Modernization of Dedusting Plants for EAF Steelmaking Shops to Increase Productivity and Improve Environmental Efficiency

摘要

A significant number of electric arc furnaces were built in the 90's and regularly modernized the years afterwards. Since that time the associated dedusting system was not the priority for investments but as many plants are now at a stage that the furnace output in terms of offgas volume and heat load exceeds the capacity limit of the dedusting system. Now it impacts the productivity of the meltshop because the furnace cannot be operated at full capacity due to the limitation of the fume treatement plant. In this case a modernization of the environmental system must be realized in order to stay competitive also in the futher.In order to systematically approach such projects Siemens VAI has developed a framework that targets the roots of the problem and provides a competitive package for the steelmaking industry. For such a modernization project the executor needs to have experience with both the furnace and the environmental plant itself to be able to determine critical parameters and develop the best concept for the individual situation.The case study developed in the article outlines that simply increasing the filter surface is not at all the best and / or cheapest solution. Rather it shows that the filter itself is often not the equipment which has to be modified. The focus is upstream at the primary suction line. A modernization of the water cooled equipment allows sufficient suction from the furnace and prevents a "smoking" EAF. Further a second stage gas cooler might be required to cool down the primary offgas to an appropriate level. Depending on the individual situation a filter upgrade with new ID-fans and a new stack can be avoided.