The RAY™ batch freeze drying plant is designed for production of small-to-medium-volume products such as instant coffee and tea, freeze dried fruit, vegetables, meat, seafood and prepared meals. It is also available in a fully sanitary design for freeze drying of bacteria, enzymes, and other bioactive products.
The RAY™ batch freeze drying plant is a cabinet with a door for loading and unloading.
Inside the cabinet are a number of heating plates made of anodized aluminium. Hot water is circulated through the system to ensure efficient heat transfer by radiation of the product to be freeze dried. The water temperature can be regulated during the freeze drying process in order to achieve optimal evaporation laps and avoid overheating of the products.
The product is placed on a wagon hanging on trolleys in a pre-weighed amount or by volume in frozen form. By correct loading of the cabinet, the product trays are placed between the heating plates for optimal heat transfer by radiation. Direct contact between the product trap and the heat plates must be avoided as heat can damage the product. The vapor condenser module made of stainless steel is built into the cabinet. Liquid NH3 is circulated in a pipe on which the sublimated water vapor will condense.
The larger RAY™ (size 75, 100, and 125) cabinets are equipped with a duplex vapor condenser for Continuous De-Icing (CDI). When one of the vapor condensers has to be de-iced (typically after one hour of operation), the section is sealed off while the other takes over the condensation function.
To melt the accumulated ice, 25 ̊ C water vapor (vacuum steam) will be led into the room. The water vapor will now condense on the cold icy surface of the condenser and thus melt the ice. In order to restore the de-iced condenser to operating condition, any remaining vapor in the condenser chamber must be condensed by cooling it down until operating temperature and vacuum is reached. A direct switch-over when the next de-icing cycle is needed can now be done without loss of operating vacuum.
Depending on the size, the RAY™ Freeze Dryers are either equipped with an internal vapor condenser with the built-in de-icing system, unique to GEA, or a water-flushing de-icing system. Compared with external condenser systems, the first system not only saves space, it is more reliable, does not cause product loss, and it consumes less energy and thus ensures the best overall equipment efficiency. A water-flushing de-icing system, ensuring minimum investment costs and a simple operation, is the most feasible solution for small installations.
