Primetals Technologies was entrusted with the task of repairing Blast Furnace No. 1 and No. 2 at the Visakhapatnam Steel Plant, with the goal of enhancing their production capacity. In addition to the repairs, Primetals Technologies was also responsible for upgrading the existing ancillary equipment to meet the requirements of a modern, state-of-the-art blast furnace.
This project involved not only restoring the furnaces to optimal working condition but also integrating advanced technologies and modernized systems to improve efficiency, safety, and overall performance. The upgrades included improvements to key components such as a clean gas system, blast furnace, stockhouse, and hot blast stoves.
Challenge
To carry out a category 1 capital repair of blast furnace No. 1 and No. 2 at the Vishakhapatnam Steel Plant owned by Rashtriya Ispat Nigam Limited (RINL). The daily production capacity of the furnace had to be increased from 5,717 t/d to 7,150 t/d, while upgrading the existing ancillary equipment to meet the requirements of a modern, state-of-the-art blast furnace.
RINL Vizag Blast Furnace No.1 blow-in
Solution
The focus of the repair was to increase the output of the furnace while maintaining large parts of the existing shell and upgrading the ancillary plants to meet the demands of the new, modern blast furnace.
By utilizing the latest thin stave technology and modern refractory design, the furnace volume was increased to allow the demands on furnace production to be achieved.
Modernization of all major blast furnace units, e.g., stoves, stockhouse, and gas cleaning plant, was carried out by Primetals Technologies from conceptual design to final commissioning of the units. These new units needed to be upgraded to be able to handle the higher throughputs generated by the production increase.
Both turnkey projects were completed with zero lost time incidents. This could only be achieved with the implementation of a strong permit-to-work system and close management of the construction and commissioning teams. It was a smooth furnace startup that was carried out by working closely with the client's operations team.
Scope of supply
- Conceptual design of blast furnace complex
- Full detail engineering and supply for category 1 capital repair equipment
- Engineering and supply of key equipment for furnace modernization
- Construction and commissioning responsibility
Technology supply
Stockhouse
- Automated stockhouse
- New weighing system
- Coke moisture monitoring
Hot blast stoves
- Five new stoves (across both furnaces)
- Blast humidification system
Blast furnace
- Tuyere shell replacement
- Remaining shell repaired as necessary
- Complete new furnace internals, including carbon hearth and staves (copper and cast iron)
- New wind distribution system
- New cooling piping installation
- New top charging system
- Centre coke charging
Clean gas system
- Davy 3-cone scrubber
- New dustcatcher discharge system
- Gas analysis system
Modernised RINL Vizag Blast Furnace No.1
Results
Furnace Design Parameters
- Average production: 7,150 t/d
- Peak production: 7,865 t/d
- Furnace hearth diameter: 12.14 m
- Furnace working volume: 3,416 m³
- Furnace inner volume: 3,891 m³
- Top gas operating pressure: 2.44 bar g
- Blast pressure at furnace: 4.59 bar g
- Normal productivity on inner volume: 1.84 tHM/d/m³
- Normal productivity per hearth area: 61.77 tHM/d/m²
- Number of tuyeres: 32 off
- Number of tapholes: 4 off
RINL Vizag Blast Furnace No.1 blow-in
Benefits
- Improved furnace top sensors
- Furnace production increased from 5,717 t/d to 7,150 t/d
- New level 1 PLC
- Level 2 system from Primetals Technologies
Conclusion
- New casthouse equipment
- Sloping casthouse floor converted to a flat, round casthouse floor
- Five new hot blast stoves across both furnaces
