Confined Space Recovery Boiler

Recovery Boiler Inspections

Jim GrahamBuckman Laboratories

TAPPI Engineering ConferenceOctober 2007

If you are going to spend three hours cutting wood, spend two hours sharpening your saw.

Inspection Discussion

SafetyEquipmentReviewing materialInspectionReporting

Safety

Follow established mill proceduresLock out / tag outConfined space entryCommunication

Never inspect a boiler without a watchContingency plan in case of emergency

Monitor conditions within the boilerAir qualityPotential for other hazards

Safety

Be aware of potential risksLeaking feedwaterBlowdown flash tank crossoverShock hazardsInter-drum hazards

Report unsafe working conditionsLearn about the equipment that will be inspected

Equipment Preparation

Inspection cameras (boroscope and still)4 gas monitorRescue HarnessScraper, magnet, sample bags (Whirlpak)Parafilm and transparent tapeDeposit test kit (qualitative)Necessary clothing, gloves and respiratorVentilation

Equipment Examples

Understand the Boiler Specifics

Review drawings and elevation diagramIdentify inspection areasNote any mechanical changes to system

Review tube inspection recordsPast inspection reportsPhotos and video records

Be aware of past chemical excursionsDate, severity, contaminant

Understand the Boiler Specifics

Know what will be accessibleWork with contractors and millTake advantage of any opportunity

Review any mechanical, operational or chemical changes since last inspection

Baffles, treatment program, controlChanges in treatment can contribute to redistribution of deposits in the boiler

Tube Inspection Map - History

Tube 1

Row 1

Inspection Areas

Upper and lower wall headersLook for debris, pluggage, Inspect accessible wall tubes

Penthouse and lower vestibuleSteam and mud drums

Waterline (loose equipment can cause steam purity issues)Check integrity of cyclones, demisters, chevrons, and all separating equipment

Inspection Areas

Generating bank and downcomersNote deposition pattern if presentIdentify signs of steam blanketingLook for corrosion at tube ends

Side wallsRun boroscope in all accessible tubesMake note of elevation and tube specifics

Floor and roof tubesRun scope as far as possible

Inspection Areas

Screen tubesMay indicate area-specific issuesFocus on slopes and bends

Superheaters and headersCarryover

FiresideBlisters and bulges indicate heat transfer issues. Changing fuels can alter the heat flux to the tube

Auxiliary equipment

General Photos

Boroscoping

Provides a convenient record of changesTubes can be tracked year after year

Newer technology makes data access easyDVD and flash drive recording media

Inspection results can be inserted into reportVirtually all areas of boiler can be accessedResults are portable

Questionable areas can be shared via email

Boroscoping MapRecovery BoilerGenerating Bank

(top view)

co lds ide

Fu rnaceho ts ide

row01

t ub e01

row10

tube01

row20

tube01

ro w30

tube01

ro w40

tube01

row50

tube01

row60

tube01

row70

tube01

row80

tube01

row84

tube01

row

01tu

be27

row

10tu

be27

row

20tu

b e2 7

row

30t u

be2 7

row

40t u

be2 7

row

50t u

be2 7

row

60t u

be27

row

70tu

b e27

row

80tu

b e27

row

84t u

be27

tube 10

tube 15

tube 20

tube 10

tube 15

tube 20

.

General Reporting

Provide as much information as possibleExecutive summaryAnalytical resultsBoroscope map / tube historyFollow-up planPhotos, video clips

Keep the report format consistentMake the data easy to access and share

Report Components

Probable Combination for Deposit

Percent of Compound

46%

27%

8%

8%4% 3% 2% 1%1%

CALCIUM CARBONATE (CALCITE)

IRON OXIDES

MAGNESIUM PHOSPHATE (MUNSONITE)SILICA / QUARTZ / CRISTOBALITE

MAGNESIUM SILICATE (SERPENTINE)

SODIUM CARBONATE

CALCIUM SULFATE (ANHYDRITE)

COPPER OXIDES

ALUMINUM, MANGANESE AND / OR ZINC OXIDES

Row 1

Tube 1

Summary

Plan well to be safeReview information from past inspectionsMake sure equipment is fully functionalYou can’t collect too much informationMake the results easily accessibleKeep good recordsAsk questions

Thank You