Drum granulator is a device that utilizes physical and chemical principles to process powder or fine granular materials into larger and more uniform particles. Its working principle mainly includes the following steps:
Raw material preparation:
The raw materials are first sent to the granulator, which can be dry powder, wet powder, or pre treated materials. The initial state and composition of the raw materials will affect the parameter settings of the subsequent granulation process.
Entering the drum:
The raw materials enter the cylindrical granulation chamber of the rotary drum granulator through the feeding port. The granulation chamber is usually a tilted cylinder, which may be equipped with lifting plates, blades, or other structures inside to promote the rolling and mixing of materials.
Humidification and bonding:
In the granulation room, evenly spray appropriate amount of water or binder to the raw materials through the spray system. The addition of water or binder is crucial in the granulation process, as their function is to bond the particles in the raw material together and form larger particles. The amount of humidification and the type of binder need to be precisely controlled based on the characteristics of the raw materials and the properties of the target particles.
Rolling granulation:
As the granulation chamber rotates, the material rolls inside, and small particles aggregate into larger particles under the action of moisture or binder. The inclination angle and rotation speed of the cylinder can be adjusted to control the size and shape of the particles. By combining physical rolling and chemical bonding, the material gradually forms the required particles.
Particle screening:
After granulation is completed, the particles are discharged through the discharge port of the granulation chamber. These particles are usually subjected to a screening device, such as a vibrating screen or a rotary screen, to remove particles that are too small or too large, ensuring uniform particle size in the final product.
Post processing:
The screened particles may require further processing, such as drying, to remove excess moisture added during the granulation process and avoid clumping during storage or transportation. In some cases, cooling, polishing, or surface treatment may also be necessary to improve the physical properties of the particles.
The workflow of a rotary drum granulator is a continuous process, which can produce granular products with specific physical and chemical properties by precisely controlling parameters such as raw material mixing, humidification amount, cylinder rotation speed, and tilt angle. This process is not only applicable to industries such as fertilizers, chemicals, and food, but also has a wide range of applications in agriculture, pharmaceuticals, and environmental protection.