Plant Optimisation by ProcessInformation Management

Mark MutterCement Performance International

Contents of Presentation

• Scale and size development of cement plants

• History of process information (PI) capture and use

• Types of PI system available

• Responsibility for PI system

• Development of PI systems

• Off-line process information

• Conclusion

Scale and Size of Plants

• Capacity of plants has increased along with size of individualpieces of equipment

– Almost all raw grinding is now VSM

– Twin string precalciners are the standard

– Calciner design developments to increase throughput

– Cement milling is now moving to VSM technology

• Aim is to reduce unit cost of operations – fuel, power,maintenance, manpower

Size and Scale of Plants

• If plant is run under optimal performance then economies ofscale are lost – and ROI becomes more difficult

– 1000 tpd plant at 5% below capacity – 50 tpd/1500tpm/16,500 tpa

– 10,000 tpd plant at 5% below capacity – 500 tpd/15,000 tpm/165,000 tpa

• Fixed costs remain the same

• Impact on fuel and power consumption

• Cost and implications of importing clinker in sold out market

History of PI Capture

• Process information stored on log sheets, filled in by controlroom operatives

• Limited data was collected

• Information was for control and end of month reporting –generally a laboratory task

• Log sheets stored in laboratory

• Pulled out of storage and “dusted down” when plant problemsoccurred by Process Engineer

PI Capture Developments

• Control systems have developed to now allow all plant sensorsto be captured, recorded and manipulated

• Many systems available– Some designed as part of control system

– Some extract data onto separate server and download to software such asExcel

• Regardless of system, must be simple to use and accessible to all

• System should have a champion

PI System Champion

• Role of champion is to:– Develop the system to the users requirements

– Monitor the data such that performance of the plant is a focal point

– Be close to the process to monitor all of the inputs, and understand theinformation

– Act as an interface between all departments

– Understand when action is required

• Recommendation is that this role falls with the ProcessEngineering department

Basis PI System

• Primary level of analysis should be the major plant KPIs– Output

– Fuel Consumption

– Power consumption

– Alternative fuel usage

• All parameters can be in actual units or converted to financialterms

– Example: Cost of fuel when using alternative fuels

• Must include plant chemistry data

Basic PI System – Further uses

• Feedback to control room operators on actions– Optimisation of kiln and start-up actions

– Chemistry control

• Assessment of operator performance to identify training

• Troubleshooting of plant when efficiency is reduced– Comparison of parameters of good vs. poor performance

Advance PI System

• Use the data to optimise performance

• Examples:– Slowdown log

– Environmental emissions predictive systems

– Variability Reduction

• Flexibility of system is key as it can be adapted to almost anyplant issue

Advance PI System

• Slowdown Log– Daily comparison of the actual performance against the target

– Results in the identification of over and underperformance

– Champion to review daily the gap (positive and negative) and identifyand log any reasons

– Builds up a record of reasons for the gap which can then produce aPareto analysis

– Root Cause Analysis of major reasons for underperformance

– Can be converted into financial terms for capital investment purposes

Advance PI System

• Environmental Emissions Predictive Systems– Real time system to prevent emission limit exceedences

– Emissions limits are often for different time periods including one hourand 24 hour emissions targets are fixed by plant authorisation

– Each hour the average emission is calculated

– The system can then calculate what the level must be for the remainderof the 24 hour period to prevent an exceedence

– Assists operators in taking actions to reduce emissions below the limitand ensure compliance

Off-line Process Information

• Must not ignore or neglect other process parameters– Those that require human measurement

– Those that require calculation and human interpretation

• Many these are the process engineering tests– Mill inspections, measurements and material analysis

– Preheater audits, cooler heat balance, calciner combustion efficieny

– In-leaking air survey

– Separator efficiency audits

Off-line Process Information

• Must not be a one-off exercise when the plant is not performing

• Frequency must be correct– Too often and there will be very little change and the workload is too high

– Not enough and the performance will have deteriorated

• Need to build a database for comparative purposes

• All information must be passed on to the relevant departments, notkept within the process engineering department

• The solution is usually a combination of actions, not just a singleaction

Conclusion

• Cement plant operators cannot afford to not use all of theavailable process information available to them

• A centralised system should be put in place, with the processengineering team championing the system

• The tool should cover all areas of the process and also be used tobring together the different departments on the plant

• Basic process engineering tests should not be forgotten

Plant Optimisation by ProcessInformation Management

Mark MutterCement Performance International