Specialist Cryogenics for Safe and Reliable Pharmaceutical Freeze-drying

Lauda has completed a cryogenic cooling system for use in a pharmaceutical freeze-drying plant. The order was placed by Martin Christ Gefriertrocknungsanlagen GmbH who relies on the expertise of Lauda for the reliable provision of the deep-freeze environment.

Precise temperature control for the freeze-dryer is provided by a Lauda Kryopac Secondary Circuit Unit, which enables cryogenic reactions to be safely controlled. The possibility of individual temperature control of the shelves and the ice condenser is of great importance in this refrigeration system. The Kryopac, a heat exchanger specially developed for the evaporation of liquid nitrogen, is the heart of the system. Depending on the design of the Kryopac system, temperatures down to -115°C are possible in the secondary refrigerant oil circuit. The -80°C required for the freeze-dryer is therefore reached quickly and exactly to the degree. Other advantages include low investment costs and lack of waste products.

The heat technology of the Kryopac system produces a temperature-controlled liquid flow and are delivered as a compact, fully insulated, ready-to-connect system with a control cabinet. Precise temperature control, compact design and high plant availability were particularly important for Martin Christ's customer. The Lauda A Kryopac Secondary Circuit Unit also meets these requirements without any problems.

The refrigeration system of the Kryopac system cools the shelves on which vessels filled with drugs are placed with a cooling capacity of 30 kW at - 80°C and freezes the pharmaceuticals in two and a half hours. Heat is supplied during evacuation, the removal of air by creating a vacuum. This results in a physical phenomenon called sublimation: The frozen water evaporates without liquefying. The drug is dried directly from the frozen state. The resulting water vapour is deposited on the ice condenser of the freeze-dryer in the form of ice crystals. The ice condenser is maintained at a temperature of -80°C by the Kryopac system. A complete freeze-drying process typically takes 48 hours.

The Kryopac system was initially completely tested at Lauda and then subjected to a further thorough inspection as a complete system at Martin Christ before the freeze-dryer was delivered to the end customer. As a result of the successful working relationship and implementation of this project, Martin Christ has already ordered two more Lauda Kryopac Secondary Circuit Units.

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