Action time of baffle plate of desulfurization pump of slurry pump
The time required for the isolation baffle from full opening to full closing, or from full closing to full opening is called action time. Generally, the fast opening time of the shutter damper used as the bypass flue is required to be no more than 25s, and the fast action is mainly required to ensure that the bypass damper door can be opened quickly when the FGD fails to shut down in an emergency, so as to ensure that the flue gas directly enters the chimney through the bypass flue. The opening of the louver bypass damper shall be adjustable in stages to reduce the negative pressure of the boiler furnace when the bypass valve is closed. The action time of other shutter door in FGD system is generally about 40s.
The operating speed of ram door when it is opened and closed is generally 1.3 ~ 2m / min. The height of the flue at the inlet of large units is more than 3m, and it takes 2-3min for the door to be fully opened or closed. Therefore, it can not be used in the bypass flue, mainly used in the system inlet or absorption tower inlet, only for isolation.
4. Effect of flue deposit on damper door action
The solid matter in the fly ash of flue deposit and slurry of absorption tower will accumulate in the flue, especially at the bottom of the flue. Therefore, it is necessary to consider the effect of these deposits on the operation of the damper door.
For the normal gate type door opening and closing, such as the inlet and outlet isolation damper doors of the system or absorption tower, the plates must be able to squeeze out these deposits and insert them into the flue。 The damper driving device, such as the motor, shall have enough power to insert the ram into the deposit。 For a long-term closed gate, the actuator of the driving device must have enough starting power to overcome the adhesion between the plate and the door frame。
For a normally open shutter door, such as FGD inlet and outlet door, or normally closed shutter door, such as bypass isolation damper door, if it is in a certain position for a long time, the flue deposit may make the blade difficult to operate。 For the bottom blade, this problem is particularly serious。 First, the bottom of the flue is the area with the most sediment; second, if other blades rotate flexibly, the whole torque of the driver acts on the bottom blades, which may damage the blades and the connecting mechanism。 Therefore, some louver baffles are equipped with two sets of drivers and connecting mechanisms。 One set is for the lowest blade and the other for other blades。
In addition, for the normally closed shutter baffle door, if the ash accumulation in the flue appears on one side of the baffle door, the rotation direction of the blade shall be toward the downstream side of the ash accumulation to avoid the ash accumulation blocking the rotation of the blade。
No matter what kind of baffle door, the best way of operation is to move the baffle widely in its range of activity regularly, so as to prevent the baffle door from jamming if it does not move for a long time. This is especially true for the bypass damper of the constant mass.
The technical requirements of flue damper are as follows: (1) high temperature resistance; (2) chemical corrosion resistance (acid corrosion); (3) overpressure; (4) negative pressure;