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BATCH DRYERS
for Powders & Bulk Solids

Nauta® Vacuum Dryer

  • Multi-purpose and multi-processing Conical Screw Dryer
  • Efficient batch drying of everything from loose powders to heavy pastes and viscous liquids
  • No segregation and no product degradation
  • Interchangeable screw agitator for dryers larger than 20,000 litres
  • Full compliance with international standards such as FDA, cGMP, EHEDG
  • Automated cleaning solutions with our patented CIP filter and CIP skids
  • Sterile processing (SIP) possible
  • Available in volumes from 5 up to 22,000 litres

Multi-Purpose Vacuum Dryer

The Nauta conical screw dryer is a universal vacuum dryer for drying materials such as powders, granules, pastes and viscous slurries, especially when these products are heat-sensitive, contain solvents and are toxic or explosive.

The Nauta conical screw dryer is capable of handling products that become heavy and sticky during drying and can also be used for vacuum operations such as reaction/crystallisation, heating/cooling, sterilization, liquid/solid separation, and de-aeration.

Principle of Operation

The Nauta conical screw dryer is a convective dryer with high drying efficiency. The rotating cantilevered (free hanging) mixing screw conveys the product from the bottom of the vessel to the product surface. The mixing screw is suspended from an orbital arm, which rotates the mixing screw along the conical inner vessel wall causing convective mixing of particles and shear.

The thermal energy required for the drying process is transferred to the product via a heated jacket, which can be heated by various media such as steam, hot oil and water. The jacket ensures rapid distribution of heat into the product in combination with efficient mixing.

The vacuum inside the dryer allows vapour to be removed at low temperatures, which makes the Nauta vacuum dryer ideal for drying heat-sensitive products. The vapours are removed through a dust filter fitted on top of the vessel. This prevents the dust from entering the vacuum system.

The Nauta vacuum dryer is equipped with a condenser with a solvent recovery tank. This condenser can be installed before or after the vacuum pump, depending on the properties of the solvents. The moisture content of the product can be controlled by monitoring the weight of the condensate or by using a Hosokawa Sampler to take samples from the product inside the dryer under vacuum.

Principle of Operation
Applications

The Nauta conical screw dryer is designed for vacuum drying solid based materials, but can be used in a wide range of other process applications requiring thermal processing or vacuum treatment of solids, including:

  • Mixing / Drying under vacuum
  • Alkalization, solid-gas reactions
  • Cooling of solids and liquids
  • Crystallization
  • De-aeration of pastes and liquids
  • Sterilization of products
  • Wet agglomeration and granulation of solids

This combination of several processes in one vessel offers tremendous savings on investment costs, labour, and space.

Models

Nauta conical screw dryers are available in many sizes and are custom made to suit your application. A number of models with their typical characteristics are described below. Please note that these values are indicative only. Detailed information on all models is available on request.

Size (water filling) [l] 5 80 500 1000 5000 12,000 22,000
Height [mm] 1420 2660 3920 4460 6840 8450 9950
Width [mm] 600 900 1470 1720 2710 3730 4290
Net volume (powder filling) [l] 4.3 68 430 840 4500 12,000 22,000
Jacket surface area [m²] 0.13 0.69 2.84 4.58 13 25 33
Max. evaporation water * [kg/h] 1 5 25 35 100 190 250
Max. evaporation ethanol * [kg/h] 3 12.5 60 85 250 400 600


* Jacket surface temperature T=50°C

Laboratory & Pilot Vacuum Dryers

Our laboratory & pilot vacuum dryers are small vacuum drying systems that have been specially developed for use in laboratories. They are multi-purpose systems for wide-ranging applications.

The complete systems, including all of the necessary ancillaries, are built on stainless steel skids with wheels. They are very suitable for process development activities, experimental purposes and for fine-tuning for optimal process parameters. The laboratory dryers are available from 5 litres to 20 litres and the pilot dryers from 40 to 120 litres.

Standard Industrial Dryers

Our industrial dryers are available in sizes of up to 22 m³. They are designed and built according to industry standards such as Stoomwezen, PED, TÜV, Lloyd’s, ASME, Afnor, ISPLE etc. and are available in all grades of stainless steel, Monel, nickel, titanium, Hastelloy, etc.

Bespoke Drying Systems

Hosokawa Micron has 90 years of experience in designing and manufacturing vacuum dryers and turn-key vacuum drying systems. This experience in designing complete installations with process guarantees and validation makes us a valuable partner for the realisation of total powder processing solutions. Our expert design and engineering team would happily work with you on a tailor-made design for any of our dryers or drying system.

Ancillaries

Enhance your Nauta vacuum dryer with a range of ancillary options tailored to fit your process needs. Hosokawa Micron provides customized solutions designed to maximize productivity and efficiency in your production plant. Our team of skilled engineers is ready to guide you in selecting the perfect ancillary equipment for your application, ensuring optimal performance and seamless integration with your dryer.

Batch Drying Systems

Hosokawa Micron has been developing innovative solids processing systems for more than a century. As a result, we can draw on an unparalleled amount of know-how when designing new drying systems. In a drying system, the equipment, process steps and interacting parameters must all work together as an integral solution in order to ensure the optimal functionality, quality and efficiency of your total system. That's why we carefully select, configure and integrate all the components and processes when designing a drying system.

Thanks to our long-standing experience, we are the ideal partner to transform your drying operation into a bespoke powder processing system, from incoming base ingredients to final products.

Batch Drying Systems

This video takes a deeper look at Nauta Mixers & Dryers, their principle of operation, history and development of Nauta technology, benefits, features and functions as well as common mixing and drying applications.

Energy-Saving Screw Dryers

Drying is responsible for more than 15% of energy consumption in modern industrial processes. This makes energy efficiency an important factor when designing a conical dryer. Hosokawa Micron is an expert in developing advanced conical screw dryers and we put a lot of our own energy into developing screw dryers that will save you energy!

Testing & Process Development

Our Test and Process Development Centre in the Netherlands offers unique possibilities for testing your product to determine the most efficient process, system or plant prior to final design. We can provide laboratory-level as well as production-sized trials. Whether you wish to test a single machine or a complete powder processing system, the same skilled and experienced staff are here to help ensure that you are entirely satisfied with the results.

We offer process equipment and technologies from individual units to large scale bespoke system solutions. Our principle is to deliver high performance yet affordable solutions that meet our customers' demands and long term challenges. We also have rental equipment available for batch drying.

Testing & Process Development

Talk to Our Experts

Let our process specialists help you develop the optimal solution for your powder and bulk solids processing – from the first trial in our test centre to a full-scale industrial production system.

Hosokawa Micron specialists for powder processing technologies and systems

Sustainable Process Technologies

Hosokawa Micron B.V. is committed to sustainable and responsible process technology. Our ISO 14001 certification covers key environmental aspects such as air, soil, energy, waste, water, noise and hazardous substances. With an EcoVadis Silver Medal, we rank among the top 15% of EcoVadis-rated companies in the special machinery industry.

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EcoVadis Silver Medal