Mixing and Crystallization: Selected papers from the International Conference on Mixing and Crystallization held at Tioman Island, Malaysia in April 1998

332 Pages·2000·11.43 MB·English

by  G. D. Rigby

MIXING AND CRYSTALLIZATION
Editorial board:
A.W. Nienow, Birmingham, United Kingdom
K. Ogawa, Tokyo, Japan
S. Rohani, Saskatchewan, Canada
L.T. Fan, Kansas, U.S.A.
J.J. Chen, Auckland, Australia
Mixing and Crystallization
Selected papers from the International Conference on Mixing
and Crystallization held at Tioman Island, Malaysia in April 1998
Edited by
Baskar Sen Gupta
and
Shaliza Ibrahim
Institute of Post Graduate Studies and Research.
University of Malaya.
Kuala Lumpur; Malaysia
The conference was organised by:
Institute of Post Graduate Studies and Research, University of Malaya, Kuala Lumpur, Malaysia
and
Special Research Centre for Multiphase Processes, University of Newcastle, Callaghan, Australia
The conference was co-sponsored by:
The Institute of Chemical Engineers, United Kingdom
The Institution of Engineers, Malaysia
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
A C.I.P. Catalogue record for this book is available from the Library of Congress.
ISBN 978-90-481-5410-4 ISBN 978-94-017-2290-2 (eBook)
DOI 10.1007/978-94-017-2290-2
Printed on acid-free paper
AII Rights Reserved
© 2000 Springer Science+Business Media Dordrecht
Originally published by Kluwer Academic Publishers in 2000
Softcover reprint ofthe hardcover Ist edition 2000
No part of the material protected by this copyright notice may be reproduced Of
utilized in any form or by any means, electronic or mechanical,
including photocopying, recording or by any information storage and
retrieval system, without written permission from the copyright owner.
To
Mohd. Ali Hashim
Professor ofC hemical Engineering, University ofM alaya,
and
NafisAhmed
Department ofC hemical Engineering, University ofN ewcastle, Australia
for their inspiration and support.
Contents
Foreword xi
MIXING
G.D. Rigby, G. Lane, G.M. Evans
CFD Modelling of Hydrodynamic Conditions within the Wake of
Mixing Impeller Blades 1
M.Liu, C.D. Andreasen, R. La Roche, S. Choudhary
Visualisation and quantification of laminar flow mixing in a stirred
tank reactor 15
K.C. Lee, N.A. Borret, M. Yianneskis
Turbulence structure and isotrophy in stirred vessels 29
Z.D. Chen, J.J.J. Chen
A study of agitated gas-liquid reactors with concave blade impellers 43
W. Bujalski, D. Hari-Prajitno, K. Takenaka, J. McKemmie,
A.W.Nienow
Studies of aerated mixing with multiple axial flow hydrofoil (APV-B2)
impellers 57
M.S. Takriff, W.R. Penney, J.B. Fasano
Interstage backmixing of a gas-liquid multistage, mechanically-agita-
ted, compartmented column 67
G.M. Evans, W.P. Mao, G.J. Jameson
Mass transfer in a plunging liquid jet 75
G.R. Drewer, N. Ahmed, G.J. Jameson
An optimum concentration for the suspension of solids in stirred vessels 83
CRYSTALLIZATION
Y. Yamazaki, H. Yazawa, Y. Hirata
Freeze concentration with ice-lining in a crystallizer of agitated vessel 95
viii
H. Schubert, A. Mersmann
How agglomeration Processes affect experimentally determined
nucleation rates 105
R.A. Williams, X. Jia, R.M. West, K.J. Roberts
On-line measurement of solids distribution I stirred tanks and
crystallizers using electrical computed tomography 113
K. Ogawa, Z. Sha, S. Palosaari
A new expression for dispersedness of multi-phase taking account of
consideration of local size distribution 125
Z. Sha, S. Palosaari
Size dependent classification function in imperfectly mixed suspen-
sion continuous crystallizer 133
M.L.J. van Leeuwen, D.S.L. Bruinsma, G.M. van Rosmalen,
M.J. Hounslow, M.M. Seckler
An experimental study to the effects of supersaturation ratio, impeller
design and Impeller speed on agglomeration of aluminium trihydroxide 151
R.M. Cooper, G.M. Parkinson, O.M.G. Newman
The precipitation of silica from acidic zinc leach liquors 163
V. Nallet, D. Mangin, J.P. Klein
Precipitation of microcrystals of salicycle acid in a T mixer:
experimental study and Modelling 177
N.S. Tavare
Mixing, reaction and precipitation: The Barium Sulphate Precipitation
System 191
R. Philips, S. Rohani, J. Baldyga
Micromixing in a Single Feed Semibatch Precipitation Process 205
A. Futia, H.M. Ang, D. Ilievski
Yield Model of a Batch Gibbsite Precipitator 215
T.S. Li, A.L. Rohl, D. Ilievski
Modelling of a Constant Supersaturation Precipitator 227
IX
A. Mersmann, C. Heyer, H. Schubert
How to Influence the Median Crystal Size of Precipitates 243
L.T. Fan, S.T. Chou, W.Y. Chen, M. Bai, J.P. Hsu
Modeling Fluctuation in the Growth Rate of a Single Crystal 253
A.M. Neumann, S.K. Bermingham, H.J.M. Kramer,
G.M. van Rosmalen
Modeling the Attrition Process in a 22 Liter Draft Tube Crystallizer 267
M.L.J. van Leeuwen, D.S.L. Bruinsma, G.M. van Rosmalen
Computational Fluid Dynamics Approach to Precipitation Reactions:
The Importance Of Subgrid-Scale Fluctations 281
J.G. Wijers, J.H.A. Schoenmakers, D. Thoenes
Scaling-up of Reactive Crystallizers 293
T. Nomura, K. Shimizu, K. Takahashi
In-situ Measurement Method of Crystal Concentration in a Seeded
Batch Crystallizer 309
K.C. Lim, M.A. Hashim, B. Sen Gupta
Monte Carlo Simulation of the Crystal Size Distribution with Attrition
Effects in a Mixed Suspension Crystallizer 317
E.T. White
A Review of the Crystallization of Sugar 329
FOREWORD
We are honoured to present this collection of selected papers from the
International Conference on Mixing and Crystallization, held at the Tioman
Island, Malaysia in April, 1998. We are grateful to the editorial board
comprising five eminent researchers in the field of mixing and crystallization
for their thoughtful review and suggestions. In order to make this book as
current as possible some of the papers have been thoroughly revised, which
caused some delay in bringing out this edited version.
We received necessary support from the Institute of Post Graduate Studies and
Research, the University of Malaya and the Special Research Centre for
Multiphase Processes, and the University of Newcastle, Australia in organizing
this conference. We are indebted to the Institute of Chemical Engineers, United
Kingdom, and the Institution of Engineers, Malaysia for their sponsorship.
We would like to thank K.C. Lim, Dr. C. Ramakanth and Ms. Zubaidah for
their help at the various stages of editing. We would also like to express our
gratitude to Professor Mohd. Ali Hashim and Dr. Nafis Ahmed for their help
and encouragement. Finally, I would like to thank Kluwer Academic Publishers
for publishing this book.
Bhaskar Sen Gupta
Shaliza Ibrahim
University of Malaya, Kuala Lumpur
xi
CFD MODELLING OF HYDRODYNAMIC CONDITIONS WITHIN
THE WAKE OF MIXING IMPELLER BLADES
G.D. RIGByl., G. LANE1. AND G.M. EVANSl.
Research Centre for Multiphase Processes, Department of
I.
Chemical Engineering, The University ofN ewcastle,
Callaghan, NSW 2038, Australia
CSIRO Division ofM inerals
2.
P.D. Box 312, Clayton South, Victoria 3169, Australia
Abstract
Computational fluid dynamics simulations have been used to simulate the flow field within the
impeller swept region of a baffled stirred tank. Rushton turbine and flat paddle impeller
configurations are investigated using sliding mesh techniques, for which no experimental input is
necessary. The results from the CFD simulations show reasonable agreement with experimental
data for the location of important flow structures close to the impeller blades, including the
position of flow recirculation and axis of trailing vortex pairs generated within the wake at the
rear of each blade, and the angle-resolved periodicity of the flow field between successive
impeller blades.
1. Introduction
1.1. BACKGROUND
The use of mechanical impeller systems for the agitation or mixing of fluids is
an important unit operation in many chemical process industries. As a result,
experimental studies of the fluid flow within the bulk region of impeller stirred
reaction vessels have been reported in great detail in literature (e.g. Ranade and
Joshi, 1990a; Jaworski et ai., 1991; Luo et ai., 1993; Jaworski et ai., 1996).
This is particularly the case for the configuration of a disc turbine, which has
probably been the most widely studied configuration, and has been essentially
established as a reference configuration both within research organisations and
the mixing industry.
There have been fewer studies of the hydrodynamic conditions within the
impeller swept region of stirred tank systems. This region is of significance in
B. Sen Gupta and S. Ibrahim (eds.), Mixing and Crystallization, 1-13.
© 2000 Kluwer Academic Publishers.