LOW-TEMPERATURE HELIUM PURIFICATION METHOD Russian patent published in 2004 - IPC

FIELD: gas treatment and cryogenic engineering.

SUBSTANCE: method comprises adsorption of O₂ and N₂ impurities at 78-80 K in two commutating adsorbers, high-temperature regeneration at 100-120^оС, evacuation, and cooling to working adsorption temperature. In particular, different amounts of sorbents are poured into adsorbers and, in secondary adsorber with lesser amount of sorbent, adsorption time is so long as maximum adsorption time in primary adsorber, after which high-temperature regeneration is carried out in secondary adsorber. Then, high-temperature regeneration is carried out in secondary adsorber and, in primary adsorber with larger amount of adsorbent, high-temperature and low-temperature regenerations are conducted. The former is followed by, for instance, 2 cycles of adsorption purification and low-temperature three-step regeneration. In the first step of low-temperature regeneration, adsorber is heated to a temperature by 30-40 K above working temperature of absorption by circulating helium through adsorber. Absorption is conducted at the same pressure as that in the adsorption of impurities using ejection of helium with higher pressure and temperature 270-300 K. Simultaneously, from regenerated adsorber is discarded "dirty stream" in volume equal to stream ejected into secondary adsorber operated under purification conditions. In the second step, helium is released from adsorber and, in the third step, adsorber is heated to 5-10^оС by pumping pure warm helium through it and ejecting part of it into purification zone. Heating is accompanied by evacuation of adsorber space by periodically cutting up pure helium stream flowing through adsorber.

EFFECT: reduced power consumption and intensified regeneration stage.

1 dwg