VFD Vacuum Freeze Drying

Flavour and vitamin-preserving freeze-drying of coffee and fruit on an industrial scale

Features of vacuum freeze drying:

• Leading process for the production of instant coffee, e.g. Robusta or Arabica, as well as freeze-dried fruit
• High-quality, reproducible product quality with natural flavour
• Plant size from 2,500 to 6,000 t/year

Production process that conserves raw materials in 8 perfectly coordinated plant steps

1. Cooling of the coffee concentrate and mixing with frozen coffee dust.

2. Continuous stirring of the coffee extract to allow ice crystals to grow in a controlled manner.
3. Transfer of the coffee extract to an air-cooled steel belt and freezing at -50 °C.
4. Transfer of the frozen coffee extract to a cold room with a mill for further processing into coffee granules with a size of 0.5–2.5 mm.
5. Transport of the freeze-drying trays clamped in hanging trolleys into the vacuum tunnel.
6. Start of the freeze-drying process with automatic pressure and temperature control.
   

   · The energy required for this is provided by heating plates
   · Pressure and temperature equalisation by raising and lowering the hanging trolleys
   · Separation of the water vapour via ammonia-cooled condensers

7. Removal of the hanging baskets and discharge of the freeze-dried coffee granules by turning them 180°.
8. Visual inspection and cleaning of the hanging baskets and return for cooling and reloading with coffee granules.

1. Freezing chamber 2. Loading chamber 3. Automatic tray filling station 4. Entry lock 5. Condenser 6. Vacuum pump system 7. Vacuum-tight shut-off valve 8. Vacuum chamber 9. Heating plates 10. Exit gate 11. Unloading station 12. Product outfeed 13. Washing machine 14. Monorail system for transporting carriers 15. Load carriers 16. Pre-cooling line for carriers