Hybrid filtration of sinter dust: an alternative for air pollution control in steel industries

Air pollution control devices need to be more and more efficient to meet air quality regulations. A promising approach is the hybrid filter, which encompasses the operating principles of electrostatic precipitation and fabric filtration. However, the performance of hybrid filters for the steel industry has not yet been addressed. This paper reports on a study which evaluated the performance of a bench-scale hybrid filter, composed of an electrostatic precipitator and a fabric filter connected in series, in the sinter dust collection. Limestone was also used as particulate matter and the results for the two dusts were compared. For both dusts, at the highest level of applied electric field, the time elapsed until the maximum pressure drop was considerably longer than the time with no applied voltage, and the dust collection efficiencies were close to 100%. For the sinter dust, although the applied voltage promoted the preferential collection of finer particles on the fabric, the cake porosities were not changed.