monitoring condensate virginia durham may 2008 - … · monitoring condensate virginia durham may...

Water Management Technologies

Weyerhaeuser_October 2007 - 1

Condensate ManagementMonitoring Condensate

Virginia DurhamMay 2008



Outline• Goals in condensate management• Monitoring

PurposeSamplingTestingMajor Streams

Contaminants Automatic dump systems



Condensate Management• Maximize quantity returned

Energy value

• Maximize qualityBoiler reliability(Condensate system reliability)



The cost of lost condensate

1 GPM: $4300 per year20 GPM: $1600 per week ($85,000/year)

in boiler fuel costAssuming :

$6/mmBTU fuel cost80 % boiler efficiency200 degF condensate70 degF make-up water



Monitoring Condensate QualityGoal:

Maximize condensate quantity and quality to provide economy and boiler protection

Contamination detectionTreatment program monitoring and controlPolisher performance monitoring and controlCondensate stream return control



Condensate quality― TAPPI Guidelines ―

30 mmhos

.05 - .1 ppm

.05 - .3 ppm

“Softened” water system (pressure dependent)

5 mmhos above “expected”Conductivity

< .01 ppmCopper

< .01 ppmIron

< .1 ppmSilica

Non -detectableTotal Hardness

High purityWater system

Parameter

From :

TAPPI Tips 0416-14

0416-03



Sampling – How?• Stainless steel sample line• Maintain adequate velocity/minimize line length• Run sample continuously• Cool sample

Follow ASTM D3370



Sampling – Where?• Routine Sampling

Critical streamsComposite streams prior to flash tanks/vented receiversBulk condensate return streams

• Non-routinePaper machine receiversOther?



Example Condensate System

Feedwater

Makeup

ReturnCondensate

Steam

Deaerator

Pulp Dryer

TurbineGenerator

PaperMachine

ResinPolisher

MagneticFilter

Boilers

evaporators Digester



Testing

ManualProgram PerformanceCorrosion Coupons

Manual:(Wet analysis, Sub-micron Filtration)Continuous:(Turbidimeters, Particle Counters)

Program Performance(Contamination)

Metals Testing

ManualContamination DetectionOxygen

ManualContamination DetectionHardness

Manual(Continuous)

Contamination DetectionSilica

ManualContinuous

Contamination DetectionConductivity

ManualContinuous

Program Chemistry/Contamination Detection

pH

Typical MethodPurposeTests



Testing




Metals Testing



Manual(Continuous)


ManualContinuous


ManualContinuous


pH




pH Testing

• Cool sample to 77oF

Avoid loss of volatile species

Accurate pH measurement



9.5

9.0

8.5

8.0

7.5

7.0

75 100 125 150 175 200

Sam

ple

pH

Sample Temperature (Degrees F)

Effect of Temperature on Sample pH



Temperature compensation of pH• Some meters have 2 levels of compensation:

“electronic”“solution chemistry”

• Many meters simply address the “electronic”compensation and do not compensate for temperature effects on solution chemistry



Sample point location for pH testing• Be sure sample points provide meaningful results

Challenging for systems with high alkalinity make up water



mainreceiver

Paper Machine

vacuumpump

heatexchanger

wet enddryers

main sectiondryers

thirdsection



Testing




Metals Testing



Manual(Continuous)


ManualContinuous


ManualContinuous


pH




Metals Testing• Manual

Wet chemistryironcopper

Sub-micron filtration

• ContinuousTurbidityParticle Counters



Sub-micron Filtration

Example of iron on a paper machine startup



Turbidity monitoring

• Indicator of particulate corrosion products

• Can be used for automatic diversion of condensate

• Correlation of turbidity with contamination levels is required



Condensate

Sample

ToPowerHouseDumped Condensate

Coo

ler

Turbidity MonitoringTurbidity

Meter



Testing




Metals Testing



Manual(Continuous)


ManualContinuous


ManualContinuous


pH




Conductivity Monitoring• Typically used as an

indication of raw water and liquor contamination

• Portable meters are a good tool

• Continuous monitoring is a critical component to a boiler protection program



Condensate

ConductivityProbe

Sample


ConductivityMeter

Coo

ler

Conductivity Monitoring



Automatic conductivity dumpsconsiderations

• Location of probeDead time – be sure that probe/meter can detect and divert condensate before contaminants reach the valve

• Set point point for dumpingLow enough to catch intrusion while avoiding nuisance alarms

• Preventive maintenanceExercise the probe, meter, and the valves.



Minimize dead time:

Line length and sample flow

Condensate

ConductivityProbe

Sample


ConductivityMeter

Coo

ler




Set Point for dumping:

Low enough for protection

Condensate

ConductivityProbe

Sample


ConductivityMeter

Coo

ler




Condensate

ConductivityProbe

Sample


ConductivityMeter

Coo

ler


Preventive Maintenance:

Exercise the valve



Automatic conductivity dumpsconsiderations

• Location of probeDead time – be sure that probe/meter can detect and divert condensate before contaminants reach the valve

• Set point point for dumpingLow enough to catch intrusion while avoiding nuisance alarms

• Preventive maintenanceExercise the probe, meter, and the valves.



Testing




Metals Testing



Manual(Continuous)


ManualContinuous


ManualContinuous


pH




Spectrophotometer

• Low level hardness testing

• Silica

• Wet testing for iron, copper



Oxygen Testing• Used typically as a troubleshooting tool in

condensateManualContinuous



Oxygen Testing



Typical Routine Monitoring




Metals Testing



Manual(Continuous)


ManualContinuous


ManualContinuous


pH




Test Sensitivity Issues• “Set-point” for dumping on conductivity• Choice of hardness test

Use spectrophotometer

• Silica/hardness test more sensitive than conductivity for raw water intrusion

• Is conductivity sensitive enough for low level acid intrusion from Chlorine dioxide generator?



Major Streams and their Contaminants

Feedwater

Makeup

ReturnCondensate

Steam

Deaerator

Pulp Dryer

TurbineGenerator

PaperMachine

ResinPolisher

MagneticFilter

Boilers

evaporators Digester



Major Streams

Corrosion ProductsAcidChlorine Dioxide Generator

Corrosion ProductsMill WaterCondensers/Mill Water Heaters

Corrosion ProductsOilLube Oil System

Corrosion ProductsGlycolGlycol System

Corrosion Products (Iron)Corrosion Products (Copper)Pulp Dryer

Corrosion ProductsLiquorDigester Liquor Heaters

Corrosion ProductsLiquorEvaporators/Concentrators

Mill WaterCorrosion Products (Iron)Paper Machine

Minor ContaminantsMajor ContaminantStreams



Boiler protection though automatic dump systems

ConductivityOther streams with possible

liquor, raw water contamination

Turbidity, (Conductivity)Paper machine

ConductivityEvaporator

Meter/Dump SystemStream

Conductivity, (pH)Chlorine Dioxide Generator

ConductivityDigester



Dumping Practices• Automatic Systems - preventive maintenance

Full testing of systemFrequency?

• Optimization Opportunity?Allow polishers/filters to do more work…

Requires a rigorous study of polisher system performance during upset conditions to avoid risk to boilerOngoing monitoring of polisher system effluent must be in place

• Monitoring of flows ContinuousWalk-downs

Also provides information on leaks



Summary• Condensate monitoring program is critical for boiler protection

• Test method sensitivity should be considered when monitoring forcontamination

• Maintenance and configuration of dump systems require attention to assure protection

• Look closely at polisher/filter operation and potential to return more condensate



Thank You

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