| 摘要 |
PURPOSE:High Ar recovery rate is provided by using impure N2 with low Ar content obtanined from rectifying lower tower, as cooling agent for crude AR condenser. CONSTITUTION:A portion of reflux liquid is taken out from the lower tower 3 of the combined type rectifying tower 1. The liquid is passed through the pipe d and the expansion valve 11, and used as cooling agent for the condenser 7 of the crude Ar tower 4. The liquid exchanges heat with the condenser 7 and gasifies, then returns to the top tower 2 through the pipe e. To prevent possible Ar solidification at the top of the tower 4, which might be caused by temperature decrease of cooling agent, the cooling agent outlet (pipe d) of the lower tower 3 should be installed below the outlet of the impure N2 (pipe b). Through this process, Ar concentration is decreased in impure N2 and Ar escape from impure N2 is reduced. Thus, high- content Ar gas is supplied from the lower portion of the top tower 2 to the tower 4, resulting in increased amount of crude Ar, that is, a high rate Ar recovery. |
