extent of the radial nonuniformity under different solids circulation rates and liquid flow rates. The radial nonuniformity index is used to qualify the radial distribution of liquid velocity. RNI values in the liquid-solid circulating fluidization regime are seen to be much higher than those in both the particulate fluidization regime and the dilute liquid transport regime, indicating the nonuniform radial distribution of local liquid velocity in the LSCFB. This illustrates the use of RNI as an effective measurement of the radial distribution of liquid velocity.

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