Flue gas baffle door is the key equipment used to control the flue gas flow path in industrial flue gas treatment system. It is commonly used in flue gas desulfurization (FGD), denitrification (DeNOx) and dust removal systems in thermal power plants, chemical plants, steel plants, cement plants and other places. Its working principle mainly involves the guidance and isolation of flue gas, and its working principle is introduced in detail below:
Structural principle
Flue gas baffle doors generally adopt a double-layer blade structure, and each layer of blade is surrounded by sealing sheets to ensure that the baffle door can provide tight isolation in the closed state. When the baffle door is closed, sealing air will be injected between the double-layer blades to form a high-pressure sealing air curtain, which further strengthens the sealing effect between the blades and ensures that the flue gas will not leak from the blade gap.
Working Status
Normal operating state: When the system is in normal operation, the original flue gas baffle door and the clean flue gas baffle door are opened, and the bypass baffle door is closed. The flue gas passes through a flue gas treatment system (such as a desulfurization tower), and the treated clean flue gas is discharged to the chimney through the clean flue gas baffle door.
Overhaul and maintenance status: When the desulfurization system needs overhaul or maintenance, the original flue gas baffle door and the clean flue gas baffle door are closed, and the bypass baffle door is opened. At this time, the untreated flue gas will be directly discharged through the bypass flue without entering the desulfurization system, ensuring the safety of the system and the personal safety of the maintenance personnel.
State of emergency: If the system fails, such as high pressure inside the desulfurization tower or other emergencies, the bypass baffle door will open quickly and the flue gas will be discharged from the bypass flue to prevent system damage or personnel injury. The original flue gas baffle door and the clean flue gas baffle door are then closed to isolate the fault area.
Sealing Principle
To ensure the tightness of the baffle door, a sealed air system is employed in addition to the physical contact seal between the blades. The sealing air is introduced into the cavity between the two layers of blades, forming a layer of high-pressure sealing air that prevents flue gas from leaking through the blade gaps. In addition, the tightness of the flapper door needs to be ensured through regular maintenance and inspection, including checking the wear of the seal and the pressure level of the sealed air system.
Drive mode
The flue gas baffle door is usually driven by an electric actuator, which drives the blade group to rotate through a connecting rod mechanism to realize the opening and closing of the baffle door. The electric actuator can be remotely controlled, which is convenient for system operation and automated management.
The working principle design of the flue gas baffle door ensures the normal operation of the flue gas treatment system, the safety of maintenance and the protection of the system in emergency situations, and is an indispensable and important part of the flue gas treatment system.