SO<sb>3</sb> SEPARATING AND REMOVING EQUIPMENT FOR FLUE GAS

摘要

An SO3 separating and removing equipment (10) capable of lowering the density of SO3 contained in flue gas and separating and removing SO3 component from the flue gas at the inlet of a wet type desulfurization equipment (7) by installing a sodium carbonate feeding device (20) for feeding sodium carbonate to the flue gas at the outlet of a boiler (1), comprising a heat exchanger of shell and tube type, wherein the flue gas is passed through a shell side and boiler feed water is passed through the tube side to cool the flue gas to the dew point of H2SO4 gas or below to react the SO3 component contained in the flue gas with moisture contained in the flue gas according to the lowering of temperature so as to produce H2SO4 gas which is condensed and adhered onto the surface of tubes, and the liquid H2SO4 adhered onto the surface of the tubes is washed out by using water to remove the SO3 component from the flue gas, whereby the consumed amount of sodium carbonate can be remarkably reduced, and a plant running cost can be prevented from increasing.