Corrosion Monitoring with theCorrosion Monitoring with theHEHEProPro

at Irving Pulp & Paperat Irving Pulp & Paper

Kelly McKeen and Andy JustasonKelly McKeen and Andy Justason

CNERCNER

May 13, 2008May 13, 2008

ObjectivesObjectives

Corrosion monitoring of recovery boiler tube Corrosion monitoring of recovery boiler tube during acid washduring acid washAssessment of corrosion during startAssessment of corrosion during start--up after up after major shutdownmajor shutdownContinuing onContinuing on--line monitoring of corrosion rate line monitoring of corrosion rate during operating transientsduring operating transients

Principle of Hydrogen EffusionPrinciple of Hydrogen EffusionCorrosion rates of steel can be predicted by Corrosion rates of steel can be predicted by measuring throughmeasuring through--wall hydrogenwall hydrogenAs iron corrodes, hydrogen atoms are produced As iron corrodes, hydrogen atoms are produced (reducing chemistry only)(reducing chemistry only)Atomic hydrogen diffuses through the pipe wall Atomic hydrogen diffuses through the pipe wall and recombines to form hydrogen gasand recombines to form hydrogen gas

BackgroundBackground

First industrial installation of the First industrial installation of the HEHEPro Pro was at was at Point Lepreau NGS Point Lepreau NGS

NonNon--intrusive, intrinsically safe, onintrusive, intrinsically safe, on--line, remote line, remote monitoring, fully automated, minimum maintenance, monitoring, fully automated, minimum maintenance, high temperaturehigh temperature

First boiler installation was at Coleson CoveFirst boiler installation was at Coleson CoveModified design to allow for attachment to boiler Modified design to allow for attachment to boiler waterwall tubewaterwall tubeReliability at temperatures in excess of 350 Reliability at temperatures in excess of 350 ooCCBoiler #1 nearly idle through the winterBoiler #1 nearly idle through the winter

IPP invited IPP invited CNERCNER for a performance test on the for a performance test on the recovery boilerrecovery boiler

Nuclear Installation on PipeNuclear Installation on Pipe

Installation on Boiler Tube Installation on Boiler Tube

Installation on Boiler Tube 2Installation on Boiler Tube 2

HEHEProPro EquipmentEquipmentSilver probe seals directly to pipe or tube Silver probe seals directly to pipe or tube without weld or owithout weld or o--ringring

Deformation of engineered silver edgeDeformation of engineered silver edge

Probe connected to instrument box withProbe connected to instrument box withVacuum pump / valveVacuum pump / valvePressure transducerPressure transducerSCADA systemSCADA systemModemModem

High sensitivity and responsivenessHigh sensitivity and responsivenessVery low absolute pressuresVery low absolute pressuresLow volumeLow volume

Location SelectionLocation Selection

Installed on middle of west side of boiler on the fifth floor

Almost half way up the boilerAlmost half way up the boilerNo residual dissolved oxygen during normal No residual dissolved oxygen during normal operationoperation

StandStand--offs welded to tubes offs welded to tubes Pipe surface preparation requiredPipe surface preparation required

Monitors background rate of corrosion, not Monitors background rate of corrosion, not local problem areas (fire side)local problem areas (fire side)

Installation ProcedureInstallation Procedure

Installation Procedure 2Installation Procedure 2

Data From First Two WeeksData From First Two Weeks

Acid CleaningAcid Cleaning

StartStart--UpUp

ConclusionsConclusionsThe The HEHEProPro was able to monitor corrosion during the was able to monitor corrosion during the acid cleaning in acid cleaning in ““near realnear real--timetime””..The corroding system changed dramatically during the The corroding system changed dramatically during the neutralization / neutralization / passivationpassivation stage.stage.The The HEHEProPro at IPP doesnat IPP doesn’’t have any leaks as evidenced t have any leaks as evidenced by the current negligible corrosion rate.by the current negligible corrosion rate.Corrosion rates during the acid wash were relatively low.Corrosion rates during the acid wash were relatively low.The corrosion rate was moderately low during startThe corrosion rate was moderately low during start--up up and decreased to extremely low after about a week.and decreased to extremely low after about a week.IPP plans to tie the IPP plans to tie the HEHEProPro data into their PhD system to data into their PhD system to enable correlation of corrosion rate to process enable correlation of corrosion rate to process parameters (pH, steaming rate, upset conditions, etc.).parameters (pH, steaming rate, upset conditions, etc.).

Questions?Questions?