The first drum dryer was invented by John Augustus Just, German born chemist for the purpose to dry milk into powder. It was patented on November 4 1902.
An engineer, John A. Merrett, made some improvement of the Just process. He also developed the modification of the scraper knife.
The drum dryer was first patented for use in the manufacture of pregelatinized starch in Germany by Mahler and Supf in 1921.
Since then, a host of other patents have appeared especially in the United States where extensive variations of feeding methods, number and configuration of drums, heating system and product removal were considered.
Drum dryer is used mainly for dehydrating fruit and cereals. The double-drum arrangement is the most popular one in the food industry because it is suitable for a wide range of materials. Besides, this type of equipment offers better economics and a more efficient operation.
Drum dryer for dehydrating liquid food
