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Real Case Study
MaintenancePlanning& RCFAfora centrifugalfan
ina de-dustingsystem
Eng.Mohammed Hamed Ahmed
Maintenance Pla...
2
Maintenance Planning for Industrial Fan
1-System Overview.
Fan for de-dusting system in a Granulated Super Single Phosph...
3
Equip code Equip
description
Downtime hrs
(average)
Downtime
frequesncy
Percentage
304K1 Centrifugal Fan 54.9 18 27%
304...
4
Chart Illustrate The Major Down Time Analysis By Equipment Break down
5System Illustration Diagram
(1) Dryer Drum
(3) Fan
(4) Bag Filter
(2)
Cyclone
Dust settling
Suction
6
Outlet
pipe
Cyclone
Bag Filter
Expansion
Joint
Fan
Cyclone
7
Motor
Inspection
Window
V-Belts
8
Shaft
Bearing 4
non-drive
end
Foundation
Bearing 3-
drive end
Pulleys
8 Qty of
V-belts
9
Clean Fan
Blade!
10
General components of centrifugal fan
Term Description
MDE Motor Drive End
MNDE Motor Non Drive End
FDE Fan Drive End
F...
11
4-System Description
Technical Data:
Fan Type= Centrifugal fan
Flow rate= 78,000m3/h
Motor Power= 200KW
Horse power= 26...
12
Spare Parts Data:
FDE Bearing: 22222EK +H322
FNDE Bearing: 22222EK +H322
MDE Bearing: 6322
MNDE Bearing: 6322
Bearing H...
13
3-System Criticality
14
Total monthly downtime caused by plant equipments=198hrs /
year (RTF Policy)
Total monthly CM downtime caused by fan ...
15
Month Total Breakdown
Hours/Month
No of Failures
April 2009 64 20
May 2009 43.6 13
June 2009 47.5 15
July 2009 49.6 18
...
16
Downtime reason Hours Percentage No of Failures
V-belts damage 20.4 37.15% 6
High noise 12.25 22.3% 5
Motor damage 6.25...
17
Spare Parts Replacement
Frequency per
month
Monthly Cost
Bearing 4 300$x(4x2)=2400$
B.Housing 4 350$x(4x2)=2800$
B.Slee...
18
General components of centrifugal fan
Term Description
MDE Motor Drive End
MNDE Motor Non Drive End
FDE Fan Drive End
F...
19
Fan Vibration Analysis
Standard acc to ISO 10816
20
Machines less than 20HP.
Machines from 20-100HP without special foundations.
Machines with rigid foundations and over 1...
21
22
POINT DESCRIPTION overall values LIMITS
1 H E-Motor non drive end horizontal 30.468 mm/s x x x
1 V E-Motor non drive en...
23
Vibration Measurements:
24
25
26
M/C type and
spindle
speed
Normal vibration level Damage
factor due
to
unbalance
(vib level
increase in
1st Band )
Dama...
27
28
Temp analysis
Camera Model: Flir i50
Emissivity: 0.96
Reflected Temp: 20C
Object distance: 1.0m
Bearing Temp: 108.4
29
Camera Model: Flir i50
Emissivity: 0.96
Reflected Temp: 20C
Object distance: 1.0m
Bearing Temp:110.9
30
Camera Model: Flir i50
Emissivity: 0.96
Reflected Temp: 20C
Object distance: 1.0m
Bearing Temp:108.4
31
32
33
Target(smartobjectives):
•Minimize Fan K1 Breakdowns.
•Increase Availability & Reliability.
•Reduce Maintenance Cost.
•...
34
Problem Problem Cause Remedy
V-belts damage -Bad v-belts type
-Belt tensioning isn’t good.
-Bad pulleys
-Pulleys misali...
35
Making a combinationbetweenthepreventive & predictive maintenance
programs to enhance the fanavailability & reliability.
36
Main Items Job plan Frequency
(1) FAN Visual inspection Daily
Bearing greasing Daily
Vibration analysis Daily
Temp anal...
37
DailyMaintenance
•Visual Inspection (grease level, oil level, belt condition, bolts
tightening, expansion joints, found...
38
•Temp Analysis (use infrared thermometer for measuring
bearing temperature).
Infrared Thermometer features:
•50:1 dista...
39
Weekly Maintenance
Performing pulleys laser alignment using a specific instrument
40
41
MonthlyMaintenance
Certain spare parts used to avoid any breakdown caused by
fake parts.
•Replace bearing with reliable...
42
6 Monthly Maintenance
•Replace bearing housing with certain type.
43
•Perform shaft laser alignment if necessary using a specific
professional tool.
Shaft Hog Laser Alignment system
44
Annual Maintenance
•Replace Motor Bearing
45
Balancing performance
We performed this on site when ever needed according to the
vibration measurements.
By performing...
46
47
Cost of resources required to implement the above
maintenance plan.
•One vibration pen= 1500$.
•One infrared thermomete...
48
We used an outsourcing partner for balancing,
alignment, and other heavy services that required
expensive instruments:
...
49
We foundafterintensivedailyvibrationmeasurementthatthisfanwill
requirebalancingweeklytoavoidbearingfailureandothercompo...
50
Break-down type Hours Percentage Freq
Bearing damage 2 19.5% 1
High noise 2 19.5% 1
High vibration 0.75 7.3% 1
Total CM...
51
Spare Part Type Replacement
Frequency per
month
Was Now
Monthly Cost of Replacement
Bearing 4 1 300$x2=600$
B.Housing 4...
52
3-Preventive Maintenance Improvenment Program for
Fan K1 (New Modified Program).
PM Levels PM Description Duration No o...
53
54
Level I Level II Level III Level IV Level V Level VI
Fan operate with high
vibration level
Bearing fails Bearing seized...
55
Failure mode Failure cause Source of
failure
Root cause Failure
chracteristics
Failure Effect
Fan operate with
high vib...
56
Centrifugal Fan
Dust
Temp 110º C
System control
Environment
Flowrate
78,000m3/h
Functional Block Diagram for the Fan
Te...
57
Recommendations for this fan acc to PDM
1-Due to high scale rate accumulation on the fan blade,
it’s very recommended t...
58
2-Never perform balancing on a scaled blade
59
Vibration
Limit
Equip
Condition
Root Cause Consequence Task
1-3 Good ----------------- ----------------- --------------...
60
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Reliability Centered Maintenance Case Study

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Reliability Centered Maintenance Case Study

  1. 1. Real Case Study MaintenancePlanning& RCFAfora centrifugalfan ina de-dustingsystem Eng.Mohammed Hamed Ahmed Maintenance Planner SID#700080583 1 Undersupervision: Prof.Dr.Attia Gomma Industrial Engineering Professor & Consultant American University in Cairo
  2. 2. 2 Maintenance Planning for Industrial Fan 1-System Overview. Fan for de-dusting system in a Granulated Super Single Phosphate Plant. Plant capacity: 500t/day. Daily production value: 100,000$. Feeding material: super fine powder. De-Dusting Fan: Present 27% of the monthly breakdowns. Working hrs/day: 22hrs/day.
  3. 3. 3 Equip code Equip description Downtime hrs (average) Downtime frequesncy Percentage 304K1 Centrifugal Fan 54.9 18 27% 304T1 Bucket Elevator 38.5 22 19% 304Z2 Granulator Drum 35 22 17% 304WG1 Feed Belt Conveyor 27 15 13.5 304N3 Recycle Belt Conveyor 13.75 26 6.8% 304F1 Bag Filter 12.95 11 6.4% 304U1 Burner 6.5 7 3.2% 304N7 Belt Conveyor 3.75 3 1.8% 304N4 Belt Conveyor 3.5 3 1.7% 304T2 Bucket Elevator 2.25 2 1.2% 2-Problem Definition (Monthly CM Downtime report for plant equipments) Remark: the above table is only for equipments which has downtime more than 2 hrs.
  4. 4. 4 Chart Illustrate The Major Down Time Analysis By Equipment Break down
  5. 5. 5System Illustration Diagram (1) Dryer Drum (3) Fan (4) Bag Filter (2) Cyclone Dust settling Suction
  6. 6. 6 Outlet pipe Cyclone Bag Filter Expansion Joint Fan Cyclone
  7. 7. 7 Motor Inspection Window V-Belts
  8. 8. 8 Shaft Bearing 4 non-drive end Foundation Bearing 3- drive end Pulleys 8 Qty of V-belts
  9. 9. 9 Clean Fan Blade!
  10. 10. 10 General components of centrifugal fan Term Description MDE Motor Drive End MNDE Motor Non Drive End FDE Fan Drive End FNDE Fan Non Drive End
  11. 11. 11 4-System Description Technical Data: Fan Type= Centrifugal fan Flow rate= 78,000m3/h Motor Power= 200KW Horse power= 268HP Motor Speed= 1500RPM Fan Speed= 1500RPM Transmission type: V-belts
  12. 12. 12 Spare Parts Data: FDE Bearing: 22222EK +H322 FNDE Bearing: 22222EK +H322 MDE Bearing: 6322 MNDE Bearing: 6322 Bearing Housing: SNH 522-619 Pulleys type: SPC335 V-belts type: SPC5300
  13. 13. 13 3-System Criticality
  14. 14. 14 Total monthly downtime caused by plant equipments=198hrs / year (RTF Policy) Total monthly CM downtime caused by fan K1=54.9hrs. Total production loss caused by fan K1=54.9 x 22.7t/h =1246 ton/ month x 200$ =Quarter Million Dollar Monthly Loss!
  15. 15. 15 Month Total Breakdown Hours/Month No of Failures April 2009 64 20 May 2009 43.6 13 June 2009 47.5 15 July 2009 49.6 18 August 2009 54.7 17 Sept 2009 70 25 Average 54.9 18
  16. 16. 16 Downtime reason Hours Percentage No of Failures V-belts damage 20.4 37.15% 6 High noise 12.25 22.3% 5 Motor damage 6.25 11.4% 1 High vibration 4.5 8.2% 1 Unblanace 3.75 6.% 1 Electric overload 2.75 5% 1 Bearing damage 2.5 4.5% 4 Crack in foundation 2.5 4.5% 1 Preventive Maintenance 0 0 0 Total Downtime 54.9 100% 20
  17. 17. 17 Spare Parts Replacement Frequency per month Monthly Cost Bearing 4 300$x(4x2)=2400$ B.Housing 4 350$x(4x2)=2800$ B.Sleeves 4 40$x(4x2)=320$ V-belts 6 6x(8setx50$)=2400$ Total cost=7920$ Spare Parts Consumption Rate: Current Maintenance Policy=Run To Failure
  18. 18. 18 General components of centrifugal fan Term Description MDE Motor Drive End MNDE Motor Non Drive End FDE Fan Drive End FNDE Fan Non Drive End
  19. 19. 19 Fan Vibration Analysis Standard acc to ISO 10816
  20. 20. 20 Machines less than 20HP. Machines from 20-100HP without special foundations. Machines with rigid foundations and over 100HP. Machines with soft foundation and over 100HP.
  21. 21. 21
  22. 22. 22 POINT DESCRIPTION overall values LIMITS 1 H E-Motor non drive end horizontal 30.468 mm/s x x x 1 V E-Motor non drive end vertical 13.611 mm/s x x x 1 A E-Motor non drive end axial - 2 H E-Motor drive end horizontal 24.302 mm/s x x x 2 V E-Motor drive end vertical 23.217 mm/s x x x 2 A E-Motor drive end axial 22.827 mm/s x x x 3 H fan fixed bearing coupling side horizontal 35.610 mm/s x x x 3 V fan fixed bearing coupling side vertical 31.521 mm/s x x x 3 A fan fixed bearing coupling side axial - 4 H Fan free bearing fan side horizontal 29.609 mm/s x x x 4 V Fan free bearing fan side vertical 26.941 mm/s x x x 4 A Fan free bearing fan side axial 24.733 mm/s x x x DANGEROUS x x x ALARM x x ACCEPTED x Vibration Measurements
  23. 23. 23 Vibration Measurements:
  24. 24. 24
  25. 25. 25
  26. 26. 26 M/C type and spindle speed Normal vibration level Damage factor due to unbalance (vib level increase in 1st Band ) Damage factor due to bearing damage (vib level increase in 2nd, 3rd, or 4th Band) 1st Band (10hz-1khz) 2nd Band (1khz- 3khz) 3rd Band (3khz- 5khz) 4th Band (5khz- 10khz) Overall (10hz- 10khz)
  27. 27. 27
  28. 28. 28 Temp analysis Camera Model: Flir i50 Emissivity: 0.96 Reflected Temp: 20C Object distance: 1.0m Bearing Temp: 108.4
  29. 29. 29 Camera Model: Flir i50 Emissivity: 0.96 Reflected Temp: 20C Object distance: 1.0m Bearing Temp:110.9
  30. 30. 30 Camera Model: Flir i50 Emissivity: 0.96 Reflected Temp: 20C Object distance: 1.0m Bearing Temp:108.4
  31. 31. 31
  32. 32. 32
  33. 33. 33 Target(smartobjectives): •Minimize Fan K1 Breakdowns. •Increase Availability & Reliability. •Reduce Maintenance Cost. •Reduce Mean Time Between Failures (MTBF). •Improve PM & Reduce CM Downtimes.
  34. 34. 34 Problem Problem Cause Remedy V-belts damage -Bad v-belts type -Belt tensioning isn’t good. -Bad pulleys -Pulleys misalignment Check belt tensioning & pulleys alignment. High noise -Unbalance issue -Bearing failure -Bearing housing failure -Crack in foundation Check for vibration & temp. Motor damage -High vibration -Electric overload Check for vibration & electric overload adjustable. High vibration -Unbalance issue -Crack in foundation Check for vibration Electric overload -Unbalance -Blockage in fan suction or discharge lines. Check for vibration Check for cleaning Bearing damage -Unbalance -Greasing problem -Shaft misalignment Check for vibration Crack in foundation -High vibration level Check for vibration Fan Troubleshooting: Vibration is the most critical measurement for all industrial fans.
  35. 35. 35 Making a combinationbetweenthepreventive & predictive maintenance programs to enhance the fanavailability & reliability.
  36. 36. 36 Main Items Job plan Frequency (1) FAN Visual inspection Daily Bearing greasing Daily Vibration analysis Daily Temp analysis Daily Replace FDE & FNDE bearing Monthly Replace bearing housing 6 Monthly Pulleys laser alignment check/perform Weekly V-belts change Monthly Shaft laser alignment check/perform 6 Monthly Balance the blade When ever needed acc to vibration monitoring (2) Motor Vibration analysis Daily Replace MDE & MNDE bearing Annually Temp analysis Daily PM & PDM program for centrifugal fans:
  37. 37. 37 DailyMaintenance •Visual Inspection (grease level, oil level, belt condition, bolts tightening, expansion joints, foundation bolts, noise…etc). •Vibration Monitoring (use simple vibration pin for measuring vibration amplitude at the bearing points). Vibra Pen Specs: •Measurements velocity range: 7- 65mm/s, 0.04-3.6 in/s. •Frequency range: 10-1000 HZ. •Frequency band 3 (500-10000 HZ).
  38. 38. 38 •Temp Analysis (use infrared thermometer for measuring bearing temperature). Infrared Thermometer features: •50:1 distance to spot size ratio •Temp range: -60-1000º C, (-76-1832ºF). •Accuracy: +-1º C •Update freq=1.4Hz •Wave length response=8-14µm
  39. 39. 39 Weekly Maintenance Performing pulleys laser alignment using a specific instrument
  40. 40. 40
  41. 41. 41 MonthlyMaintenance Certain spare parts used to avoid any breakdown caused by fake parts. •Replace bearing with reliable bearing type. •Replace v-belts with reliable v-belts type.
  42. 42. 42 6 Monthly Maintenance •Replace bearing housing with certain type.
  43. 43. 43 •Perform shaft laser alignment if necessary using a specific professional tool. Shaft Hog Laser Alignment system
  44. 44. 44 Annual Maintenance •Replace Motor Bearing
  45. 45. 45 Balancing performance We performed this on site when ever needed according to the vibration measurements. By performing the balancing on site you reduce the balancing time by 90%! Even if you have a spare blade!
  46. 46. 46
  47. 47. 47 Cost of resources required to implement the above maintenance plan. •One vibration pen= 1500$. •One infrared thermometer= 500$. •One electrical technician to perform the daily analysis (labor from the company). •Two Mechanical technicians to perform the daily inspection & other routine maintenance (labor from the company). •Bonus for labors
  48. 48. 48 We used an outsourcing partner for balancing, alignment, and other heavy services that required expensive instruments: •Balancing on site cost= 250$ (perform weekly). •Laser pulley alignment cost= 50$ (perform weekly). •Laser shaft alignment=300$ (perform 6 monthly).
  49. 49. 49 We foundafterintensivedailyvibrationmeasurementthatthisfanwill requirebalancingweeklytoavoidbearingfailureandothercomponents damage.
  50. 50. 50 Break-down type Hours Percentage Freq Bearing damage 2 19.5% 1 High noise 2 19.5% 1 High vibration 0.75 7.3% 1 Total CM (unplanned) 4.75 46.3% Total PM (Planned) 5.5 53.7% 1- Improved of Equip Availability & Production (Monthly Downtimes report for fan K1) Total downtime=10.25 hrs /month (Reduced from 54.9 to 10.25). Loss in production=10.25hr/month * 22.7ton/hr=233ton/month =233ton*200$=46,600$/monthly Improvement in production (compared to previous status) =250,000$-46,600$=203,400$ monthly. Improvements & results (after 2 months from applying the maintenance program).
  51. 51. 51 Spare Part Type Replacement Frequency per month Was Now Monthly Cost of Replacement Bearing 4 1 300$x2=600$ B.Housing 4 1 350$x2=700$ B.Sleeves 4 1 40$x2=80$ V-belts 6 0 0 Total Spare parts cost=1380$ Total cost reduction=7920-1380=6540$ 2-Spare parts cost reduction:
  52. 52. 52 3-Preventive Maintenance Improvenment Program for Fan K1 (New Modified Program). PM Levels PM Description Duration No of workers Daily -Visual Inspection -Vibration Test -Temperature Test -Greasing & Oiling -Blade Cleaning 20 min 20 min 20 min 10 min 30min 1 worker Weekly Perform Pulley Laser Alignment & Belt Tensioning Perform Balancing on Site 1 hr 1 worker Monthly Replace Fan Bearing & Bearing Housing 4hrs 2 workers 6 Monthly Check for Shaft Alignment 30 min 1 worker Annually Replace Motor Bearings 3 hrs 1 workers
  53. 53. 53
  54. 54. 54 Level I Level II Level III Level IV Level V Level VI Fan operate with high vibration level Bearing fails Bearing seized Parts damage Aging Design life limit Improper lubricant quantity Housing wear High friction Bearing damage Bearing seized Parts damage Unbalance fan blade High vibration Shaft wear Shaft misalignm ent Fan damage Looseness in foundation bolts High vibration Cracks in foundation Breaks Design life limit Shaft wear Shaft misalignment Bearing damage Sleeve looseness Design life limit
  55. 55. 55 Failure mode Failure cause Source of failure Root cause Failure chracteristics Failure Effect Fan operate with high vibration level Bearing fails Bearing seized Poor Maint Wear in&out Unexpected plant shutdown Housing wear Deterioration Poor Maint Wear in&out Unexpected plant shutdown Unbalance fan blade Shaft wear Poor Maint Wear in&out Unexpected plant shutdown Looseness in foundation Poor Maint Wear in&out Unexpected plant shutdown Shaft wear Deterioration Poor Maint Wear in&out Unexpected plant shutdown
  56. 56. 56 Centrifugal Fan Dust Temp 110º C System control Environment Flowrate 78,000m3/h Functional Block Diagram for the Fan Temp 90-100ºC
  57. 57. 57 Recommendations for this fan acc to PDM 1-Due to high scale rate accumulation on the fan blade, it’s very recommended to follow up the vibration analysis on daily basis to avoid unbalance issue High scale accumulation require intensive daily cleaning!
  58. 58. 58 2-Never perform balancing on a scaled blade
  59. 59. 59 Vibration Limit Equip Condition Root Cause Consequence Task 1-3 Good ----------------- ----------------- ------------------ 3-6 Call for service High scale accumulation on the blade Unbalance issue Perform sandblasting & balancing if needed 6-10 Call for repair Fan left without the necessary service Looseness in the foundation and the bearing housing Perform balancing & retighten all components 10 and over Breakdown Fan left without the necessary service Damage to mechanical parts Costly repair 3-Perform necessary maintenance acc to vibration measurements
  60. 60. 60 -

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