Pilot study on demister-based dust removal methods for boiler flue gas

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/Nm(3) 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/Nm(3), 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/Nm(3) when the liquid-gas ratio (L/G) is more than 3.5. This research shows that when the inlet dust concentration is <= 35 mg/Nm(3), 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.

Automated summary

This study investigates the synergistic removal effect of different schemes based on demisters on boiler flue gas dust. The results show that when demisters are used alone, the dust removal efficiency ranges from 28.43% to 51.30%. The efficiency increases with higher inlet dust concentration, but it still falls short of the ultra-low emission standard of 10 mg/Nm³. When wet electro-static precipitator and demisters are used simultaneously, the dust removal efficiency reaches 93.13%, with an outlet dust concentration lower than 5 mg/Nm³. The research also suggests that the combination of water-washing layer and demisters can achieve a dust removal efficiency of 70.98%-78.37%, with an outlet dust concentration meeting the 10 mg/Nm³ standard when the liquid-gas ratio (L/G) is above 3.5.