Pulse-Jet Bag Filter Performances for Treatment of Submicronic and Nanosized Particles from Waste Incineration

The main objectives of this study were to develop an experimental set-up to perform clogging/unclogging tests on a single baghouse fabric filter, and to evaluate its filtration performance regarding submicronic and nanosized particles, for operating conditions as close as possible to those found in real-scale waste incineration facilities in terms of gas flowrate, temperature and humidity, inlet concentrations for both the dust and the sorbent, the pressure and duration of the cleaning pulse-jet. The performances of a bag filter during several clogging/unclogging cycles were evaluated regarding the filtration of a submicronic aerosol whose particle size distribution is representative of nanowaste incineration emissions at the boiler outlet. In order to reproduce the real operating conditions in the flue gas treatment line, the airflow and the bag filter were heated to 150 °C and the filtration unit was insulated. The water content was maintained in the airflow in the range of 10–12% (i.e. 3% relative humidity) by water injection and the filtration velocity throughout the bag filter was 2 cm/s. Moreover, a mix of suspended particles of activated carbon and sodium bicarbonate, used in flue gas treatment lines mainly for dioxin/furan and acid gas removal, were generated simultaneously with the submicronic aerosol. The results showed a high total particle collection efficiency of the bag filter, which increased rapidly with clogging from 98 to 99.99%. Particles with a diameter of 90 nm were the most penetrating across the filter, for which the fractional efficiency reached a minimum value of 97.5%. These results demonstrated the effectiveness of bag filters for submicronic and nanosized particle filtration in industrial conditions for the treatment of waste incineration fumes.