The rotary screening machine is a critical piece of quality control equipment in organic and compound fertilizer production lines, ensuring that the finished product meets particle size specifications. Since granules vary in size after the granulation process, screening is required to separate those that meet the standards; undersized fines are returned for re-granulation, while oversized granules are sent back for crushing. The machine performs this classification task within a rotating screen drum, where materials tumble gently, minimizing granule breakage. It can be configured with multi-layer screen drums to produce multiple particle size grades in a single screening pass. For fertilizer manufacturers prioritizing consistent particle size and visual quality, the rotary screening machine is an indispensable core component of the screening stage.

The screen drum is installed at a specific inclination and rotates at a constant speed, with material entering uniformly through the high-end inlet. Driven by the rotational friction of the drum, the material is lifted to a certain height before cascading down under gravity, undergoing continuous circumferential tumbling and axial movement. Particles smaller than the screen mesh size pass through the openings into the collection hopper during this tumbling process, while larger particles move along the drum toward the lower end and are discharged through the outlet. In a multi-layer drum configuration, material first passes through an inner, finer mesh to separate the fines, while the remaining coarser material proceeds to the outer mesh for further screening, thereby achieving multi-stage classification.