The new secondary dedusting system has a total of 24 new and two existing extraction points as well as an existing alloying group with multiple extraction points, which are combined into seven groups for the ladle furnaces, the alloying groups, the conditioning stand and the bunker extraction. A 2,300 kW, induced-draught, speed-controlled fan enables the extraction capacity to be adjusted to match changing operational conditions. In normal operation, the system cleans 610,000 working m3 of off-gas per h at temperatures up to 130 °C. The maximum capacity is 700,000 m3/h.
The dust is separated by bag filters with a total surface area of almost 9,900 m2. The expected clean gas dust content is less than one mg per standard m3. The filters are equipped with compressed-air cleaning developed by Primetals. This enables the bags to be cleaned gently but effectively with economical use of the compressed air. The electric motor of the induced-draft fan is partially enclosed to minimize noise emissions. Troughed chain conveyors and pneumatic conveyors carry the separated dust to either a silo or the granulation plant.
The scope of delivery also included the mechanical and electrical equipment, the instrumentation and control equipment, and the visualization. Primetals was also responsible for the engineering, installation and commissioning of the plant. SGS Industrial Services from Dorf an der Pram, Austria, performed the mechanical assembly work such as structural steel work, piping, raw and clean gas ducts, clean-gas stack, fan system and reconnection work on existing system sections.
(Source: Primetals Technologies, Limited)