Double-Shell Drums TT


In double-shell drums, drying/cooling takes place in 2 concentric cylinders. During the transition from the inner 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 the same side of the double-shell drum.

In comparison to single-shell drums, double-shell drums can be designed with a 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 inner and outer drums, which are connected to each other, ensure that there is significant contact between the loosened bulk material and the hot gas (for drying or heating up the material) flowing through the drum in a turbulent pattern or the air (for cooling down the material) flowing through the drum.

This makes it possible to achieve an extremely intensive transfer of mass and heat, and, accordingly, very efficient drying or cooling.

Ideal for: Minerals, sand, slag, ore, coal, clay, bentonite, chemicals, fertilizers, digestates, waste recycling, refuse-derived fuels


  • Proven Mozer system design
  • Compact overall lengths even when high throughputs are required
  • High thermal efficiency and low fuel consumption even if the drum is not separately insulated
  • The material infeed and outlet are located on the same side (advantageous for many installation configurations)


Double-shell drums can be designed as dryers, coolers, or combined dryers/coolers.


Jochen Brenk

Allgaier Process Technology

+49 (0) 7161 301-5088
+49 (0) 7161 34268


Allgaier Process Technology

Tel.: +49 7161 301-175
Fax: +49 7161 34268

contact form