Oscillating Granulator

An Oscillating Granulator is equipment that is frequently used in pharmaceutical industries during tablet manufacturing & is also known as a dry granulator. It is called Oscillating due to the to & fro movements of its rotor.

In this article, we will learn the below points.

  • Use Of Oscillating Granulator
  • Principle Of Oscillating Granulator
  • Components Of Oscillating Granulator
  • Working Of Oscillating Granulator
  • Advantages & Disadvantages 
Oscillating Granulator


Use Of Oscillating Granulator

As we discussed earlier it is used for tablet manufacturing but here will discuss in detail for which purposes & at which stages this dry granulator is used.

  • Oscillating Granulator is used for sieving powders at 2nd stage  of wet granulation, dry granulation & direct compression.2nd step of the above-mentioned manufacturing process is Sieving. 

If you are not familiar with the steps of granulation, read the following article.

Steps Of Granulation

  • An oscillating granulator is used to screen dry granules in the wet granulation process.
  • The oscillating granulator is used for screening or crushing slugs in the dry granulation process.
  • An oscillating granulator can also be used for screening powder sheets that are formed by a roller compactor during the dry granulation process.

Principle Of Oscillating Granulator

An oscillating granulator works on the principle of oscillation where its rotating shaft rotates to & fro around its axis and applies a force over powder or granules for sieving or crushing.

Components Of Oscillating Granulator

Oscillating granulators consist of the following components.

  • Hopper
  • Rotor 
  • Milling Chamber
  • Sieve
  • Discharge Chute 
  • Mechanical Chamber 
  • Electric Chamber 


The hopper is part of the Oscillating Granulator where we add powder or granules for sieving or crushing. Hopper acts as a storage reservoir & supply powder or granules to the milling chamber.


The rotating shaft of the granulator is known as a rotor. It is an arm-like structure that has 5 edges & it rotates in an oscillating pattern. The arms of the rotor apply crushing force over powders or granules.

 Milling Chamber

The Milling Chamber is the enclosed box where the rotor is installed & has transparent glass sheets on both sides for visual observation. It is the main component of the granulator where the sieving or crushing process takes place.


The sieve of the Oscillating Granulator is in the shape of a half circle & is fitted around the rotor arm in the milling Chamber. The size of granules after crushing depends on the size of the sieve or mesh which is installed.

Discharge Chute 

The discharge chute is the structure installed at the lower side of the oscillating granulator from which the sieved or crushed material is collected into a container.

Mechanical Chamber 

It is usually on the backside of the granulator where mechanical parts like gearbox, chain, motor, etc are installed.

Electric Chamber

The Electric chamber contains electric wires, supplies & other operating buttons of the oscillating granulator.

Working Of Oscillating Granulator

  • First of all, install the rotor & then sieve or mesh in an oscillating granulator according to the sieve number mentioned in Batch Manufacturing Record
  • Assemble all other parts of the granulator & press ON button to run it empty to ensure that there is no striking of rotor arms with the mesh.
  • Place a container below the chute & add powder or granules in the hopper of an oscillating granulator & cover it with a lid to avoid a dusty environment.
  • Press the ON button to start the sieving process & collect all the sieved material in containers.

 Advantages Of Oscillating Granulator

  • It is Easy to use.
  • It can be used for sieving of both powders & granules.
  • Can easily be assembled for usage & dismantled for cleaning.

Dis-Advantages Of Oscillating Granulator 

Seals that are installed for rotor fittings may damage soon.

Black particles are generated in powder or granules if seals are damaged.

Read More 

  1. Advancements Granulation Techniques.
  2. End point determination or wet granulation.
  3. Equipments used for Granulation.
  4. Working of Rapid Mixing Granulator.