Steel and ferroalloys manufacturing processes involve high temperature exhaust streams, often at more than 900 ºC. Typically, the gas flows from the furnace (usually electric arch type) and goes into a gas conditioning tower to cool down below 200 ºC so that it can be treated by a Bag Filter. It's also common to have ESP´s as end dedusters that can be preceded by a multicyclone serving as pre-separators.
Treating these flue gases can be very maintenance demanding for bag filters and the small particle size limits the use of common low efficiency dedusters such as regular cyclones and multicyclones, as pre-separators. Bag filter failure is consequently a very common problem for clients in this industry.
Similar problems with existing dedusters occur with the recovery of slag (resulting from the fusion process in the furnace) after pneumatic transportation. Slag powder is an extremely hard material and very aggressive for common dedusters.
Client's needs include a very robust dedusting system, either serving as end-stage collector avoiding the need to cool down flue gases, or considerably decreasing the loads of aggressive material to bag filters.