In triple-shell drums, drying/cooling takes place in 3 concentric cylinders. During the transition from the inner drum to the center drum and from the center drum to the outer drum, the bulk material’s axial direction of movement is reversed, meaning that the infeed and outlet for the bulk material are located on opposite sides of the triple-shell drum.
In comparison to single-shell and double-shell drums, triple-shell drums can be designed with a considerably larger diameter and a significantly reduced length. This comes with enormous advantages when it comes to integrating the dryer or cooler into an existing system.
An application-specific design of the internal configuration and the joint rotation of the drums, which are connected to each other, ensure that there is significant contact between the loosened bulk material and the hot gas (for drying the material) flowing through the drum in a turbulent pattern or the air (for cooling down the material) flowing through the drum.