Benefits of high-temperature membrane filter media for the dedusting of electric arc furnaces

In October 1996, Tuscaloosa Steel Corporation (TSC), a subsidiary of Britis h Steel pie., started up an electric steelmaking plant incorporating a twin -shell electric are furnace, a ladle furnace and a continuous easter. The s teel plant was equipped with an air pollution control system which comprise d a dedusting facility as well as fume collection equipment and ductwork. A low-temperature filter medium was installed in the dedusting system. Due t o the frequent high-temperature conditions in the dedusting system, it was soon found that this material had only a short service life and that a modi fied mode of operation was required. The modification consisted in operatin g the dedusting system with increased dilution air levels and thus with air throughputs above the design Value to be able to cope with the off-gas tem perature. A new membrane filter medium designed specially for high temperat ures reduces this amount of dilution air and achieves an optimum negative p ressure in the furnace at all times. It has thereby been possible to effect ively lower the emission of dust at the furnace. The combination of less di lution air and smaller drop in pressure at the filter also reduces the ener gy consumption of the induced-draft fan system. The high-temperature membra ne filter material additionally shows a superior resistance to sparks, as a result of which filter repairs and changes become less frequent, and maint enance costs can be cut.