The use of Polycold to trap water vapor is a concept developed by Dale Meissner in the 1970s as a way to speed up vacuum chamber evacuation and reduce base pressure to enhance vacuum coating. In an evacuation system, you can remove gas molecules from the chamber or, in the case of water vapor, change the state of the gas by condensing (trapping) water vapor molecules on a cold surface.
some scientific principles
When the chamber is pumped from the atmosphere, between ~10-3 to ~10-8 Torr, 65% to 95% of the molecules in the chamber are water vapor. Whenever the vacuum system is opened to the air, the inner surface of the chamber will be covered with layer after layer of water molecules. The thickness of this layer will depend on the relative humidity of the air, exposure history, etc. As the vacuum pressure in the chamber decreases, this water vapor is released from the walls and surfaces of the chamber, which must then be pumped or collected further afield. Reduce the pressure in the chamber.
Mechanical traps like the XIEYI CRYOCHILLER use refrigerant to cool stainless steel or copper coils in the chamber. The ability of this coil to trap water vapor depends primarily on the amount of cryogenic cooling surface area in the chamber. As water vapors are released from walls or other interior chamber surfaces, they must be pumped or trapped to further reduce the vacuum pressure in the chamber. If you increase the number of coils in the chamber, the ability to trap water vapor molecules increases as they “bounce” around the chamber.
in conclusion
The XIEYI CRYO CHILLER is essential for quickly evacuating vacuum chambers for production applications. In addition to speeding up the elimination of water vapor molecules in the chamber, it also reduces the vacuum base pressure and improves the quality of vacuum coatings in many applications. Using an appropriately sized XIEYI Water vapor pump to increase the surface area of the copper or stainless steel coils can increase the yield.
Post time: Apr-01-2022