The Atlas Ray™ Batch freeze drying pant is designed and delivered by GEA Niro. It is used for small and medium capacities of liquids like coffee concentrate, segments of/or whole fruits, berries, vegetables, shrimps, fish or meat products, or a combination of liquid and solid products like e.g. soups.

Common for all products is that they must appear in frozen form before the actual freeze drying. The Ray™ freeze drying plant is designed as a modular system with the cabinet – the vessel – with one door at one end for loading and unloading of the product to be freeze dried. The cabinet is usually made of stainless steel.

Inside the cabinet is placed a number of heating plates made of anodized aluminum. Hot water is circulated through the system to secure an efficient heat transfer by radiation to the product to be freeze dried. The water temperature can be regulated during the freeze drying process to achieve the optimal evaporation laps and avoid overheating of the products.

The product to be freeze dried is placed in a pre-weighed amount or by volume in frozen form on transloaded onto a wagon hanging on trolleys. By correct loading into the cabinet, the product trays are placed between the heating plates for optimal heat transfer by radiation. Direct contact between the product trap and heat plates must be avoided as heat damage of the product will be the result. The vapor condenser module made of stainless steel is build into the cabinet. Liquid NH₃ is circulated in a pipe, on which the sublimated water vapor will condense.

For the smaller Ray™ (8, 17, 30, 45, and 50) cabinets the condenser is flushed with warm water at the end of each freeze drying circle. The ice will melt within 10 minutes. This method ensures:

• Minimum investment costs
• Simple operation

The larger Ray™ (75, 100, 125, 150, 200, and 250) 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 operations) the section is sealed off while the other takes over the condensation function.

To melt the accumulated ice, water vapor (vacuum steam) at 25 ̊ C is 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 conditions any remaining vapor in the condenser chamber must be condensed by cooling it down until operating temperature and vacuum is reached. A direct over switch when the next de-icing cycle is needed can now be done without loss of operating vacuum.

The CDI system is fully automatic. It ensures:

• A maximum ice build up to 5 millimeter resulting in a neglicable temperature drop over the ice and a low energy consumption
• Constant condenser temperature
• High freeze drying capacity/m2 of tray surface
• Short time from one change to another
• Continuous de-icing

Freeze drying of bacteria 
The Ray™ freeze drying plant is also available in a fully sanitary design: the Ray™-S. It is used for freeze drying of bacteria, enzymes and similar sensitive products.

Freeze drying Factory
In all new projects the actual freeze drying cabinet is only part of the factory. GEA Niro has the experience and know-how to support you in plant layout to achieve optimal process facilities.

Pilot freeze drying plants
The Ray™ is also available in a pilot plant size Ray™-1. Here it is possible to establish drying curves, weight loss curves and temperature development during the freeze drying process. A plant that is a must if you want to develop new freeze dried products.