Condition monitoring- dr subhash sharma Nov11

Monitor Your Machine’s Health: 

Monitor Your Machine’s Health Your Next Step 17 Nov 2010 Dr Subhash Sharma

Slide 2: 

NRG power Queensland Alumina Limited Boyan Smelter Loading Terminal CQUniversity

Breakdown: 

Breakdown

Condition Monitoring or Health monitoring: 

Condition Monitoring or Health monitoring

WHAT IS MACHINE ?? : 

WHAT IS MACHINE ?? A device consisting of fixed and moving parts that modifies mechanical energy and transmits it in a more useful form.

HEALTHY MACHINE: 

HEALTHY MACHINE A machine that performs the job that it is designed for within the expected tolerance limit.

Life cycle cost ownership: 

Life cycle cost ownership Power 87% 8% maintenance 5% purchase price

WHY MACHINE HEALTH GETS AFFECTED ??: 

WHY MACHINE HEALTH GETS AFFECTED ?? DUE TO USE (Aging, wear and tear) DUE TO ABUSE (over speed, over load, non conducive environment, improper maintenance)

Bath Tub Curve: 

Bath Tub Curve

Failure Data (MIT): 

Failure Data (MIT) Obsolete 15% Accident 15% Surface degraded 70%: Corrosion 20%: water in oil, process contaminants, degradedoil, coolant, condensation Wear 50%: Abrasive : caused by wear particles, dirt secondary wear, process contaminants -Adhesive Wear: inadequate lube, low viscosity, high temp, excess load, slow speed. - Fatigue Wear: misalignment, imbalance, improper fitment

WHAT IS MAINTENANCE ?? : 

WHAT IS MAINTENANCE ?? Any work done after the breakdown Any effort done prior to breakdown with an aim to prevent it

Aging of moving components: 

Aging of moving components Surfaces are rough Form cold welds Cold weld break when bodies move When welds break, debris shred cause wear

Mechanics of friction: 

Mechanics of friction What is friction force?? Force required to break these cold welds Force required in ploughing Elastic deformation Noise Heat Sound

How to reduce Friction force: 

How to reduce Friction force Choose metal that form weaker cold welds Choose metals with low shear strength Solution: Lubricate them means; Introduce third body with lower shear strength such as oil, grease, air, magnetic flux

HOW TO RETAIN LUBRICANT??: 

HOW TO RETAIN LUBRICANT??

How does a bearing work?: 

How does a bearing work? ( Wedge Principle V + V = ) V iscosity V elocity edge

What does oil do?: 

What does oil do? Reduces friction and wear Carry away heat Performs other duties such as: Disperses contaminants Detergent Inhibits rust VI Improver EP etc

What is Lubricant ??: 

What is Lubricant ?? Oil + additives (chemicals) Types of additives: Deposit control ( detergent, dispersant, antioxidants) Film forming: (friction modifiers) Anti-wear (antiwear, EP, ) Viscosity control (VI, pour point depressants) Surface: rust inhibitors, corrosion inhibitors Miscellaneous: Antifoaming Tackifiers Antimisting, selaswell, antimicrobial, corrosion inhibitors, bioderived and biodegradable

WHAT HAPPENS TO LURICANT ??: 

WHAT HAPPENS TO LURICANT ?? Viscous shearing Heat Chemical reactions

Healthy machines require:: 

Healthy machines require: Use of correct oil viscosity Working within max load limits Running under optimum speeds Correct fitment of components Conducive environment

What happens if oil film is thin??: 

What happens if oil film is thin??

WHAT HAPPENS WHEN OIL FILM BREAKS ?? : 

WHAT HAPPENS WHEN OIL FILM BREAKS ??

Sick Machine: 

Sick Machine Clearances more than required Oil does not retain in the moving joints Metal to metal contact, more friction & Wear

SYMPTOMS OF A SICK MACHINE: 

SYMPTOMS OF A SICK MACHINE Fever, shiver, bones break, parts fragile. Temperature rise, noise, excessive vibration, oil dirty, Cracks, corrosion etc. WARNINGS Visual look , Pain, Fever, Blood test, ECG, Non evasive symptoms: MRI, X-Ray, Ultrasound etc.

Methods of Health Monitoring: 

Methods of Health Monitoring Visual inspection Oil analysis Vibration analysis Non-destructive testing

Comparison of oil and vibration nalysis: 

Comparison of oil and vibration nalysis Vibration Analysis can best detect Oil Analysis can best detect • Imbalance • Oil contamination • Bent shaft • Wear debris in the oil • Gear or coupling misalignment • Oil deterioration • Bearing faults • Wrong lubricant • Worn or damaged gear teeth • Faulty filter or breather

Proactive Maintenance : 

Proactive Maintenance Maintenance Strategy Machine Maintenance Human Maintenance Proactive Maintenance Monitoring and correction of failing root causes, e.g., contamination Cholesterol and blood pressure monitoring with diet control Predictive Maintenance Monitoring of vibration, heat, alignment, wear dibris Detection of heart disease using ECG, Eco-graph/angiogram Preventive Maintenance Periodic component replacement Exercise, By-pass or transplant surgery, change denture. filling Breakdown Maintenance Large maintenance budget Heart attack or stroke 30

Visual inspection: 

Visual inspection Test Type On-site Lab OXIDATION ODOR X BLOTTER SPOT VISCOSITY x INSOLUBLES x INFRARED x ADDITIVE LOSS BLOTTER x INSOLUBLES x TBN x FUEL CONTAMINANT APPEARANCE, ODOR BLOTTER SOLID WEAR PARTICLE APPEARANCE WATER APPEARANCE, CRACKLE

OIL ANALYSIS: 

OIL ANALYSIS Monitoring of Deterioration of Oil Lubricating Properties Change in physical and chemical properties Contamination of oil

Lubricant analysis: 

Lubricant analysis Like a blood test Physical property: (viscosity flash and pour point) Chemical properties: (TAN, TBN etc.) Contaminates: (Like Haematology) Solid: Particle count, particle geometry particle type. solid, liquid and gas: change in physical properties

Viscosity: 

Viscosity Enemies of oil causing oxidation Temperature Oxygen Metal (copper)

Elements presence in different oils: 

Elements presence in different oils Oil Type Calcium Magnesium Molylodenum Phosphorus Zinc Petrol engine High Some Possible Some Some Locomotive Diesel High nil - - nil Hydraulic oil Type A nil nil - High nil Hydraulic oil Type B nil nil - Some High Gear oil nil nil - High (or Boron) nil Moly Gear oil nil nil Some High nil

HEALTH MONITORING TECHNIQUES & Human health : 

HEALTH MONITORING TECHNIQUES & Human health Oil Analysis (Blood test) Vibration analysis (ECG) NDT (Non-invasive tests: MRI, X-Ray, Die penetrant, magnetic Particle Inspection, UT, Eddy Current))

Degradation: 

Degradation Oxidation Nitration Additive depletion Permanent viscosity drop Wear particles

CONTAMINANTS: 

CONTAMINANTS From manufacturing burs, Wear debris Paint flakes insects Dist dirt Rust pieces Soot from combustion Water from vapours, fuel/chemicals leaks

Contamination: 

Contamination Solid : dust, wear particles, inbuilt burrs, wear particles Liquid: water, fuel, coolants, gases liquids from other compartments, condensation Leaks from cooling system Solvents, fuel dilution Ammonia from refrigerant

Particle Analysis: 

Particle Analysis Particle count Wear debris analysis Elemental Analysis

Cleanliness ISO code4406-99: 

Cleanliness ISO code4406-99 ISO Code Minimum particles Maximum particles 1 0 0.2 2 0.02 0.04 3 0.04 0.08 4 0.08 0.15 5 0.15 0.3 6 0.3 0.6 7 0.6 1.3 8 1.3 2.5 9 2.5 5 10 5 10 11 10 20 12 20 40 13 40 80 14 80 160 15 160 320 16 320 640 17 640 1300 18 1300 2500 19 2500 5000 20 5000 10,000 21 10,000 20,000 22 20,000 40,000 23 40,000 80,000 24 80,000 160,000 25 160,000 320,000 26 320,000 640,000 27 640,000 1,300,000 28 1,300,000 2,000,000 29 2, 500, 000 5,000,000 30 5, 000, 000 10,000,000

ISO 4406:99: 

ISO 4406:99 ISO Code 19/16/13 Particle size Minimum no Maximum no >4 micron 2500 5000 >6 microns 320 640 >14 microns 40 80

Elemental analysis : 

Elemental analysis AA Spectrometer ICP Spectrometer

Elements presence in different oils: 

Elements presence in different oils Oil Type Calcium Magnesium Molylodenum Phosphorus Zinc Petrol engine High Some Possible Some Some Locomotive Diesel High nil - - nil Hydraulic oil Type A nil nil - High nil Hydraulic oil Type B nil nil - Some High Gear oil nil nil - High (or Boron) nil Moly Gear oil nil nil Some High nil

Filter gram and ferogram: 

(a) Lead/tin particle on ferrogram Filter gram and ferogram

Particle between the clearance : 

Particle between the clearance

Tests : 

Tests Sensory on site Laboratory microscopic Elemental analysis Particle count Wear debris analysis

Sensory tests: 

Sensory tests View: dark, lacquer, sticky oxidation, grey means emulsified Smell: pungent, like kerosene /diesel , ammonia (refrigerant) crackle test for water Let oil settle sediments will settle down like wear particles sludge etc. Touch: solid contaminants like dust or metal particles Magnetic plug for wear particle sources DO NOT TASTE

Laboratory Tests and Limits: 

Laboratory Tests and Limits Viscosity — Industrial limit warning± 10% engine ±20% Action at 15% and 30% respectively Flash point — Dielectric — Infra red (IR) absorption — Titration — (TAN) or (TBN). Limit 2 to 2.25 new oil level Pentane insoluble's —solid contaminants Fuel dilution Limit ±3% warning 5% action Oxidation: Limit industrial warning 6 action 10, Engine oil warning 14 action 20. Cu + Water can increase oxidation by approx 1000 times Nitration: Warning 15020 action 20-30 Cooling system leak : warning: 0.1% action .1 to .2 TBN due to High sulphur level Limit 50% of new value Soots : warning 1 action 2 ICP: 1 -10 micron particles 16 types of elements can be detected.

Benefits of oil analysis : 

Benefits of oil analysis Preventing equipment failure • Predicting equipment failure • Maximising equipment life • Reduced oil usage • reduced maintenance costs • increased equipment availability • extended oil change intervals • longer equipment life • improved confidence in the reliability of equipment.

Crack detection: 

Crack detection Many failures occur due to crack growth from point of stress concentration or material defect. Fatigue failures occur without warning, is not true because crack develops first though it is too small to detect some times. There are several crack detection techniques:

Crack detection techniques: 

Crack detection techniques Dye penetrant testing Dye penetration into the cracks allow detection as small as 0.025 micron. Clean Apply liquid dye penetrant Wipe excess liquid penetrant Apply develoer cracks appear on the surface. Fluorescent dyes drawn are seen better in the ultra voilet light.

Dye penetration: 

Dye penetration

Magnetic particle testing: 

Magnetic particle testing Suitable for detecting cracks in ferrous materials Clean and dry specimen Coat it with white background Apply magnetic field Spray magnetic ink Examine the pattern of flux lines

Magnetic Particle Inspection: 

Magnetic Particle Inspection The part is magnetized. Finely milled iron particles coated with a dye pigment are then applied to the specimen. These particles are attracted to magnetic flux leakage fields and will cluster to form an indication directly over the discontinuity. This indication can be visually detected under proper lighting conditions.

THANK YOU : 

THANK YOU ? ?

Eddy Current testing: 

Eddy Current testing Eddy Current method is based on the principle of measuring changes in the impedance of a electromagnetic coil as it is scanned over a surface of conductive material. The test is performed by a electromagnetic coil that is placed over a conductive material. The coil produces a magnetic field that is induced in the material. To counter the coil's primary magnetic field, eddy currents are produced in the material. Eddy currents produce a secondary magnetic field to oppose the coil's primary magnetic field. When the coil is scanned over a defect, the secondary magnetic field is distorted thereby changing the loading on coil. Changes in coil loading directly affect the coil impedance. These changes in coil impedance are related to the defect. Flaw detection with eddy currents is limited to the penetration depth. Penetration depth is inversely proportional to the square root of conductivity, frequency and permeability. For most applications, the penetration depth in non-ferromagnetic material is limited to approximately 5 mm (0.20 inches). In case of ferromagnetic materials, such as carbon steel, the penetration depth is extremely shallow because of high permeability. Inspection of ferromagnetic material is therefore limited to surface flaws only.

Eddy current testing: 

Eddy current testing

Eddy Current Testing: 

Conductive material Coil Coil's magnetic field Eddy currents Eddy current's magnetic field Eddy Current Testing

Eddy Current Testing: 

Eddy Current Testing Eddy current testing is particularly well suited for detecting surface cracks but can also be used to make electrical conductivity and coating thickness measurements. Here a small surface probe is scanned over the part surface in an attempt to detect a crack.

Radiography: 

Radiography The radiation used in radiography testing is a higher energy (shorter wavelength) version of the electromagnetic waves that we see as visible light. The radiation can come from an X-ray generator or a radioactive source. High Electrical Potential Electrons - + X-ray Generator or Radioactive Source Creates Radiation Exposure Recording Device Radiation Penetrate the Sample

Ultrasonic Inspection (Pulse-Echo) : 

High frequency sound waves are introduced into a material and they are reflected back from surfaces or flaws. Reflected sound energy is displayed versus time, and inspector can visualize a cross section of the specimen showing the depth of features that reflect sound. f plate crack 0 2 4 6 8 10 initial pulse crack echo back surface echo Oscilloscope, or flaw detector screen Ultrasonic Inspection (Pulse-Echo)

Ultrasonic Imaging: 

Ultrasonic Imaging Gray scale image produced using the sound reflected from the front surface of the coin Gray scale image produced using the sound reflected from the back surface of the coin (inspected from “heads” side) High resolution images can be produced by plotting signal strength or time-of-flight using a computer-controlled scanning system.

Corrosion Monitoring: 

Corrosion Monitoring Deterioration of a material because of chemical reaction with the environment The report of the 1972 Committee on Corrosion and Protection (The Hoar Committee) estimated that the annual cost of corrosion in the UK was approximately 3% of the Gross National Product, and that savings of almost one third of this were possible by better or wider use of existing techniques such as corrosion monitoring.