Indirect Drying Drums


Indirectly acting drying drums are suitable for drying free-flowing bulk materials with a small particle size that may need to be intensely heated up or calcined. In addition, when it comes to drying materials containing solvents, these drums are generally preferred over direct drying methods that use hot air as a drying medium, as the drum can work with a reduced-oxygen atmosphere on the inside.


In indirect drying, the wet material is moved on one side of a partition wall while the wall is heated up from the other side. Due to the large temperature differentials, an effective transfer of heat from the hot wall to the bulk material is achieved, with the bulk material being heated up and dried as a result. The partition wall can be heated up in a variety of ways.

Ideal for: Bulk materials that are not sticky and have good flowing properties and small particle sizes, e.g., zeolite, gypsum, sodium silicate, titanium dioxide


  • Perfect for high-temperature applications such as calcination
  • Low investment costs for exhaust air filters
  • Working with a reduced-oxygen atmosphere is possible (in order to prevent material oxidation or prevent/reduce harmful exhaust gas flows)
  • Heavy-duty design with a long service life
  • Optimum energy recovery: exhaust air that is heated up, dust-free, and dry can be used in other process stages (e.g., dryers or rotary kilns)
  • Low electric power needs as a result of low process air volumes


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

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