Cetek Technology for Coal-fired Power Plants:

Ceramic Coatings

Cetek Agenda• Challenges/Solutions in the Coal-Fired

Power Industry• Introduction to Cetek • Case Study I:

– 820 MW Supercritical Boiler– 420 MW Subcritical Boiler– 420 MW Subcritical Boiler

• Case Study II: 650 MW Supercritical Boiler• Cetek Coating Benefit Summary

Challenges in the Coal-Fired Power Industry: Slagging

• Inefficiency – $20 billion USD in North America

• Current Solutions– SS tubes

• Very expensive, Cl attack– Online Cleaning

• Soot Blowing– Erosion, Cost

• Water Blasting– Tube Quenching

• Explosive Blasting– Boiler Damage

– Increases thermal transfer to boiler tubes

– Lowers maintenance costs

• Eliminates damage to slope or other components due to large falling clinker

Slagging Solution: Ceramic Coating

Challenges in the Coal-Fired Power Industry: Corrosion

• Primary cause of 50% of forced outages

• Current Solutions– High Alloy Tubes

• Very expensive, cycling issues– Overlay

• Weld Overlay– Cost, Cracking, Application Time

• Thermal Spray– Cost, Porosity, Hazards

• Minimizes Forced Outages

• Increases reliability • Lowers

maintenance costs– Increased run

times– Longer boiler tube

life

Corrosion Solution: Ceramic Coating

Cetek’s Ceramic Coating Technology

• 15 years industrial experience• Multiple industries

– Power Generation– Refining– Chemical Processing– Steel

• Thousands of coating applications• Benefits delivered

– Corrosion Prevention– Fouling Prevention– Fuel Savings– NOX Reduction– Production Increases

Case Study I: 820 MW Supercritical Boiler 420 MW Subcritical Boiler 420 MW Subcritical Boiler

Trials to Full Scale Projects

Spring 2006 Unit 4

March 27, 2006

Spring 2006 Unit 4Unit Properties

• 820 MW CE Supercritical• T-fired, 8-corner• Commissioned 1973 • 2004

• Low NOx Burner use initiated• Eastern Bituminous Coal 2.5% Sulfur

• WashedObjectives

• Test Cetek’s Ceramic Coating in a high corrosion environment– Minimize the corrosion rate

• ~500 µm per year• Show a slag reduction

833'-8"

804'807'810'-6"

845'-6"

840'

837'-8"

841'

117

#4

221

98

80

862'-8"

858'

854'850'-4"

224

73

#1

183

155

Bottom Bend of Lower Slope

163

127

202

198

169

Top Bend of Lower Slope

Unit 4: “A” Front Wall

= March 2001 Weld Overlay= April/May 2004 Weld Overlay=8.0m2 of aluminum metal spray= 2 waterwall panels installed = Cetek installed 2006 1m wide by 4m high

Areas Treated1m x 4m’ area “A” Furnace

Right of burner #4Top Burner

elevation

Spring 2006 Unit 4• 6 month Inspection

– Coating Intact • Thickness readings taken by Plant and Cetek were

in proper coating range– No visible damage to coating– Slag on coated area is significantly less

Spring 2006 Unit 4

Per Plant Management: Per Plant Management: ““Coating still has a green hue to it Coating still has a green hue to it and there is no visible slag build up on the tubes.and there is no visible slag build up on the tubes.””

Spring 2006 Unit 4• Spring 2008

– 2 years in service– Significant slag reduction– No wastage in areas of coating vs.

~500 µm per year in region around coating

Fall 2006 Unit 5

November 1, 2006

Fall 2006 Unit 5Unit Properties

• 420 MW CE Sub-critical Drum, T-fired• Commissioned 1976 • 2003: Low NOx Burner use initiated• Eastern Bituminous Coal 3.5% - 4.5% Sulfur

– 30% WashedObjectives

• Minimize the corrosion rate– 711 µm average per year over the last outage cycle (up

to 1.27mm per year)• Minimize slag

Fall 2006 Unit 5Front Wall

Fall 2006 Unit 5Rear Wall

Fall 2006 Unit 5Side Walls

Fall 2006 Unit 5• One year later, Sept 2007 forced outage

note from Plant Management stated:– The walls looked very clean where the Cetek

coating had been applied. – There were sheets of slag above the coated

areas on the waterwalls. – The coating was still visible.

Fall 2006 Unit 5• Spring 2008 Inspection

– Coating Intact– Minimal WW loss of +/- 75 µm

• Inspected every 67cm vertical ; every 5 tubes– Slag still not attaching to tubes

Unit 5 vs. Unit 6 Comparison Fall 2006-18 month run

Unit 5• 370 m2 of coating applied

• No tube leaks in coated areas

• No Slagging on coated surfaces– Increase in Heat

Absorption

• Max of 75 µm loss in waterwall tubes

Unit 6• No coating applied due to

shortened outage

• 2 tube leaks in targeted areas– Result 2 Forced Outages

• 6.5 Days offline

• 711 µm avg per year loss in targeted areas (up to 1.27mm per year)

Spring 2008 Unit 6

May 1, 2008

Spring 2008 Unit 6Unit Properties

• 420 MW CE Sub-critical Drum, T-fired• Commissioned 1978 • 2003: Low NOx Burner use initiated• Eastern Bituminous Coal 3.5% - 4.5% Sulfur

– 30% Washed

Objectives• Minimize slag

– Decrease Furnace Exit Gas Temperature• Minimize the corrosion rate

– ~711 µm average per year over the last outage cycle (up to 1.27mm per year)

Spring 2008 Unit 6• Areas Treated

– Front Wall, 247 Tubes– Rear Wall, 247 Tubes– Side Wall, 194 Tubes

• All tubes are 5.1cm on 6.4cm center.– El. 803 to El. 845 (12.8 m)– Total surface area 1,050 m2

• Additional Outage Work Completed– New Final Reheat Section Installed

• Stainless steel• Reduced surface area

– Not related to a performance issue

Spring 2008 Unit 6• Initial Benefits to date

– Slag Reduction > Increased Boiler Efficiency• Economizer Exit Gas Temp reduced by 17°C

– Pre vs. Post Outage: 382°C vs. 365°C• Boiler Heat Rate Improvements (vs. pre outage)

– July 15th: 11.3 KCal/kWh– August 5th : 19.6 KCal/kWh– $575,000 annual savings

• NOx Reduction– Estimated 4.3% under same pre outage firing

conditions.– Estimated 72,350 Kg/year

Unit 6 – Boiler Heat Rate Improvement

Source: Plant Management, using HRDR system.

Spring 2008 CVU6• Project tracking

– Per Plant Management: • “We have seen a 18.1 KCal/kWh reduction in

these 3 parameters in August compared to pre-outage.”

• “The results of the testing showed a drop in FEGT of 62.0°C on Unit 6.” (Testing completed by third party)

• “This year the Unit 6 NOx is 22.6% below our target. 345 tons of NOx less than the target.”

Case Study II 650 MW CE Supercritical Boiler

Case Study II: 650 MW C-E Supercritical Boiler

Unit Properties• Currently operated at 700-

720 MW• T-fired, 8-corner• Double Reheat Unit• Commissioned 1969 • 2001

• Low Nox Burners• March 2007

• Fluidized Gas Desulfurization

• Intelligent soot blowing system

Results after 6 Months• Coated Areas require 93%

less soot-blowing frequency than uncoated areas to achieve same results

• Coated unit projected soot blowing steam utilization savings of $130,000/yr (side benefit of coating)

• Reduced furnace exit gas temp.

• Minimized waterwall cycling

Case Study II

Cerak M870

Cerak M670

Total Area of 405m2

Cerak M870 = 362m2

Cerak M670 (Chemical Set Coating) = 43m2

13m

5.5m

3m

Case Study II

Cerak M670

Cerak M870

Case Study II

Uncoated Area

Coated Area

Front-wall after 3 months of boiler operation

3 WALL BLOWER D13 NOT AT REST3 WALL BLOWER D14 NOT AT REST3 Tube Crown Temp Right D133 Tube Crown Temp Right D14Gross Load, EXDESC=Gross Load

ZS3BS01D13

ZS3BS01D14

TE3BS01D13D

DEG FTE3BS01D14D

DEG F3LOAD

MW

3 Temp WB D Lev el 13&14

7/16/2007 9:26:44.881 AM 7/23/2007 9:26:44.881 AM7.00 day s

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0

1

0

1

700

800

700

800

650

900

709.18

734.80

751.25

FALSE

FALSE

Case Study II

Uncoated Area Delta T: 50°C Frequency: 14 Times

3 WALL BLOWER D17 NOT AT REST3 WALL BLOWER D18 NOT AT REST3 Tube Crown Temp Right WB D173 Tube Crown Temp Right WB D18Gross Load, EXDESC=Gross Load

ZS3BS02D17

ZS3BS02D18

TE3BS02D17D

DEG FTE3BS02D18D

DEG F3LOAD

MW

3 Temp WB D Lev el 17 & 18

7/16/2007 9:11:13.614 AM 7/23/2007 9:11:13.614 AM7.00 day s

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0

1

0

1

650

750

650

750

650

800

709.77

704.07

703.63

FALSE

FALSE

Case Study II

Coated Area Delta T: 18°C Frequency: 7 Times

Cetek Coating Benefit Summary• Cetek Ceramic Coatings proven to significantly

reduce slag and increase efficiency– Improve heat transfer– Minimize thermal cycling– Minimize soot blowing– Lower FEGT

• Cetek Ceramic Coatings proven to minimize corrosion– Extend tube life– Decrease tube leaks

Cetek Coating Benefit Summary• Improves heat rate• Lowers NOx

• Reduces maintenance costs• Increases asset life• Increases reliability• Increases efficiency• Decreases forced outages

20600 Sheldon Road, Brook Park, OH 44142Telephone: 216/362-3900 Fax: 216/362-3901Internet: http://www.ceteklimited.com

The Cetek Service Portfolio includes Ceramic Coatings,

High Temperature Inspections& Hot Refractory Repairs

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