What is the difference between a roller extrusion granulator and a rotary drum granulator

 Roll extrusion granulator and drum granulator are commonly used granulation equipment, each with its own unique granulation mechanism and application scenarios. The main differences between the two are as follows:

The granulation principle is different

Roll squeezing granulator: Based on the principle of pressure granulation, powder or sheet materials are extruded into continuous strips under high pressure by one or more pairs of rotating rollers in opposite directions, and then cut into particles of the desired particle size. This process is similar to "pressing a cake and cutting it into pieces".

Drum granulator: utilizing the rolling and stirring effect inside a rotating cylindrical container, adding an appropriate amount of liquid binder to aggregate the material and gradually increase it on the container wall to form spherical particles. This is a dynamic granulation process, similar to a 'snowball rolling'.

Applicable material types

Roll extrusion granulator: suitable for dry or plastic materials, especially those that can be formed by extrusion, such as mineral powder, chemicals, and some fertilizers.

Drum granulator: more suitable for materials with strong viscosity and good fluidity, such as some organic fertilizers, drugs, and food additives.

Finished product features

Roll granulation: The produced particles have high uniformity, regular shape, and high particle strength, but the shape is relatively flat.

Drum granulation: The produced particles have a more rounded shape and beautiful appearance, but due to the rolling process, there may be some differences in particle size.

Equipment construction

Roller squeezing granulator: The structure is relatively compact, the footprint is small, and the installation and debugging are relatively simple.

Drum granulator: The equipment has a large volume and consists of one or more rotating cylindrical bodies, used for containing and rolling materials.

Energy consumption and cost

Roller squeezing granulator: Due to its granulation process not relying on external heat sources, its energy consumption is relatively low.

Drum granulator: Additional heat or liquid additives may be required, resulting in slightly higher energy consumption and initial preparation costs.

Application scenarios

Roll squeezing granulator: widely used in chemical, fertilizer manufacturing, building materials and other fields, especially in the granulation of hard materials.

Drum granulator: It is widely used in the food processing, pharmaceutical, feed, and fine chemical industries, and is particularly suitable for producing substances that are easy to agglomerate.

Maintenance and operation

Roller squeezing granulator: maintenance is relatively simple, mainly cleaning and lubrication.

Drum granulator: More cleaning and maintenance work may be required, especially to keep the inner wall of the drum clean to prevent material accumulation.

Overall, both roller extrusion granulators and drum granulators have their own advantages and disadvantages. The choice of granulation method should be determined based on specific production needs, material properties, and expected particle characteristics. In practical applications, it is sometimes necessary to combine the advantages of these two methods, such as first extruding the initial shape with a pair of rollers, and then polishing and shaping it with a rotary drum to achieve the desired granulation effect.