【FAQ】How should the inclination angle and rotational speed of a disc granulator be set?

The inclination angle and rotational speed of a disc granulator directly determine the granulation rate, particle size distribution, and output. Both parameters must be adjusted in coordination based on material characteristics: Inclination Angle Setting: The disc inclination angle (the angle between the disc surface and the horizontal plane) generally ranges from 40° to 55°. A smaller angle results in a longer material residence time within the disc, allowing granules to grow larger; this is suitable for producing large granules (4–6 mm). A larger angle accelerates the downward sliding of material, resulting in smaller, more uniform granules; this is suitable for producing 2–4 mm granules. It is recommended to start with a 45° setting and fine-tune based on the output particle size distribution; adjust by no more than 2° at a time and observe for half an hour before making further corrections. Rotational Speed ​​Setting: The disc rotation speed is typically controlled between 10 and 18 r/min. If the speed is too low, the throwing force is insufficient, leading to a lower granulation rate and increased fine powder. If the speed is too high, excessive centrifugal force may cause granules to be thrown out of the disc, resulting in smaller particle sizes and accelerated wear on the disc surface. In practice, the speed can be assessed by observing the movement of material inside the disc: the material should form a "crescent-shaped" curtain, with granules rolling and growing at the bottom of the disc before naturally overflowing at the rim. For highly cohesive materials, a lower speed (12–14 r/min) combined with a slightly steeper inclination angle is advisable to prevent material from sticking to the disc bottom. Additionally, the position of the scraper blade should be adjusted accordingly to ensure no material accumulates at the bottom or adheres to the disc walls.