Hot air drying system

continuous

By feeding hot air in the material layer at rest from the bottom of gas straightening vane such as a perforated plate, when the material layer reaches a certain flow velocity (i.e., minimum air velocity for fluidization), it makes a minimal expansion from rest, enabling particles to start moving and leading to minimum fluidization. When the flow velocity accelerates a bit, particle groups gradually come to make active movements gradually. In that case, the hot air pressure loss due to the material layer comes to be in proportion to the weight of material particles on the unit area of the straightening vane. With further accelerating the flow velocity, the particle groups make vigorous movements to mix with gas in all directions, resulting in a state of suspension. The material layer expands to 1.2 to 1.6 times in height what it was at rest. Furthermore, it behaves as it is liquid and shows an appearance as it is boiling. This state is what is termed "Fluid Bed" and in stable state. Such fluid bed can be formed within a certain range of flow velocity determined with the particle size, specific gravity, and others of the material. Throughout the fluid bed step, the hot air pressure loss due to the material layer comes to be in proportion to the weight of material particles on the unit area of the straightening vane and remains constant. Features Uniform temperature in fluid bed and exceedingly easy adjustments In the fluid bed, the hot air and the material vigorously mix each other to prompt heat transfer.