PROCESS OPTIMISATION using MODEL BASED CONTROL IN THE MELTER
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Transcript of PROCESS OPTIMISATION using MODEL BASED CONTROL IN THE MELTER
PROCESS OPTIMISATION PROCESS OPTIMISATION usingusing
MODEL BASED CONTROLMODEL BASED CONTROLIN THE MELTERIN THE MELTER
“We have millions of dollars
invested in our plant…”
“…are we getting the mostfrom our processes?”
“We’re designing a complex integrated process…”
“…how do we know it’s going to work?”
“We have a complex control scheme…”
“…how do we know it will run our plant to it’s optimum efficiency?”
The Answer – The Answer – Adaptive Model Based ControlAdaptive Model Based Control
ADVANCED CONTROL SOLUTIONS INC
The way PID control worksThe way PID control works• Cannot easily control long dead time
processes • No action taken until process pushed off
target• Doesn’t respond well to non-linear processes• Can’t handle process disturbances quickly
Most PID control loops are detuned or not performing as intended because the loop is out of tune with the dynamics of the process
The result of poor PID The result of poor PID control:control:
• Increased process variability• Inconsistent product quality• Lower production rates• Higher energy costs• Decrease in overall plant efficiency• Leads to Acceptance of controlling what
you can – not what matters• Dependence on experienced operators to
manually run, start up, and recover critical processes
MBC out performs PIDMBC out performs PID
MBC out performs PID because of its two main components:
• An adaptive model
• A predictive controller
The MBC advantageThe MBC advantage• Integrates with existing control systems
• Average implementation time is less than 2 weeks
• Ease of use — customer can deploy and maintain with existing manpower
• Attractive project economics (Payback)
• Operates reliably 100% of the time
Adaptive Model Based Adaptive Model Based ControlControl
• Builds and adapts its own live models during normal plant operations– Models are built in closed loop while the plant
is running
• Patented methodology builds high fidelity models in real time without disrupting operations– This patented method is the key to our fast
implementation
• Models adapt as the dynamics change due to weather, wear, and other factors
predictive controllerpredictive controller• Accurately forecasts process responses
and accounts for multiple objectives• Predicts and prevents disturbances before
process is pushed off target– (PID cannot do this, PID must wait for the error)
• Start ups and grade changes are automated and uneventful
• Solves difficult process control problems• Achieves automatic control of manually
controlled processes
MBC runs where YOU decide, in MBC runs where YOU decide, in one or multiple placesone or multiple places
Ethernet
If you have OPC, you can run Model Based Control
MBC can run on your DCS or on its own server
MBC can simultaneously communicate to multiple PLCs
Ethernet, Modbus Plus, Data Highway Plus
DCSOperator Station
DCSEngineering Station
MBC SERVER
PLC
DCS Controller
Building the Adaptive ModelBuilding the Adaptive Model
The impact of improved control, closer The impact of improved control, closer upper and lower set point limitsupper and lower set point limits
Energy CostEnergy Cost
Productivity and YieldProductivity and Yield
Product QualityProduct Quality
Operating Average ShiftLow Set Point.Limit
OperatingAverage
Low Set Point.Limit
High Set Point.Limit
MBC ApplicationsMBC Applications• Glass melter
temperature• Glass furnace level• Channel
temperature• Forehearth
temperatures• 9 point grid
temperature
• Gob exit temperature
• Large Energy consumers
• Bottlenecks• Annealing oven• Bottle weight
ResultsResults
• Float Glass – Stabilize at new setpoint in 4% of the previous time.
• Fiberglass – huge reduction in variability and improved machine availability.
• Float Glass Level Control – reduction in variance.• Lighting Glass – Reduce Temperature
variation in Furnace and Forehearth.• Container – increase in line efficiency –
increase profit annually.
MBC How to set it up?MBC How to set it up?
• Installed on an NT desktop PC• Communication to Existing Control System
via Ethernet / OPC Server• Initial Models Developed from Historical
Data Review• Models validated with one setpoint change• Entire system installed and operational in
less than one week
MBC Results
Improved process dynamics Reduced level control variations Steady state control improved by 7X Scrap rates reduced Product change time reduced:
Product Changeover MBC vs PID
Glass Level Loop
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BWC vs PIDLevel Sp Change
BWC Control PID Control
PV (Level)PV (Level)
BWC CV PID CV
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Level Control – Steady StateLevel Control – Steady State
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Glass Level Loop - Steady State
PID ControlMBC Control (CV) MBC Control (CV)60 s sample
10s sample 10s sample
PV (Level) PV (Level)
Level Control - PIDLevel Control - PID
PID Control (Oct 21 99)
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Level Control-MBCLevel Control-MBC
Glass Furnace - Level, MBC Control
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Container ApplicationContainer Application
• MBC installed and connected to existing Forehearth PLC or SLC control system
• Goal was to improve stabilization time in forehearths after pull / product change.
• Allow operators to focus on machine changes and control loops stay in automatic.
Container Glass ResultsContainer Glass Results• Forehearth Temperature stabilization time
reduced by 50% after job changes – leading to more machine availability at optimum conditions
• Ability to control using Mass Flow Temp (9-point grid as control parameter
• Ability to control using Gob Exit Temperature as control parameter
• Increased yield, 0.5 to 1% due to improved process stability.
Pull Change – conventionalPull Change – conventional
PID Control Performance
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Pull Change - MBCPull Change - MBC
AC Control Performance
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Steady State ControlSteady State Control
PID-AC Control Comparison
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Fiberglass ManufacturingFiberglass Manufacturing
• Goal is to stabilize process & reduce variability in downstream processes.
• Level control in melt tank is primary cause of defects.
• MBC connected to existing DCS via OPC server.
Fiberglass ResultsFiberglass Results
• Profoundly stabilized system• Better bushing control• Reduced spinner blockage• Better quality• Higher production rates
Fiberglass Melter Fiberglass Melter TempTemp
Float Glass ProjectFloat Glass Project
• Major manufacturer of Flat/Float Glass
• Level control variability decreases product quality
• Installed to existing DCS• Commissioned in only 2 days• Immediate profound effect in
operation
Increased Glass Level Increased Glass Level StabilityStability
Melter Crown temperature Melter Crown temperature stabilitystability
Reduction In Exit Temp Reduction In Exit Temp VariationVariation
Float Glass - PIDFloat Glass - PIDPID Level Control
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Level (Thou)
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Feed Rate ()
Float Glass - MBCFloat Glass - MBCModel Based Control
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Float Glass ResultsFloat Glass Results
“The control continues to be excellent. We had a port failure Tuesday night that took the MBC offline. For the 8-10 hours that we were back in DCS control, our level control was +/- 0.015", while MBC was able to maintain +/- 0.002". I printed the 24-hour trend chart for that period showing MBC controlling for 7 hours, Bailey DCS for 10 hours, and back to MBC for the remaining 7 hours and the charts show a graphic picture of why we need MBC for controlling glass level in our furnace!” – Ernie Curley, QA Manager, Cardinal Glass – Portage, WI
TestimonialTestimonial
“In PID control, our level control was +/- 0.015", while MBC was able to maintain +/- 0.002”; the charts show a graphic picture of why we need MBC!”
Ernie Curley, QA Manager, Cardinal Glass
>7 times better level control with MBC
PID Level Control
BrainWave Level Control
Lighting Glass OptimizationLighting Glass Optimization
• Major manufacturer of Lighting Glass• Temperature Control Critical for proper
forming• Installed to existing TI PLC environment• Commissioned in only 1 week• Immediate profound effect in operation
Lighting Glass ResultsLighting Glass Results
•Dramatic Reduction in variability•Complete Automatic Control•Improved recovery from disturbances•Reduced operator workload•Reduced scrap•Increased profits
TestimonialTestimonial“MBC stabilized our toughest loops – ones we have spent countless hours working on .”
Steve HolmesSenior Process Controls Engineer
Bowater Newsprint
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Steam Valve
TestimonialTestimonial
“ This was something that could be done immediately with very little cost. And it did not require any outages; it was done on the run.”
Andrey PawelczakContract Engineer, Syncrude Canada
MeadWestvaco TestimonialMeadWestvaco Testimonial
“Reducing Lime Kiln temperature variability with MBC was easy and it reduced our fuel consumption over $400,000/year!” Our operators love it and rely on it for efficient operation.
Terry Canup, Process & IT Manager, MeadWestvaco
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Before: +/- 90 degrees or more MBC +/- 5 to 10 degrees Saturday 27th October
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NCG Flow
ID Fan
Production Rate
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