| 摘要 |
<p>PURPOSE: To raise the recovery rate of argon, by using a heat pump cycle for transmitting cold from the bottom of a low-pressure distilling column to the top of a crude argon distilling column, and using a heat pump fluid having a nitrogen content equal to or greater than material air with the heat pump cycle. CONSTITUTION: A flow 50 includes a heat pump fluid, and besides consists of a part of the amount for a nitrogen column head from a high-pressure distilling tower 107 which is condensed, being heat-exchanged with liquid nitrogen for gasification from a low-pressure distilling column 119 with a boiler/condenser 115. Moreover, the flow 51 where the pressure of a heat pump fluid has dropped is gasified, with the heat exchange for liquefying a part of the amount for the column head in a crude argon distilling column 135 being performed with a boiler/condenser 128. Furthermore, the gasified heat pump fluid of the flow 52 is condensed to a proper pressure within a compressor 58 through each sub cooler 126 and 127 and a main heat exchanger 105, and also is cooled with a cooler 59 and the main heat exchanger 105. Then, the low- temperature pump fluid of a flow 237 is circulated again to the column head of the high-pressure distilling column 107.</p> |
