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Build-up control(in Preheater Kilns)Mastering Riser and Tower Build-ups

BuildBuild--up controlup control(in (in PreheaterPreheater Kilns)Kilns)Mastering Riser and Tower BuildMastering Riser and Tower Build--upsups

TechnicTechnicallgenda

Build-up Control (in preheater kilns)

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General information

Objective• Consolidate know-how on build up control in PH Towers• Identify practical ways & means to master build-up

Deliverables • Produce a complete reference book and a shorter practical quick

reference guide for plant users

Division wide team• C. Venkateswarlu (ATC, leader) J. Desseix (RR)C. Landais (CTEO)• H. Schoffmann (CTEC) P. Muithya (CTI)S. Fujimoto (CTS)

Present Status• Document completed in September’05

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Target Group

Plants

Optimization Managers ,Process & Production Engineers

CCR operators

Key MessagesPreheater buildups can be mastered under any circumstances as long

as the appropriate levers(Specific to each plant) are applied.

Implementation of this TA will lead to significant improvement in kiln

performance and reliability even with high usage of alternative fuels.

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Content of study

Reference Main document, Quick Reference Guide & Otherreferences in annex

TA Agenda covers:• Chemistry

• Operations

• Refractory

• Geometry (design)

• Build-up Removal equipment sections

• Quick Reference Guide• Key recommendations

• Check-lists

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Preventive measures• Control Chemistry of kiln inputs

• Kiln operation by Managing • Burning zone

• Combustion

• Kiln control loops

• Refractory

• Geometry of preheated

Curative measures• Build up detection & cleaning

Content of study

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1 - Chemistry

Determine balance (SO3, Cl & Alkalis)• Reduce inputs – to regain balance where possible

Track bottom stage meal Cl vs. SO3• Track tendency to determine thresholds

• Control levers

• Maintaining Chart

• Unique to each plant

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CTEC Region Plants- Hot meal monitoring

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2 - Operations

Check-List of Kiln Mastery items • Calciner

• Kiln

• Burner

• Cooler

Special techniques for older & smaller calcinerdesignsMeal curtains are more effect techniques• Creating dirty backend

• Alternatives are ESW chains to lifters

• Appendix includes a more complete meal curtain report (design&optimization)

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Figure A1: Meal

Meal Curtain

• Recommended: • Best variable control

• Plants with no bypass

• Likely a standard feature on new kilns

• Cost depends on layout

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3 - Refractory

CKHC Reference

Use of SiC refractory• Better refractory life

• Coating Repellent

SiC percentage in refractory• Buildup Severity

• Check with Suppliers / Technical Centers

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4 – Geometry (Design)

Designs to avoid build-up by eliminating dead zonesTopics include• Cyclones

• ducts

• Meal pipes

• Flaps

• Splash boxes

Key notes• Simple changes

• Correct Design mistakes

• Corrective Case Studies

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5 – Removal Equipment

Preventive equipments.• Safety

• Optimize Blasters

• Placement maintenance

• CO2 cartridges

• High pressure water gun

When build-ups are minimized cleaning is effective in managing the problem

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Conclusions•Build-up can be mastered

• ARM / AF is not a good excuse for poor performance

Solution can be complex – often a mixture of techniques

• Bigger challenge on older designs

• TA document is a tool to help plants to self audit & use to determine

plant unique final solutions.