Any material can be dried quickly if maximum surface of the material is exposed to hot environment.
Fluidization principle is used in Fluidized bed Dryer for drying Solid particle in size from 15mm down.
The Fluidized Bed Dryer consists of Two Cylindrical bodies, separated by a Distributor plate. The Distributor plate has a number of Air Nozzles through which Hot Air is made to pass.
The bottom body generally known as “Wind Box” serves as the Air distribution Chamber. The Hot air required for drying, may be received from a separate Hot Air Generator or from a Combustion Chamber attached to the Wind box.
The material to be dried forms a fluidized bed due to the aeration of the same and thus maximum surface comes in contact with the Hot air being supplied by the nozzles. Material is fed from one end of the fluid bed, moves along the bed in a fluid state to the other end of the fluid bed. The Dried material leaves the Dryer via the discharge chute in to the Vibrating feeder/conveyor.
After interacting with the material, the Air loses its heat to the material and is made to pass through a dust collector before venting in to atmosphere. The Upper body is so designed that the material does not carry along with the exhaust Air.
Advantages
- The Fluidized Bed Dryer is very efficient.
- The Solids are in fluid state ensuring perfect mixing.
- Maximum surface area is exposed to Hot Air.
- High degree of heat and mass transfer.
- Less retention time.
- Fluidized Bed Dryers are completely automatic.
- FBD can run uninterrupted once the plant starts.
- No moving parts in contact with the material hence minimum maintenance.