This study explores the synergistic removal effect of various schemes based on demisters on boiler flue gas dust on a pilot-scale experimental bench. The results show that the dust removal efficiency is 28.43-51.30% when demisters are put into operation alone; the larger the inlet dust concentration of demisters is, the higher the dust removal efficiency will be; but it still cannot reach the 10 mg/Nm3 ultra-low emission standard. The dust removal efficiency is 93.13% when wet electro-static precipitator and demisters are put into operation simultaneously. Furthermore, the outlet dust concentration is lower than 5 mg/Nm3, and the dust removal efficiency of the demisters themselves increases to 67.28%, which has shown a significant improvement compared with operation alone. The dust removal efficiency is 70.98-78.37% when the water-washing layer and demisters are put into operation simultaneously. Moreover, the outlet dust concentration reaches the standard of 10 mg/Nm3 when the liquid-gas ratio (L/G) is more than 3.5. This research shows that when the inlet dust concentration is ≤ 35 mg/Nm3, the method of "water-washing layer + demisters" can be used as an equivalent alternative to the wet electro-static precipitator when L/G ≥ 3.5, which has reference value for reducing the construction cost of ultra-low emission reformation.
Keywords: Demister; Dust removal; Flue gas; Liquid–gas ratio; Ultra-low emission; Wet desulfurization; Wet electro-static precipitator.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.