The flue gas damper door generally requires 100% tightness under the action of pressure difference. The flue gas damper door usually adopts double louver type. In addition to the sealing element on each damper door, sealing gas is usually passed into the cavity of the two damper door to further improve the sealing of the damper door. Sex. If the inlet and outlet baffle doors are not equipped with a sealed air system, when the FGD is out of operation, due to the gaps in the blades of the baffle, hot flue gas will leak into the FGD system, causing corrosion in the system.
The baffle sealing system includes a sealed fan and its sealed wind station. The sealing gas pressure is maintained at least 5mbar higher than the flue gas pressure, so the fan is designed with sufficient capacity and pressure head.
Sealed fans can be arranged centrally or distributed. The centralized arrangement is a sealed system, generally two sets per furnace, which are designed according to 2×100% capacity, one for transportation and one for equipment. The decentralized design adopts each baffle with its own sealed fan.
Compared with centralized arrangement, the distributed arrangement of sealed fans has the following advantages:
1. The sealing effect of the baffle is better.
2. Since the baffle doors have their own fans, they are mutually independent, and each baffle has a spare fan, so the reliability of the fan itself does not need to be too strict, and the reliability of the seal is better.
3. No need for large pipelines, it can be arranged on the spot, and the system is simple.
4. It is convenient to maintain and has no influence on other systems.