The Vrieco-Nauta® Vacuum Dryer is a universal batch dryer suitable for drying materials such as powders, granules, pastes and viscous slurries, especially when products are heat sensitive, contain solvents and are toxic or explosive.   
   
The Vrieco-Nauta® Vacuum Dryer is capable of handling products that become heavy and sticky during drying and can also be used for vacuum operations such as reaction/crystallization, heating / cooling, sterilization, liquid/solid separation and de-aeration.    
   
The thermal energy needed for drying is introduced into the product through a heated jacket that can be heated by various media including steam, hot oil and water. The jacket provides rapid distribution of heat into the product in combination with efficient mixing.   
   
The vacuum inside the dryer allows vapor to be removed at low temperatures, which makes the Vrieco-Nauta® Vacuum Dryer ideal for drying heat-sensitive products. The vapors are removed through a dust filter fitted on top of the vessel. This then prevents the dust from penetrating into the vacuum system.   
   
The conical screw vacuum dryer is fitted with a condenser with a receptacle for recovering solvents. This condenser can be installed before the vacuum pump, or after it, depending on the characteristics of the solvents.   
   
The moisture content of the product can be controlled by monitoring the weight of condensate or using the Hosokawa sampler for taking samples from the product inside the dryer under vacuum.   
   
Hosokawa conical dryers are designed for vacuum drying of solid based materials, but can be used in a wide range of other applications requiring thermal processing or vacuum treatment of solids, such as:   

Chemical reactions: alkalization, solid-gas reactions   

Crystallization   

Wet agglomeration and granulation of solids   

Sterilization of products   

Homogenizing under vacuum   

Cooling of solids and liquids   

De-aeration of pastes and liquids