The drying process of the fluidized bed dryer firstly places different forms of fluid materials such as powder, paste and the like on a gas flow distribution plate such as a perforated plate, and the lower portion thereof is fed into a drying medium having a considerable speed. When the medium flow rate is low, gas flows between the material particles and the entire material layer does not move. As the gas flow rate increases, the layer begins to expand and the interparticle gap increases.
Continue to increase the speed of the airflow, so that a large part of the material will be suspended, and gradually form a gas-solid mixed bed, that is, a fluidized bed. It can be seen that the gas flow rate is the most fundamental control factor of the fluidized bed dryer, and the suitable gas flow rate should be between the fluidization of the material layer and the take-out of the material.
In the process of drying, it is usually necessary to add some inert carrier at the bottom of the fluidized bed dryer. When they are fluidized under a certain flow of air, the wet material adheres to the surface, which makes it a A dry outer shell. In addition, the inert carrier collides with each other to cause the dry outer casing to fall off and be carried away by the medium flow; and the carrier itself is in contact with the new wet material to form a dry outer casing. This cycle allows the fine wet-adhesive material to be sufficiently dried in a fluid bed dryer.