51002763 Vibration Monitoring
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Transcript of 51002763 Vibration Monitoring
Vibration MonitoringVibration Monitoring
Maintenance MethodsMaintenance Methods
1. Breakdown Maintenance : The machine is allowed to run until complete failure forces shutdown.
Disadvantages: Untimely/ unplanned failure. Often require extensive repair. More downtime of machine. Loss of production is higher.
Maintenance MethodsMaintenance Methods2. Schedule Maintenance :
The machine is shutdown after specified period of operation & partially or completely dismantled for thorough inspection/ maintenance. This approach is having advantage of reducing the frequencies of shutdown.
Disadvantages:- Full life of machine parts can not be extracted.- Machine may be degraded by frequent disassembly.
Maintenance MethodsMaintenance Methods3. Predictive Maintenance or Condition
Based Maintenance :
Maintenance carried out in response to significant deterioration in a machine as indicated by a change in monitored parameters of the machine condition.
Maintenance MethodsMaintenance MethodsAdvantages of Condition Based Maintenance :
- Scheduled shutdown with minimum effect on production.
- Well prepared work schedule results in to reliable repair.
- Minimises unscheduled breakdowns.- Prolong machinery life.- Increase machinery / human safety
Down Time Comparison Down Time Comparison
Baseline Data Baseline data representative of an
equipment in a new and/or properly operating condition.
The baseline data is the foundation of the predictive trending analysis required to forecast equipment condition.
The baseline readings and periodic monitoring data should be taken under the same conditions (or as close as can be achieved).
Condition MonitoringCondition Monitoring
Flow Chart of Condition MonitoringFlow Chart of Condition Monitoring
1. Vibration Monitoring2. Shock Pulse Monitoring3. Temperature Monitoring4. Lubricant Wear Particle Monitoring5. Ultrasonic InspectionNon- Destructive testing: Radiography Ultrasonic testing Magnetic Particle. Dye Penetrant Hydrostatic Testing. Eddy Current Testing
Monitoring TechniquesMonitoring Techniques
1. Vibration Monitoring1. Vibration MonitoringDefination of VibrationCharacteristics of VibrationMeasurement of Vibration
– Transducers– Instrument
Analysis of Vibration
Vibration MonitoringVibration Monitoring What is vibration
– Motion of machine or machine part back & forth from its position of rest
Detect 60 to 70% of the faults
All machines vibrate Mechanical defect
generate vibration in unique way
Vibration CharacteristicsVibration CharacteristicsThree Characteristics of Vibration are
1. Amplitude
2. Frequency
3. Phase
Vibration CharacteristicsVibration Characteristics1. Amplitude
Primary indicator of machine’s condition
DisplacementMeasurement of distance an object travels from position of rest.
VelocityMeasurement of observed displacement over some specific period of time
AccelerationMeasurement of observed velocity over some specific period of time
Vibration Characteristics - AmplitudeVibration Characteristics - Amplitude
Vibration CharacteristicsVibration Characteristics2. Frequency
Measure of the number of complete cycles that occur in a specified period of time.
f=1/T Helps in identifying the probable
cause of vibration
3. Phase Position of vibration part at given
instance with reference to a fixed point.
Vibration Measurement & Vibration Measurement & AnalysisAnalysis Signal Transudation (Transducers or
Pickups) Signal Conversion Signal Analysis Signal Display Instrument
Vibration TransducersVibration Transducers
Non contact displacement transducer (eddy current probe)
Velocity pickup Accelerometer pickup
Vibration TransducersVibration Transducers
Velocity pickup
Vibration TransducersVibration Transducers
Accelerometer pickup
Vibration TransducersVibration Transducers
Non contact displacement transducer
Vibration InstrumentVibration Instrument
Vibration Instruments – FFT AnalysersVibration Instruments – FFT Analysers
Vibration SoftwareVibration Software
Machine SketchMachine Sketch
Vibration AnalysisVibration Analysis Tri Axial Measurement
Horizontal Vertical Axial
Vibration Spectrum Display of Vibration Amplitude vs. Frequency
Vibration SpectrumVibration Spectrum
Guide Line - OEMGuide Line - OEM
ISO 10816 : Mechanical vibration - evaluation of machine vibration with measurements of non rotating parts The measurement returns the RMS value of vibration velocity in mm/s or inch/s.
part 1: general of guidelines part 2: Land-based steam turbines and generators in
excess of 50 MW with normal operating speeds of 1500 r/min, 1800 r/min, 3000 r/min and 3600 r/min
part 3: Industrial machines with nominally power above 15 KW of and nominally speeds between 120 r/min and 15000 r/min when measured in situ
part 4: Gas turbine sets driven excluding aircraft of derivative
part 5: Machine sets in hydraulic power generating and pumping plants
Part 6: Reciprocating machines with power ratings above 100 kW
Vibration Identification ChartVibration Identification Chart
Vibration Case StudyVibration Case Study
Limits of Vibration
Rough Very rough
Disp. µm,H 100-200 >200
Vel.(pk) mm/s 8.0-12.0 >16.0
Date 02-Dec-98 02-Dec-98After
BalancingPos Dir Units Ampl. Ampl.
1 A µm,H 134.0 11.0A mm/s 11.0 1.6H µm,H 100.0 16.0H mm/s 9.0 2.3V µm,H 48.0 6.0V mm/s 5.0 1.2
2 A µm,H 132.0 11.0A mm/s 11.0 1.6H µm,H 178.0 20.0H mm/s 15.0 2.7V µm,H 135.0 9.0V mm/s 12.0 1.9
3 A µm,H 80.0 18.0A mm/s 7.2 2.3H µm,H 195.0 30.0H mm/s 18.0 4.0V µm,H 52.0 11.0V mm/s 6.3 1.7
Vibration ReportMachine : F Station C.T.I.D.Fan 3D
Motor
Sketch321
Gear Box & Fan
Vibration Case StudyVibration Case Study
Limits of Vibration as per BHEL
Rough Very rough
Disp. µm,H 120-240 >240
Vel.(pk) mm/s 6.4-12.7 >12.7
Date 14-Jul-01 17-Aug-01 18-Aug-01Ampere 69 69 71
Vane 65 65 75Pos Dir Units Ampl. Ampl. Ampl.
1 A µm,H 8.6 19.1 12.0A mm/s 1.1 3.4 1.2H µm,H 13.9 38.5 13.1H mm/s 1.8 6.6 1.4V µm,H 12.9 37.7 12.5V mm/s 1.6 6.0 1.5
2 A µm,H 18.5 33.0 21.9A mm/s 1.2 5.7 1.4H µm,H 28.5 33.7 30.4H mm/s 2.0 5.6 2.2V µm,H 15.6 27.4 22.6V mm/s 1.8 2.4 1.4
3 A µm,H 13.9 213.7 73.4A mm/s 2.7 24.0 5.2H µm,H 11.3 124.6 38.8H mm/s 1.0 10.2 2.6V µm,H 7.6 60.4 23.0V mm/s 1.0 4.7 1.7
4 A µm,H 59.6 88.9 90.2A mm/s 5.1 11.0 9.8H µm,H 15.4 17.1 17.0H mm/s 1.7 3.7 1.7V µm,H 7.4 18.3 15.3V mm/s 1.0 2.6 1.6
Vibration ReportMachine : C1 Station I.D.Fan B
Motor
Sketch
Fan
321 4
Vibration Spectrum (before & after attending)Vibration Spectrum (before & after attending)
D stn PA Fan AD stn PA Fan A
Vibration higher on foundation bolt than bearings
Recommended to check foundation bolt looseness
Limits of VibrationRough Very rough
Disp. µm,H 80-160 >160Vel. mm/s 6.4-12.7 >12.7
10/05/05 07/07/05Pos. Brg. Dir Units Ampl. Ampl.
3 Fan DE H µm,H 14.5 16.9H mm/s 1.3 1.7
V µm,H 42.2 62.8V mm/s 3.0 4.4A µm,H 66.4 93.0A mm/s 4.0 6.1
4 Fan NDE H µm,H 43.3 48.4H mm/s 2.6 3.4V µm,H 19.8 29.2V mm/s 1.7 2.2
A µm,H 62.4 85.8A mm/s 4.0 5.7
Remarks
CMC
Loosness was suspected. Vib.at Base of fan stool on DE side (Estn. Side) were
up to 108 micron.
TORRENT POWER AEC LIMITEDSabarmati Thermal Power Station
1 2 3 4
Motor Fan
D stn PA Fan AD stn PA Fan A
Tightening of the bolts carried out immediately by BMS
Potential loss of equipment breakdown & Generation loss of 50 MW for 8 hrs (0.4 MU , Rs 7.2 lacs) could be avoided
Limits of VibrationRough Very rough
Disp. µm,H 80-160 >160Vel. mm/s 6.4-12.7 >12.7
10/05/05 07/07/05 07/07/05Pos. Brg. Dir Units Ampl. Ampl. Ampl.
3 Fan DE H µm,H 14.5 16.9 16.8H mm/s 1.3 1.7 1.4
V µm,H 42.2 62.8 17.6V mm/s 3.0 4.4 1.3A µm,H 66.4 93.0 34.2A mm/s 4.0 6.1 2.3
4 Fan NDE H µm,H 43.3 48.4 26.0H mm/s 2.6 3.4 1.8V µm,H 19.8 29.2 20.6V mm/s 1.7 2.2 1.5
A µm,H 62.4 85.8 31.7A mm/s 4.0 5.7 2.1
Remarks vib. at base of fan stool
upto 6 microns
CMC
Loosness was suspected. Vib.at Base of fan stool on DE side (Estn. Side) were
up to 108 microns
TORRENT POWER AEC LIMITEDSabarmati Thermal Power Station
Thank youThank you
Shock Pulse MonitoringShock Pulse Monitoring
Antifriction Bearing’s life influenced byo Installationo Lubricationo Maintenance
The technique is based on monitoring the mechanical impacts caused by bearing damage & operating condition problems is known as Shock Pulse Method (SPM)
Shock Pulse Measuring InstrumentShock Pulse Measuring Instrument
Modes of MeasurementModes of Measurement
Data Input prior to measurement SPM Type no. (1-8) Norm no., (10-58)
o Last three digits of Brg.’s ISO number
o RPM Manual Mode
Input data for bearing to be assessed
Note down the readings
Modes of MeasurementModes of Measurement
Data Logging Mode For setup of
measuring points Software is used
Measured readings are Stored in Instrument
Stored data reported back to software
Measurement of Shock Pulse Measurement of Shock Pulse ReadingsReadings
Evaluation of Shock Pulse ReadingsEvaluation of Shock Pulse Readings
LR & HR CODE LUB No. COND No.
SPM Measurement DataSPM Measurement Data
Machine : D Stn. CEP 1C
Measuring Point Date Time LatestReadingsD-115-02 LR: 60C.E.Pump C 28-10-1997, 08:25 HR: 52Motor DE brg. Lub. : -Brg. No.: NU 322 Code : DSpeed :1480 Cond : 38
44
Thank youThank you
Principle of Shock Pulse MethodPrinciple of Shock Pulse Method
Monitoring of Shock PulsesMonitoring of Shock Pulses
Initial Shock Pulse is affected by Bearing Geometry Rolling Velocity
LR and HRLR and HR
CODECODE
Lubrication No.Lubrication No.
COND NumberCOND Number
< 30 Minor Damage
30 - 40 Increasing Damage
> 40 Severe Damage
Relationship of Output DataRelationship of Output Data
Brg. No. 6230, RPM 990
LR :41, HR 37,
Code A, Lub No.2
Brg. No. NU230, RPM 990
LR :52, HR 48,
Code A, Lub No.5
52
53