Industrial Vacuum Dryers for Powders, Pastes and Slurries
Hosokawa Micron supplies industrial vacuum dryers for low-temperature processing of heat-sensitive, oxygen-sensitive and solvent-containing materials. Operating under vacuum lowers the boiling point of moisture and solvents, enabling efficient drying in a closed system while limiting thermal degradation and supporting solvent recovery.
The Nauta® conical screw dryer and Conical Paddle Dryer (CPD) are designed for different product behaviours and process duties. The Nauta dryer provides gentle, low-shear handling, while the CPD offers more intensive agitation for cohesive or high-viscosity materials, combined drying and mixing, and process steps such as heating, cooling or reaction.
How Vacuum Drying Works
In a Hosokawa vacuum dryer, thermal energy is transferred through the heated vessel wall. Product is gently agitated to maintain uniform temperature and prevent clumping. Under vacuum, the boiling point of the solvent is reduced, allowing it to evaporate at low temperatures. Vapours are continuously removed via a vacuum line, then condensed and collected in a closed-loop system—ideal for solvent recovery and safe handling of hazardous substances. This closed system ensures safe, efficient drying of moisture- or solvent-containing products, while minimising contamination and thermal degradation.
Which vacuum dryer is right for your process?
The Nauta® Vacuum Dryer and Conical Paddle Dryer both support low-temperature batch drying in a closed system. The most suitable configuration depends on the product behaviour, required process intensity, batch size and additional processing steps.
| Selection criterion | Nauta® Vacuum Dryer | Conical Paddle Dryer CPD |
|---|---|---|
| Agitator | Orbiting conical screw | Centrally driven paddle rotor |
| Best suited for | Fragile, segregation-sensitive and heat-sensitive products | Cohesive, viscous or poorly flowing products and filter cakes |
| Processing action | Gentle, low-shear product movement | More intensive mixing and heat transfer |
| Main advantage | Wide processing range with minimal product degradation | Short drying times and a compact installation |
| Available volumes | 5–22,000 litres | 5–15,000 litres |
| Additional processes | Mixing, crystallisation, sterilisation, cooling and de-aeration | Mixing, reaction, crystallisation, heating, cooling and sterilisation |
Both dryers can be configured for solvent recovery, inert operation and hygienic or sterile processing. Trials at our Test Centre help determine the appropriate dryer, operating conditions and scale-up parameters for your product.
Nauta® Vacuum Dryer – Gentle, Universal
The Nauta conical screw dryer was one of the first agitated vacuum dryers designed to replace vacuum tray dryers—and it remains a trusted industry standard today. Its vertical screw agitator gently lifts product along the heated wall, while gravity returns it through the centre, creating a continuous, convective flow.
Thanks to its low-shear operation, the Nauta dryer is ideal for drying:
- Segregative, fragile or free-flowing powders
- Temperature- and oxygen-sensitive substances
- Sticky pastes or slurries requiring solvent recovery
Its versatility makes it suitable for GMP, sterile or aseptic installations, with options for CIP/SIP and FDA-compliant designs.
CPD – for Fast Drying and Reactions
The Conical Paddle Dryer (CPD) offers fast vacuum drying, mixing and reaction capabilities in a compact footprint. Its centrally driven rotating paddles ensure intensive contact between the product and heated surface, enabling faster drying cycles and excellent thermal transfer.
This makes the CPD highly suitable for:
- Crystallisation under vacuum
- High-viscosity or sticky materials
- Reactions, heating, cooling or solvent removal in one system
Its robust agitator design allows handling of heavy, cohesive and poorly flowing products without clogging or dead zones.
Full Process Integration
Hosokawa vacuum dryers support multiple processing steps beyond drying. Depending on your process needs, a single unit can perform:
- Crystallisation and reaction under vacuum
- Heating or cooling with precise control
- Sterilisation of heat-sensitive materials
- Liquid/solid separation and de-aeration
We can deliver sterile, aseptic, ATEX- and FDA-compliant systems designed for pharmaceutical and food-grade production environments.
Energy-Efficient Drying Systems
Drying accounts for over 15% of total energy use in many industrial processes. Our vacuum dryers are engineered to reduce energy consumption through:
- Low-temperature drying under vacuum
- Efficient heat transfer via jacketed vessels
- Closed-loop solvent recovery
- Precision temperature and pressure control
These features reduce utility costs, minimise emissions, and improve yield in solvent recovery operations.
Test before you invest
Run trials with your own materials on lab and production-scale equipment at our 2,000 m² Test Centre in the Netherlands. Our experienced process specialists work with you to determine the right process, equipment or system configuration for your application. Each trial is supported by a detailed technical report, helping you select the best solution with confidence.
Learn more
Talk to our experts
Let our specialists help you configure the ideal vacuum drying system — tailored to your process and optimised for efficiency, safety and product quality.
Applications
Hosokawa Micron vacuum dryers are ideal for a wide range of products. Here are a few examples:
Sustainable process technologies
Hosokawa Micron B.V. is committed to sustainable and responsible process technology. Our environmental management system is certified to ISO 14001, while our EcoVadis Silver Medal places us among the top 3% of rated companies in the special-purpose machinery industry.
