What are the functional requirements of the circulating fluidized bed boiler material return device?

　　(1) The material flow is stable. Due to the high temperature of the material, in order to ensure the fluidization of the material and prevent coking, the material return device is equipped with a loose air.

　　(2) Prevent the flue gas from channeling back. The pressure in the separator is lower than the pressure in the combustion chamber. The returner needs to send the material from the low-pressure area to the high-pressure area. There must be enough pressure to overcome the negative pressure difference, which not only plays a role of sealing the flue gas but also can send solid particles back to the hearth.

　　(3) Stable return of materials. For the self-balancing material return control device, the material separated by the separator should be returned to the furnace evenly and stably.