1
Introduction Emirates Aluminium Company (EMAL) is a strategic joint venture between  aluminium producer Dubai Aluminium C...
Aluminium Smelting             ProcessPower    DC PowerPlant                     Molten AluminiumPort    Alumina          ...
Project Charter                   Anode effect frequency was increasing drastically during and           A       after bre...
Project Charter1.The Goal Statement.To reduce the impact of Pot feed system and Gas treatment center stoppageduring breakd...
Project Charter3.Stakeholders model:          • Supplying                                    • Manufacturing            Al...
Project Charter4.The Project Timelines    Problem                                           Plant wide         Controls   ...
MeasureLine-2 Sec -4                                                                                            Line-2 Sec...
MeasureLine-2 Sec -4                             Line-2 Sec -8• During and after Pot feed system stoppage anode effect fre...
AnalyzeA.Problem Statement•   Avoid disturbance in reduction pots by reducing the    Anode effects frequency in reduction ...
AnalyzeB. Validation of the Root cause                                           •During silo and pot hopper filling fine ...
ImproveA. Solution Criteria:    The solution should allow the alumina silo to vary between 40-    80% level    The solutio...
ImproveC. Solution Selection Process                          Reacted Alumina Silo   Automatic Pot          Rotary Feeder ...
ImproveC. Solution Selection Process                                            Ranking                                   ...
Implementation                 85%                 83%                 Silo Level Trend
Implementation                   X                 85%                 35%                                                ...
Implementation                   X                 85%                 35%                                                ...
ImplementationReacted alumina rotary feeder is being operated with a continuous 6-hourcyclic stopping interval.           ...
Results of Trial                                               Action Plan                                                ...
Results of Project                                        Action Plan                                                     ...
Results of Project                                    Action Plan                                                         ...
Control                              Action Plan                                                                 Check Do ...
Benefits of Projects                                       Action Plan                                                    ...
Results achieved                         Action Plan                                                          Check Do    ...
Project Closure                                Action Plan                                                              Ch...
Action PlanCheck Do         26
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WQD2011 - Breakthrough Process Improvement - EMAL - Alumina Silo Rotary feeder Cyclic Stopping Interval

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Breakthrough Process Improvement case study submitted by Emirates Aluminium during 3rd Continual Improvement & Innovation Symposium organized by Dubai Quality Group's Continual Improvement Subgroup to celebrate World Quality Day 2011.

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WQD2011 - Breakthrough Process Improvement - EMAL - Alumina Silo Rotary feeder Cyclic Stopping Interval

  1. 1. 1
  2. 2. Introduction Emirates Aluminium Company (EMAL) is a strategic joint venture between aluminium producer Dubai Aluminium Company (DUBAL) and Mubadala Development Company (MUBADALA). The company’s facility at Al Taweelah, halfway between Abu Dhabi and Dubai, EMAL’s present work force is 2500 employees on rolls. EMAL will be largest single site Aluminium smelter complex at the end of phase- 2 with a capacity of 1.3 Million Ton of aluminium per year EMAL produces a wide range of high grade semi finished aluminium products, like low profile sow , high profile sow, standard ingots, billets, sheet ingots etc. Supplying to worldwide customers. 2
  3. 3. Aluminium Smelting ProcessPower DC PowerPlant Molten AluminiumPort Alumina 3
  4. 4. Project Charter Anode effect frequency was increasing drastically during and A after breakdown in Gas treatment center/ Pot feed system. Which was creating disturbances in Reduction pots.Problem Huge number of people were involved in quenching thefaced by B anode effects and stabilizing the pots.EMAL C Heavy PFC generation during anode effects, not safe for employees and environment. 4
  5. 5. Project Charter1.The Goal Statement.To reduce the impact of Pot feed system and Gas treatment center stoppageduring breakdown and power outage on Reduction Pot performance byimproving Alumina quality supplied to pots2.The teams involved: Teams Roles Process Control Controlling and monitoring Operation ( Pot feed system & Pot line) Operating the system Maintenance Maintaining the system 5
  6. 6. Project Charter3.Stakeholders model: • Supplying • Manufacturing Alumina to Pot Aluminium from lines Alumina Pot feed Pot lines system Operations operations Process Maintenance Control • Controlling and • Maintaining the monitoring the equipments in process and good working equipments condition 6
  7. 7. Project Charter4.The Project Timelines Problem Plant wide Controls Selection of Identificatio Trials implementat and solution n ion monitoring Oct - 2010 Dec - 2011 Jan-March 2011 April-June 2011 June-July 2011 7
  8. 8. MeasureLine-2 Sec -4 Line-2 Sec -8 2B045 2A144 60.0 60.0 50.0 50.0 Feeder 1 Feeder 3 Feeder 2 Feeder 4 40.0 40.0 -325 %-325 % 30.0 30.0 20.0 20.0 10.0 10.0 0.0 0.0 10/13/201 10/13/201 10/13/201 10/13/201 10/14/201 10/14/201 10/14/201 10/14/201 10/13/2010 10/13/2010 10/13/2010 10/13/2010 10/14/2010 10/14/2010 10/14/2010 10/14/2010 0 4:48 0 9:36 0 14:24 0 19:12 0 0:00 0 4:48 0 9:36 0 14:24 4:48 9:36 14:24 19:12 0:00 4:48 9:36 14:24 Time Time 2B039 60.0 50.0 Feeder 2 Feeder 4 40.0-325 % 30.0 20.0 10.0 0.0 10/13/2010 10/13/2010 10/13/2010 10/13/2010 10/14/2010 10/14/2010 10/14/2010 10/14/2010 4:48 9:36 14:24 19:12 0:00 4:48 9:36 14:24 Time During pot feed system stoppage Fines content increases in Alumina 8
  9. 9. MeasureLine-2 Sec -4 Line-2 Sec -8• During and after Pot feed system stoppage anode effect frequency increases drastically .• This indicates whenever Fine contents increases in alumina it creates anode effects and disturbs the pot performance. 9
  10. 10. AnalyzeA.Problem Statement• Avoid disturbance in reduction pots by reducing the Anode effects frequency in reduction pots from 0.4 AE/Day to less than 0.15 AE/Day during and after breakdown or stoppage of pot feed system and GTC.• Reduce the fines content in Secondary alumina from 40 % to less than 20% by avoiding segregation of alumina inside Secondary alumina silo, transport air slides, and reduction pots. 10
  11. 11. AnalyzeB. Validation of the Root cause •During silo and pot hopper filling fine Alumina entering to Pot hopper/ Silo alumina gets segregated and accumulates along the wall of pot Finest particles hopper and alumina silo. This is due to settles out and accumulates here the static, near to full level operation of the silo and hopper. These areas may have become inactive by the cohesive nature of reacted alumina when left static over long periods of time. •During any breakdown in GTC or Pot feed system these fine material starts entering in to the pot and causes anode effects which affects pot performance. 11
  12. 12. ImproveA. Solution Criteria: The solution should allow the alumina silo to vary between 40- 80% level The solution should allow the pot to vary 75-100% levelB. Solution evaluation: Trial conducted for one pot for evaluating purpose by stopping alumina filling manually after every 6Hrs duration .During trial no change in quality of alumina observed. 12
  13. 13. ImproveC. Solution Selection Process Reacted Alumina Silo Automatic Pot Rotary Feeder Cyclic Hopper Exercising Stopping Interval and Alumina Silo Through PLC Logic Feed Modifications Modification 13
  14. 14. ImproveC. Solution Selection Process Ranking Engineering In-House Sr.No Criteria Solution Solution 1 Easy implementation 1 5 2 Cost involved 1 5 3 Time to implement 2 4 4 Maintenance and control 1 4 5 The results 5 4 14
  15. 15. Implementation 85% 83% Silo Level Trend
  16. 16. Implementation X 85% 35% Y Reacted Alumina Silo Level Trend
  17. 17. Implementation X 85% 35% Y Reacted Alumina Silo Level Trend
  18. 18. ImplementationReacted alumina rotary feeder is being operated with a continuous 6-hourcyclic stopping interval. 18
  19. 19. Results of Trial Action Plan Check Do Comparison of % fines in the hopper after stoppage of pot feeding system After Potfeed system stopage for 6 Hrs After Potfeed system stopage for 6 Hrs (During Trial ) (During normal operations) Pot No % Fines Pot No % Fines 2A105 9.9 2A142 39.1 2A094 11.8 2A144 53.4 2A117 10.9 2A146 49.5 2A128 11.4 2A189 18.6 2A136 12.8 2B01 53.4 2A146 13.9 2B039 49.3 2A152 13.4 2B045 38.5 2A164 12 2A142 40.7 2A172 12 2A144 44.1 2A189 12.2 2A146 39 Average 12 2A189 20.2 2B01 35.1 2B039 49.2 2B045 48.6 Average 41.3Stoppage of GTC or Pot feed system in normal situation % fines in pot aluminaincreases, where as % fines in pot alumina remains unchanged where reactedalumina rotary feeder cyclic stopping interval has been implemented. 19
  20. 20. Results of Project Action Plan Check Do On 23rd April during GTC breakdown Sec-3, & Sec-4 are not affected as much as normal sectionsAE-frequency in normal sections was 0.365 AE/Pd whereas in Sec-3 & Sec-4 AE-frequency was 0.167 AE/Pd where reacted alumina rotary feeder cyclic stopping intervalhas been implemented. This indicates the change in the quality of alumina. 20
  21. 21. Results of Project Action Plan Check Do On 23rd April during GTC breakdown Sec-3, & Sec-4 are not affected as much as normal sectionsThe underfeed duration went down in the normal sections where as it was normal inSec-3 & Sec-4 where reacted alumina rotary feeder cyclic stopping interval has beenimplemented. This indicates the change in the quality of alumina. 21
  22. 22. Control Action Plan Check Do Alumina Silo level Rotary Feeders OperationSystem is controlled by SCADA, and continuously monitored byoperations and Process control 22
  23. 23. Benefits of Projects Action Plan Check Do • In-House Control Modification • Engineering Solution• For Automatic Pot hopper Exercise • Project covered both engineering = $27,810 x 8 sections x 2 Lines proposal to a single cost-effective and cost avoidance solution. = $444,960 • Regular man-hours was used in• For Reacted Alumina 700t Silo developing the PLC logic modification Modifications and monitoring the system. = $800,618.47 • Control flexibility was incorporated to• Total Proposed Project Cost enhance mass-balance of the upstream and downstream process. = $444,960 + $800,618.47 =$1,245,578.47 or = AED 4,575,321.07Total Cost Avoidance: AED 4,575,321.07 23
  24. 24. Results achieved Action Plan Check Do Supply of good quality Alumina to Potlines will improve Pot performance Improved work environment in the Pot lines as emissions reduced (Environment Protection) Problem of AE frequency Eliminated / AvoidedSegregation of reduced during costly engineering Alumina is GTC/Pot feed solutions for the eliminated. stoppage Alumina segregation problem. 24
  25. 25. Project Closure Action Plan Check DoTeam Recognition:Team was recognized by EMAL management by selecting bestimprovement project in June-2011, and team is nominated for2011 Annual FALAH award. 25
  26. 26. Action PlanCheck Do 26

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