study on equipment diagnostic technology utilizing...

17 Oct 2011. , Los Angeles WEFTEC2011Session10 Asset Management – New Tools to Repair Old Problems

St d on eq ipment diagnostic Study on equipment diagnostic technology utilizing Tribologygy g gy

Masahiro ItoJapan Institute of Wastewater Engineering Technology（JIWET）Japan Institute of Wastewater Engineering Technology（JIWET）

INTRODUCTIONINTRODUCTIONIn Japan (Today) ・・・

About 800 out of the 2,000 wastewater t t t l t J h b i

p y

treatment plants across Japan have been in operation for more than 15 years.

It is expected that upgrades of aged equipment will increase in the coming yearswill increase in the coming years.

INTRODUCTIONINTRODUCTIONCosts can possibly be reduced if the service life of equipment can be extended through properequipment can be extended through proper maintenance.

Condition-based maintenance, a method to keep track of equipment deterioration is a highlytrack of equipment deterioration, is a highly anticipated technology to allow proper maintenance.

Diagnostic technology utilizing tribology, which isDiagnostic technology utilizing tribology, which is one of the technologies used for condition-based maintenance.

Tribology is defined as 「The science and engineering of surfaces「The science and engineering of surfaces

where friction occurs and of lubrication」

It is a field of engineering studying lubrication and friction, which affect machine reliability and durability. , y y

Lubrication diagnosisLubrication diagnosisTechnology for evaluating the integrity of equipment through close analysis of lubricant oil by making use g y y gof the fact that wear debris in the lubricant oil used in rotating machines is closely correlated with the

f d f b i dsurface damage of bearings and gears.

Object of diagnosis

Equipment Type Machine element

Bearing Object of diagnosisBearing

Gear wheel

L b i ti Seal

BeltMachinery equipments

Lubricationequipments

Wastewater …ScrewNon-lubrication

…

ElectricalPower electrics system

Light electrics system

This technology is a technology that diagnosisThis technology is a technology that diagnosis the lubrication part (bearing).

ring

Time when lubrication diagnosis is especially effective

Breakager

of b

ea

effective Abnormal temperatureAbnormal vibration

Initial

otal

wea

Initialfailure

To

TimeEarly wear Regular wear Unusual wear

Figure. Characteristics of lubrication diagnosis

ring


Breakager

of b

ea


Initial

otal

wea

Initialfailure

To


Figure. Characteristics of lubrication diagnosisLubrication diagnosis technology is sometimes compared to the blood testing of human beings, because the lubrication conditions in bearings and other devices, which are one factor causing anomalies in machines are directly analyzedin machines, are directly analyzed.

ring


Breakager

of b

ea


Initial

otal

wea

Initialfailure

To


Figure. Characteristics of lubrication diagnosisThe technology is characterized by being capable of detecting anomalies earlier than other diagnostic

h dmethods.

Sampling for Analytical of Evaluation of

Procedures to diagnosis

lubricant oil lubricant oil analysis result

The objective of lubrication diagnosis is to detect anomalies by keeping track of any changes in y p g y gcomparison with the standard amount and shape of wear debris under normal operational conditions.

In lubrication diagnosis, lubricant oil conditions with g ,regard to deterioration and contamination, which can cause wear, are analyzed in their entirety to allow a

h i di i b icomprehensive diagnosis to be given.

Kinematic viscosity

・The analytical test items

(1)Deterioration

Kinematic viscosityMoistureNeutralization numberof lubricant oil Neutralization number

f d b

Oxidation Stability

(2)ContaminationQuantitative degree of

Infrared absorption spectrum

(2)Contaminationof lubricant oil

contaminationDegree of contamination measured

by weight

(3)Wear of bearingsAnalysis of metal in oilQuantitative of ferrography

y g

Quantitative of ferrography

Kinematic viscosity


(1)Deterioration

Kinematic viscosityMoistureNeutralization numberof lubricant oil Neutralization number

f d b

Oxidation Stability


Infrared absorption spectrum

Deterioration of lubricant oil can be roughly divided(2)Contaminationof lubricant oil


by weight

Deterioration of lubricant oil can be roughly divided into kinematic viscosity, moisture, and degree of deterioration.


y gAnalytical methods for these categories are defined in the Japanese Industrial Standards

(h i f f d “JIS”)Quantitative of ferrography(hereinafter referred to as “JIS”).

Kinematic viscosity

・The analytical test itemsTwo methods are available to measure contamination:

(1)Deterioration

Kinematic viscosityMoistureNeutralization number

Two methods are available to measure contamination:count-based contamination, in which the number of particles of contaminant is examined; and weight-

of lubricant oil Neutralization number

f d b

Oxidation Stability

p gbased contamination, in which the weight of contaminant is examined.Th t t f l ti l th d d fi d i JIS


Infrared absorption spectrumThese two types of analytical method are defined in JIS.

(2)Contaminationof lubricant oil


by weight


y g


Kinematic viscosity


Two methods are available for measuring wear:

(1)Deterioration

Kinematic viscosityMoistureNeutralization number

Two methods are available for measuring wear: metal in oil analysis, in which the degree to which wear has advanced and the location of areas where itof lubricant oil Neutralization number

f d b

Oxidation Stability

wear has advanced and the location of areas where it has occurred are identified; and wear debris analysis (ferrography method), in


Infrared absorption spectrumwhich characteristics of wear debris including its size, shape and concentration are analyzed and observed. (2)Contamination

of lubricant oilcontamination

Degree of contamination measured by weight


y g


Representative microscopic images of wear debris that can be observed by using quantitative of ferrography.

Normal Anomaly

20μm 20μm

(1) Normal wear debris, minute, flaky

(2) Cutting wear debris,curl, crescent-shaped linear

AnomalyAnomaly

20μm20μm

(4) Adhesion wear debris(3) Melting wear debris (4) Adhesion wear debris, large, slip line

(3) Melting wear debris,ball

To examine the applicability of lubrication diagnosis technology, Lubrication diagnosis was carried out on a blower that was scheduled for an overhaulwas scheduled for an overhaul.

＜Equipment specification＞Equipment：BlowerType：Multiple-stage turbo blowerFlow rate：55m3/min Service years：11Operation hours：50,629Overhauled since installation：No

To validate the diagnosis, we disassembled the blower g ,after completing lubrication diagnostics and directly observed damage to the bearings.

・Deterioration of lubricant oilThe oil’s kinematic viscosity, moisture, and total acid value which are indicators of deterioration did not differ

Oil nameLublication

value, which are indicators of deterioration, did not differ significantly from those of new oil (Table).

Oil diagnosed New oil valueKinematic viscosity ㎜

2/s 32.97 32.23

Oil nameLublicationdiagnostic item Good

G dMoisture ppm 12 26.6

Total acid value mgKOH/g 0.07 0.09 GoodGood

・The infrared absorption spectraThe wave shape and transmittance in h i f d b i did

透過率

新油使用油 New oilUsed oil

ce(%

)

the infrared absorption spectra did not differ greatly from those of new oil(Figure).

％

Transm

ittan

(Figure). 波数(cm-1)Wave number(cm‐1)

・Deterioration of lubricant oilThe oil’s kinematic viscosity, moisture, and total acid value which are indicators of deterioration did not differ

Oil nameLublication

value, which are indicators of deterioration, did not differ significantly from those of new oil (Table).

Oil diagnosed New oil valueKinematic viscosity ㎜

2/s 32.97 32.23

Oil nameLublicationdiagnostic item Good

G dMoisture ppm 12 26.6

Total acid value mgKOH/g 0.07 0.09 GoodGood

・The infrared absorption spectraThe wave shape and transmittance in h i f d b i did

透過率

新油使用油 New oilUsed oil

ce(%

)

the infrared absorption spectra did not differ greatly from those of new oil(Figure).

％

Transm

ittan

Therefore, It suggested that oxidative deterioration had (Figure). 波数(cm-1)Wave number(cm‐1)

, ggnot progressed, which allows us to determine it is possible to continue to use the blower.

・Contamination of lubricant oilAnalytical data

Oildiagnosed

The allowable limit value

5～15μ Number of particles/100ml 336,390～25μ Number of particles/100ml 28,903

Lublication diagnostic item

Within class ofNAS 12.25μ Number of particles/100ml 28,903

～50μ Number of particles/100ml 10,537～100μ Number of particles/100ml 1,220100μ＜ Number of particles/100ml 60

NAS Cl *1 Cl 11

Count-basedcontamination

NAS Class 1 Class 11mg/100ml 0.35

NAS Class*1 Class 104 *1 NAS class：AUS NASA standard, which is an evaluation criteria concerning contamination.

Weight-based contamination

Within class ofNAS 107.

It was therefore decided to closely・Contamination of lubricant oilAnalytical data

It was therefore decided to closely examine analytical data of the subsequent year for any changes.Oil

diagnosedThe allowable

limit value5～15μ Number of particles/100ml 336,390～25μ Number of particles/100ml 28,903

Lublication diagnostic item


subsequent year for any changes.

25μ Number of particles/100ml 28,903～50μ Number of particles/100ml 10,537～100μ Number of particles/100ml 1,220100μ＜ Number of particles/100ml 60

NAS Cl *1 Cl 11

Count-basedcontamination

Poor

GoodNAS Class 1 Class 11

mg/100ml 0.35 NAS Class*1 Class 104

*1 NAS class：AUS NASA standard, which is an evaluation criteria concerning contamination.

Weight-based contamination


While the count-based contamination values measured were l S d d ( S) Cl 11 d hNational Aerospace Standard (NAS) Class 11, indicating that

contamination is somewhat advanced, the weight-based contamination value was NAS Class 104, indicating that the degree of contamination is satisfactory.

Therefore we determined the

Large wear particles ％/mlS ll i l l 0 15

Lublication diagnostic item Oil diagnosed3.15

・Wear of lubricant oil Therefore, we determined the conditions to be satisfactory.

Small wear particles ％/mlTotal wear ％/ml

Level of wear ％/mlSeverity of wear －

Ion Solid Total

0.15 3.3

3 9.9

Quantitativeferrography

GoodIon Solid Total

Iron Weight ppm 0 0.1 0.1Lead Weight ppm 0 0.0 0.0Copper Weight ppm 2 0.1 2.1Chromium Weight ppm 0 0.0 0.0

0 0 0 0

Unquestionable(for a small amount)

Antimony Weight ppm － 0.0 0.0Nickel Weight ppm 0 － 0.0Tin Weight ppm 0 0.0 0.0Phosphorus Weight ppm 1 0.0 1.0Zinc Weight ppm 3 0.0 3.0

Analysis ofmetal in oil

Poor

Calcium Weight ppm 0 0.1 0.1Barium Weight ppm 0 0.0 0.0Aluminum Weight ppm 0 0.1 0.1Silicon Weight ppm 2 － 2.0Sodium Weight ppm 0 0.2 0.2Magnesium Weight ppm 0 0.0 0.0Boron Weight ppm 0 － 0.0

The results of the metal ion concentration measurements show that no metal elements are detected including iron the mainthat no metal elements are detected, including iron, the main component of the rolling bearings.

・Wear of lubricant oil

＜Notes＞③Cut wear particles④Sever wear particles④Sever wear particles⑫Corrosion wear particles⑰Sand and other foreign objects

Fi i i i f d b i i f h th dFigure. microscopic images of wear debris in ferrography method

Many cut particles, which are generated by foreign particles becoming stuck, were observed.

It suggesting that wear may progress further.

・Wear of lubricant oil

Analysis of metal in oil：Analysis of metal in oil：→good.

Microscopic images of wear debrisin ferrography method：

→Many cut particles were observed.

Because of this concern, it was therefore decided to closely examine analytical

fdata of the subsequent year to check the trends.

(1)The results of lubrication diagnosisWhile contamination and wear are somewhat advanced,

urgent action is not necessaryurgent action is not necessary.

The results of the study show that we were successful

(2)Conditions of the actual machine

in verifying the validity of the diagnosis results.

Bearing( )

(confirmation of the bearing surface)

Disassemble

The results of disassembling the blower to confirm the conditions suggest that although the bearing surfaces have gg g gsome visible cut marks, the machine is still useable.

e

Current status Introduction of lubrication diagnosticse

＜Example estimates of maintenance cost reductions＞nt

enan

cco

st

diagnostics

tena

nce

cost

Mai

n c

30 30 ears

Mai

n c

５years ８yearsCurrent status

(overhaul every 5 years)If lubrication is introduced

(extends overhauls to every 8 years)

30 years 30 years

(overhaul every 5 years) (extends overhauls to every 8 years)Overhaul 5 million yen×6 Overhaul 5 million yen×3

Lubrication 0 1 million yen×27diagnostics 0.1 million yen×27

T o t a l 30 million yen T o t a l 17.7 million yen

It will be achieved by the introduction of lubrication diagnosis technology for equipment subject to which time-based maintenance every 5 year.

e

Current status Introduction of lubrication diagnosticse

＜Example estimates of maintenance cost reductions＞nt

enan

cco

st

diagnostics

tena

nce

cost

Mai

n c

30 30 ears

Mai

n c

５years ８yearsCurrent status

(overhaul every 5 years)If lubrication is introduced

(extends overhauls to every 8 years)

30 years 30 years

(overhaul every 5 years) (extends overhauls to every 8 years)Overhaul 5 million yen×6 Overhaul 5 million yen×3

Lubrication 0 1 million yen×27diagnostics 0.1 million yen×27

T o t a l 30 million yen T o t a l 17.7 million yen

If h l b d d 8 h l l f h 5 lIt will be achieved by the introduction of lubrication diagnosis technology for equipment subject to which time-based maintenance every 5 year.

If the cycle can be extended to an 8-year overhaul cycle from the current 5-year cycle by introducing lubrication diagnosis technology, it is possible to reduce costs by about 40% based on calculations that assume the planning period to be 30 years.

Based on the results of proof test, and estimations of the effect of introduction of the technology,the effect of introduction of the technology, →the issues that need to be considered when

introducing lubrication diagnosis are summarized.

・The flow chart for the review process

Classification of maintenancePreventive maintenance Breakdown maintenance

The flow chart for the review process

Deteriorated area

Preventive maintenance Breakdown maintenance

Many parts other than bearingsl l d

The main objective of overhauls is tol b i

Conditions for oil samplingare also replacedreplace bearings

Oil sampling requires large scale workOil sampling is easy

Cost effectivenessDiagnostics are lessexpensive than an overhaul

Diagnostics are moreexpensive than an overhaul

Lubricating agentsGreaseLubricant

Not applicableApplicability：lowApplicability：highWh i t d i l b i ti di i t h l it i i t t t idWhen introducing lubrication diagnosis technology, it is important to consider the issues described below in advance, and implement the technology for those equipment/machines that present high applicability.

The applicability of the lubrication diagnosisWe verified the following:

The applicability of the lubrication diagnosis technology.The points that need to be considered whenThe points that need to be considered when implementing the technology.The effects of the technology.gy

I ddi i i h h i l fIn addition to presenting the technical aspects of lubrication diagnosis, we also showed a flow chart for the selection of maintenance methods forfor the selection of maintenance methods for equipment/machines in wastewater treatment plants based on the findings obtained in the study.g y

In recent years in JapanThere has been an increasing amount existing facilitiesThere has been an increasing amount existing facilitiesand a program has been established to support the extension of the service life of wastewater facilities.

In the light of this situation, condition-based maintenance for equipment/machines in wastewater q p /treatment plants is increasingly becoming the subject of public attention, and as such there are great expectations regarding the effective utilization of this technology.

Study on equipment diagnostic technology utilizing Tribology

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