In the smoke of a large thermal power generating units desulfurization (FGD) system, flue gas damper is an important equipment of desulfurization equipment to enter and exit the operation, divided into FGD main flue gas damper (including the original flue gas damper and flue gas damper) and bypass damper. The FGD main smoke baffle satisfies the requirement that the FGD equipment be checked and repaired when the boiler is running, and the bypass smoke baffle is used for separating the desulfurization device from the chimney during the operation of the desulfurization device, so as to ensure that the 100% flue gas enters the absorption tower.

Each FGD desulfurization baffle system consists of inlet and outlet baffle doors and bypass tailgate doors, and a common sealed air system (including an electric heater). Each sealing air system includes two sets of (a preparation) seal fan and an electric heater, and the throttle (valve), compensator, check valve etc..

The desulfurization baffle door adopts a single shaft double baffle structure with sealed air. The periphery of each baffle blade is provided with a nickel alloy sealing piece, and a sealing air valve is arranged on the sealing air inlet of the baffle door body, and a mechanical linkage is arranged between the baffle door and the damper door. The smoke baffle is opened and the sealed air valve is closed; the smoke damper is closed and the sealing air valve is opened. When the baffle door is closed, the sealed air is injected between the double blades to achieve the purpose of effectively isolating the front and back mediums.