| 摘要 |
PURPOSE:To minimize time delay for control and permit the collection of product oxygen and argon with a high recovery rate by a method wherein the heat of material air, generating cold heat, and the heat of one part of the product oxygen, fractionated and separated in a fractionating tower, are exchanged and the temperature of the product oxygen is regulated by controlling the flow rate of the product oxygen to adjust the collecting amount of oxygen and argon. CONSTITUTION:When the set temperature of a temperature regulating meter 22 is elevated, sufficient cold heat recovery is effected by a turbine low temperature heat exchanger 8 and a valve 12 is operated so as to be opened while another valve 13 is operated so as to be closed. According to these operations, the temperature of product oxygen, supplied to an air heat exchanger 1, is increased and, therefore, the amount of cold heat is reduced. Accordingly, the flow rate of material air, supplied to the lower tower 2 of a fractionating tower, is not changed but the temperature of the same is increased. According to this increase, a heat load for a main condenser 3 is increased and ascending gas in the upper tower 4 of the fractionating tower is increased whereby a ratio (L/V ratio) with respect to the amount of descending liquid becomes small and fractionating operation becomes easy. The change of a temperature distribution in the tower becomes possible without changing the processing amount of material air for the upper tower 4 of the fractionating tower under a condition that the condition of the lower tower 2 of the fractionating tower is not changed substantially.
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