Development of a “ Condition Based Preventive Maintenance Action ” for “ Coal Handling Plant of Thermal Power Station.” In the onsite operation phase, failures are the main causes of worsened performance and degraded reliability. Consequently, an effective maintenance is the main approach to failure reduction. The basic theory of condition Based Preventive Maintenance is to Propose routine inspection to identify any degradation in the integrity of the systems during their service life and to provide an early warning in order that remedial action can be taken before failure occurs. Note :- Assessing the deteriorating condition is necessary to optimize inspection and maintenance schedules, of Coal Handling Plant to make decisions and to avoid unplanned outages.

A Basic Layout of Coal Handling Plant Unloading Station Transfer House Crushing & Screening Plant Transfer House Stockyard Bunker Transfer House The Main Objective :- 1.Establishing an alarm level based on variation of a physical parameter. 2. Prediction of impending failures of critical plant components in real time.

Condition Monitoring Implementations: - The steps in implementing CBM are :- 1.Divide Plant For Ease Of Maintenance Unloading Unit Feeding Unit Crushing & Screening Unit Stacking & Reclaiming Unit Bunkers 2. Detection Of Physical Parameters 3. In Service Examination By Using NDT 4. Analysis or Fault Diagnosis 5. Correction.

Condition Measurement techniques :- ParameterInstrumentationPositionDescription VibrationsVibration analyzers/data collectors, hand held overall meters Transducer placed in path of vibration transmission i.e. bearing housings Crushers & Pulley Bearings, Gearbox, Crusher Rotors VibrationsDetection meters, Shock pulse etc. As close to source of vibrations. Crushers & Pulley Bearings, Gearbox, Crusher Rotor Temperature (Contact) Thermocouples, RTDSurface or internally mounted Crushers & Pulley Bearings, Gearbox Temperature (Non-Contact) Infra red cameras, Pyrometers, Laser Thermometer SurfaceCrushers & Pulley Bearings, Gearbox Lubricants (Condition) Analytical lab or Portable lab kitAny lubrication sampleGearbox, Fluid Couplings Lubricants (Wear Debris) Spectrographic analysis, On-line systems Ferrography Wear Debris in lubricant used between wear surface via magnetic plugs Gearbox, Fluid Couplings Speed and current Relations Taco generators with current transformer Mounted on shaftsFluid Couplings CurrentLoad cell with Current Transformer Below the conveyors and in panels Electromagnetic vibrating feeders

In Service Examination By Using NDT :- ParameterInstrumentationPositionsDescription ThicknessUltrasonic thickness gage like “ Nova TG2” SurfaceTransfer Chute Liners, Grinding jib of crushers, Conveyor structures etc. ThicknessDigital RadiographySurfaceTransfer Chute Liners, Grinding jib of crushers, Conveyor structures etc. Flaw Ultrasonic Flaw Detector like “Quantam TE” SurfaceCrusher Rotors; Jack shaft, Grinding jibs; Suspension Bars, Arms, Sprocket Tiers etc. Flaw Acoustic Impact TechniqueSurfaceCrusher Rotors, Bearings Flaw Magnetic Flaw Detector like “MD20 Wire Rope Tester” SurfaceWire ropes of Aerial Ropeway

Limitations As the plant operating conditions change, it makes it hard to compare the readings and the data scatter will be more difficult to trend. Condition based Maintenance may not easily achieve the confidence of maintenance, due to culture, management buy-in, or regulatory resistance. There needs to be a good balance between training of CBM technicians, good equipment for monitoring, knowledge of the equipment being monitored, and plant historical performance. Be aware of false indications and manage them so as not to discredit the programme. Data from the programme should be widely accessible. Although data management is very important, keep it simple so that it takes little time to get it instituted. Team work is a requirement for the programme to be successful. The CBM programme is not an all inclusive programme and must be balanced with other maintenance processes.

References Technical paper on “Quality Assured Maintenance Management For Coal Handling Plant” by Makarand Joshi at web site Technical paper on “Development and Implementation of Reliability centered Maintenance using Vibration Analysis: Experiences at Rourkela Steel Plant” by S.Parida, N.R.Kotu, M.M.Prasad Research & Development Centre for Iron and Steel, Steel Authority of India Limited (SAIL), Rourkela Centre. Technical article received from web site of WM Engineering Ltd. Technical paper on “Maintenance Method For Critical Equipments Of Coal Handling Plant” by Makarand Joshi at web site Technical paper on “Application & Implementation of Residual Life Assessment Techniques For Coal Handling Plant” by Makarand Joshi presented in National Seminar of The Indian Society For Non Destructive Testing 5-7 December 2002 at Chennai.

Thankyou Q/A