Heating System of Freeze Dryers (Part Five)

TOFFON Freeze Dryer - Heating System of Freeze Dryers (Part Five)

The heating system of a freeze dryer can employ different heating methods depending on the machine type. One method utilizes direct electric heating, while another uses an intermediate medium for heating, circulated continuously by a pump.

The function of the heating system is to supply heat to the products inside the freeze-drying chamber, enabling continuous sublimation of moisture within the products and achieving the specified residual moisture requirements. During operation, the heating system typically works in conjunction with the control system to precisely adjust the shelf temperature in stages according to a pre-set freeze-drying curve. In the primary drying stage, the temperature is increased slowly and steadily; during the secondary drying stage, the temperature is further raised to remove bound water, ensuring the final product’s moisture content meets requirements.

Precise control of the heating system is critical to the freeze-drying process. It must not only provide sufficient heat to promote the sublimation of ice crystals but also ensure uniform temperature distribution to avoid localized overheating that could cause product denaturation or structural damage.