This type of trommel screen is used in both stationary and mobile machines. They are characterised by high rigidity and provide a compact and durable construction.
They are most often equipped with a spiral ribbon welded to the inner surface of the screen. In addition to its transport function, the spiral additionally stiffens the entire trommel structure, forming a monolithic whole with the other components (i.e. rings, raceways, etc.). The use of this type of trommel design allows for a reduction in tare weight compared to a framework design with replaceable screen inserts. In monolithic trommel screens, the diameter usually does not exceed 2.5m and the length can be up to 10m. The advantage is the quick replacement in the machine and the short retooling time.
Segmental - with interchangeable screens
The rotary screen consists of a frame and perforated metal sheets or woven mesh attached to it with screws. Such a method of assembly (inside or outside of the structure) allows quick change of the screens according to the processed material.
If woven mesh is used, good self-cleaning properties are additionally achieved through the vibrations created during drum operation. Frame-mounted screens are mostly used in stationary machines. The diameter of the drum is as large as 3m and the total length can reach almost 20m. Due to the weight in excess of 20t, an appropriately sized drive and support structure are required.