The steel plant of Dillinger Hütte, one of the most traditional German steel producers, has successfully produced high-quality steel at this location for 325 years. However, the plant was equipped only with a converter primary off-gas dedusting system. Primetals Technologies and Dillinger Hüttenwerke have jointly developed a solution for integrating a secondary dedusting system into the existing steel plant.
Challenge
The existing steel plant was originally equipped with a basic primary off-gas dedusting system. However, emissions generated during critical process phases, such as charging and tapping, were released into the surrounding environment without filtration. This resulted in significant secondary emissions, making it difficult to meet modern environmental standards. The integration of an upgraded solution also needed to account for the constraints and complexities of the existing brownfield infrastructure.
Solution
To address secondary emissions from the LD converter, a comprehensive exhaust system was implemented featuring static coolers that lower the temperature of hot off-gases through heat accumulation. Emissions generated during charging, tapping, deslagging, and oxygen blowing are effectively captured using charging suction hoods and a doghouse enclosure.
These off-gases are transported via a dedicated duct system with suction control valves to the filter plant. The system design, including CFD-optimized suction hoods and doghouse geometry, ensures efficient gas capture. A high-performance control and monitoring system integrated into the ductwork and stack further enhances process reliability and workplace safety.
Cooled off-gases are cleaned in a fabric filter system, where coarse dust and sparks are pre-separated in an upstream spark arrestor, which extends the lifespan of the filter bags. In parallel, a separate dedusting system was installed for lime and material handling operations, also equipped with modern bag filters to ensure effective off-gas treatment across the plant.
LD converter secondary dedusting system
3D Rendering of LD converter (BOF) dedusting system at Dillinger Hütte, Germany
Benefits
- High dedusting efficiency with bag filters
- Increased capacity and safety through static coolers
- Integration into the existing steelmaking plant
- Low consumption figures because of VVVF-controlled ID fans
- Fully automated operation of the dedusting system
Conclusion
- Installation of a new LD converter (BOF) secondary dedusting system in the existing steel plant
- Introduction of static coolers
- New lime and material handling dedusting system
- Incorporation of a process automation system
- Achieved environmental compliance with emissions below current limits
