Scaled down Design of a Cold and Hot Flow Model Based on a Bubbling Fluidized Bed Pilot Plant Gasifier

2015 ◽  
Vol 786 ◽  
pp. 232-237 ◽  
Author(s):  
Iman Eslami Afrooz ◽  
Chandra Mohan Sinnathambi ◽  
Saravanan Karuppanan ◽  
Dennis Ling Chuan Ching

Bubbling fluidized bed (BFB) is a vital equipment in many applications in the energy, pharmaceuticals, and chemicals process industries due to its numerous advantages such as large heat capacity inside a bed, and rapid heat and mass transfer rate. In spite of numerous research activities, achieving high fluidization performances in BFB process is still a challenge of science. This research is being conducted to study the hydrodynamic regime of a BFB pilot plant gasifier. To this end, a lab-scale cold model was first designed based on the empirical equations and scaling laws. The scaling laws was used to scale down the Tenaga Nasional Berhad-PETRONAS (TNBR-PETRONAS) pilot plant gasifier into a small scale laboratory model. Moreover, the empirical equations were utilized to determine the critical parameters such as bed pressure drop, height of the bed, number of orifices of the distributor plate and the pitch size. Finally a lab-scale hot flow model will be designed based on the cold model geometric dimensions but under a real operating conditions as that of a pilot plant.

2017 ◽  
Vol 305 ◽  
pp. 340-346 ◽  
Author(s):  
Esmail R. Monazam ◽  
Ronald W. Breault ◽  
Justin Weber ◽  
Ky Layfield

2013 ◽  
Vol 102 ◽  
pp. 860-867 ◽  
Author(s):  
L.F. de Diego ◽  
M. de las Obras-Loscertales ◽  
A. Rufas ◽  
F. García-Labiano ◽  
P. Gayán ◽  
...  

10.14311/1568 ◽  
2012 ◽  
Vol 52 (3) ◽  
Author(s):  
Jiří Štefanica ◽  
Jan Hrdlička

In a fluidized bed boiler, the combustion efficiency, the NOX formation rate, flue gas desulphurization and fluidized bed heat transfer are all ruled by the gas distribution. In this investigation, the tracer gas method is used for evaluating the radial gas dispersion coefficient. CO2 is used as a tracer gas, and the experiment is carried out in a bubbling fluidized bed cold model. Ceramic balls are used as the bed material. The effect of gas velocity, radial position and bed height is investigated.


2018 ◽  
Vol 12 (5) ◽  
pp. 735-748 ◽  
Author(s):  
Zakir Khan ◽  
Suzana Yusup ◽  
Murni M Ahmad ◽  
Abrar Inayat ◽  
Muhammad Naqvi ◽  
...  

2012 ◽  
Vol 550-553 ◽  
pp. 529-533
Author(s):  
De Wu Wang ◽  
Meng Da Jia ◽  
Shao Feng Zhang ◽  
Chun Xi Lu

A large-scale cold model experimental setup of combined riser with variable constraint exit (CRVCE) was established. The axial and radial distributions of solids holdup and particle velocity, under different operating conditions, were investigated experimentally, and the results were compared with conventional riser (CR). Experimental results showed that, the exit restrictive effect of combined riser with variable constraint exit was weak when particle circulation flux and static bed height in upper fluidized bed were lower, while it turned to be strong when superficial gas velocity and static bed height in upper fluidized bed were higher. Under the same conditions, averaged cross-sectional solids holdup of CRVCE was characterized by C type distribution when article circulation flux was higher, while that of CR with weak constraint exit was characterized by linear distribution. In axial direction, averaged cross-sectional particle velocity of CRVCE changed in order: acceleration-constant-decrease velocity, while that of CR changed in another: acceleration-constant velocity. The maximum of local solids holdup value of CRVCE appeared at the dimensionless radius position r/R=0.7, while that of CR appeared in the wall region. Their local particle velocities were similar in the core region, while local particle velocity of CRVCE was lower than that of CR in the annular region.


Author(s):  
Cesar Martin Venier ◽  
Andrés Reyes Urrutia ◽  
Juan Pablo Capossio ◽  
Jan Baeyens ◽  
Germán Mazza

Purpose The purpose of this study is to assess the performance of ANSYS Fluent® and OpenFOAM®, at their current state of development, to study the relevant bubbling fluidized bed (BFB) characteristics with Geldart A, B and D particles. Design/methodology/approach For typical Geldart B and D particles, both a three-dimensional cylindrical and a pseudo-two-dimensional arrangement were used to measure the bed pressure drop and solids volume fraction, the latter by digital image analysis techniques. For a typical Geldart A particle, specifically to examine bubbling and slugging phenomena, a 2 m high three-dimensional cylindrical arrangement of small internal diameter was used. The hydrodynamics of the experimentally investigated BFB cases were also simulated for identical geometries and operating conditions using OpenFOAM® v6.0 and ANSYS Fluent® v19.2 at identical mesh and numerical setups. Findings The comparison between experimental and simulated results showed that both ANSYS Fluent® and OpenFOAM® provide a fair qualitative prediction of the bubble sizes and solids fraction for freely-bubbling Geldart B and D particles. For Geldart A particles, operated in a slugging mode, the qualitative predictions are again quite fair, but numerical values of relevant slug characteristics (length, velocity and frequency) slightly favor the use of OpenFOAM®, despite some deviations of predicted slug velocities. Originality/value A useful comparison of computational fluid dynamics (CFD) software performance for different fluidized regimes is presented. The results are discussed and recommendations are formulated for the selection of the CFD software and models involved.


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