1
Oscillatory Flow Mixing; a review
Malcolm Mackley
Department of Chemical Engineering and Biotechnology
University of Cambridge
June 2010
2
Flow Visualisation
Lightsource
1970s
3
Bristol, 1970 PhD, The Impinging Jet Apparatus
The late Sir Charles Frank and Andrew Keller
4
Bristol, 1976 Post Doc, The Six Roll Mill
Prof Sir Michael Berry
5
Oscillatory Flow Mixing (OFM). Wave Energy devices
Dr Graham Knott
Air turbine generates power
1976-79 Sussex University; Applied Sciences; Material Science Division.
6
Go to wave movie Sussex 1978
7
Phil Trans Roy Soc
8
Chem Eng SciPart 2b project
1980s
9
Oscillation and sharp edges
Go to OFM movie
10
Oscillatory Flow Mixing, (OFM).
Paul Stonestreet 1990
11
Chem Eng SciPart 2b project
12
Chem Eng Sci
Tony Howes
Go to OFM Simulation movie
13
OFM Movie; poetry in motion
Adam Harvey
Go to OFM Harvey movie
14
Heat transfer Chen Eng SciPart 2b project
15
Mass transfer Cheng Eng SciPart 2b project
16
1990s; “Industry will commercialise OFM technology”
1. ICI Wilton, Nylon Monomer. Pilot plant kg /hr for 2 years
2. BP Sunbury Pilot OFM Plant
1990s
17
- Oscillator Base Unit
- Feed inlet section
- Shell and baffled tube vessels
- Product outlet section
Chem Eng Oscillatory Flow Reactor (OFR)
Dr Paul Stonestreet
18
Chem Eng Lab Scale OFR
Paul Stonestreet, Adam Harvey 1999
19Net Flow In
Net FlowOut
Biodiesel Reaction Progressalong Reactor
20
• 0.55 m3 total volume
• Ren=500, Reo=2000
• f= 4 Hz, xo=2.4 cm
• 4 X 150mm tubes @ 3.5m
2 units @ 1.1 m3/hr
Approx 50 tonnes/day
Full-scale OFR reactor
Paul Stonestreet
21
Prof Xiongwei Ni
22
The OFM Meso Reactor
Nuno Reis, Minghzi Zheng
System configuration
Meso tube,diameter d
Smooth constrictions: spacing 3dMinimum constriction diameter 0.4d
Scale- down
2000s
23
45º
35 mm, V 4.5 mL
45º
35 mm, V 4.5 mL
a)
b)
L
d d0
24
The meso-tube and dimensionless groups
• Geometry
d=5.0 mm, λ=15.2 mm, h=1.6 mm, δ=6.4 mm, β≈45o
• Governing dimensionless groups
dfxo
o2
Re Oscillatory Reynolds number
Strouhal numberox
dSt
4
Net flow Reynolds numberdU
n Re
Smooth Periodic Constrictions Oscillatory flow Meso-Reactor
Fluid oscillation Reynolds number
The ratio of tube diameter to amplitude
Fluid net flow Reynolds number
h
d
25
Experimental and ModellingExperiment setup Numerical Modelling
Particle Imaging velocimetry (PIV) system
Phase position for an oscillation cycle
Phase position
0 1
2
3 4 5
6
7 8
X0
The 3-D hexahedral mesh for simulation (Fluent®)
4)()(
2Dtutm
•Periodic boundary condition
u( t) 2fx0 cos(2ft)
26
Meso Fluid Mechanics
Minghzi Zheng
Go to OFM PIV movie
Go to OFM LES movie
27
Chem EngLab Meso Reactor
28
RTD experiment set-up
Probe3
Probe1
Dye Injection
Probe2
29
Dispersion model
Z
C
Z
C
uL
DC
2
2
Governing equation Imperfect injection method; numerical fitting
0)(
)()(
dttc
tctC
2
31
/4exp
4 t
t
Pe
t
PetTR
t
dppCptTRtC0 12 )('
2
122 '
N
iiiC tCtC
uL
D
30
Model fitting • Net flow with oscillation
• Ren=58, Reo=312, St=0.4
Net flow without oscillation
Ren=58,Reo=0
0 200 400 600 800 1000 12000
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
Time (s)
C(t
) (-
)
(a)
Probe 1
Probe 2
Probe 3
Exp-C(t)1
Exp-C(t)2
Exp-C(t)3
Fit-C(t)3 ' (2->3)
0 100 200 300 400 500 600 700 800 9000
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0.02
Time (s)
E(t
) (-
)
b) Exp-E(t)1
Exp-E(t)2
Exp-E(t)3
Fit-E(t)2 (1->2)
Fit-E(t)3 (1->3)
Fit-E(t)3 (2->3)
31
Liquid-liquid dispersion
Silicon oil (4.6mPas,2.5%) mixing with water at xo=2 mm
Silicon oil (4.6mPas, 2.5%) mixing with water at f=6Hz
a) f=6Hz
b) f=10Hz
a) xo=3 mm
b) xo=4 mm
32
Particles in suspension
Instantaneous velocity vector maps of fluid phase at Reo = 625, x0 = 2 mm, f = 10.0 Hz at vertical position in the presence of 3% (v/v ) amount of ion-exchange particles
33
And finally;The BT 1000
Go to BT 1000 movie
34
The BT 1000
35
What went right with OFM invention.
The science was a lot of fun
What went wrong.
Lack of focus in pushing the technology
36
Acknowledgments.A cast of many;
In particular,
Part 2B StudentsPostgraduatesPostdoctorates
Chem Eng support staffBob Skelton
“The Department”“For allowing me the freedom to develop speculative ideas”
Thank you!
Top Related