WATERSIDE CLEANING OF RECOVERY BOILERS

2 Confidential and proprietary.

• Pay Now or Pay Later!

- The Price of Deposition - Evaluating your Boiler’s Health - The Decision to Clean - Options

• Summary

WATERSIDE CLEANING OF RECOVERY BOILERS AGENDA

3 Confidential and proprietary.

THE PRICE OF DEPOSITION

4 Confidential and proprietary.

• Surprises!

• Unscheduled Downtime

• Budget Variances

THE PRICE OF DEPOSITION - RELIABILITY

5 Confidential and proprietary.

RELIABILITY

6 Confidential and proprietary.

• Threat to Personnel!

• Threat to Equipment

THE PRICE OF DEPOSITION - SAFETY

7 Confidential and proprietary.

SAFETY

8 Confidential and proprietary.

THE PRICE OF DEPOSITION - ECONOMY

•Fuel to energy conversion

•Heat transfer efficiency

9 Confidential and proprietary.

Deposit Morphology versus Heat Transfer

02468

101214161820

1/64 1/32 3/64 1/16 5/64 3/32

Deposit Thickness, inches

Perc

ent H

eat T

rans

fer L

oss

Normal Phosphate SludgeSludge with 4% FeSludge with 8% FeSludge with 8% Fe & SiO2

THE PRICE OF DEPOSITION - ECONOMY

10 Confidential and proprietary.

Material Btu / hr-ft2-ºF/ inch Boiler Steel 310 Calcium Phosphate 25 Magnetic Iron Oxide 20 Calcium Sulfate 16 Calcium Carbonate 15.6 Magnesium Phosphate 15 Analcite (NaO . Al2O3

. 4SiO2 . 2H2O) 8.8

Fire Brick 7 Insulating Brick 0.7 Porous silicate scale 0.6

THE PRICE OF DEPOSITION - ECONOMY Selected Thermal Conductivity Values

11 Confidential and proprietary.

ECONOMY

12 Confidential and proprietary.

EVALUATING YOUR BOILER’S HEALTH

13 Confidential and proprietary.

THE DECISION TO CLEAN

Elapsed Time Since Chemical Cleaning

Ris

k $

$

Che

mic

al C

lean

ing

Cos

t $$

14 Confidential and proprietary.

Convenience After Failure Company Policy -- Time and/or Data Based Engineering approach History: Failures, Excursions, Inspections

System: Mechanical Treatment

Data: Deposit data, BFW Quality

Control: Duration and Severity of Excursions

Internal boiler water treatment

EVALUATING YOUR BOILER’S HEALTH: THE DECISION TO CLEAN

15 Confidential and proprietary.

EVALUATING YOUR BOILER’S HEALTH 2005 AF&PA SURVEY RESULTS

16 Confidential and proprietary.

2005 AF&PA Survey Results

EVALUATING YOUR BOILER’S HEALTH

17 Confidential and proprietary.

Time Based Alstom (ABB/CE) = 7 years for Recovery Boilers AF&PA Survey says = 30% time based

Data Based B&W = 20 to 40 g/ft2 @ < 1000 psig

12 – 20 g/ft2 @ > 1000 psig and ALL BLRBs AF&PA Survey says = 52% data based

Both Time and Data Based AF&PA Survey says = 18%

EVALUATING YOUR BOILER’S HEALTH: WHEN TO CLEAN?

18 Confidential and proprietary.

2 feet

2 feet

2 feet

Tube portion to be removed

Year 0 Year 1 Year 2 Year 3 Year 4

2 feet

0

0

0

0

1 1

1

1

2

3

4

Tube Sample Protocol

EVALUATING YOUR BOILER’S HEALTH – WHEN TO CLEAN?

19 Confidential and proprietary.

THE CLEANING PROCESS

Safety

Pre-engineering / Consultation

Preparation and Execution

Post cleaning evaluation

20 Confidential and proprietary.

ALTERNATIVES TO CLEANING: “OPTIONS?”

21 Confidential and proprietary.

MECHANICAL OPTIONS

Feedwater Makeup

Demineralized water or better

Redundant protection against contaminant intrusion

Condensate

Resin and/or Electromagnetic Filtration Polishers

Redundant protection against contamination

22 Confidential and proprietary.

CHEMICAL OPTIONS

Condensate Treatment Chemistry

Appropriate treatment for existing metallurgy

Passivating agent to maximize condensate return

Internal Treatment Chemistry

Congruent Phosphate with high purity feedwater

Boiler water dispersant

23 Confidential and proprietary.

0

100

200

300

400

500

600

700

800

900

1000

23-A

ug-9

4

21-D

ec-9

4

23-M

ar-9

5

19-Ju

l-95

12-O

ct-9

5

9-Ja

n-96

3-Ap

r-96

20-A

pr-9

6

23-A

pr-9

6

29-A

pr-9

6

10-Ju

n-96

10-Ju

l-96

12-A

ug-9

6

29-A

ug-9

6

30-S

ep-9

6

21-O

ct-9

6

18-N

ov-9

6

16-D

ec-9

6

13-Ja

n-97

26-F

eb-9

7

17-M

ar-9

7

7-Ap

r-97

9-Ju

l-97

17-S

ep-9

7

6-N

ov-9

7

14-Ja

n-98

12-M

ar-9

8

12-M

ay-9

8

24-M

ar-9

9

16-Ju

n-99

21-S

ep-9

9

20-Ja

n-00

ppb

Start of Dispersant Trial

Boiler comingon-line

Canadian Kraft MillRecovery Boiler - Iron Transport

CHEMICAL OPTIONS – BOILER WATER TREATMENT

24 Confidential and proprietary.

Blowdown Iron versus Time

0

50

100

150

200

250

300

350

400

450

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73

Sample Day

Tota

l Iro

n, p

pb

1500 psig 75 - 100 cycles 5 ppb FW Iron

Start Dispersant Here

CHEMICAL OPTIONS – BOILER WATER TREATMENT

25 Confidential and proprietary.

SOUTHERN U.S. PAPER MILL DEPOSIT LOADING HISTORY

0 5

10 15 20 25 30 35 40 45 50

1989 1990 1991 1992 1993 1994 1995

DW

D -

g / f

t2

Started Iron Dispersant

Acid Cleaned

Acid Cleaned

26 Confidential and proprietary.

MONITORING – DECISION MAKING DATA

27 Confidential and proprietary.

STG

Superheater

Deaerator

FeedwaterStorage

BlowdownHeat Exchanger

FeedwaterMakeup

To Waste

BlowdownFlash Tank

Cooling Water

Pulp MillDigester Paper Mill

Cooling Water

Fresh SteamMultiple Effect

EvaporatorDirtyCondensate

Weak Black Liquor from Washers

StrongBlack Liquor

Condenser

Clean Condensateto Utilities

Process Steam UsersLow Pressure Steam

High Pressure Steam

HP CondensateFlash Tank

LP Condensate

CondensateCollection

Tank

Condensate Polisher (Resin and/or Magnetic)

HP Condensate

Sweet Water Condenser

Economizer

FeedwaterRegulator

Valve

PRV

SP

SP

Typical Sample Point

SP

SP

SP

SP

SP

SP

SPSP

SPSP

SP

SP

SP

SP

BEST PRACTICES – MONITORING AND CONTROL

28 Confidential and proprietary.

SUMMARY…….PAY NOW OR PAY LATER

Operating Costs

Treatment Costs

Cleaning Costs

29 Confidential and proprietary.

POSTPONE, MAYBE?……. BUT, CLEAN AT SOME POINT FOR SURE!

30 Confidential and proprietary.

QUESTIONS?