What is the typical combustion air pressure at the FD fan in an atmospheric fluidized bed boiler?

In atmospheric fluidized bed boilers, the combustion air is vital for the fluidization of the bed and the combustion process. The air is typically supplied by a forced draft (FD) fan, which must deliver air at a pressure sufficient to overcome the resistance of the fluidized bed and ensure proper combustion.

The typical combustion air pressure at the FD fan in such a system is around 2.5 kPa. This pressure is suitable as it provides an adequate flow of air to support combustion while maintaining the stability of the fluidized bed. At this pressure, the fan can efficiently propel the required airflow through the system, ensuring that the fuel particles remain suspended and achieve uniform combustion.

Higher pressures, such as those represented by other choices, can lead to unnecessary energy consumption without providing significant benefits in combustion efficiency. Therefore, 2.5 kPa is recognized as a standard pressure that balances efficiency and performance in atmospheric fluidized bed boilers.