Dec 21 2010
Siemens VAI Metals Technologies GmbH received the Final Acceptance Certificate (FAC) from Dragon Steel Corporation (Dragon Steel) following the successful start-up and fulfillment of the guarantee performance figures of Sinter Plant No. 1.
The plant incorporates the latest sintering technologies to ensure a high and constant sinter quality, low operating costs and a minimum environmental impact. Sinter Plant No. 2, with a larger production capacity, is currently being constructed and is scheduled to commence operations in October 2012.
At Dragon Steel, located in the harbor of Taichung in Taiwan, Phase 1 of a new greenfield integrated iron and steel works was recently completed. This industrial complex, for which Siemens VAI designed and supplied a new sinter plant, a blast furnace with a inner volume exceeding 3,200 m3 and a two 2-strand slab caster, is capable of producing 5.2 million tons of high-quality slabs per year.
Sinter Plant No. 1 at Dragon Steel, Taiwan
The sinter plant, which has a surface area of 248 m2, produces in excess of 7,440 tons (nominal capacity) of sinter per day, or more than 2.4million tons of sinter per year. A wide range of innovative technological packages and systems are installed in the sinter plant at Dragon Steel. This is the basis for reliable production operations, high plant performance and exceptional product quality.
The Intensive Mixing and Granulation System, comprised of an intensive mixer and a granulation drum, processes 100% of the sinter raw materials, including residuals recycled from the steelworks. Thanks to the high homogeneity of the sinter raw mix produced by the system, there is no need for raw material blending beds at Dragon Steel. This considerably reduces the size of the raw material storage and handling areas.
Segregation of the raw mix into larger- and smaller-sized particles is made possible by the Twin-Layer Charging System. The initial layer of coarser particles of the sinter raw mix is first deposited onto the sinter bed. This is followed by the charging of a second layer of smaller-sized particles, including an increased portion of the solid-fuel content. This simple and practical solution significantly improves the permeability of the sinter bed, leads to an improved fuel efficiency and supports an intensive and uniform ignition of the sinter layer. The Twin-Layer Charging System was installed for the first time in the world at Dragon Steel.
The Selective Waste Gas Recirculation system recirculates approximately 30% to 40% of the waste gas emitted from the sinter strand back to the process. This reduces the volume of waste gas requiring treatment in the downstream gas-cleaning facilities. Consequently, the size – and thus the related investment costs – of the electrostatic precipitator, and the desulfurization and denitrification systems at Dragon Steel could be reduced.
Another innovation highlight is the installed Level 2 Sinter VAiron automation system, which includes a number of closed-loop control modules and an expert system. On the basis of raw-material and sinter analyses, the entire sintering process, from the raw-mix composition, process control – related to the return-fines ratio, coke ratio, burn-through point and basicity calculation, etc. – up to the finished sinter product, is completely optimized. This leads to improved and consistent product quality, decreased coke rates and lower production costs.
Siemens VAI is currently installing a second sinter plant (Sinter Plant No. 2) at Dragon Steel. The suction area of the sinter strand will be 387 m2, allowing a sinter output of approximately 3.8 million tons per year. The plant will be equipped with the same technologies and systems that are installed in Sinter Plant No. 1.