taux de sublimation

CONT: A Unique Freeze Dryer Shelf and Condenser Chilling System. Most lyophilizers (freeze dryers) are designed with a single refrigeration system, which is required to switch from product chilling to condenser cooling in the lyophilization phase. If the shelf heating cycle should demand both cooling and heating to maintain a given temperature set point during the drying phase (as is the case with long and slow shelf temperature rises), the refrigeration system must operate in the dual role of cooling both the shelves and the condenser in order to maintain operational vacuum. If the sublimation rate from the product is high, this can often result in the refrigeration systems inability to meet both requirements. Most manufacturers attempt to compensate for these conditions by oversizing the compressor, which can lead to overloading in the terminal phase, resulting in reducing compressor life and reliability.