| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cryogenic rectification system to reduce thermodynamic irreversibility of an argon column top condenser and a lower temperature column. SOLUTION: In the cryogenic rectification of feed air using argon columns 52 and 53 having a double column main plant with a higher pressure column 37 and a lower pressure column 38 and a top condenser 48, a part of feed air is condensed at a product boiler 36 to generate a liquid feed air, and the liquid feed air and gaseous feed air are passed through a stripping column 34 to generate a stripping column gaseous product having the concentration of nitrogen exceeding that of air and another stripping column liquid product having the concentration of oxygen exceeding 25 mol.%. Moreover, the former is passed through the higher column to be separated by cryogenic rectification and the latter is evaporated by indirect heat exchange with a fluid containing argon in the argon column top condenser to generate a gas containing oxygen. The gas containing oxygen is passed through the lower pressure column to be separated by cryogenic rectification. |
