The migration and transformation characteristics of SO_3 in SCR denitration system

air preheater

ultra low temperature electrostatic precipitator

seawater desulfurization and wet electrostatic precipitator of a 300 MW unit in a power plant under conditions with different coal types and loads were studied experimentally.The experimental results showed that

the removal efficiency of ultra low temperature electrostatic precipitator on SO_3 could reach 65%.The removal efficiency of SO_3 through seawater desulfurization was about 15%.The SO_3 removal efficiency of the wet electrostatic precipitator was about 5%.The SO_3 concentration of flue gas increased significantly after passing through the SCR denitration device

which was the main reason for the increase of SO_3 concentration in the tail flue gas.In general

low temperature electrostatic precipitator

seawater desulfurization device and wet electrostatic precipitator all have high removal efficiency for SO_3 in flue gas

and can effectively control the final SO_3 emission mass concentration in flue gas to reach less than 2 mg/m~3.