In operation, powdered organic material is continuously fed into the inclined rotating drum through the feed inlet. As the drum rotates, the material is carried up the wall and then tumbles back down, creating a continuous rolling motion. Simultaneously, water, steam, or organic binders are sprayed through the liquid distribution system, causing the moistened fines to collide, adhere, and agglomerate into clusters. The tumbling action rounds the agglomerates into uniform spherical organic fertilizer pellets.

To prevent material from sticking to the inner wall, the drum is lined with flexible rubber strips secured by steel bars and bolts. Breathing holes are placed behind each rubber strip and through the shell. When the drum rotates to the top, the rubber strips sag under their own weight and that of any adhered material, causing the buildup to crack and fall off – effectively self‑cleaning the drum without the need for traditional scrapers.