scholarly journals CFD Modeling and Simulation of Hydrodynamics in a Fluidized Bed Dryer with Experimental Validation

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Mahdi Hamzehei
Keyword(s):  
Fluidized Bed ◽  
Fluid Dynamic ◽  
Expansion Ratio ◽  
Industrial Applications ◽  
Solid Particles ◽  
Cfd Modeling ◽  
Momentum Exchange ◽  
Fluidized Bed Dryer ◽  
Wide Range ◽  
Simulation Results

Gas-solid fluidized bed dryers are used in a wide range of industrial applications. With applying computational fluid dynamic (CFD) techniques, hydrodynamics of a two-dimensional nonreactive gas-solid fluidized bed dryer was investigated. A multifluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady state behavior of this dryer and momentum exchange coefficients were calculated by using the Syamlal-O'Brien drag functions. A suitable numerical method that employed finite volume method was used to discretize the equations. Simulation results also indicated that small bubbles were produced at the bottom of the bed. These bubbles collided with each other as they moved upwards forming larger bubbles. Also, solid particles diameter and superficial gas velocity effect on hydrodynamics were studied. Simulation results were compared with the experimental data in order to validate the CFD model. Pressure drops and bed expansion ratio as well as the qualitative gas-solid flow patterns predicted by the simulations were in good agreement with experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Furthermore, this comparison showed that the model can predict hydrodynamic behavior of gas solid fluidized bed reasonably well.

Studies of Gas Velocity And Particles Size Effects on Fluidized Bed Hydrodynamics with Cfd Modeling and Experimental Investigation

2010 ◽  
Vol 26 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Mahdi Hamzehei ◽  
Hassan Rahimzadeh ◽  
Goodarz Ahmadi
Keyword(s):  
Fluidized Bed ◽  
Expansion Ratio ◽  
Solid Particles ◽  
Cfd Modeling ◽  
Gas Velocity ◽  
Momentum Exchange ◽  
State Behavior ◽  
Pressure Drops ◽  
Simulation Results ◽  
Superficial Gas Velocity

AbstractWith applying Computational Fluid Dynamics (CFD) techniques, hydrodynamics of a twodimensional non-reactive gas-solid fluidized bed reactor was investigated. A multi fluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady state behavior of this reactor and momentum exchange coefficients were calculated by using the Syamlal-O'Brien drag functions. A suitable numerical method that employed finite volume method applied to discritize the equations. Simulation results also indicated that small bubbles were produced at the bottom of the bed. These bubbles collided with each other as they moved upwards forming larger bubbles. Also, solid particles diameter and superficial gas velocity effect on hydrodynamics were studied. Simulation results were compared with the experimental data in order to validate the CFD model. Pressure drops and bed expansion ratio as well as the qualitative Gas-Solid flow patterns predicted by the simulations were in good agreement with experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Furthermore, this comparison showed that the model can predict hydrodynamicsbehavior of gas solid fluidized bed reasonably well.

Experiment and Numerical Simulation on Slugging Fluidization of Large Particles in Gas-Solid Fluidized Bed

2014 ◽  
Vol 881-883 ◽  
pp. 689-697
Author(s):  
Hui Yang ◽  
Dong Yu Wan ◽  
Chang Qing Cao
Keyword(s):  
Fluidized Bed ◽  
Expansion Ratio ◽  
Solid Particles ◽  
Momentum Exchange ◽  
Cold Model ◽  
State Behavior ◽  
Large Particles ◽  
Computational Fluid Dynamics Cfd ◽  
Bed Expansion

The hydrodynamics of a two-dimensional gas-solid fluidized bed with 0.03 m diameter and 0.3 m height were studied experimentally and computationally. The slugging fluidization of large particles was experimentally investigated and simulated using the Fluent 6.3 computational fluid dynamics (CFD) package. By a series of cold-model test, characterization of gas-solid fluidization with large particles was studied. These results can be used to research slugging characteristics. A multifluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady-state behavior and momentum exchange coefficients were calculated by using the Syamlal-OBrien drag functions. These results of the transfer of fluidization state, maximum bed expansion ratio and pressure fluctuation were systemically simulated in a gas-solid fluidized bed. The modeling predictions compared reasonably well with experimental data and qualitative slugging regime. The simulation results can better predict the slugging fluidization characterization of large particles.

scholarly journals Analisa Pengeringan Secara Konveksi Butiran Teh pada Fluidized Bed Dryer Menggunakan Computational Fluid Dynamic (CFD)

ROTASI ◽  
2017 ◽  
Vol 19 (4) ◽  
pp. 206
Author(s):  
MSK Tony Suryo Utomo ◽  
Ghiffar Yanuar
Keyword(s):  
Fluidized Bed ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Fluidized Bed Dryer

Simulasi numerik perpindahan panas pada teh dilakukan dengan menempatkan material teh pada domain komputasi sebuah aliran eksternal. Penurunan massa pada teh dihitung secara analitik dengan menggunakan persamaan laju penurunan massa. Teh dimodelkan dengan bentuk menyerupai bola setelah dilakukan pelayuan untuk kemudian dikeringkan. Kecepatan masuk aliran udara divariasikan sesuai dengan batas kecepatan minimum dan maksimum fluidisasi pada fluidized bed dryer. Kecepatan yang divariasikan yaitu 3 m/s, 5 m/s, dan 7 m/s. Temperatur masuk aliran udara juga divariasikan berdasarkan temperatur pengeringan teh untuk fluidized bed dryer yaitu 920C, 950C, dan 1000C. Model aliran yang digunakan yaitu aliran laminar dengan Re < 105 untuk aliran external. Hasil penelitian menunjukkan bahwa perpindahan panas dan perpindahan massa terjadi dengan cepat untuk material teh. Berdasarkan variasi kecepatan aliran udara dan temperatur, maka semakin tinggi kecepatan dan temperatur masuk aliran udara mengakibatkan semakin menurunnya waktu yang dibutuhkan untuk mengurangi kadar air pada teh. Waktu yang digunakan untuk menurunkan kadar air hingga 3% berdasarkan temperatur pada kecepatan 3 m/s secara berurutan adalah 515 s (920C), 455 s (950C), dan 380 s (1000C). Sementara pada kecepatan 5 m/s waktu yag dibutuhkan adalah 400 s (920C), 355 s (950C), dan 295 s (1000C) serta untuk kecepatan 7 m/s berturut-turut 340 s (920C), 300 s (950C), dan 250 s (1000C). Untuk pengeringan teh lebih optimal dilakukan dengan menaikkan kececepatan masuk aliran fluida dibandingkan dengan menaikkan temperatur.

Fluid Dynamic Simulation of a Wall-Jet-Flow Loaded with Solid Particles Using the Finite Analytic/Grid Method of PDF Model

2013 ◽  
Vol 345 ◽  
pp. 336-340
Author(s):  
Ying Tian ◽  
Jiang Rong Xu ◽  
Su Juan Hu ◽  
Wei Wei Ye
Keyword(s):  
Fluid Dynamic ◽  
Grid Method ◽  
Particle Method ◽  
Jet Flow ◽  
Solid Particles ◽  
Particle Flow ◽  
Wall Jet ◽  
Simulation Results ◽  
Wall Jet Flow ◽  
Pdf Model

In this paper, a classical wall-jet-flow loaded with particles is simulated by the finite analysis /grid method using the particle PDF transport equation, as well as by the finite analysis / particle method, and then the simulation results ​​obtained by the two methods are compared with the experimental results. It is shown that the finite analysis/grid method is effective for the prediction of the particle flow.

scholarly journals Analisis Distribusi Temperatur dan Aliran Fluida pada Proses Pengeringan Butiran Teh Bentuk Silinder Di Dalam Fluidized Bed Dryer Menggunakan Computational Fluid Dynamic (CFD)

ROTASI ◽  
2019 ◽  
Vol 20 (4) ◽  
pp. 237
Author(s):  
MSK Tony Suryo Utomo ◽  
Eflita Yohana ◽  
Mauli Astuti Khoiriyah
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluidized Bed ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Fluidized Bed Dryer ◽  
Computational Fluid Dynamics Cfd

Pengeringan merupakan proses perpindahan panas dan uap air secara simultan yang memerlukan energi panas untuk menguapkan kandungan air dari bahan yang akan dikeringkan. Penelitian ini dilakukan dengan cara simulasi. Produk yang dipilih untuk simulasi ini yaitu teh. Simulasi numerik perpindahan massa pada teh dilakukan dengan menempatkan material teh pada domain komputasi sebuah aliran eksternal. Penelitian ini bertujuan untuk menganalisis distribusi temperatur pada partikel teh dengan menggunakan Computational Fluid Dynamics (CFD) dan menganalisis pengaruh variasi kecepatan inlet dan temperatur inlet terhadap waktu pengeringan sehingga diperoleh metode pengeringan yang paling optimum pada pengeringan teh. Penurunan massa pada teh dihitung secara analitik dengan menggunakan persamaan laju penurunan massa. Teh dimodelkan dengan bentuk menyerupai silinder setelah dilakukan pelayuan untuk kemudian dikeringkan. Kecepatan masuk aliran udara dan temperatur masuk divariasikan sesuai dengan batas kecepatan minimum dan maksimum fluidisasi dan temperatur pengeringan teh untuk fluidized bed dryer. Waktu yang digunakan untuk menurunkan kadar air hingga 3% berdasarkan temperatur pada kecepatan 1,6 m/s secara berurutan adalah 354 s (880C), 300 s (930C), dan 256 s (980C). Sementara pada kecepatan 2,6 m/s waktu yag dibutuhkan adalah 277 s (880C), 234 s (930C), dan 200 s (980C) serta untuk kecepatan 3,6 m/s berturut-turut 235 s (880C), 199 s (930C), dan 169 s (980C). Untuk pengeringan teh lebih optimal dilakukan dengan menaikkan kececepatan masuk aliran fluida dibandingkan dengan menaikkan temperatur.

Fluidization Characteristic of Sewage Sludge Particles

2015 ◽  
Vol 776 ◽  
pp. 294-299
Author(s):  
I. Nyoman Suprapta Winaya ◽  
Rukmi Sari Hartati ◽  
I. Nyoman Gde Sujana
Keyword(s):  
Sewage Sludge ◽  
Fluid Dynamic ◽  
Solid Particles ◽  
Cfd Modeling ◽  
Multiphase Model ◽  
Particle Sizes ◽  
Eulerian Model ◽  
Visual Phenomena ◽  
Basic Characteristics ◽  
Sludge Particle

The main objective of this study is to determine the basic characteristics of fluidization using sewage sludge particle as non-visual phenomena which can then be modeled physically and numerically with the program of Computational Fluid Dynamic (CFD). CFD modeling using Eulerian model incorporating the kinetic theory for solid particles was applied to the gas-solid flow at various superficial velocities for different particle sizes. The transfer momentum was calculated using Syamlal-O'Brien drag function and Eulerian multiphase model was used for analysis. Two-Dimensional computational domains discretized using rectangular cells (Quad), made within the 20 iteration steps of 0,001s. The gas velocity is found to be the ​​the most important factors that influence the formation process of fluidization; by increasing the rate of fluidization the bed expanse occurs higher as well the time of onset fluidization is shorter. The phenomenon can be explained well by modeling and simulation.

Multiphase CFD Model Development for a Rotating Centrifugal Separator

2012 ◽  
Author(s):  
Daniel DeMore ◽  
William Maier
Keyword(s):  
Separation Efficiency ◽  
Fluid Dynamic ◽  
Model Development ◽  
Modeling Method ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Separation Performance ◽  
Centrifugal Separator ◽  
Wide Range ◽  
The Impact

The present paper describes the development of a Computational Fluid Dynamic (CFD) modeling approach suitable for the analysis, design, and optimization of rotating centrifugal separator stage geometries. The Homogeneous Multiple Size Group (MUSIG) model implemented in the commercial code CFX V13.0 was utilized as a basis for the CFD modeling method. The model was developed through a series of studies to understand the impact of droplet size distribution, particle coalescence, rotor/stator interface treatment, and mesh resolution on the prediction of separation efficiency for a given rotating separator geometry. This model was then validated against the OEM’s extensive in-house experimental separation testing database. The resulting CFD modeling method is shown to adequately reproduce observed trends in separation performance over a wide range of operating conditions.

CFD Modeling of Heat and Mass Transfer in the Fluidized Bed Dryer

2011 ◽  
Vol 6 (6) ◽  
pp. 595-605 ◽  
Author(s):  
M. Keshavarz Moraveji ◽  
S.A. Kazemi ◽  
R. Davarnejad
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Fluidized Bed ◽  
Cfd Modeling ◽  
Fluidized Bed Dryer

scholarly journals CFD Modeling of Gas–Solid Cyclone Separators at Ambient and Elevated Temperatures

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 228 ◽  
Author(s):  
Mohammadhadi Nakhaei ◽  
Bona Lu ◽  
Yujie Tian ◽  
Wei Wang ◽  
Kim Dam-Johansen ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Cfd Simulation ◽  
Separation Efficiency ◽  
Flow Behavior ◽  
Industrial Applications ◽  
High Mass ◽  
Cfd Modeling ◽  
Solid Flow ◽  
Solids Loading ◽  
Wide Range

Gas–solid cyclone separators are widely utilized in many industrial applications and usually involve complex multi-physics of gas–solid flow and heat transfer. In recent years, there has been a progressive interest in the application of computational fluid dynamics (CFD) to understand the gas–solid flow behavior of cyclones and predict their performance. In this paper, a review of the existing CFD studies of cyclone separators, operating in a wide range of solids loadings and at ambient and elevated temperatures, is presented. In the first part, a brief background on the important performance parameters of cyclones, namely pressure drop and separation efficiency, as well as how they are affected by the solids loading and operating temperature, is described. This is followed by a summary of the existing CFD simulation studies of cyclones at ambient temperature, with an emphasis on the high mass loading of particles, and at elevated temperatures. The capabilities as well as the challenges and limitations of the existing CFD approaches in predicting the performance of cyclones operating in such conditions are evaluated. Finally, an outlook on the prospects of CFD simulation of cyclone separators is provided.

Study of Heat Transfer and Hydrodynamics in a Gas-Solid Fluidized Bed Reactor Experimentally and Numerically

2011 ◽  
Vol 110-116 ◽  
pp. 4187-4197
Author(s):  
Mahdi Hamzehei ◽  
Hassan Rahimzadeh ◽  
Goodarz Ahmadi
Keyword(s):  
Heat Transfer ◽  
Computational Model ◽  
Fluidized Bed ◽  
Particle Temperature ◽  
Fluidized Bed Reactor ◽  
Solid Particles ◽  
Experimental Results ◽  
Heat Conducting ◽  
Momentum Exchange ◽  
Good Agreement

—In this research, the heat transfer and hydrodynamics of a gas–solid fluidized bed reactor were studied experimentally and computationally. A multi-fluid Eulerian computational model incorporating the kinetic theory for solid particles was developed and used to simulate the heat conducting gas–solid flows in a fluidized bed configuration. Momentum exchange coefficients were evaluated using the Syamlal–O’Brien drag functions. Temperature distributions of different phases in the reactor were also computed. Good agreement was found between the model predictions and the experimentally obtained data for the bed expansion ratio as well as the qualitative gas–solid flow patterns. The simulation and experimental results showed that the gas temperature decreases as it moves upward in the reactor, while the solid particle temperature increases. Pressure drop and temperature distribution predicted by the simulations were in good agreement with the experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Also, the predicted time-average local voidage profiles were in reasonable agreement with the experimental results. The study showed that the computational model was capable of predicting the heat transfer and the hydrodynamic behavior of gas-solid fluidized bed flows with reasonable accuracy.

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