Airtight baffle door device for flue

The utility model relates to a flue airtight type baffle door device which comprises a door plate body (1), a lifting lug (1a) is connected to the upper portion of the door plate body (1), the door plate body (1) is of a hollow structure, a group of gaps (1b) are formed in the periphery of the door plate body (1), an air inlet pipe (2) is arranged on the upper portion of the door plate body (1), a first flange (3) is connected to the air inlet pipe (2), and the air inlet pipe (2) is connected with an air conveying pipe (4) through the first flange (3). One end of the air delivery pipe (4) is connected with a sealing fan (5), and an electric valve (6) is arranged at an outlet of the sealing fan (5). The flue gas bypass sealing device has the advantages that gas sealing is adopted, raw flue gas is prevented from penetrating through the bypass flue flashboard and being mixed with clean flue gas at a desulfurization and denitrification outlet, and the content of SO2, NOX and dust in flue gas at the outlet of a ch