Working principle and schematic diagram of cryogenic pump
The working principle of cryogenic pump is to exhaust gas by physical adsorption on the ultra-low temperature surface.
The cryogenic pump can achieve extremely high vacuum (10-11 Pa) and has the advantages of fast exhaust speed, no oil and unlimited installation direction. Its structure is shown in figure 1.
FIG. 1 schematic diagram of cryogenic pump structure
1 - first stage cooling table; 2 - secondary cooling table; 3 - cryogenic cover; 4 - shielding cover; 5 - baffle
The first stage cold table of cryogenic pump is equipped with shield cover and baffle, and the temperature is maintained at 80K. The secondary cooling table is maintained at 15K, on which a low temperature cover and activated carbon adsorbent are set.
Water vapor solidifies on the 80K shield and 80K baffle. Nitrogen, oxygen and argon are solidified on a 15K cryogenic mask. Hydrogen, helium, and neon are adsorbed onto the adsorbent on the inside of the 15K low temperature housing. The cryogenic pump can exhaust all gases, but if too much gas is absorbed, the exhaust speed decreases. At this point, the cryogenic pump needs to be heated to release the adsorbed gas and reused.