Group Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Title: 10.5.3 - Discrete Particle Simulation of Gas-Solid Flow and Heat Transfer in Gas Fluidized Beds
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Permanent Link: http://ufdc.ufl.edu/UF00102023/00262
 Material Information
Title: 10.5.3 - Discrete Particle Simulation of Gas-Solid Flow and Heat Transfer in Gas Fluidized Beds Particle-Laden Flows
Series Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Physical Description: Conference Papers
Creator: Hou, Q.F.
Zhou, Z.Y.
Yu, A.B.
Publisher: International Conference on Multiphase Flow (ICMF)
Publication Date: June 4, 2010
 Subjects
Subject: discrete particle simulation
immersed tube
heat transfer
 Notes
Abstract: Fluidization is widely used in industries as a major flow mode for fluid bed reactors. Immersed tubes are frequently used for temperature control and heat recovery. The flow and heat transfer in a fluidized bed are of fundamental importance in its applications and optimization. These have been extensively studied by experiments and mathematical models in the past decades. However, different heat transfer mechanisms are difficult to quantify. Recently, a combined discrete particle simulation and computational fluid dynamics method has been developed to study heat transfer in gas fluidization (Zhou et al., 2009). This method can examine the heat transfer at a particle level and quantify the contributions of different heat transfer mechanisms, such as convection, conduction and radiation. This work extends the model to study heat transfer between a bed and an immersed tube in bubbling fluidized beds with Geldart A and B powders (Geldart, 1973). Solid flow pattern (cf. Fig. 1) is firstly obtained and the results show consistent characteristics with those of experimental and simulation studies (Glass and Harrison, 1964; Rong et al., 1999; Wong and Seville, 2006). Then heat transfer process is analyzed. The results show that convective heat transfer is dominant for Powder B, whereas the conductive heat transfer is dominant for Powder A (Fig. 2). This prediction provides evidence to support with the literature understanding (Flamant et al., 1992). In conductive heat transfer, heat flux through the particle-fluid-tube path under noncontact condition is dominant for both types of powders (Zhou et al., 2009). The results show that a bed with higher tube temperature and larger gas velocity has a larger overall deviation of temperature, and therefore less uniformity of temperature field, particularly for type B powders. The study shows that a smaller powder is better from the viewpoint of the uniformity of temperature field.
General Note: The International Conference on Multiphase Flow (ICMF) first was held in Tsukuba, Japan in 1991 and the second ICMF took place in Kyoto, Japan in 1995. During this conference, it was decided to establish an International Governing Board which oversees the major aspects of the conference and makes decisions about future conference locations. Due to the great importance of the field, it was furthermore decided to hold the conference every three years successively in Asia including Australia, Europe including Africa, Russia and the Near East and America. Hence, ICMF 1998 was held in Lyon, France, ICMF 2001 in New Orleans, USA, ICMF 2004 in Yokohama, Japan, and ICMF 2007 in Leipzig, Germany. ICMF-2010 is devoted to all aspects of Multiphase Flow. Researchers from all over the world gathered in order to introduce their recent advances in the field and thereby promote the exchange of new ideas, results and techniques. The conference is a key event in Multiphase Flow and supports the advancement of science in this very important field. The major research topics relevant for the conference are as follows: Bio-Fluid Dynamics; Boiling; Bubbly Flows; Cavitation; Colloidal and Suspension Dynamics; Collision, Agglomeration and Breakup; Computational Techniques for Multiphase Flows; Droplet Flows; Environmental and Geophysical Flows; Experimental Methods for Multiphase Flows; Fluidized and Circulating Fluidized Beds; Fluid Structure Interactions; Granular Media; Industrial Applications; Instabilities; Interfacial Flows; Micro and Nano-Scale Multiphase Flows; Microgravity in Two-Phase Flow; Multiphase Flows with Heat and Mass Transfer; Non-Newtonian Multiphase Flows; Particle-Laden Flows; Particle, Bubble and Drop Dynamics; Reactive Multiphase Flows
 Record Information
Bibliographic ID: UF00102023
Volume ID: VID00262
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: 1053-Hou-ICMF2010.pdf

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Paper No 7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010

Discrete Particle Simulation of Gas-Solid Flow and Heat Transfer in Gas Fluidized Beds

(Extended Abstract)

Q.F. Hou, Z. Y. Zhou and A.B. Yu


Laboratory for Simulation and Modelling of Particulate Systems, School of Materials Science and Engineering
The University of New South Wales, Sydney, NSW 2052, Australia
q.hou @student.unsw.edu.au
Keywords: Discrete particle simulation, immersed tube, heat transfer


Abstract
Fluidization is widely used in industries as a major
flow mode for fluid bed reactors. Immersed tubes
are frequently used for temperature control and
heat recovery. The flow and heat transfer in a
fluidized bed are of fundamental importance in its
applications and optimization. These have been
extensively studied by experiments and
mathematical models in the past decades.
However, different heat transfer mechanisms are
difficult to quantify. Recently, a combined discrete
particle simulation and computational fluid
dynamics method has been developed to study heat
transfer in gas fluidization (Zhou et al., 2009). This
method can examine the heat transfer at a particle
level and quantify the contributions of different
heat transfer mechanisms, such as convection,
conduction and radiation. This work extends the
model to study heat transfer between a bed and an
immersed tube in bubbling fluidized beds with
Geldart A and B powders (Geldart, 1973). Solid
flow pattern (cf Fig. 1) is firstly obtained and the
results show consistent characteristics with those
of experimental and simulation studies (Glass and
Harrison, 1964; Rong et al., 1999; Wong and
Seville, 2006). Then heat transfer process is
analyzed. The results show that convective heat
transfer is dominant for Powder B, whereas the
conductive heat transfer is dominant for Powder A
(Fig. 2). This prediction provides evidence to
support with the literature understanding (Flamant
et al., 1992). In conductive heat transfer, heat flux
through the particle-fluid-tube path under non-


contact condition is dominant for both types of
powders (Zhou et al., 2009). The results show that
a bed with higher tube temperature and larger gas
velocity has a larger overall deviation of
temperature, and therefore less uniformity of
temperature field, particularly for type B powders.
The study shows that a smaller powder is better
from the viewpoint of the uniformity of
temperature field.

References
Flamant, G., Fatah, N. and Flitris, Y., 1992. Wall-to-bed
heat transfer in gas--solid fluidized beds: Prediction of heat
transfer regimes. Powder Technology, 69, 223-230.
Geldart, D., 1973. Types of gas fluidization. Powder
Technology, 7, 285-292.
Glass, D.H. and Harrison, D., 1964. Flow patterns near a
solid obstacle in a fluidized bed. Chemical Engineering
Science, 19, 1001-1002.
Rong, D.G., Mikami, T. and Horio, M., 1999. Particle and
bubble movements around tubes immersed in fluidized beds
- a numerical study. Chemical Engineering Science, 54,
5737-5754.
Wong, Y.S. and Seville, J.P.K., 2006. Single-particle
motion and heat transfer in fluidized beds. AIChE Journal,
52, 4099-4109.
Zhou, Z.Y., Yu, A.B. and Zulli, P., 2009. Particle scale
study of heat transfer in packed and bubbling fluidized beds.
AIChE Journal, 55, 868-884.











7th International Conference on Multiphase Flow
ICMF 2010, Tampa, FL USA, May 30-June 4, 2010


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