EXTRACTS FROM THE METALOGUE

Thirty Three minus twenty five is equal to Eight days and Eight days is equal to at least 3200 tonnes

The recent mid-term repair of the MBF#2 can be quoted as an instance wherein utmost dedication shown by the employees, closely supervised execution, application of predetermined modern processes, techniques and tools and above all TEAM WORK helped in beating even the stretched target set for the purpose.

Here are some of the glimpses - of the challenges faced by the team and how the team managed to tackle various types of bottlenecks. Also TML, as a team notched up few milestones that we would like to share.

Mini Blast Furnace#2 was commissioned during Mar’05. After 18 months of operation, furnace top equipments like bell and basin had started showing signs of leakage. There were also signs of dislodging of refractory in the bosh region and erosion of refractory in the hearth region of the furnace. To address effectively the above mentioned problems, it was decided to take up mid-term repair of the furnace in the month of June 07.

The team decided to complete execution of this entire project within 25 days. It was a Herculean task as the same job earlier took 33days during year’2000 MBF#1 relining. Also, during MBF#1 relining’2006, similar jobs were planned for 33 days of execution. But, the team did not dither while accepting the challenge of completing Mid Term Repair within 25 days despite knowing that they had to face various challenges: for instance quantity of solid salamander to be extracted out, execution of the project at the onset of rainy season etc.

 

 

Challenges we faced

What we did….

This job traditionally takes 33. The team decided to finish it within 25days. The shut – down was taken with an aim to carry out extensive and comprehensive repairing jobs like furnace top equipment replacement, Furnace refractory replacement, Economiser coil replacement, damaged water line replacement etc. well within the stipulated time.

 We did two things:
1. We drew a realistic plan, involved everyone and did a rigorous job and resource planning
2. We consulted Vector consultants who helped us to implement TOC concept in project management. The technique is popularly known as CCPM i.e. Critical Chain Project Management. Application of CCPM has helped us in fine tuning the plan
Minimization of solid salamander

Since this problem could have derailed the entire project, we sought the help from experts to carry out blow down and salamander tapping. Eventually, first time in the history of TML, hot salamander tapping was carried out with two blowers running and surprisingly at the end of the salamander tapping, slag was found flowing down. There was no solid salamander inside the furnace.

Since, removal of solid salamander had previously proved to be a big bottleneck for timely execution of similar project, the team had taken few precautions.

1. Application to Dy. Chief Controller of explosives for getting license for possession and use of explosives. (We now have an in-house facility for storing of explosives at TML, Kgp)
2. Oxygen tanker kept ready for smooth supply of oxygen (license for use of oxygen was also arranged).
3. At the same time, we could locate and engage a group having license for carrying out salamander blasting using explosives possessed by the group. This step had ensured uninterrupted blasting operation.

Speeding up the process of arranging refractory bricks near the tap hole. For the first time in the history of TML, bricking arrangement near the tap hole was first assembled outside the furnace and each brick was given a number for separate identity. This effort resulted in speeding up the entire process of assembling the bricks inside the furnace. Whole job could be completed within 36 hrs which otherwise could have taken 3 days.
Our team noticed cracks on the shell just a day before shutdown. Elaborate plan for the repair of the shell was drawn under the guidance of structural experts from Tata Steel. Almost 500mtrs of extra welding and structural fabrications for shell strengthening could be accommodated within 25 days through planning and dedicated execution effort.
Crown castable was found to be in bad shape. The problem was immediately addressed, We planned for 60 hrs duration of additional job in a flawless manner. It did not affect the progress of the main job.
Initial plan was to cool down all the Stoves. Later, after further data analysis, re-planning was done to cool only the Stove#2 to check for the problem of less dome temp.. Responding to the change, cooling water line for other two stoves were arranged, the job was planned in such a fashion that the return water could be utilized for Thickner filling after completion of repair of the thickner.
Economiser Coil replacement was to be done in-house for the first time. Complete coil fabrication and assembling could be completed well within time with in-house efforts
During previous blow downs, job was done without monitoring of Hydrogen generation. Fear of explosion prevailed during all previous blow downs Arrangement for off line Hydrogen monitoring was done for the first time.
Onslaught of Rain Delays due to rain were minimized through effective resource planning.