General Purpose Freeze Dryers

The FDL series general purpose freeze dryer features rectangular product chamber which offers the highest space using rate (>90%). All the shelves and product trays have the same size which is easy to handle.

The drying chamber is engineered and produced strictly follow pressure vessel directive, stainless steel made, long lifespan and never distortion. External of the drying chamber wall, up to 150mm thick PUF is covered for insulation.

The vapor collect condenser is external type, can be installed behind/beneath/lateral of the product chamber, connect to it by a stainless steel pipe, a pneumatic operated butterfly valve can be installed to isolate the condenser and to perform pressure rise test.

A group of stainless steel coils are installed in condenser chamber to collect vapors, cooled by refrigerant direct expand, each compressor has an independent circuit to guarantee the temperature uniformity.

The shelf system is always temperature controlled: silicone oil circulates inside sandwich type heat-plates for product pre-freezing and later heating for sublimation. The shelves are cooled through a brazed plate heat exchanger and are heated by an electric bar. PID control, heating and cooling rate >1C/Min.

An additional heat-plate is installed on top of shelf module to provide extra energy for thermal balance. Temperature sensors have been installed on both the fluid inlet and return pipe, as well as the fluid heating bar point, to control and monitor shelves temperature. Temperature variance between heat-plates and plate points are less than +/-1C.

Subsystems such as vacuum pumps, refrigeration compressors, heat transfer fluid pump and heaters are placed below and behind the condenser/chamber. Each sub-system as an individual module and linked together by the PLC. This design has been proved easy to install and maintain.

A wide range of accessories and options can be selected to match the particular needs of customers, which deliver cost-effective solutions.

PLC and user-friendly HMI based control system is applied to FDL commercial freeze dryer, to perform interlock checks, monitoring system working status, execute freeze drying processes and generate alarms. Which has the following functions.

• Interlock checks and sound-light alarms.
• Graphic displays system working status and key parameters.
• Freeze drying recipes management.
• Real-time freeze drying curve and historical trend review.
• Drying data-logging and can be exported via USB.
• Automatic and semi-automatic working.
• Users and authorizations.
• Sensors calibration

For production environment processes where minimal contamination is essential, the FDL freeze dryers offer in-place freezing function to reduce materials transfer frequency. Raw products are placed on shelves in product chamber, in-place freezing and later heating for sublimation, automatic vacuum freeze drying process.