laboratory grease analysis with grease thief sampling ...· laboratory grease analysis with grease

LaboratoryGreaseAnalysiswithGreaseThiefSampling&AnalysisSystem

GreaseThiefDieExtrusion Analex fdM+ MetalSpectroscopy RULER FTIR AnalyticalFerrography Rheology

Offsite Grease Tests

Ferrous Debris

Anti-oxidants

AnalyticalFerrography

Patch Microscopy

Grease Rheology

Metals Spectroscopy

Comparative FTIR

Grease Consistency

PrepforAnalysis

Whengreaseistestedforconsistency,itcanbeextrudedontosamplesubstrates: IRCardforFTIR SubstrateforweighinganddissolutioninRULERvial

Substrateforweighinganddissolutionforspectroscopy;samedissolvedgreasecanbeusedforFerrography/MicroPatch

SampleHandlingandPreservation

SamplingProcedures:ASTMStandardPracticeD7718

UseproperPPE Instrumentation

Wipedownbetweenruns DonotreuseExtrusionDiesorGreaseThieves(GT)

AnalysisTechniques

Sample is received. fdM+ is run Grease Thief Analyzer is performed and substrate is made

Two strips are used to make a dilution to run RDE/ICP.

One Strip is used for FT-IR.

One Strip is Dissolved in Green RULER solution to run RULER.

WearMonitoringwiththeANALEXfdM+

Halleffecttypesensortodeterminetheamountofferrousdebrispresentinthesample.

InstrumenthascalibrationstandardsforGreaseThief.

Theinstrumentmeasurestheentiresamplewhichisimportantduetothenonhomogenousnatureofgrease.

WearMonitoringMethodComparison Samplewastakeningreasesampler Extrudedsamplewasweighedanddissolvedfordirectreadingferrography

Resultswerenormalizedto0.1gramgrease Fullsampleranalyzedbyferrousdensityinstrument(Halleffectsensor)forppmFeresult

Quantityofgreaseinsamplerweighedandtared,andresultinppmnormalizedto1.0gramgrease

Method Average Standard DeviationRelative Standard

DeviationfdM+ 277 ppm 7 2.53DR- 205 46 22.44RDE 57 ppm 16 28.07

Method Average Standard DeviationRelative Standard

DeviationfdM+ 277 ppm 7 2.53DR- 205 46 22.44RDE 57 ppm 16 28.07

GreaseThiefDieExtrusionTest

Thisinstrumentdetectschangesintheconsistencyofagrease.

Itissensitivetothepresenceofhardparticles,seenasspikesinthedata,andhardenedchunksofgrease,seenasbroadpeaksinthegraph.

Thistestonlyrequiresonegramofgrease. GreaseThiefIndex(GTI)calculatesthedeviationin

percentoftheforceofthesamplecomparedtothatofthebaseline.AGTIof100showsaperfectmatchtothebaseline.

Dieextrusionandsamplepreparation

Greaseextrudedthroughdietocreateribbononsubstrate Loadprofileatvaryingspeedsdevelopedforconsistencyevaluation Samplepreparedforsubsequentanalyses

PredictedResponseGraph Averagestableloadvalue

afterspeedchangerelatedtoNLGIgrade,orpenetrationvalues

RapidspeedchangesusedtoleveragenonNewtonianresponse

Criticalareasexpectedimmediatelyafterspeedchange;possibledatarichregionstocharacterizerheology,oilshear,dryness,etc.

GreaseThiefAnalysisProfilesNormal Profile

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272 372 472 572 672 772 872

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Sample Baseline

GTI = 89

Hardened Sample

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GTI = 183

Sample with Hard Particles

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GTI = 76

Softened Grease

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272 372 472 572 672 772

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GTI = 31

ActualLoadResponseGraphs

ConsistencyTesting

StandardLaboratoryTests FTIR Takesafingerprintofthegrease.Helpsdetermineifmixingispresent.Itisalsousedtodeterminethepresenceandoriginofunknowncontaminantsandoxidation.

RULER Measurestheamountofantioxidantremaininginthegrease.

MetalSpectroscopy RDE/ICP/XRFdeterminesthewearmetals,additivemetalsandthickenermetalsusedinthegreaseformulation.Thistestalsoaidsinthedetectingmixingofgreases.

OpticalSpectroscopy Usesvisualcolorabsorbancetoevaluatedegradationandpotentialmixing.

FTIRAnalysis

PrepforAnalysis

LinearSweepVoltammetry(RULER)analysisforgrease

Preparationofthinfilmsubstratestreamlinesandstandardizesanalysis

Additivelevelsnormalizedtomassofgrease

LinearSweepVoltammetry Samplesfromsimilarcoal

crushers,sametimeinservice Bothhaveanadequate

remainingantioxidantleveltoprotectgreasefromoxidation

Lowersampleshowsmorerapiddegradationofantioxidants,duetohighertemperatures,contaminants,orotheroxidationstressors.

Differencesintimeofserviceorrelubricationquantitiesoreffectivenesscouldalsoaffectantioxidantamount

OpticalSpectroscopyCell

InServiceSpectrum

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NewFluid inserviceFluid

Mobilith SHC 220

50:50Mixture

NewLubricanttoEndofLife

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New Fluid

In-Service Fluid

End of Life Fluid

New: Mobil XHP 222 S, In-service: Used Mobil XHP 222, EOT: Used Unirex N2 (both were the same at end of life).

ChemometricTechniques

Evaluateparticulatecontaminationofnewandinservicegreases

Coaldust,otherknownandcommoncontaminants Establishingcontaminantleveltargets

CarbonResidueExperiment Carbonresidueusedtomakea1%bymassmixture.

Dilutionsmadetoprepare9additionalsamples.

Extrudedsamplesontosubstrates.

AnalyzedsampleswiththeiLabusingtheopticalspectroscopybox.

y = 564.03x + 56.949R = 0.969

y = -640.87x + 58.179R = 0.9534

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Carbon Residue (percent mass)

CIE and L* Vs. % Carbon Residue

CIE E L*

CarbonResidueExperimentCarbon Residue Experiment 2 Visual Spectra Comparison

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AdvancedLaboratoryTesting

RheometricAnalysis isanewertechniquethatutilizesarheometertoanalyzethephysicalpropertiesofagrease.Thesepropertiesare Resistancetoflow(pumpability)

Consistency RecoverableCompliance(tunneling)

AnalyticalFerrographymicroscopictechniqueusedinoilandgreaseanalysis.Itisusedto Discovertheoriginsofthewear.

Thesizeoftheparticles. Detectsignsofacidcorrosion.

Rheometertesting

WorkbyNolanandSiviktoevaluategreasepropertieswithrheometer

BryanJohnsonpublishedmethodforcorrelatingpenetrationtorheometer

GermanDINdraftmethod Yieldstresspointandequilibriumrecoverablecompliance

Measuringflowpointandelasticrecoil

RheometerConsistencyTesting

ElasticityorRecoverableCompliance

ConsistencyTesting

NewfreshgreaseG=18,260Pa

SuspectedMixtureG=10,510Pa

G is 57% of new

FerrographicandMicroPatchinspections

FerrographicandMicroPatchinspections

Analyticalferrographymoredifficultthanoil;mayrequirespecialfixermixtures

Patchcanbecloudedbyresidualgreaseparticles,butcanbemoreeffectiveatfindingnonferrous

WindTurbinegreasesamplingandanalysis

2yearprojectconductedwithDONGEnergyandVattenfall,twolargestoffshorewindoperatorsintheworld

Dr.KimEsbensen,internationallyrecognizedexpertinTheoryofSampling(TOS),Denmark

RichWurzbach,MRGLabs,inventorofGreaseThief Systematicevaluationofgreaseheterogeneity,samplingmethodology,andanalysisvalidityandrepeatabilityforwindturbinemainbearingsinonshoreandoffshoreapplications

ResultspublishedatOilDoc,LUBMAT,andAWEA

FundamentalSamplingPrincipleUsingtheGreaseThief

RepresentativesamplingThoroughcharacterizationoftheheterogeneityofgreaseinmainbearings

TestparametersofGrease

Fortheheterogeneitycharacterization ofgreaseinmainbearingsofwindturbinesthefollowingparameterswereused:

ConsistencyandflowcharacteristicsFerromagneticiron(Halleffectsensor)WearmetalsParticlecharacterization(size&distribution)ResidualoilingreaseAntioxidants

HeterogeneitycharacterizationFerromagneticiron

Samplingofgreasewhiledrainingthemainbearingthroughthedrainplug

27incrementscollected(eachsampleapproximately20grams)

Onsitesampling

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Iron

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