TPM2015 Presentation by Andre Gibson - Key Engineering Solutions
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Transcript of TPM2015 Presentation by Andre Gibson - Key Engineering Solutions
UNLOCKING POTENTIAL
André Gerard GibsonKey Engineering Solutions
Improving Productivity Through Process
Optimisation
UNLOCKING POTENTIAL
UNLOCKING POTENTIAL
Agenda
1. Introduction – About Key & background2. Identification of the bottlenecks3. New control philosophy implementation4. Challenging designs to increase throughput5. Sustainability6. Demonstrate results
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About Key
Suite 5, 531 Hay StreetSubiaco WA 6008
• Hands on engineers with a passion for optimisation
• Engineering services for resources, building services, manufacturing & agriculture
• Specialise in automation and debottlenecking
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Industry Background
• Commodity prices continue to decline• Capital expenditure significantly reduced
Mining – Western Australia
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Automation in Industry
• Most facilities have a form of automation• State of automation varies from site to site• Allows for repeatability and predicatbility• Rarely utilised to its full potential
Current state
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Automation in Industry
• Equipment run rates controlled manually• Automation systems too difficult for users to
understand• Challenging to maintain over time• “Black Box” implementations
Some automation issues within industry
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Process Stability• Poor throughput stability
leads to overloads• Many automation systems
negatively impact stability
• Improving stability reduces breakdowns
• Allows for greater certainty to increase production
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• Equipment availability• Compliance to
preventative maintenance
• Overall shutdown effectiveness
Maintenance vs Production
• Increase Production
• Increase Production
• Increase Production
Department Objectives
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Why use this approach?• Simple to use & visualize• Easy to maintain• Ensures equipment run to design• Standard methods used in process control• Reduces variability and pushes active
constraint
Excellence = Quality x AcceptanceExcellence = Quality x Acceptance
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Identifying the bottlenecksPerformance workshops
Prepare for the workshop
Facilitate workshop
Close-out workshop
• Plan agenda & brainstorming activity• Invite experienced operations personnel from all disciplines• Send through any relevant details prior
• Explore opinions on issues limiting increased performance• Question why they are an issue• Ensure everyone has input
• Ask group for possible fixes• Provide examples of automated solutions• Summarise solutions from the group
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Identifying the bottlenecksData analysis
• Break system down into distinct areas
• Determine utilization calculation for each
• Develop utilisation histogram
Area Utilization calculation
Infeed % utilization = rate / max rate
Screening % utilization = average screen house bin level / nominal maximum level
Scrubbing % utilization = total rate / (max. line rate x number available lines)
Desands % utilization = % level in feed tank / nominal maximum level
Crushing % utilization = average crusher building bin level / nominal maximum level
Stacking % utilization = rate / max rate
Thickener % utilization = slurry export rate / maximum export capacity
Underutilized True when % utilization for all other areas is under an acceptable level (e.g. 85%)
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Identifying the bottlenecksConstraint utilisation visualization
• Live representation of previous histogram
• Provides real-time data on current bottlenecks & utilisation
• Easy to identify when the bottleneck shifts
• Useful tool for management decisions (e.g. capital projects)
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Implementation – constraint control
Standard process control “tool chest”
• Proportional, integral & derivative (PID) controllers– Simple feedback control– Controls process to a
desired setpoint– Commonly implemented
in industry and understood
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Implementation – constraint control
Standard process control “tool chest”
• Smith predictors– Predicts actual process
output (i.e. rates, level, etc) before actual measurement
– Eliminates dead-time issues (Delay)
– Allows for quicker PID response to correct
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Implementation – constraint control
Standard process control “tool chest”
• Override control scheme– Used for various PIDs
controlling the same equipment (e.g. screenhouse feeder)
– Lowest output controls process
– Ensures equipment runs to maximum limit of at least one constraint
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Implementation – constraint control
Putting it all together – Feed rate example
• Feed rate control for a conveying system with multiple feed points• Large dead-time prior to each weightometer feedback• Requirement to maintain consistent set-point tonnage
• Simple Smith predictor to mitigate dead-time• Filter = 1st order model of process• Delay = Weightometer dead-time (Delay3)
• Smith predictor with delayed PV input from previous weightometer
• Delay1 = time between weightometers• Delay4 = dead-time from feeder to
weightometer• Set-point adjusted to cater for
peaks/dips from previous controller
• Same process as previous controller• Correction for controller & process
variation maximized• Reduced variability & maximum
performance
Design & implementation: 8 daysCommissioning: 2 hours
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Implementation – constraint controlPutting it all together – screening example
Fines /Final Product
Tertiary
Secondary
Desands
W
W
W
W
PID
PVSP
CV
PID
PVSP
CV
PID
PVSP
CV
<
S S
PID
PVSP
CV
PID
PVSP
CV
PID
PVSP
CV
S S
<
P
PVSP
CV
P
PVSP
CV
P
PVSP
CV
• Six primary constraints to control• Three secondary constraints to control• Two separate feeder areas to control
ProductFeeders
DesandsFeeders
PID
PVSP
CV
PID
PVSP
CV
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Challenging equipment designs
• With now tighter control, minimised risk of overloading• Original designs come with generic assumptions that may not
always be true (e.g. motor winding temps calculated at ambient temperature of 60 degrees)
• Equipment designs cater for worst case scenario. If you can control the scenario, you can alleviate the risk
• Just needs a simple first principles engineering approach
Why can we challenge the design?
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Challenging equipment designs
Common equipment design process• Capacity requirements
specified prior to design• Multiple disciplines
involved in detailed design
• Each has separate design considerations
• Selection typically based on next size up
Discipline Design criteria
Mechanical Belt width/speed for ore profile, gearbox & coupling torque ratings, belt tension
Electrical Overall power consumption, variable speed drives, motor protection relays for motor protection
Structural Supporting structure sizing, cyclone/hurricane rating, extreme wind protection
Process Transfer chute design for ore flow & presentation, wear linear material and location in relation to product stream, particle sizing & material flow characteristics, downstream equipment capacity
Rate required = 5000 tph
Electrical, Mechanical, Process, Structural, etc.
Power required = 292kWSuitable motor = 315kW
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Challenging equipment designsExamples of challenging designs
- Ore profile of conveyor at capacity
- Torque & power within design limits
- VSD max. frequency of 50Hz
- Tripper designed for 10,000tph
- Tripper movement speed 0.5m/s
- Conveyor speed 4.5m/s
- Transfer chute at maximum capacity
- Increase VSD max. frequency to 60Hz
- Reduction in profile to 83.3%
- Reduce tripper speed to 0.25m/s in VSD
- Allows increase in maximum rate to approx. 10,500tph
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Sustainability
Excellence = Quality x AcceptanceExcellence = Quality x Acceptance• Quality
– Invest time in philosophy design– Correctly tune system prior to
completion– Cater for abnormal situations– Provide visual implementation
of what is in control– Develop “issues” log book for
operators and address problems– Coach operators in best
methods to control
• Acceptance– Prior to implementation, sit
with all operators– Be open to feedback from
operators– Make them feel like part of the
solution– Never reject operator concerns,
even when incorrect
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Results
• Reduction in Standard Deviation• Before: 1251• After: 925.2
• Whilst there is no increase in rate, variability reduction generated confidence for step change increase in rate set-point
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Results
• Reduction in Standard Deviation• Before: 3428• After: 2476
• Increase in rate• Before:
15,258tph• After:
16,671tph
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Conclusion• Simple problems don’t require complex
solutions• Methods used understood by site teams• Great results can be obtained if correctly
planned, designed & executed• Never underestimate the importance of
acceptance• Always be willing to challenge constraints
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Get in Touch
Address:Suite 5, 531 Hay StreetSubiaco WA 6008
@keyengs