Drying/ concentration
With thermal drying, the moisture contained in a moist substance is brought into a gas state through warming and the resulting vaporisation or evaporation and the arising moisture vapour is drawn away. The dried commodity is created.
The apparatus, plant and machinery with which DVA carries out drying processes is called a contact dryer. DVA offers its customers nearly all apparatus for contact drying.
With contact drying, the commodity to be dried comes directly into contact with the heated tank or well wall.
The liquid which evaporates, i.e. becomes a vapour, is appropriately suctioned or transported away.
- Bucket dryer
- Drum dryer
Drying commodities and residual moisture
Drying or solid-liquid separation processes overall are often defined by their so-called residual moisture. Here, when centrifuging residual moisture this refers to free (surface) water.
When centrifuging and pressing, a maximum residual moisture of 30-40% cannot usually be surpassed.
With the DVA contact dryer, residual moistures measured in ppm can be achieved and depending on crystal or pore structures, even water of crystallisation can be expelled at high temperatures and with the help of a vacuum.