This presentation reviews the way in which Oscillatory Flow Mixing (OFM) was developed from work at Sussex University and then Cambridge University

1. June 2010
Oscillatory Flow Mixing;
a review
Malcolm Mackley
Department of Chemical Engineering and
Biotechnology
University of Cambridge
1

2. Flow Visualisation
Light
source
1970s 2

3. Bristol, 1970 PhD, The Impinging Jet Apparatus
The late Sir Charles Frank and Andrew Keller 3

4. Bristol, 1976 Post Doc, The Six Roll Mill
4
Prof Sir Michael Berry

5. Oscillatory Flow Mixing (OFM). Wave Energy devices
1976-79 Sussex University; Applied Sciences; Material Science Division.
Air turbine generates power
Dr Graham Knott 5

6. Go to wave movie Sussex 1978
6

7. Phil Trans Roy Soc
7

8. Chem Eng Sci
Part 2b project
1980s 8

9. Oscillation and sharp edges
Go to OFM movie
9

10. Oscillatory Flow Mixing, (OFM).
Paul Stonestreet 1990 10

11. Part 2b project
Chem Eng Sci
11

12. Chem Eng Sci
Go to OFM Simulation movie
Tony Howes 12

13. OFM Movie; poetry in motion
Go to OFM Harvey movie
Adam Harvey 13

14. Part 2b project
Heat transfer Chen Eng Sci
14

15. Part 2b project Mass transfer Cheng Eng Sci
15

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 16

17. Chem Eng Oscillatory Flow Reactor (OFR)
- Oscillator Base Unit
- Feed inlet section
- Shell and baffled tube vessels
- Product outlet section
Dr Paul Stonestreet 17

18. Chem Eng Lab Scale OFR
Paul Stonestreet, Adam Harvey 1999
18

19. Biodiesel Reaction Progress
along Reactor
Net Flow
Net Flow In Out 19

20. Full-scale OFR reactor
• 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
Paul Stonestreet 20

21. Prof Xiongwei Ni
21

22. The OFM Meso Reactor
System configuration
Meso tube,
diameter d
Smooth constrictions:
Nuno Reis, Minghzi Zheng spacing 3d
2000s Minimum constriction
diameter 0.4d 22

23. 3 5 m m , V  4 .5 m L
a)
L
d d0
  45º
b)
23

24. The meso-tube and dimensionless groups
• Governing dimensionless groups
• Geometr Oscillatory Reynolds number Re o 
2  fx o  d

y
Fluid oscillation Reynolds number
l d
Strouhal number St 
4 x o
h d
b
The ratio of tube diameter to

amplitude
d=5.0 mm, λ=15.2 mm, h=1.6 mm,
δ=6.4 mm, β≈45o U d
Net flow Reynolds number Re n 

Smooth Periodic Constrictions
Oscillatory flow Meso-Reactor Fluid net flow Reynolds number
24

25. Experimental and Modelling
Experiment setup Numerical Modelling
The 3-D hexahedral mesh for simulation (Fluent®)
Particle Imaging velocimetry (PIV) system
u( t )  2  fx 0 cos( 2  ft )
Phase position
4 D
2
3 5
m (t )    u (t ) 

2 6
X0
4
0 1 7 8
•Periodic boundary condition
Phase position for an oscillation cycle
25

26. Meso Fluid Mechanics
Go to OFM PIV movie
Go to OFM LES movie
Minghzi Zheng 26

27. Chem Eng
Lab Meso Reactor
27

28. RTD experiment set-up
Probe3
Probe2
Probe1
Dye Injection
28

29. Dispersion model
Governing equation Imperfect injection method; numerical fitting
c (t )   Pe  t  
2
C (t )  Pe   
C D  C C
2
 TR t   exp  1   
  D  c ( t ) dt 4 t
3
 4t /     
 
 uL  Z Z
2 0
uL
N 2
 C t   C t ' C 2 t '  TR ( t  p ) C 1  p dp
t
C 
i 1
2 i 2 i 0
29

30. Model fitting
Net flow without oscillation • Net flow with oscillation
Ren=58,Reo=0 • Ren=58, Reo=312, St=0.4
0.016 0.02
Exp-C(t) b) Exp-E(t)1
(a) 1 0.018
0.014 Exp-E(t)2
Exp-C(t)
2 0.016
Probe 1 Exp-E(t)3
0.012 Exp-C(t)
3 Fit-E(t)2 (1->2)
0.014
Fit-C(t)3 ' (2->3)
Fit-E(t)3 (1->3)
0.01 0.012
Fit-E(t)3 (2->3)
E(t) (-)
C(t) (-)
0.008 0.01
0.008
0.006
Probe 2 0.006
0.004 Probe 3 0.004
0.002 0.002
0 0
0 100 200 300 400 500 600 700 800 900
0 200 400 600 800 1000 1200
Time (s)
Time (s)
30

31. Liquid-liquid dispersion
a) f=6Hz a) xo=3 mm
b) f=10Hz b) xo=4 mm
Silicon oil (4.6mPas,2.5%) mixing Silicon oil (4.6mPas, 2.5%) mixing
with water at xo=2 mm with water at f=6Hz
31

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% 32
(v/v ) amount of ion-exchange particles

33. And finally;
The BT 1000
Go to BT 1000 movie
33

34. The BT 1000
34

35. What went right with OFM invention.
The science was a lot of fun
What went wrong.
Lack of focus in pushing the technology
35

36. Acknowledgments.
A cast of many;
In particular,
Part 2B Students
Postgraduates
Postdoctorates
Chem Eng support staff
Bob Skelton
“The Department”
“For allowing me the freedom to develop speculative ideas”
Thank you! 36