Allgaier drum dryers or rotary kiln dryers are produced as multi-shell dryers (single, double and triple-shell dryers). They process materials with very differing granulometric properties, or highly fluctuating moisture levels and throughputs with a high throughput rate.
Multi-shell dryers consist of several tubes inserted one inside another. Longer holding times for the solid materials combined with a compact design permit high performance without taking up too much space.
The drums are heated directly by oil or gas burners. The combustion chamber on the infeed end ensures that the fuel is used optimally, and that homogenous drying air temperatures are achieved.
Speciality – heating and cooling
Indirectly heated rotary kiln dryers are used for temperature control and calcination at temperatures up to 600 °C. They are used for cooling very hot solids from calcination drums and rotary kilns, and permit heat energy to be recovered effectively.
In the mineral industry for drying sands, limestone, stones and soil, ores. For fertilisers, wood chips, coal, iron sulphate, filter cakes, sewage sludge, etc.