What flow visualisation What flow visualisation can can teach us about reactor teach us about reactor design design What? Flow visualisation can What? Flow visualisation can teach us about reactor design? teach us about reactor design? Hugh Stitt [1] & Peter Jackson [2] [1] [2]
What flow visualisation can teach us about reactor design What? Flow visualisation can teach us about reactor design?. Hugh Stitt [1] & Peter Jackson [2]. [1]. [2]. Outline. In research Laboratory experiments, Model development Scale up Role of flow visualisation - PowerPoint PPT Presentation
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
What flow visualisation can What flow visualisation can teach us about reactor designteach us about reactor design
What? Flow visualisation can What? Flow visualisation can teach us about reactor design?teach us about reactor design?
Hugh Stitt [1] & Peter Jackson [2]
[1] [2]
OutlineOutline
• In research– Laboratory experiments, – Model development
• Scale up– Role of flow visualisation– Measurement density
• Flow visualisation in the field– Reactors behaving badly– Knowledge vs. information vs. data– Implementation
Stirred Tank Tomography in 4D Stirred Tank Tomography in 4D at Medium Scaleat Medium Scale
• 3 m3 demonstration scale mixing tank with 8 planes of electrical sensors
R Mann et al., Chem Eng Sci, 52, 2087-2097 (1997)
– Sensor readings reconstructred to give resistivity map
Stirred Tank Tomography in 4DStirred Tank Tomography in 4D
• Video frame and tomogram showing tracer distribution after 3 secs
R Mann et al., Chem Eng Sci, 52, 2087-2097 (1997)
Stirred Tank Tomography in 4DStirred Tank Tomography in 4D
• Video frame and tomogram showing tracer distribution after 3 secs
R Mann et al., Chem Eng Sci, 52, 2087-2097 (1997)
This is great – good picture!! – But gives little quantitative
information on mixing UNLESS
we have a model to compare it with
Getting High Quality Information on Getting High Quality Information on Stirred TanksStirred Tanks
• Needs a Lagrangian experimental approach– Velocimetry – or particle Tracking
Bolton, Hooper, Mann & Stitt, Chem Eng Sci, 54, 1989 (2004)
• Qualitatively reproduces main features– Quantitation is less conclusive
What? Flow visualisation can teach us What? Flow visualisation can teach us about larger scale operation?about larger scale operation?
• Scale up– Use measurement system and measurement
density appropriate to validation of design concept and models
• Does not need same precision as lab scale.• Objective different
– Justification of scale up protocol– Testing of models at increased scale– NOT fundamental understanding and
derivation of models per se
• But what about manufacturing scale ?
• Tracking of fluid movement – within and between oil and gas
reservoir wells • during drilling and production.
• Examination of transfer pipelines to and from processing facilities– for slugging effects, phase flow
rates, solids build-up or blockage, pigging operation monitoring.
It’s only one dimensional and single pass but ……….. it is an invaluable technique
Priority list : 1) Is there a blockage?2) If yes, then where is it? 3) Then characterise the blockage
Tomography & Velocimetry in the Field Tomography & Velocimetry in the Field Large Scale Particle Tracking : An old technologyLarge Scale Particle Tracking : An old technology
Reactors Behaving BadlyReactors Behaving BadlyStirred Tank ReactorsStirred Tank Reactors
““Field” Particle Tracking Technology?Field” Particle Tracking Technology?• What are the objectives ?
– Detailed diagnosis of flow patterns with high spatial resolution ?
• But how high a spatial resolution is required?
• Customer requirement– Measuring the degree of mixing with
sufficient resolution to establish:• overall quality of mixing and • any severe maloperation • at minimum cost
– Do mixing and flow patterns adversely affect production and profits?
– ——————————————————————————————
• ——————————————————————
Modality for “Field” OperationModality for “Field” Operation
• Key requirements for field and research use are not the same
Research Priorities Field Priorities
Resolution Tomography Technique
Spatial Temporal
Transp- ortable
Sees through
Metal -ray Good None Yes Yes
e+ emission Good Moderate No Yes X-ray Good Some Moderate Moderate Electrical Moderate Excellent Yes No
Optical Good Good Yes No MRI Good Good No No
Modality for “Field” OperationModality for “Field” Operation
• Currently - only -ray systems meet all the requirements for field use
Research Priorities Field Priorities
Resolution Tomography Technique
Spatial Temporal
Transp- ortable
Sees through
Metal -ray Good None Yes Yes
e+ emission Good Moderate No Yes X-ray Good Some Moderate Moderate Electrical Moderate Excellent Yes No
Optical Good Good Yes No MRI Good Good No No
10
100
1000
80 90 100
Information Obtained (%)
Co
st (A
rbitr
ary
)
BUT : Cost vs. Information is exponential
The 80 : 20 RuleThe 80 : 20 Rule• 80% of the information is only 20% of the cost
– And that 80% is normally sufficient to make an educated decision or diagnosis
• Corollary : the remaining 20% of information requires an additional 80% of the total effort
• Cost vs number of data points may be linear
““Field” Tomography Technology?Field” Tomography Technology?• What information are we trying to obtain ?
– And at what level ?• High levels of information cost money & time• Diagnosis of good, adequate or poor operation
can often be done with little measurement and information– Provided you know what information or data to
measure ……. & how to interpret it• Detailed measurement will only be done in the
field where it is essential– Where it adds value
• Hence - if an operator can get enough information to understand what he critically needs to know by a 1D, 1m measurement– Then he won’t pay for more!!!Then he won’t pay for more!!!