The amount of water vapor in the compressed air is determined by the temperature of the compressed air: Reducing the temperature of the compressed air reduces the water vapor content of the compressed air while maintaining the pressure of the compressed air substantially constant, while excess water vapor condenses Into liquid. Freeze dryer is the use of this principle of refrigeration technology to dry compressed air. Therefore, the dryer has a refrigeration system. Gree freeze dryer principle front view
Freeze-drying refrigeration system belongs to the compression refrigeration, refrigeration compressor, condenser, evaporator, expansion valve and other four basic components. They are connected by pipes, forming a closed system where the refrigerant circulates continuously, changes in state, and exchanges heat with compressed air and cooling medium.
The refrigerant compressor sucks the low-pressure (low-temperature) refrigerant in the evaporator into the compressor cylinder, the refrigerant vapor is compressed, the pressure and the temperature increase at the same time; the high-pressure and high-temperature refrigerant vapor is pressed to the condenser, The higher temperature refrigerant vapor exchanges heat with the cooler water or air at a lower temperature, the heat of the refrigerant is condensed by the entrainment of water or air, and the refrigerant vapor becomes liquid. This part of the liquid is then sent to the expansion valve, the expansion valve throttling into low temperature and low pressure liquid and into the evaporator; in the evaporator, the low temperature, low pressure refrigerant liquid absorbs the heat of compressed air to vaporize (commonly known as "evaporation"), , While the compressed air is cooled to condense a large amount of liquid water; the refrigerant vapor in the evaporator is again sucked by the compressor, so that the refrigerant undergoes the four processes of compression, condensation, throttling and evaporation in the system Completed a loop.
In the freeze dryer refrigeration system, the evaporator is the transport of cold equipment, in which the refrigerant absorbs the heat of compressed air, to achieve dehydration and drying purposes. Compressor is the heart, plays the role of inhalation, compression, conveying refrigerant vapor. Condenser is a device that emits heat and conveys the heat absorbed by the evaporator to the cooling medium (such as water or air) along with the heat converted by the compressor's input power. The expansion valve / throttle valve plays a role of reducing the pressure of the refrigerant in the throttle and simultaneously controls and regulates the quantity of the refrigerant liquid flowing into the evaporator, and divides the system into two parts of a high pressure side and a low pressure side.
http://www.sumerinstrument.com