Application of bag filter in integrated technology of dry desulfurization and dust collection

Abstract

A new technical route is explored to realize the integrated design of dry gas desulfurization and dust collection, combining dry duct injection technology with bag filter technology. Sodium bicarbonate (NaHCO3) was used as desulfurizer, outside and inside filtration bag filters were used as the main body of the reaction device. A series of experiments were carried out, and the temperature, NaHCO3 particle size, inlet SO2 concentration, sodium to sulphur ratio and dust concentration were evaluated. The results showed that the desulfurization reaction was mainly composed of two parts: the NaHCO3 injection section of duct and the filtration of bag filter. The desulfurization efficiency of the inside filtration was better than that of the outside filtration, and collection efficiency was maintained above 99.9%. From 130°C to 150°C, the desulfurization efficiency of both inside and outside filtration bag filter increased with temperature increased, but the efficiency decreased at the temperatures of 150°C∼200°C because of the thermal decomposition reaction of sodium bicarbonate. After adding 1000mg·m−3 dust, the desulfurization efficiency of both the inside filtration and outside filtration bag filters increased by 10%, and the trend of desulfurization efficiency with temperature was the same as that before adding dust. It was found that the desulfurization reaction was better with the NaHCO3 particles size was smaller, and the inlet SO2 gas concentration had little effect on the desulfurization efficiency.