| 摘要 |
PROBLEM TO BE SOLVED: To mitigate an unbalance in a reflux ratio upon controlling the amount of increasing or decreasing by a method wherein a crude argon tower is provided with a liquid reservoir, for reserving reflux liquid, and a means for regulating the flow rate of the reflux liquid which flows through a route via the liquid reservoir. SOLUTION: A liquefying argon route 70 is provided with a liquid reservoir 6, a flow rate indicating and regulater meter 21 and a regulating valve 21V on the way of the same. According to this method, the amount of reflux liquid in the crude argon tower 7 can be set arbitrarily in accordance with the operating condition of a device. Accordingly, the changing amount of the reflux liquid upon controlling the increasing or decreasing amount of the device is permitted to be changed while preceding the changing amount of ascending gas whereby the fluctuation of purity of crude argon can be reduced. Further, an upper tower 2 and the like, which receive the affection of operating condition of the crude argon tower 7, can be retained in the optimum operating condition whereby the fluctuation of purity of product oxygen gas and the like can be reduced and the purity of respective product gas will not be deteriorated to a purity lower than a specified purity.
|
