On-line Process Rheometry Using Oscillatory Squeeze Flow
Transcript of On-line Process Rheometry Using Oscillatory Squeeze Flow
On-line Process Rheometry Using Oscillatory Squeeze Flow XVIth International Congress on Rheology, Lisbon, August 2012 David Konigsberg1, T. M. Nicholson1, P. J. Halley 1 P. Koria2, E. Owen3, P. K. Bhattacharjee4 and T. J. Kealy4 1Department of Chemical Engineering, The University of Queensland, St. Lucia, QLD, Australia 2GlaxoSmithKline, Consumer Healthcare Technical, GSK House, TW8 9GS, UK 3GlaxoSmithKline, Consumer Healthcare R&D,Surrey, KT13 0DE, UK 4Rheology Solutions, OLR Group, Bacchus Marsh, Victoria, Australia
The OnLine Rheometer
• A process rheometer that delivers a flow curve characterising the viscoelastic behaviour of process fluids in real-time
• In/On-line, Real-time measurements • Accelerate decision making • Reduce time associated with sampling and sample
handling processes
• Distinguished from many online viscometers that provide a single point measurement
• Plates separate and the sample is replenished
• Top plate oscillates at predefined frequencies.
• Bottom plate registers the force
• Plates come within specified distance of each other
Installations
OLR
In-line Operation
OLR
On-line Operation
Further processing required
Ready for next processing step
PLC / Operator
Fields et al , JNNFM, 1996, 65, 177-194 Bell et al Rheol Acta. 2006;46(1):111-121.
Background Theory
p0= force amplitude; c = phase lag; (distance the plate moves) = h; = density of the fluid; a = radius of the top plate and * =
complex viscosity
• Gap varies in the z-direction about the equilibrium distance of h with a frequency in time such that
• Total normal force is given by
Limits??
a) If the measured force is influenced because the plates are submerged
b) Effect of geometry/fluid constitutive behaviour on the measurements
• Flow Solve® • Lagrangian finite element code • Developed by University of Leeds ( Bishko et al, JNNFM, 1999;82,255-273) • Employs a Delauney mesh that is embedded in the fluid, such that the elements carry their strain history with them
• Combines a finite element solution of the momentum and continuity equations with the constitutive equations
• Produces a time dependent solution of the flow; which is assumed to start from rest
• Program can account for mesh distortions by reconnecting points as required to preserve the Delauney triangulation
Test Geometries
A. Submerged (bounded) : Plates submerged and fluid bounded by the sensor walls
(A)
D. Semi-submerged : Unbounded fluid but top-plate not completely submerged
(D)
(B)
B. Submerged (unbounded) : Plates submerged in an infinite sea
(C)
C. Unsubmerged : Fluids confined between two endplates
(E)
( )
E. Submerged (confined) : Fluid confined within a small cavity and plates completely submerged
Results: Simulations
• Fluid: commercial soap (Dettol ®)
• Characterised using ARES (TA Instruments, USA) and response fitted to a Maxwell model
Secondary flow patterns develop
ndar
mm/s
Comparison With Experiments
8
15% 200K PS in DEP
Dettol® • Simulations provide a handle on design of the sensor
• Predicts experimental observations reasonably well
• Experiments with OLR simulate On-line operation
• High frequency data via time temperature superposition
Pilot Plant Experiments
Φ
• OnLine Rheometer : Strain 0.75%, Swept (1-100Hz) Sine wave • Laboratory Rheometer : HaakeMARS III ® (Thermo Fisher Scientific) • In-line Viscometers : Proline Promass® (Endress & Hauser)
VA Series ® (Marimex) • Test Material : 2.5% solution of carboxymethyl
cellulose (CMC) in water
1: OLR 2: Flowmeter 3: Measuring tank
4: Bulk tank 5: Mono pump 6: Online Viscometer
7: Inspection window 8: Pressure transducers 9: Valves
Results of experiments conducted at various flow-rates.
Results: OLR & Laboratory Rheometer
• Laboratory rheometer represented using cross symbols ( ) are linear viscoelastic response
• Other symbols represent measurements made by the OLR for repeated experiments at a fixed flow-rates
1500 kgs/hr 0.11m/s
1900 kgs/hr 0.14m/s
2900 kgs/hr 0.21m/s
Results: Pipe-loop & Process Viscometers
P in a flowing pipe
Marimex ViscoScope®
Laboratory rheometer E&H Proline
flowmeter
®
• Laminar flow • Use wall shear rate • Use Metzner-Reed Reynolds number
(Metzner AB, Reed JC.. AIChE J. 1955,1,434-440.)
Results: Pipe-Loop & Process Viscometers
E&H Proline flowmeter
Laboratory rheometer
oratory
P in a flowing pipe
Marimex ViscoScope ®
•
• OnLine Rheometer for in/on-line, real-time QA/QC
demonstrated
• Design is based on rigorous mathematical analysis and simulations
• Demonstrated success in producing viscoelastic measurements that agree quantitatively with Laboratory rheometers, on-line and in real-time under controlled conditions.
• Offers superior finger-printing of complex fluids flowing in a pipe compared to prototypical on-line viscometers.
Conclusions
• The OLR commercialisation project at Rheology Solutions is part-funded by the Australian Government Commercialisation Australia ESC Funding from Dept. Innovation, Industry & Science
• PKB acknowledges library support through Department of Materials Engineering, Monash University, Clayton, Victoria
Acknowledgements