New Smart Models for Minimum Fluidization Velocity Forecasting in the Tapered Fluidized Beds Based on Particle Size Distribution

2021 ◽  
Author(s):  
Seyyed Hossein Hosseini ◽  
Mohammad Amin Moradkhani ◽  
Mojtaba Rasteh ◽  
Masoud Rahimi
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Beds ◽  
Minimum Fluidization Velocity ◽  
Fluidization Velocity ◽  
Minimum Fluidization

Fluidization characteristics of wide-size-distribution particles in a gas-solid fluidized bed reactor

2020 ◽  
Vol 18 (12) ◽  
Author(s):  
Chaojie Li ◽  
Weiwen Wang ◽  
Xiuling Guo ◽  
Jihai Duan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Particle System ◽  
Fluidized Bed Reactor ◽  
Minimum Fluidization Velocity ◽  
Fluidization Velocity ◽  
Minimum Fluidization ◽  
Wide Size Distribution

AbstractFluidization characteristics of wide-size-distribution particles in the gas-solid fluidized bed reactor are investigated by applying experiment and computational fluid dynamics (CFD) methods. In this study, three types of narrow-cut particles and two sets of wide-size-distribution particles are used. A model considering particle size distribution is developed in the Eulerian frame, and good agreement between numerical results and experimental data is observed. The particle size distribution has an important effect on the average bed voidage. The axial particle diameter profiles along bed height have a “S” type feature. Minimum fluidization velocity is determined from the standard deviation of pressure fluctuations and bubble dynamics are analyzed based on power spectra. Results indicate that fine particle composition can reduce the minimum fluidization velocity of wide-size-distribution particle system and the bubble diameter in the fluidized bed.

Fluidization of Geldart Type-D Particles in a Swirling Fluidized Bed

2011 ◽  
Vol 110-116 ◽  
pp. 3720-3727 ◽  
Author(s):  
Mohd Faizal Mohideen ◽  
Suzairin Md Seri ◽  
Vijay Raj Raghavan
Keyword(s):  
Particle Size ◽  
Pressure Drop ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Superficial Velocity ◽  
Minimum Fluidization Velocity ◽  
Fluidization Velocity ◽  
Type D ◽  
Minimum Fluidization ◽  
Bed Material

Geldart Type-D particles are often associated with poor fluidization characteristics due to their large sizes and higher densities. This paper reports the hydrodynamics of various Geldart Type-D particles when fluidized in a swirling fluidized bed (SFB). Four different sizes of particles ranging from 3.85 mm to 9.84 mm with respective densities ranging from 840 kg/m3 to 1200 kg/m3 were used as bed material to study the effect of various bed weights (500 gram to 2000 gram) and centre bodies (cone and cylinder) for superficial velocities up to 6 m/s. The performance of the SFB was assessed in terms of pressure drop values, minimum fluidization velocity, Umf and fluidization quality by physical observation on regimes of operation. The swirling fluidized bed showed excellent capability in fluidizing Geldart Type-D particles in contrast to the conventional fluidized beds. The bed pressure drop of increased with superficial velocity after minimum fluidization as a result of increasing centrifugal bed weight. It was also found that the particle size and centre body strongly influence the bed hydrodynamics.

Convective Heat Transfer at Minimum Fluidization Velocity for Gas-Solid Fluidized Beds

1999 ◽  
Author(s):  
Kal R. Sharma
Keyword(s):  
Heat Transfer ◽  
Fluidized Beds ◽  
Empirical Correlations ◽  
Transfer Coefficients ◽  
Minimum Fluidization Velocity ◽  
Heat Transfer Coefficients ◽  
Fluidization Velocity ◽  
Minimum Fluidization ◽  
Semi Empirical ◽  
The Heat Transfer Coefficient

Abstract Experimentally measured values for the minimum fluidization velocities and time averaged local surface heat transfer coefficients are provided for 16 different cases of fluidizing conditions for gas-solid dense fluidized beds. Semi-empirical Correlations for the minimum fluidization velocity and the heat transfer coefficient at minimum fluidization velocities are provided. The implications of the Peclet number dependence in terms of diffusion and convection is discussed.

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