History of drum drying

Drum drying is a unique drying process in which both cooking and drying take place. Drum dryers were introduced into industries about 100 years ago, starting with the double-drum dryer which featured the feeding by nipping between two drums.

John A. Just from United States was one of the first inventors to receive patent rights on a drum dryer with two rolls on 1902. It consists of applying pre-concentrated milk as a thin film upon the smooth surface of a continuously rotating, steam-heated metal drum.

It rapidly became the predominant method for producing dried dairy products, such as infant formula.

The top feeding single-drum dryer, which is more suitable for viscous feed materials was introduced in 1945.

Drum dryers were used in drying almost all liquid food materials before spray drying came into used. 

Typical drum dried food products include milk, milk products, soup mixes, ingredients for baby foods, navy bean meal and pea meal, potato slurries, and instant cereal.

In a drying operation, liquid, slurry or puree material is applied as a thin layer into the outer surface of revolving drums that internally heated by steam. After about three quarters of a revolution from the point of feeding, the product is dried and removed with a static scraper.
History of drum drying

The invention of spray drying

The history of spray drying is traceable to a United States patent issued in 1872. The patent no 125,406 entitled ‘Improvement in Drying and Concentrating Liquid Substances by Atomizing.’

Samuel Percy was first described the principle of spray drying and he is considered to be the inventor of spray drying technology.

It took nearly 50 years for the first commercially successful spray dryer design to be developed and operated on so-called heat sensitive products.

Since that time, the spray drying process has been developed for use in a wide range of industrial applications including the manufacture of powdered soaps and detergents, powdered milk, instant coffee, corn starch, fertilizer production, powdered polymer resins and the production of mineral ores and clays.

 It has also been employed as a process technology to impart unique functional attributes onto excipients such as lactose, mannitol and micro-crystalline.

The big step forward in spray drying technology was the invention of instantization by Peebles.

Further innovations were the development of membrane methods for concentrating and fractionating prior to spray drying and the introduction of three stage drying procedure.

The invention of spray drying