Comparative Study of the Hydrodynamic Performance of Shorter and Longer Blades in a Swirling Fluidized Bed

2013 ◽  
Vol 772 ◽  
pp. 560-565 ◽  
Author(s):  
Vinod Kumar Venkiteswaran ◽  
Shaharin Anwar Sulaiman ◽  
Vijay R. Raghavan
Keyword(s):  
Pressure Drop ◽  
Comparative Study ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Hydrodynamic Performance ◽  
Industrial Processes ◽  
Blade Length ◽  
Bed Height ◽  
Current Systems

Fluidized beds have been widely used in industrial processes. The inefficiency of current systems provides opportunities for improvement and development of new fluidized bed techniques. The swirling fluidized bed is an outcome of such a quest. The main shortcomings of present day SFB systems are the underutilization of available annular area and massing of bed particles at the periphery of the bed column. In this work the authors report the effect of increasing the annular area in a Swirling Fluidized Bed (SFB) by using longer blades for the distributor and compare it to the conventional blade length of 50 mm. Distributor blades of two different lengths, 50 mm and 100 mm, was used in this work and the bed height was measured with spherical bed particle of three different sizes (4 mm, 5 mm, 6 mm) at varying bed weight and superficial velocity. For a given bed weight, the benefits are achieved through a lower bed pressure drop as well as better quality of fluidization.

Fluidization Behavior of Mixtures of Nanoparticles in Vibrated Fluidized Beds

2012 ◽  
Vol 550-553 ◽  
pp. 2968-2971 ◽  
Author(s):  
Xi Zhen Liang ◽  
Tao Zhou ◽  
Hao Duan
Keyword(s):  
Fluidized Bed ◽  
Zno Nanoparticles ◽  
Vibration Amplitude ◽  
Fluidized Beds ◽  
Mass Ratio ◽  
Pressure Drops ◽  
Bed Height ◽  
Vibrated Fluidized Bed ◽  
Mixed Nanoparticles

The experiments of mixtures of SiO2 and ZnO nanoparticles in a vibrated fluidized bed were carried out. The effects of ratio of initial static bed height to diameter (h0/D), vibration amplitude (A), frequency (f) and mass ratio of mixed SiO2 and ZnO nanoparticles on the behavior of mixtures of SiO2 and ZnO nanoparticles were studied. The experimental results proved that the fluidization quality of mixed nanoparticles can be enhanced under h0/D=1, A=3.0 mm, f =45Hz, leading to larger bed pressure drops at low superficial gas velocities. The bed height decreases with increase in the mass ratio of ZnO component of the mixture.

The Pressure Drop at Critical Fluidization of Large Particles in Vibrated Fluidization Bed

2012 ◽  
Vol 550-553 ◽  
pp. 2763-2766
Author(s):  
Xue Jun Zhu ◽  
Jun Deng
Keyword(s):  
Pressure Drop ◽  
Fluidized Bed ◽  
Large Particle ◽  
Particle Diameter ◽  
Future Design ◽  
Vibration Strength ◽  
Bed Height ◽  
Large Particles ◽  
Vibrated Fluidized Bed ◽  
Critical Fluidization

The pressure drop at critical fluidization for two-dimensional vibrated fluidized bed(240 mm×80 mm) was studied, with large particle glass beads of average diameters dp of 1.8mm, 2.5mm and 3.2mm.The effect of the vibration strength, the static bed height and the particle diameter on the pressure drop was analyzed. The results of the study show that the pressure drop decreases with the increase of the vibration strength. It plays an even more prominent part with decreases of the static bed height and the particle diameter. The empirical correlation equations to predict the pressure drop was established, and the results of the prediction was compared with the experimental data, the error is in range of ±10%. The results can provide references for future design and research on the vibrated fluidized bed.

scholarly journals Study on Fluidization Characteristics of Magnetically Fluidized Beds for Microfine Particles

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Yakun Tian ◽  
Shulei Song ◽  
Xuan Xu ◽  
Xinyu Wei ◽  
Shanwen Yan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Fluidized Bed ◽  
Magnetic Field Strength ◽  
Fluidized Beds ◽  
Expansion Rate ◽  
Gas Velocity ◽  
Bed Height ◽  
Bed Expansion ◽  
The Magnetic Field

The bed pressure drop, minimum fluidized gas velocity, bed density, and bed expansion rate are important parameters characterizing the fluidization characteristics of gas-solid fluidized beds. By analyzing these parameters, the advantages and disadvantages of the fluidization state can be known. In this study, experiments were conducted to study the fluidization characteristics of a gas-solid magnetically fluidized bed for microfine particles by changing the magnetic field strength, magnetic field addition sequence, and static bed height. The experimental results show that when the magnetic field strength increased from 0 KA/m to 5 KA/m, the minimum fluidized gas velocity of particles increased from 4.42 cm/s to 10.32 cm/s, while the bed pressure drop first increased and then decreased. When the magnetic field strength is less than 3.4 KA/m, the microfine particles in the bed are mainly acted on by the airflow; while when the magnetic field strength is greater than 3.4 KA/m, the microfine particles are mainly dominated by the magnetic field. The magnetic field addition sequence affects the fluidization quality of microfine particles. The fluidized bed with ‘adding magnetic field first’ shows a more stable fluidization state than ‘adding magnetic field later’. Increasing of the static bed height reduces the bed expansion rate. The bed expansion rate is up to 112.5% at a static bed height of h0 = 40 mm and H = 5 KA/m. This will broaden the range of density regulation of a single magnetic particle and lay the advantage of gas-solid magnetically fluidized bed for microfine particles in the field of separation of fine coal.

Numerical Simulation on Thermal Field in the Fluidized Bed with Internal Heating Plates

2013 ◽  
Vol 690-693 ◽  
pp. 3162-3165
Author(s):  
Ji Hai Duan ◽  
Qi Wang
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Thermal Field ◽  
Side Reactions ◽  
Internal Heating ◽  
New Type ◽  
Over Time

Fluidized beds are widely used in the factories. However, the traditional heating methods can not meet the actual needs. Then we propose a new type fluidized-bed, which can effectively resolve the problem occurred in conventional fluidized-bed. The temperature of the reaction gas can be distributed uniformly in the new type fluidized-bed, the bed pressure drop is relatively stable over time. The above situations are conducive to the reactions stability, and reduce the occurrence of side reactions as well.

Effect of Pressure Drop of Distributor on Flow Pattern in 2-D Fluidized Bed: DEM Simulation and Experiment

2003 ◽  
Author(s):  
Toshihiro Kawaguchi ◽  
Yunosuke Mizushima ◽  
Toshitsugu Tanaka ◽  
Yutaka Tsuji
Keyword(s):  
Pressure Drop ◽  
Discrete Element Method ◽  
Flow Pattern ◽  
Fluidized Bed ◽  
Particle Motion ◽  
Fluidized Beds ◽  
Gas Flows ◽  
Dem Simulation ◽  
Effect Of Pressure ◽  
Simulation And Experiment

In the present study, effects of pressure drop across a distributor on particle motion in fluidized beds are studied numerically and empirically. The discrete element method (DEM) is employed to calculate the motion of individual particle. The predicted pressure drop across the distributor required to achieve uniform gas flows agreed well with previous empirical findings.

CFD Simulation Research on Flow Characteristics of Fluidized Beds

2014 ◽  
Vol 881-883 ◽  
pp. 1809-1813
Author(s):  
Li Ning Han ◽  
Lu Min Wang
Keyword(s):  
Particle Size ◽  
Pressure Drop ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Particle Distribution ◽  
Cfd Simulation ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Fluidization Velocity ◽  
Motion Characteristics

The Euler-Euler two-fluid model incorporating the kinetic theory of granular flow was applied to simulate the gas-solid flow in fluidized beds. The pressure drop, particle distribution and motion characteristics were studied in this paper. In order to investigate the effect of structure of the fluidized bed on flow characteristics, fluidized beds with different diameters and structures were applied. User defined functions (UDF) were applied to study the flow characteristics when the particle size and mass changed over time. The results showed that with the increase of particle size, higher minimum fluidization velocity was required, but lower pressure drop was obtained. For a certain fluidizing medium, the bed critical fluidization velocity depended only on the size and nature of the particles. The structure of a fluidized bed had an influence on the particle distribution and motion characteristics.

A Study on Fluidized Bed-Type Particulate Filter for Diesel Engines

2007 ◽  
Vol 129 (4) ◽  
pp. 1072-1078 ◽  
Author(s):  
Sung-Sub Kee ◽  
Ali Mohammadi ◽  
Takuji Ishiyama ◽  
Takaaki Kakuta
Keyword(s):  
Particle Size ◽  
Diesel Engine ◽  
Pressure Drop ◽  
Fluidized Bed ◽  
Particle Diameter ◽  
Filtration Efficiency ◽  
Particulate Filter ◽  
Design Parameters ◽  
Gas Velocity ◽  
Bed Height

A fluidized bed-type diesel particulate filter (DPF) was applied to filter particulate matter (PM) in diesel engine exhaust gas. The effects of the fluidized bed design parameters, such as gas velocity, bed particle size, and height, on PM and smoke filtration efficiencies, and pressure drop were experimentally investigated using a single-cylinder direct injection (DI) diesel engine. High PM filtration efficiency and low pressure drop were achieved with the DPF, especially at a lower gas velocity. The PM filtration efficiency was higher with a smaller bed particle size at the lower gas velocity; however, it drastically decreased with an increase in gas velocity due to excessive fluidization of the bed particles. Increase in bed height led to higher PM filtration efficiency while causing an increase in pressure drop. The theoretical work was also conducted for further investigation of the effects of the above-mentioned parameters on PM filtration. These results indicated that diffusion filtration was the dominant mechanism for PM filtration under the conditions of this study and that the decrease in PM filtration efficiency at high gas velocity was caused by a deterioration in the diffusion filtration. The bed particle diameter and the bed height should be optimized in order to obtain a high filtration efficiency without increasing the DPF size.

scholarly journals COMPARATIVE STUDY BETWEEN METHODOLOGIES USED FOR DETERMINATION OF THE TOTAL HARDNESS IN AQUEOUS MATRICES

2015 ◽  
Vol 12 (24) ◽  
pp. 91-95
Author(s):  
Natasha L. FERNANDES ◽  
Natacha M. B. BARRETO ◽  
Alessandro C. MACHADO ◽  
Genilda P. ROCHA
Keyword(s):  
Comparative Study ◽  
Industrial Processes ◽  
Total Hardness ◽  
Spectrometric Method ◽  
Human Consumption ◽  
Advantages And Disadvantages ◽  
Quality Of Water ◽  
Aqueous Matrices

Hardness affects the quality of water, making it unsuitable for human consumption and undesirable for the use in industrial processes. This paper compares the titrimetric method with the spectrometric method for the determination of hardness in aqueous matrices, evaluating the advantages and disadvantages of each application.

scholarly journals A CFD Study of Industrial Double-Cyclone in HDPE Drying Process

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
S.A. Razavi Alavi ◽  
E. Nemati Lay ◽  
Z.S. Alizadeh Makhmali
Keyword(s):  
Pressure Drop ◽  
Fluidized Bed ◽  
Solid Particles ◽  
Ansys Fluent ◽  
Lagrangian Framework ◽  
Inlet Flow Rate ◽  
Drying Behavior ◽  
Fluent Software ◽  
Fluidized Bed Drying

Double-cyclone in fluidized bed drying is an important equipment which reflects the conditions of drying in HDPE slurry process. Cyclone is an important unite of fluidized bed drying in order to move the solid particles outward to its wall. Therefore, flow pattern created in fluidized bed will affect industrial cyclones installed in dryer for dust removing. Pressure drop of the cyclones is an effective parameter represents the drying behavior. Substantially, geometry of cyclone, inlet flow rate of gas, density and particle size distribution (PSD) can affect the pressure drop value. Fluidized bed hydrodynamic regime is very complex and must be understood to improve fluidized bed operations through theoretical, industrial and CFD study of double-cyclone. Pressure drop is introduced as parameter related to the cyclone efficiency can be calculated with ANSYS Fluent software in the Eulerian-Lagrangian framework with RNG k-ɛ turbulence model used as a mathematical method. Proper pressure drop concluded from industrial experiments and CFD calculation shows good fluidization of HDPE particles in the bed of nitrogen and powder  to reach the best fluidized bed situation and suitable quality of HDPE powdery product.

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.

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