Working principle of freeze dryer
The amount of water vapor in the compressed air is determined by the temperature of the compressed air: while keeping the pressure of the compressed air basically unchanged, lowering the temperature of the compressed air can reduce the water vapor content in the compressed air, and the excess water vapor will condense Into liquid. The freeze dryer uses this principle to use refrigeration technology to dry compressed air. Therefore, the dryer has a refrigeration system. Front view of Gree freeze dryer principle
The refrigeration system of the freeze dryer is a compression refrigeration, which is composed of four basic components such as a refrigeration compressor, a condenser, an evaporator, and an expansion valve. They are connected by pipelines to form a closed system. The refrigerant circulates continuously in the system, changes state and exchanges heat with compressed air and cooling medium.
The refrigeration compressor draws the low-pressure (low-temperature) refrigerant in the evaporator into the compressor cylinder. The refrigerant vapor is compressed, and the pressure and temperature increase at the same time. The high-pressure and high-temperature refrigerant vapor is pressed to the condenser. In the condenser, The higher-temperature refrigerant vapor exchanges heat with the lower-temperature cooling water or air. The heat of the refrigerant is taken away by water or air and condensed. The refrigerant vapor becomes a liquid. This part of the liquid is sent to the expansion valve, which is throttled by the expansion valve to become a low-temperature and low-pressure liquid and enters the evaporator; the low-temperature, low-pressure refrigerant liquid in the evaporator absorbs the heat of compressed air and vaporizes (commonly known as "evaporation") After the compressed air is cooled, a large amount of liquid water is condensed; the refrigerant vapor in the evaporator is sucked away by the compressor, so that the refrigerant passes through the four processes of compression, condensation, throttling, and evaporation in the system, thereby Completed a cycle.
In the refrigeration system of the freeze dryer, the evaporator is a device that transports cold energy, in which the refrigerant absorbs the heat of the compressed air to achieve the purpose of dehydration and drying. The compressor is the heart and plays the role of sucking, compressing, and delivering refrigerant vapor. The condenser is a device that releases heat, and transfers the heat absorbed in the evaporator together with the heat converted by the input power of the compressor to the cooling medium (such as water or air) to take away. The expansion valve/throttle valve has a throttling and pressure-reducing effect on the refrigerant, and simultaneously controls and regulates the amount of refrigerant liquid flowing into the evaporator, and divides the system into two parts, a high-pressure side and a low-pressure side.
1.Stainless steel is polished with excellent brand to ensure surface roughness to ensure sterility requirements
2.Cabinet, board level,and hose are tested after multiple procedures to ensure without leakage
3.Screw compressor is used Blitzer refrigeration compressor, more stable performance, reliable, easy to maintain
4.Temperature and pressure of compressor has multiple protection features
5.Suction filter settings, prevent degeneration of stolen goods and acid materials into the compressor chamber , corrosion internal parts and refrigeration oil.
6.Exhaust temperature protection set to avoid oil degeneration in extreme conditions , to reduce the exhaust temperature by cooling motor
7.Compliance with the Montreal Convention, with environmentally friendly refrigerants;
SED-50DG Vacuum Freeze Dryer
Cooling water Quantity
Defrost water Quantity