If you deal in industries such as pharma and chemical, you may be familiar with the product rapid mixer granulator. This is a multi-purpose machine used for both dry grinding and wet granulation of materials/ingredients. A mixer granulator mixes dry powders and makes granules before tablet compression. The machine features a high-speed impeller and chopper to mix ingredients.
This article will guide you through the basic instructions for operating an RMG. This step-by-step guide will help you understand how to run the RMG smoothly.
RMG (Rapid Mixer Granulator) Operating Principle and Working:
A granulator is used for blending and granule preparation. In the mixer granulator (RMG), particulate material rises, whirls, and tumbles, forming granules. When mixing, ingredients are supplied to the impeller and chopper, and they rotate at high speeds.
The mixer granulator is designed to produce great mixing and consistent granules at a lower running cost while increasing output. In a matter of minutes, you can dry mix and wet granulate in the same bowl. The entire operation, including discharge, is automated.
Bottom entrance main mixing impellers apply significant shear forces to the mass, resulting in intense mixes in exceptionally short process durations. Flat bottom contour reduces cavitations and dead zones. Flush discharge guarantees that as much process material as possible is removed without the need for manual intervention. Suitable endpoint controls through. Torque/load on the drive or customized probes simplifies operation and improves cGMP compliance.
First, learn the rapid mixer granulator components:
- Mixing Bowl
- Filter assembly
- Impeller
- Discharging Port
- Binder solution
- Sealing lid
- Chopper
Mixing Bowl.
The mixing bowl is shaped like an arch and uses an impeller to coordinate loose particles into spinning movement. There is no welding portion included. The bowl is designed in a funnel shape. It is quite smooth and has no dead ends.
Filter Assembly
The filter assembly is located on the top of the vent air filter, allowing purging air to exit the mixing chamber while keeping the granules within. Purging air from the gasket below the impeller at a pressure of 5-6 kg prevents granules from combining with impeller lubricant, hence preventing contamination.
Impeller
The impeller's speed should be balanced because if it is too high, the molecule estimate will increase, and if it is too high for an extended period of time owing to persistent particle contact, the granule estimate will decrease. It is made up of two full and two half-filled strong blending edges.
The size of granules grows as the speed of the impeller increases, and if the high speed is maintained for an extended period of time, the size of granules decreases owing to continual collisions between particles. The distance between the base of the mixing bowl is approximately 2.0 mm, which allows the grains to pass below the impeller blade without breaking.
Chopper
The chopper should not be used all the time since it would shatter the grains.
First, determine if the active is free-flowing or cohesive and whether it lumps. The purpose of the chopper is to break down bigger molecules and convert them into granules. A rapid mixer granulator employs an extremely well-designed V-shaped chopping blade.
Binder
The binder should be added gradually rather than suddenly, as sudden addition results in inefficient binder distribution and may cause hardness variations in tablets.
Discharge port
The releasing harbor is balanced on a level plane in a bowl with a 45-degree inclination, and the granular cloth can be completely discharged. Pneumatic barrels are used to open and release the cloth.
Liquid binder inlet port
The binder solution should be applied gently, not suddenly, because sudden addition increases the odds of an increase in the binder, resulting in poor binder distribution and changes in hardness in the pellet.
Planetary Mixer (PLM) vs. Rapid Mixer Granulator
The Planetary Mixer (PLM) and Rapid Mixer cum Granulator (RMG) have different designs and operating principles. With the Planetary mixer (PLM), particles are dry mixed before granulation, and granulation is done in part. This is due to the PLM's tendency to generate lumps from moist matter. Hence, following the first stage of granulation, the granular mass is transferred and passes through a sieve or a multimill to acquire the appropriate size of granule.
However, in the case of a rapid mixer granulator, there are high-speed "chopper" blades that shatter the granular mass (lumps) to produce the necessary size of granules. As a result, separate sieving may be unnecessary in the majority of circumstances. However, it is dependent on the type of product and the wet granulation procedures we apply.
When producing commercial-scale batches, both PLM and RMG processes must be verified. The same granulation technology utilized during product development in R&D must be employed for commercial batch production. We cannot exchange the equipment used to make batches of a product. Process optimization and validation must be performed as part of the "technology transfer" from R&D to commercial scale.
Conclusion
You might think of operating a rapid mixer granulator as a difficult process. However, you can operate it with ease with the instructions given in this article. Check all components before starting your machine, and then follow the steps for dry and wet mixing. After using, clean the granulator for easy maintenance. It is recommended to follow the safety instructions when using your mixer granulator.
