Working and Principle of Rapid Mixer Granulator (RMG) : Pharmaguideline

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Working and Principle of Rapid Mixer Granulator (RMG)

Rapid mixer granulator is used for granulation in pharmaceutical manufacturing. Impellers and choppers are responsible for uniform mixing and granule formation.
Rapid mixer granulator is widely used equipment in pharmaceutical manufacturing. It is used to mix the pharmaceutical ingredients and make the granules before compression and also called a high shear mixer. Impellers and chopper are mainly responsible for wet granulation in the rapid mixer granulator.

Impellers: Impellers are fixed at the bottom of the dome-shaped stainless steel bowl. It has two full length and two half-length blades. These impellers are designed in such a way that small blades lift the material and full-length blades push the material to mix well. These impellers break up the wet mass into small pieces and granules.

RMG Chopper: These are specially designed small blades located at the bottom of the dome. It rotates at high speed (1440/2880) RPM to give easy and uniform granulation. Chopper cuts the wet lumps of material into small sized parts those are mixed equally by the impellers and its speed is responsible for the size of the granules. Chopper doesn't have any significant effect on the granule size when impeller speed is high (above 200 RPM)

Discharge Port: A discharge port is located horizontally at bottom of the dome. Granules are unloaded in the container through the discharge port. The opening of the discharge port is operated by a compressed air regulated cylinder known as a pneumatic cylinder that requires 3-5 kg/cm2 pressure of compressed air.

Related: Dry Granulation Process

The principle of Working:

In rapid mixer granulator, the formation of granules occurs by rising, whirling and tumbling motion of the material. Dry mixing is done by adding all ingredients into the RMG by rotation of impeller and chopper at high speed. During the addition of binder solutions to the powder impeller and chopper are operated at low speed. After the formation of wet mass impeller and chopper are operated at high speed to form the granules of the required size.

Dry mixing takes about 3-5 minutes to mix the ingredients, wet mixing takes 5-10 minutes to make the wet mass of material while the granulation process takes 5-10 minutes to make 0.5 mm to 1.5 mm sized granules. Mixing time consumed in processing is depends upon the ingredients quantity and their particle size.

Ankur Choudhary is India's first professional pharmaceutical blogger, author and founder of, a widely-read pharmaceutical blog since 2008. Sign-up for the free email updates for your daily dose of pharmaceutical tips.
.moc.enilediugamrahp@ofni :liamENeed Help: Ask Question

13 comments: Post Yours! Read Comment Policy ▼

  1. how can I save the information ankur ji?

  2. Bookmark page in your browser.

  3. How to capacity of any equipment like octagonal blender, fluid bed equipment,rapid mixture granulators?

  4. How Many Impeler anD choper to distern

  5. What is the directions of rotations of both main and chopper motors in slow and fast speed

  6. mr Nazrul islam the directin of impeller will be in clock wise and the chopper direction is in anti clock wise

  7. It's so encouraging

  8. Impeller direction - clockwise (both speed slow 72rpm & fast 144rpm)

    Chopper direction - Anti-clockwise (slow 1440rpm & fast 2880rpm)

  9. why 3 blades Impeller available in RMG

  10. How to define capacity of an pharma equipment like FBD, OCB RMG etc

  11. FBD ,RMG capacity difine in Liter
    According to bulk density of product


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