From Mash to Flake: Drum Designs Boost Capacity and Product Quality in Drying
To reach an effective drying procedure, rapid water movement is crucial. Water can migrate quickly and uniformly across a drying drum’s surface by forming a thin layer.
Due to the product’s uniform thermal treatment, the finished dry product has a low water activity, which prevents bacterial growth while being stored. In this sense, there is no comparison between the drum dryer process and any other drying method. In terms of appearance, consistency, and flavor, the uniform treatment also guarantees a lump-free instant result upon reconstitution that is equivalent to freshly prepared potato puree.
The level of water evaporation is determined by the heat input into the potato mash, the temperature at which the mash is fed into the dryer, the consistency of the mash, and how long it is exposed to the air necessary for absorbing and expelling moisture, as well as the temperature, velocity, and humidity of that air.
It is necessary to break the saturated vapor boundary layer above the product layer that is drying to provide the conditions required for more potato mash evaporation. The density, film thickness, and air quality in the surrounding area must be consistent throughout the dyer’s width to provide a homogeneous moisture profile. The air being extracted that contains water vapor must be balanced with a well-distributed supply of fresh air. Achieving the intended uniform moisture profile and high output requires a certain amount of time after the nearly dry coating has evaporated.
The Andritz Gouda Drum Dryer Evaporates All of the Liquid in a Single Drum Rotation
With its continuous indirect drying technique, the Andritz Gouda drum dryer evaporates all the liquid in a single drum rotation while allowing for brief heat retention periods. It not only almost completely removes the possibility of the product getting damaged, but it also allows it to maintain its distinctive qualities, such as flavor, texture, and aroma.
Steam heats the inside of the drum dryer’s drum body. The drier benefits from a unique composition of cast iron, which provides exceptional “scraping properties” for the scraping knife and precise shape retention even at high temperatures and steam pressures.
A consistent product quality is produced by the constant temperature distribution that steam heating provides over the drum surface. On the inside of the drying drum, the steam condenses. To leave the most surface area inside the drum available for steam condensation, the condensate is continuously evacuated from the drum. Since the steam system is closed, neither the steam nor the condensate can touch the product.
You can read the rest of this article in your complimentary e-copy of Issue 3 of Potato Business Dossier 2024, which you can access by clicking here.
