| 摘要 |
PURPOSE:To improve the performance of a rectifying column without making larger the heat transfer area of a changeover heat exchanger, by delivering a portion of air introduced through a reheating circuit of the changeover heat exchanger to an expansion turbine, then after heat-exchange with liq. O2 or N2, by injecting it into the upper part of the low press. tower or lower part of the medium press. tower. CONSTITUTION:In large size air separation plant, because air quantity to be reheated by a changeover heat exchanger 2 is larger than that sent by a turbine, the surplus air over the turbine capacity is extracted from the reheating circuit 7 of the heat exchanger 2 thorugh a duct 16. The extracted air is introduced into a reboiler condenser 5 arranged between the medium press. tower 4 and the lower press. tower 6 of a duplex rectifying column, where it interchanges heat with liq. O2 and is cooled nearly to the saturation temp. of the liq. O2, then it is expanded to 0.3 kg/cm<2>G through a valve 18, and is blown into the upper part of the low press. tower 6. |
