PREPARATION OF ARGON

摘要

PURPOSE:To prepare Ar gas in a high recovery ratio, by returning Ar gas used for washing and regenerating a nitrogen adsorbent and oxygen adsorbent to a rectifying column of an air low temperature separation apparatus. CONSTITUTION:A mixed gas of Ar with O and N taken out of the upper rectifying column 2 of a rectifying column 1 in a low temperature air separation apparatus is heated in a heat exchanger 3, and pressurized in a compressor 4, introduced into the first-stage adsorber (5a) of an adsorption apparatus 5 to adsorb and remove N2 in a nitrogen adsorption cylinder (5a-MS). The gas is then passed through a pipe (6a) and valve (7a) and introduced into an oxygen adsorption cylinder (5a-CS) to adsorb and remove the O2 and give the aimed Ar gas. On the other hand, valves (8c) and (9c) of the third adsorber (5c) after completing the adsorption stage are closed to open a valve (11c) and reduce the pressure of the third adsorber (5c) to almost atmospheric pressure. Thus, N and O adsorbed in the nitrogen and oxygen adsorption cylinders (5c- MS) and (5c-CS) are desorbed. A valve (7b) of the second adsorber (5b) after completing the desorption stage under reduced pressure is closed to feed O from the apparatus 1 through a valve 16, pipe 15 and valve 14 to the nitrogen adsorption cylinder (5c-MS) to wash and regenerate the nitrogen adsorbent. The Ar is partially fed to the oxygen adsorbent cylinder (5b-CS) to wash and regenerate the oxygen adsorbent, and the resultant gas is then introduced into the rectifying column 2.