Fluid Bed Drier

Fluid bed dryers are most suitable for drying granular, crystalline, coarse or similar materials in pharmaceuticals, fine chemicals, dyes, food and allied industries. It is also possible to dry fine crystals or coarse materials in fluid bed dryers.

The wet material is introduced into the dryer as batch of material in a product container which is provided with air distributor plate and dutch weave. Induced draught is created by blower and fresh air is sucked into the unit. After filteration, clear air passes through heating elements. This hot air then passes through the product container, creating turbulance in the product and hence the product moves up and down in the product container. Due to this the heat transfer is quick and the product is dried fast without appreciable loss of heat. Filter bags prevent particles escaping from the dryer.

Fluid bed dryers can be supplied in electric heating, steam heating or hot water/oil circulation system. Electrically heated dryers are provided with electric heating elements and are suitable to raise air temperature by about 60 deg c to 70 deg c depending upon pressure of steam. Generally dryers bigger than tr-60 are incorporated with steam heating system, as steam heating is more economical.

GMP Model

 

The drying time depends upon various factors such as physical properties of material, moisture content, type of moisture (free moisture or water of crystallisation), drying temperature etc., the crystalline products can be dried faster than amorphous product containing some percentage of moisture at the same temperature. Generally pharmaceuticals granules or crystals containing free moisture of about 20 to 25% can be easily dried in about 30 to 40 minutes at a temperature of about 80 deg c. Certain crystalline materials containing about 40% of moisture can be dried in fluid bed dryer within 35 to 45 minutes.

In case the product contains solvents or inflammable substances, it is essential that the dryer is steam operated and provided with flame proof motor.

Fluid bed dryer is available in various capacities ranging from 15 litres to 900 litres to handle 5 kgs to 300 kgs per batch.

All contact parts are made of SS 304.