Size Of FBD Sieve

FBD commonly known as a fluid bed or fluidized bed dryer is used in pharma industries for drying products manufactured by a wet granulation process.

A Fluid Bed Dryer has a trolley or detachable bowl in which we add the product for drying by fluidization.For Fluidization the air enters into the product trolley through the bottom of the FBD trolley so the bottom of the product trolley is perforated. 

Dutch Woven Screen

For perforation, a sieve or screen is fitted at the bottom of the FBD product trolley & this sieve or screen is known as Dutch Woven Screen or Dutch Woven sieve.

The sieve or dutch woven screen is attached with the bottom of FBD product trolley with the help of hand-driven screw clumps so it can easily be removed during washing & can be installed later on.

Purpose Of Dutch Woven Screen

The mesh or screen of Fluidized Bed Dryer is constructed in a way that it only allows the air to pass & retains the product inside.FBD trolley mesh or sieve provides a passage for air & prevents product loss through the bottom of FBD trolley.

Construction Of Dutch Woven Screen

As the sieve of the FBD trolley is in direct contact with the product, it is made of SS grade 316L. 

Size Of FBD Trolley Sieve

The size of the screen fitted with Fluidized bed dryer trolley is different for different models & sizes of FBD.Usually, the pore size of the FBD sieve ranges between 100 to 200 microns.Mesh size is usually written as follows,




  • The first numbers represent Standard Wire Gauge (SWG) and the second numbers represent sieve size.
  • Generally 24 × 110 mesh is used & if the particle size is very small then 30 ×150 number or 40 × 200 pore size FBD screen is used. 

Also, Read 

  1. Working of fluid bed dryer.
  2. Application of tray dryers in pharmaceuticals.
  3. SOP Of Fluid Bed Dryer
  4. Quality Assurance Interview Questions