Latest Developments in Coke Oven Health Diagnostics and Battery Life Extension

StrategiesInternational Conclave for Iron & Steel Making

- Raipur, 7th February, 2015

K.G.VenkatesanFosbel India Pvt. Ltd.

4 Key Elements of Condition Monitoring

Predictive Life of Coke Oven Battery

QUALITY STABILITY

Flue Temperature

Surveys

Battery Expansion

Survey

STRUCTURAL STABILITY

Emissions Survey

ENVIRONMENTAL STABILITY

Battery Condition COMIT

PRODUCTION STABILITY

Background & Philosophy

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•Refractory consumption in steel in the 1970’s was over 25kgs per tonne liquid steel. Today world’s best is just below 5kgs.

•Most product groups and repair strategies are now well known but the strategic application of these is often overlooked.

•The refractory industry has mostly mature product technologies and innovation in service based technologies is the next quantum improvement.

•The implementation of Condition Monitoring with iterative feedback mechanisms is essential for asset preservation.

•Refractory installers must look to software based tools and even robotics to extend and preserve campaign life performance.

Established Refractory Inspection SystemsOwner Method Freq Type Meas. PurposeJapan (NSC) Visual Ann + PM Cracks Life PredictionArcelor (NSC) Visual Ann + PM Cracks Life PredictionEurope(OSC) Visual Ann + RM Exper. Rebuild focusCOMIT(Fosbel) Visual Mon + PM Rank Prev + Life + Op Sec.Comments:• Japan & Arcelor

– Process has no measure for deep oven condition.– Counting cracked bricks does not account for movement or prior repair– No day to day repair prioritisation capability– Life Prediction curve is not modifiable to match battery design and ops.

• Europe– Subjective basis only, no measures of relative condition– Based on rebuild requirements, no provision for PM strategies– Report is out of date before it is fully assessed by customer– No facility to predict operational security risks.

4 Key Elements of Best Practice

Battery Diagnostics

(COMIT)

Total Operational

Control

Remedial Battery Repairs

Total Operating

Costs Contained

Preventative Maintenance

Battery Deterioration Factors

Battery deterioration can be classified into two factors:

CAUSAL• Battery heating stability• Operating Temperature• Operating Practices• Coal Properties• Operational Reliability

(PRI)• Battery Design• Mechanical Maintenance

CONSEQUENTIAL• Refractory Condition• Ram or Pushing Force• Flue Leakage• Battery expansion• Stickers

Some consequential factors can also be part of an ongoing causal chain.

Coke Oven Walls

Heating

Leakag

e

Pushing

Structura

l

Coals

Causal Wheel to Battery Life

Key Consequential Indicator

“The refractory condition is the indicator of all trauma and

operating practices past and present in the coke oven battery.”

Refractory Condition:

What is COMIT™?

What is COMIT™?

• Coke Oven Management Information Technology

• A comprehensive coke oven condition monitoring program

• Web-based application that provides a variety of reporting options with the ability to drill down to see the underlying details

• Translates day-to-day condition monitoring data into meaningful output

• Provides insights into battery deterioration and improvement trends

• Enables more effective and proactive coke battery maintenance

• Provides visibility across multiple battery and plant locations

• Adaptable for many battery designs and operating condition, including Non-Recovery/Heat Recovery batteries

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Elements of COMIT™

COMIT™ is structured in a modular format:

• Wall Analysis and Prioritization (using Fosbel assessment data)• Ranking

• Inspections

• Life of Repair

• Risk Analysis

• Operational Data Collection & Reporting (using customer-provided data)• Temperature• Pushing Amps• Battery Expansion• Door Repairs• Stack Emissions

• Battery Analysis and Reporting

• Life Prediction13

COMIT™ Condition Assessment

COMIT™ identifies and assesses oven refractory condition in two ways:

1. Before repair: Visual rankings performed by Fosbel technicians are

used to assess refractory damage.

2. After repair: Oven status is verified using calculations based on Fosbel

repair material volume to provide the most accurate view of current

oven condition.

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COMIT™ Assessment Ranking Criteria

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Estimated Time before repair

(months) Rank

Recommended inspection frequency

(weeks) CBM stage Typical condition

120+ 0.0 104 New, undamaged. Recent thru-wall rebuild.

48-120 0.5 52

Condition Monitoring Recent end-flue rebuild.

24-48 1.0 26 Future CBM repairs expected

18-24 1.5 20 Imminent CBM repairs forecast

12-18 2.0 10 Minor damage - regular CBM

6-12 2.5 6 Medium damage - frequent CBM

3-6 3.0 4

Preventative Maintenance

High damage - intense CBM

2-3 3.5 2 Major damage - brick patch

1-2 4.0 1 Extensive damage - end flue forecast

0-1 4.5 Every push Extensive damage - end flue planned

0 5.0 -

Remedial Maintenance

Out of service

Examples of COMIT™ Output

COMIT™ Dashboard: Plant OverviewEnables Visibility Across Multiple Batteries

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COMIT™ Battery Status: Battery Condition with Drill Down Interactivity

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COMIT™ provides drill down interactivity, e.g. in battery status view shown above, user can click on one oven to drill down to see individual oven data.

COMIT™ Visual Rankings:Enables Identification of Problem Areas

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For this customer, a spike in the visual rankings in COMIT™ was identified (see Feb & Mar 2005 in graph above). This brought to light

an issue that was rectified with a change in coal blend.

Additional COMIT™ Modules: Temperature Enables overall view of battery temperatures

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Example above: Thermograph of Oven Crosswalls without temperature values. Maps actual temperatures on oven diagram using color-coding.

Additional COMIT™ Modules: Battery ExpansionEnables better visibility and more proactive maintenance

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Above: Battery Expansion Deflection Profile Diagram illustrates profile of individual oven buckstay

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COMIT Summary

• A day to day condition monitoring system that predicts operational security risks.

• Ensures production is maintained through elimination of oven failures.

• More functional for daily monitoring of oven repair priority than an Annual Diagnosis

• Most importantly feeds directly into battery life prediction monitoring.

• Enables continuous monitoring of battery life trends.

• Only software that will quantify life of repairs including ceramic welding.

Elements of Condition Monitoring

Flue Temperature

Surveys

Refractory Condition

Survey

Battery Expansion & Bracing

Survey

Flue Leakage, Fugitive &

Stack Emission Survey

Coke Oven Battery Life Determined

HEATING SECURITY

STRUCTURAL SECURITY

ENVIRONMENTAL SECURITY

OPERATIONAL SECURITY

COMITTM can track all of these Elements

Ram Pushing

Force

PRODUCTION SECURITY

Battery Life Projection Model

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