Flue gas treating device

TLDR: In this article, the authors proposed to reduce the SO3 concn. at the outlet of combustion waste gas to zero and to prevent the generation of blue smoke by equipping an alkali charging device for charging alkali powder at the place at which the temp. of the combustion waste gases is higher than a specified temperature.

Abstract: PROBLEM TO BE SOLVED: To reduce the SO3 concn. at the outlet of combustion waste gas to zero and to prevent the generation of blue smoke by equipping an alkali charging device for charging alkali powder at the place at which the temp. of the combustion waste gas is higher than a specified temp. at the upstream side of a desulfurizing device in the treatment of the combustion waste gas containing gaseous SO3. SOLUTION: In the flue gas treating device of a boiler, a denitration device 2, an air preheater 3, a device 5 for recovering heat of a gas heater, an electric dust collector 4, a desulfurizer 6, a reheater 8 of the gas heater and a smoke stack are arranged successively toward the downstream side from a boiler main body 1, and a calcium carbonate charging device 15 is connected to the upstream side of the air preheater 3. The calcium carbonate charging device 15 charges calcium carbonate at the place at which the temp. of the combustion waste gas is higher than 90 deg.C to the combustion waste gas from which nitrogen oxides are removed at the denitration device 2 and neutralizes the SO3 in the combustion waste gas. The contact with the SO3 is promoted and the complete removal is realized by keeping the specific surface area of calcium carbonate particles at >=10 m2/g.