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

Download Laboratory Grease Analysis with Grease Thief Sampling ...· Laboratory Grease Analysis with Grease

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  • 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

    Forc

    e (g

    ram

    s)

    Sample Baseline

    GTI = 89

    Hardened Sample

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    Forc

    e (g

    ram

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    sample baseline

    GTI = 183

    Sample with Hard Particles

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    Forc

    e (g

    ram

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    Sample Baseline

    GTI = 76

    Softened Grease

    0

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    272 372 472 572 672 772

    Forc

    e (g

    ram

    s)

    Sample Baseline

    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

    0.0000

    0.1000

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    0.4000

    0.5000

    0.6000

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    413

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    439

    452

    465

    478

    491

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    517

    530

    543

    556

    569

    582

    595

    608

    621

    634

    647

    660

    673

    686

    699

    NewFluid inserviceFluid

    Mobilith SHC 220

  • 50:50Mixture

  • NewLubricanttoEndofLife

    0.000.050.100.150.200.250.300.350.400.450.50

    400 450 500 550 600 650 700

    Wavelength(nm)

    Transm

    ission

    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

    40

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    0.00% 0.20% 0.40% 0.60% 0.80% 1.00%

    Carbon Residue (percent mass)

    CIE and L* Vs. % Carbon Residue

    CIE E L*

  • CarbonResidueExperimentCarbon Residue Experiment 2 Visual Spectra Comparison

    0

    0.1

    0.2

    0.3

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    0.5

    0.6

    0.7

    400 450 500 550 600 650 700

    wavelength (nm)

    Tran

    smitt

    ance

    1.00% 0.90% 0.80% 0.70% 0.60% 0.50% 0.40%0.30% 0.20% 0.10% 0.00%

  • 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

    10000

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    20000

    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

    Sample no

    Iron

    (FdM

    Plu

    s)