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Vacuum Dryer

Vacuum heating and drying ovens for the gentle drying of temperature sensitive, easy decomposable goods and components with a complex geometry (decreased temperature of ebullition and higher drying rate under vacuum conditions), also available in explosion-proof design.

VVT Series

You can dry products from almost all branches of industry in a vacuum drying oven, for example:

  • Pharmaceutical industryProduct Image (Main)
  • Chemical industry
  • Cosmetics industry
  • Food processing industry
  • Electrical and electronic engineering
  • Precision engineering and optics
  • Aerospace industry
  • Research and development
  • Microstructure techniques
  • Nanotechniques
  • Plastics and ceramics
  • Textiles
  • Surface techniques

The advantages

The advantages of using the Votsch VVT Vacuum Oven:

Heat-sensitive mediums (e. g. pharmaceutical products) are dried with care.

Reduced drying times due to lowering of the pressure.

Due to the extremely low remaining oxygen content in the drying oven there are no oxidation processes.

Evaporating fluids (e. g. solvents) can be recovered.

Optimum drying conditions for light, powdery products as there is no turbulence (no convection).

No “skin-forming” on the product being dried; therefore constant drying performance.

Economic because steam or warm water from other processes can be used as a heat medium.

Flexible heating.

Range of applications.

Design

Our vacuum drying ovens are of compact design. The major components are:

  • Drying oven with shelves
  • Heating and cooling aggregate for the thermal medium
  • Vacuum pump
  • Condenser with storage vessel

Construction features

All components of the drying oven itself are of stainless steel with material class 1.4571 as these may come into contact with the product. The external housing and reinforcements are made of stainless steel with the material class 1.4301.

The interior of the drying oven is designed in compliance with GMP-/FDA regulations. This is important when the product being dried should on no account react to other substances or when product entrainment shall be prevented during loading/unloading.

Heating modes

We offer four heating solutions:

  • Electrical
  • With heating medium
  • Infrared radiation
  • Microwave (HF)

The first two processes are based on the principle of contact heating. This means that the heat is conducted from the heat medium through contact areas to the product. With the electrical version, tubular heaters are fed in coils through the hollow shelves (sandwich construction). With the version using heat medium you have three possibilities:

  • Warm water
  • Thermal oil
  • Steam

If you wish to heat using a heat medium, we equip the drying oven with pressure-tight, hollow shelves.

The difference from the electrical version is that the heat transfer medium flows through channels and then fills the entire cavity of the shelf. A separate thermostat controls the temperature of the heat medium. The heated medium is pumped in a cycle through the individual shelves. With the steam heating version a special valve is responsible for controlling the amount of steam. This control operates without auxiliary power so that it is possible to use this type of control in an explosion-proof room. With steam it is possible to heat in two different ways, the temperature of the steam being important:

- When T is

- When T is >100 °C the steam is fed into the distribution system for the shelves.

  • Inspection glass (200 mm diameter) in the door
  • Heat-resistant silicon seal in the door
  • Seals can be easily replaced when necessary
  • Double-jointed hinge to ensure that the door closes tightly and prevents overwearing the seals
  • Additional flanges are provided for special applications
  • Heating modes - electrical, warm water, thermal oil and steam
  • Infrared radiation
  • Microwave (HF)

Temperature range

The maximum rated temperatures that can be reached at the product being dried depend upon the mode of heating used for the drying oven.

Mode of Maximum Heating     Temperature in °C

Electric                               200 / 400

Warm water                        95 / 140

Thermal oil                          200 / 250

Steam                                according to the steam pressure

- Use of special materials for all components that come into contact with evaporating fluids (e. g. Inconel,

Hasteloy)

- Combination with recirculation air for heating up of products at normal atmosphere

- Design in accordance with GMP-/FDA

- Qualification documents are issued as verification of our tests

- In order to avoid condensation in the drying oven, the door and walls can be heated

- Pneumatically-controlled doors for the automatic loading of the drying oven

- Designed for high-vacuum processes

- Special dimensions

- Special vacuum pumps

- S!MPATI* Software

- Digital pressure display

- Pressure control in conjunction with a solenoid valve in the suction line

- Temperature sensor for product being dried

- Nitrogen supply for quick extraction of released vapour

- For aggressive solvents: door seals of viton or with FEP cover

- External housing with surrounding frame for installation in wall.

Please refer to PDF brochure for further details.