Allgaier rotary drum driers are used mainly in the minerals industry for the drying of sand, limestone, natural stone and ores. In addition, they are used for drying fertilizers, wood chips, coal, iron sulphate, filter cakes, sewage sludge, etc. Their main features are high throughput rates and the ability to process goods with widely varying grain sizes, moisture content and feed rates.
The drum driers are built as single-, double- and triple-shell driers. Multi-shell driers consist of several tubes mounted inside each other and permit longer retention times in compact units and thus high performance without large space requirements.
- Gravel and sand
- Iron-sulphate (copperas)
- Biological waste
- Wood chips
The drums are preferably heated by direct oil or gas burners. Optimum utilisation of the fuel and uniform drying-air temperatures are achieved with preceding combustion chambers.
Indirectly heated rotary drum driers are also available for tempering and calcination at temperatures of up to 600°C.
Special versions permit several processes in a single stage, such as:
- Drying and cooling
- Drying and separating
- Drying and cleaning
- Drying and crushing