Fluidized bed dryer (also called fluid bed dryer
) is a kind of equipment used extensively in the pharmaceutical industries to reduce the moisture content of pharmaceutical powder and granules. The Fluidized bed drying equipment
works on a principle of fluidization of the feed materials. In fluidization process, hot air is introduced at high pressure through a perforated bed of moist solid particulate. The wet solids are lifted from the bottom and suspended in a stream of air (fluidized state). Heat transfer is accomplished by direct contact between the wet solid and hot gases. The vaporised liquid is carried away by the drying gasses. Sometimes to save energy, the exit gas is partially recycled.
Fluidized bed dryer (FBD) is well known and widely used equipment in granulation area of pharmaceutical manufacturing
. It is used in the granulation process for drying the material to get desired moisture content in the tablet formulation granules
required for perfect compression of tablets.pharmaceutical manufacturing. It is used in the granulation process for drying the material to get desired moisture content in the tablet formulation granules required for perfect compression of tablets.
How does a fluidized bed dryer work?
In a fluid bed dryer used for powder drying, initially the air is sucked inside from the surroundings with a fan run with electric motor inside the dryer. The air then passes through heating system within the dryer and gets heated up. This hot drying air is then made to flow through bed of the moist materials that are laid on shaking perforated steel bed. This air is introduced with required velocity and temperature that the bed gets fluidized allowing intimate contact of each particle with the air. As the bed vibrates or shakes, the particles in the bed are carried forward slowly along the length of the dryer. All the moisture present in particles get sucked by the hot air which then escapes into the dust recovery system and is recycled for the further use in process. The velocity and temperature of air can be controlled as the particles pass on the bed and hence very wet to sticky materials can also be dried with a fluid bed dryer effectively. The dried material is then fed into the cooling zone where cool air reduces the temperature of the material to the required state.