CASE STUDY OF MILL OUTAGE DUE TO HIGH REJECTION. DETAILED ANALYSIS AND VARIOUS EXAMPLES DISCUSSED

CASE STUDY OF MILL OUTAGE DUE TO HIGH REJECTION. DETAILED ANALYSIS AND VARIOUS EXAMPLES DISCUSSED

1. QC-SHAPATH FOR PROJECT LEVEL QUALITY CIRCLE CONVENTION O&M-NTPC TANDA A case study for Mill outage due to High rejection SHAPATH Better Together

2. Project Profile Project Name NTPC Tanda Location Ambedkar Nagar Establishment Year 1979 Taken Over By NTPC 2001 Installed Capacity 4X110 MW (STAGE-I) 2X660MW (STAGE-II) Main Raw Materials Coal, Water, Air

3. ABOUT TEAM MEMBERS HEAD OF DEPT : S R THAKUR FACILITATOR : GAGANDEEP SINGH DY FACILITATOR : VIKAS MISHRA TEAM LEADER : V K SRIVASTAVA TEAM DY LEADER : ABDUL QYYOOM TEAM MEMBERS :RAJESH KUMAR :SHIVAM SHARMA 3 SHAPATH Better Together

4. ABOUT TEAM NAME : SHAPATH DEPARTMENT : BMD FORMATION : JAN 2021 DAY OF MEETING : WEDNESDAY TIME : 5:30-6:30 PM PERIOD : IN 15 DAYS NO. OF MEETINGS : 14 % OF ATTENDANCE : 92% SOLVED PROBLEM : 01 ( TILL DATE) SHAPATH Better Together

5. ABOUT TEAM

6. ABOUT TEAM

7. STEP-1: IDENTIFICATION OF PROBLEMS BRAIN STORMING

8. STEP-1: IDENTIFICATION OF PROBLEMS S NO. NAME OF PROBLEM CATEGORY 1 Atomizing Valve Oil Gun Gland Leakage A 2 Frequently damage of soot blower line flange gasket A 3 Soot blower line pressure gauge line leakage B 4 Oil gun choking problem A 5 Frequently raking out of feeder inlet gate C 6 Mill 4G continuous poor fineness B 7 Mill 2A less air flow. A 8 MRHS gate limit switch rod frequently broken. A 9 Mill 1A high vibration below 17A load. B 10 MRHS line mill G frequently chocking. B 11 Mill frequent outage due to high mill reject A 12 BFP#2B discharge NRV passing. B 13 Mill G Seal air Line leakage A SOLVED

9. STEP-1: IDENTIFICATION OF PROBLEMS Problem Categorization   Type of Problem A B C TOTAL NO OF PROBLEMS 7 5 1 UNSOLVED PROBLEMS 6 5 1 SOLVED PROVLEMS 1 TYPE OF PROBLEMS NO OF PROBLEMS

10. STEP-2: SELECTION OF PROBLEMS

11. STEP-2: SELECTION OF PROBLEMS Out of 13 identified problems we have selected 4 problems(one by each member). S. No. Symbol Problem Selected By 4 P1 Oil gun choking problem V K SRIVASTAVA 7 P2 Mill 2A less air flow. SHIVAM SHARMA 11 P3 Mill-5C frequent outage due to high mill reject ABDUL QYYOOM 13 P4 Mill G Seal air Line leakage RAJESH KUMAR

12. Points Assigned By Every Members To Each Problem (Scale 1 to 10) V K SRI VASTAVA   SHIVAM SHARMA Criteria Safety Environment Urgency Easy To Work Time Saving Total Criteria Safety Environment Urgency Easy To Work Time Saving Total Problem Problem P1 6 4 2 3 3 18 P1 2 3 6 2 6 19 P2 4 4 6 5 5 24 P2 1 3 8 9 3 24 P3 6 7 7 8 9 37 P3 6 8 8 9 4 35 P4 6 5 4 4 5 24 P4 2 4 3 7 5 21 ABDUL QYYOOM RAJESH KUMAR Criteria Safety Environment Urgency Easy To Work Time Saving Total Criteria Safety Environment Urgency Easy To Work Time Saving Total Problem Problem P1 7 4 3 4 3 21 P1 3 3 6 4 3 19 P2 5 5 7 6 6 29 P2 5 2 4 3 1 15 P3 6 6 6 8 9 35 P3 3 8 6 5 7 29 P4 5 6 5 5 5 26 P4 6 7 2 6 1 22 STEP-2: SELECTION OF PROBLEMS

13. PROBLEMS P1 P2 P3 P4 MEMBERS VK SRIVASTAV 18 24 37 24 SHIVAM SHARMA 19 24 35 21 ABDUL QYYOOM 21 29 35 26 RAJESH KUMAR 19 15 24 22 GRAND TOTAL 77 92 131 93 RANK 4 3 1 2 STEP-2: SELECTION OF PROBLEMS Weightage Matrix

14. STEP-2: SELECTION OF PROBLEM Mills frequent outage due to high mill reject

15. Topic Font Size: 28 Subtitle Font size: 24 Font Family: Tw Cen MT (Normal) 15 Planning mile stone chart ( Project activity planning) Q. C. Name Department Facilitator Members SHAPATH O&M(BMD) Mr. GAGANDEEP SINGH VK SRIVASTAV (TEAM LEADER) PROJECT : HOD: AGM BMD 2. ABDUL QYYOOM MILL OUTAGE DUE TO HIGH REJECTION Date of start Date of completion Dy Facilitator VIKAS MISHRA 3. SHIVAM SHARMA 16.02.2021 15.07.2021 4. RAJESH KUMAR Steps Weeks 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Target Actual Defining the problem                                           1   Analysis of the problem                                         2   Identification of causes                                         2   Root cause analysis                                         2   Data analysis of root causes                                         2   Developing of solution                                         2   Foreseeing probable resistances                                         2   Trial implementation and check performence                                     4   Regular implementation                                         2   Follow up and review                                         2  

16. Topic Font Size: 28 Subtitle Font size: 24 Font Family: Tw Cen MT (Normal) 16 STEP-3: DEFINE THE PROBLEM HIGH QUANTAM OF REJECT IN MILLS

17. 17 STEP-3: DEFINE THE PROBLEM

18. 18 STEP-4: ANALYZE THE PROBLEM

19. STEP-4: ANALYZE THE PROBLEM Frequency of high reject issue SL Notif.date Notification Description SL Notif.date Notification Description 1 21.07.2021 105012149 MILL-6E: REJECT HIGH   16 21.03.2021 104809045 Mill#5F High reject 2 18.07.2021 105007645 Mill 5F reject choke   17 02.03.2021 104773073 MRHS MILL-A REJECT LINE CHOKE 3 10.07.2021 104992011 MILL-6G: reject choke   18 01.03.2021 104770654 MILL G REJECT CHOCK 4 04.07.2021 104981025 millD,rejection choking   19 14.02.2021 104743534 MILL-F HAVING HIGH REJECT. 5 30.06.2021 104974014 MILL-H REJECT LINE CHOKED.   20 10.02.2021 104735366 MILL-F REJECT IS VERY HIGH 6 29.06.2021 104970755 MILL#F,HIGH REJECTION   21 02.02.2021 104720168 MILL-F REJECT IS VERY HIGH 7 06.06.2021 104932292 MILL-C,REJECTION HIGH   22 09.01.2021 104674606 COAL MILL-C HIGH REJECT. 8 18.04.2021 104858784 MRHS#A,HIGH REJECTION   23 04.01.2021 104664287 Mill H reject chock 9 16.04.2021 104856399 MILL-H REJECT CHOKE   24 17.11.2020 104588748 Mill F high reject and current 10 15.04.2021 104853308 MILL-E HIGH REJECT.   25 17.11.2020 104573696 Mill H Reject foreign material stuck 11 09.04.2021 104845119 mill G,rejection dome v/v fire   26 04.11.2020 104568715 MILL#D, HIGHER REJECTION 12 08.04.2021 104841840 MILL A HIGH REJECT MRHS IN MANUAL   27 02.11.2020 104563767 MILL C HIGH REJECT 13 07.04.2021 104841191 MILL-F HIGH REJECT & ABNORMAL SOUND.   28 16.10.2020 104540186 MILL-5C:reject high 14 26.03.2021 104819264 U-6 MILL REJECT DUST COMING TO LOP SIDE   29 12.10.2020 104531849 MIll-5C:high reject 15 22.03.2021 104810080 Mill#5C reject passage choked   30 26.08.2020 104461052 MILL#C,HAVING HIGH REJECTION

20. STEP-4: ANALYZE THE PROBLEM Frequency of high reject issue Serial No Month Frequency 1 Aug-20 1 2 Sept-20 1 3 Oct-20 2 4 Nov-20 4 5 Dec-20 1 6 Jan-21 2 7 Feb-21 3 8 Mar-21 5 9 Apr-21 6 10 May-21 1 11 June-21 3 12 July-21 4

21. 21 Content Font Size 14 Fnt Family: Tw Cen MT (Normal) STEP-4: ANALYZE THE PROBLEM Frequency of high reject issue

22. STEP-4: ANALYZE THE PROBLEM IMPACT OF THE PROBLEM UNAVAILABILITY OF EQUIPMENT FINANCIAL LOSSES SAFETY HAZARD

23. IMPACTS MILL OUTAGE TIME INCREASED. LOSSES DUE TO MILL OUTAGES A. POOR FLAME STABILITY. B. LDO CONSUMPTION INCREASED. C. COAL WASTAGE.

24. STEP-4: ANALYZE THE PROBLEM MILL UNAVAILABILITY DUE TO HIGH REJECT ISSUE Time Required To Rake In The Inlet Gate Of RC Feeder ~ 6 HOURS Number Of Times Mill had to be taken out of service Due to high reject in Mill (From August 2020 To July 2021) : 30 TIMES Total hours unavailability in 12 months :30X6=180 Hours Total hours unavailability in 1 Year : 180 Hours

25. STEP-4: ANALYZE THE PROBLEM ASSUMING OIL GUNS AT ONE ELEVATION ARE USED FOR EXTRA 4 HOURS IN A ONE YEAR DUE TO OUTAGE OF MILLS. OIL CONSUMPTION BY 8 GUNS FOR 4 HOUR ~ 54.4 KL LDO COST OF LDO : Rs 47700 per KL Total Loss : Rs 25,94,880 LDO FOR POOR FLAME

26. COST OF MANPOWER TO MANUALLY CLEAR REJECT IN MILL Total no of unavailability of coal mill in one year : 30 Times Manpower Required to clear one Mill : 5 Manpower for 2 hours Cost of manpower to clear one mill : Rs 825/- Total Cost of Manpower in one year : Rs 74250/- STEP-4: ANALYZE THE PROBLEM

27. STEP-4: ANALYZE THE PROBLEM ESTIMATION OF LOSSES HEAD OF LOSS QUANTIFIED VALUE OF LOSS LDO FOR POOR FLAME Rs. 25,94,880.00 PER YEAR MILLS UNAVAILIBILTY DUE TO RACKING OUT 180 HOURS PER YEAR COST OF MANPOWER TO CLEAR THE MILL FOR ONE YEAR Rs 74250/-

28. STEP-5: FIND OUT CAUSES

29. 29 29 29 The following 6 probable causes have been listed through brain storming method- Poor coal quality. Low air flow Improper fuel air mixture ratio. Damaging of deflector plate. Less opening of classifier. High Roller gap. STEP-5: FIND OUT CAUSES

30. 30 30 30 STEP-5: FIND OUT CAUSES CAUSE AND EFFECT DIAGRAM Frequent racking out of feeder inlet gate ENVIRONMENT METHOD MACHINE MAN Improper method unawareness Untrained manpower Untrained manpower Lack of awareness Improper roller gap setting High gape b/w air inlet ring & liner Design problem High roller gape Lack of knowledge Lack of qualified manpower Improper operation Low air flow Improper air fuel ratio Lack of Knowledge less Opening of Classifier Untrained manpower Low thickness of upper ring High reject generation High loading of mill Low GCV coal (poor Coal) Heavy coal Wet coal Rainy season High reject High quantity of metle & foreign material Poor coal supply MATERIALS

31. 31 31 31 STEP-6: FIND OUT ROOT CAUSE

32. 32 STEP-6 FIND OUT ROOT CUASE MAIN CAUSE SUB CAUSE VALIDITY RANK OUT OF 10 MAN Untrained manpower NO 1 Lack of qualified manpower NO 1 MACHINE Design problem YES 10 less Opening of Classifier YES 3 METHOD Improper air fuel ratio YES 8 Improper roller gap setting NO 1 MATERIAL Low GCV coal (poor Coal) YES 6 Poor coal supply NO 2 ENVIRONMENT Rainy season YES 3 VALIDATION METHOD

33. 33 33 33 STEP-7: DATA ANALYSIS

34. 34 34 34 STEP-7: DATA ANALYSIS STRATIFICATION PROBABLE ROOT CAUSES MARKS CUMULATIVE MARKS PERCENTAGE CUMMULATIVE % Design problem 10 10 28.57% 28.57% Improper air fuel ratio 8 18 22.86% 51.43% Low GCV coal (poor Coal) 6 24 17.14% 68.57% Rainy season 3 27 8.57% 77.14% less Opening of Classifier 3 30 8.57% 85.71% Poor coal supply 2 32 5.71% 91.43% Improper roller gap setting 1 33 2.86% 94.28% Untrained manpower 1 34 2.86% 97.14% Lack of qualified manpower 1 35 2.86% 100.00%

35. RC1 RC3 RC2 RC4 RC5 VITAL FEW USEFUL MANY 100 9 8 7 60 50 4 3 20 1 Root Causes Number of occurences 68.57% 77.14% 85.71% 100% Break even point Pe r cen t age 35 15 10 5 20 25 30 35 RC6 Other 91.43%

36. 36 STEP-8: DEVELOPMENT OF SOLUTION

37. SN. SOLUTION ACCEPT/REJECT REASON 1 Covering of complete coal stock yard REJECT Very high cost 2 Better quality control at source of coal supply REJECT Not in our control 3 Increase in air flow to mill REJECT Mill stability adversely effected 4 OEM support REJECT High cost 5 Reduced the gap b/w air inlet ring and liner ACCEPTED Easy to install 37 DEVELOPMENT OF SOLUTION

38. 38 STEP-9 FORSEEING PROBABLE RESISTANCE By Brain storming our team have identified the following probable constraints and found the ways to overcome them. S. No RESISTANCE ELIMINATION 1 MILL & FEEDER TO BE IN SHUTDOWN CONDITION DURING OVERHAULING 2 MATERIAL & MAN POWER MATERIAL ARRANGED FROM STORES 3 PERMISSION FOR IMPLEMENTATION OF SOLUTION DEPARTMENTAL NOTE FOR APPROVAL 4 20 DAYS FOR IMPLEMENTATION OF SOLUTION SOLUTION IMPLEMENTED DURING OVERHAULING

39. 39 FORSEEING PROBABLE RESISTANCE

40. STEP-10: TRIAL IMPLEMENTATION AND CHECK PERFORMANCE

41. 41 STEP-10: TRIAL IMPLEMENTATION AND CHECK PERFORMANCE

42. STEP-10: TRIAL IMPLEMENTATION AND CHECK PERFORMANCE Notification were raised during 15 Aug to 24 Oct 2021 (During Light up, Sync & Running) Date Notification No Order No Description Functional Location Inlet gate racking out 15.08.2021 104537874 201776853 MRHS C DOME SEAL AIR V/V jam 1007-S2U05-BLR-MIL-030-LOS No 18.08.2021 104542199 201781149 MILL-D CAD PASSING. 1007-S2U05-BLR-MIL-040-CAG No 18.08.2021 104542904 201778710 MRHS H CHOKING SUSPECTED 1007-S2U05-BLR-MIL-080-CAG No 19.08.2021 104543050 201778721 MRHS H SEAL AIR Pr. LOW 1007-S2U05-BLR-MIL-080-GRB No 20.08.2021 104545425 201779990 MIll-5H:MDV3 LINK SHEARED 1007-S2U05-BLR-MIL-080-LOS No 21.08.2021 104547024 201780770 MRCS H seal damage 1007-S2U05-BLR-MIL-080-HAG No 21.08.2021 104547778 201781034 MRCS-B CONVEYING LINE CHOKED. 1007-S2U05-BLR-MIL-020 No 22.08.2021 104548418 201781149 MILL D INSPECTION 1007-S2U05-BLR-MIL No 23.08.2021 104551019 201787845 MRHS G seal air pr. low 1007-S2U05-BLR-MIL-030-CAG No

43. STEP-10: TRIAL IMPLEMENTATION AND CHECK PERFORMANCE Notification were raised during 15 Aug to 24 Oct 2021 (During Light up, Sync & Running) Date Notification No Order No Description Functional Location Inlet gate racking out 23.08.2021 104551022 201789805 MRHS D conveying line choke 1007-S2U05-BLR-MIL-040-GRB No 27.08.2021 104555565 201784225 Mill C hydraullic DP high 1007-S2U05-BLR-MIL-030-HOS No 28.08.2021 104556917 201771312 MILL G O/L TEMP MAINT LOW AT 80 TPH 1007-S2U05-BLR-MIL-070 No 28.08.2021 104557261 201785038 MRHS G DOME V/V FOREIGN MATRIAL STUCK 1007-S2U05-BLR-MIL-070-GRB No 03.09.2021 104566716 100747479 Mill 5a to 5G Greasing don 1007-S2U05-BLR-MIL-010 No 04.09.2021 104568460 201789413 mill#B,HAD SIDE DUCT INSULATION REQ. 1007-S2U05-BLR-MIL-020 No 05.09.2021 104569099 201789654 MRCS -G CONVEYING LINE CHOKE 1007-S2U05-BLR-MIL-070-GRB No 12.10.2021 104582219 201794495 FEEDER #E INTERNAL CHECKING REQUIRED 1007-S2U05-BLR-RCF-050 No 12.10.2021 104582592 201794618 MILL-D COC NOT RUNNING 1007-S2U05-BLR-RCF-040 No

44. STEP-10: TRIAL IMPLEMENTATION AND CHECK PERFORMANCE Notification were raised during 15 2021 Aug to 24 Oct 2021 (During Light up, Sync & Running) Date Notification No Order No Description Functional Location Inlet gate racking out 13.10.2021 104583053 201795141 MRHS MIL#B &D CONVEYING LINE CHOKING 1007-S2U05-BLR-MIL-020-HAG No 13.10.2021 104584207 201795258 MRCS-H CONVEYING LINE CHOKED. 1007-S2U05-BLR-MIL-080-GRB No 18.10.2021 104590095 201797582 Coal Feeder B belt swayed 1007-S2U05-BLR-MIL-020-CAG No 19.10.2021 104590988 201797909 U#5 MRHS E conveying line choke 1007-S2U05-BLR-MIL-050-CAG No 20.10.2021 104592378 201798527 Mill D scraper chamber choke 1007-S2U05-BLR-MIL-040 No 21.10.2021 104594458 201799636 MRHS C DOME SEAL V/V JAM 1007-S2U05-BLR-MIL-030-CAG No 21.10.2021 104593897 201799322 Feeder A COC tripped. 1007-S2U05-BLR-MIL-010 No 23.10.2021 104596681 201800067 MILL#5B HAVING HIGH VIBRATION 1007-S2U05-BLR-MIL-020 No 24.11.2020 104597783 201800968 mill#E,conveying line choking 1007-S2U05-BLR-MIL-050-HAG No

45. STEP-10: TRIAL IMPLEMENTATION AND CHECK PERFORMANCE Analysis of Notification raised from Aug 2020 to Oct 2021 (During Light up, Sync & Running)

46. STEP-11: REGULAR IMPLEMENTATION

47. STEP-11: REGULAR IMPLEMENTATION 05 Years rolling plan from MTP Department Page of Tanda Website TANDA SUPER THERMAL POWER STATION UNIT OVERHAUL 5 Year ROLLING PLAN (Proposed)                 UNIT-5 660MW) STAGE- II FIRST SYNCHRONIZATION 09-06-2019 COMMERCIAL OPERATION 07-11-2019 28.09.2020 MAJOR EQUIPMENT PLANNED   PG TEST PREPARATION OH START DATE (P)   8/27/2020 0:00 09/07/2021 0:00 END DATE (P) ####### 9/28/2020 23:59 10/10/2021 23:59 PLANNED DURATION (D)   14 35 START DATE (A)       END DATE (A)       ACTUAL DURATION (D)                       UNIT-6 (660MW) STAGE- II   26.04.2021 MAJOR EQUIPMENT PLANNED       START DATE (P)       END DATE (P)       PLANNED DURATION (D)       START DATE (A)       END DATE (A)       ACTUAL DURATION (D)       UNIT RUNNING HRS SINCE LAST CAPITAL OH      

48. STEP-12: FOLLOW-UP AND REVIEW

49. 49 S. N. Steps Weeks 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Target Actual 1 Defining the problem                         1 1                         2 Analysis of the problem                       2 2                       3 Identification of causes                       2 2                       4 Root cause analysis                         2 2                         5 Data analysis of root                         2 2                         6 Developing of solution                       2 2                       7 Foreseeing probable                         2 2                         8 Trial implementation and                         4 4                       9 Regular implementation                         2 2                         10 Follow up and review                         2 2 STEP-12: FOLLOW-UP AND REVIEW Q. C. Name Department Facilitator Members SHAPATH O&M(BMD) Mr. GAGANDEEP SINGH VK SRIVASTAV (TEAM LEADER) PROJECT : HOD: AGM BMD 2. ABDUL QYYOOM MILL OUTAGE DUE TO HIGH REJECTION Date of start Date of completion Dy Facilitator VIKAS MISHRA 3. SHIVAM SHARMA 16.02.2020 15.07.2021 4. RAJESH KUMAR

50. COST OF INSTALLING UPPER RING (A) TOTAL COST OF MATERIALS – 20 MM THICK UPPER RING : Rs. 90247/- (B) TOTAL COST OF MANPOWER BEING USED – Service Cost for Executing Job in One mill= Rs 7128 (C) TOTAL COST INSTALLING UPPER RING IN FIVE MILLS C = (A +B)X5 = Rs (90247+7128)X5= 97375 x 5 = Rs 4,86,875

51. COST BENEFIT ANALYSIS FOR 05 MILLS IN 01 YEAR STEP-12: FOLLOW-UP AND REVIEW COST OF INSTALLASION 5X 97375 ~Rs. 4,86,875 BENEFIT PER ANNUM SAVING OF LDO PER YEAR : RS 25,94,880 SAVING DUE TO MANPOWER: RS74250 TOTAL : RS 26,69,130.00 ~Rs. 26,69,130.00 PAYBACK: 66 DAYS

52. ADVANTAGES STEP-12: FOLLOW-UP AND REVIEW TANGIBLE ADVANTAGES INTANGIBLE ADVANTAGES Rs 25,94,880 saved in LDO per annum. Availability of all Mills and Mill’s Reject System. Stability of Unit by availability of All Mills. A great rider on safety Reduction in health hazards Sustainable & Environment Friendly Development Exposure to QC tools and techniques Motivation and Better T eam Spirit Feeling of achievement among team members Reduce operational stress

53. WAY FORWARD Frequent Chocking of ID fan U#5 Seal Air fan Filter

54. ACKNOWLEDGEMENT SENIORS, COLLEAGUES , FRIENDS AND WORKERS FROM : BE DEPARTMENT EEMG DEPARTMENT OPERATION DEPARTMENT BMD DEPARTMENT MTP DEPARTMENT

55. THANK YOU