| 摘要 |
<p>A cooled, purified air feed 84 is admitted to a distillation column 70 provided with a reboiler 76 at its bottom and a condenser 78 at its top. Gaseous nitrogen collects at the top of the column 70 and liquid oxygen at the bottom thereof. A stream 86 relatively rich in argon is taken from an intermediate level of the column 70 and is rectified in an auxiliary distillation column 72 to yield a stream 89 of argon product. A liquid oxygen stream is passed from the bottom of the column 70 to the top of a liquid-vapour contact column 74 and mixing it therein with a vaporous nitrogen stream taken from the inlet side of the condenser 78. A mixed oxygen-nitrogen 'waste' stream is discharged from the column 74 through an outlet 98.
<??>Gaseous oxygen is withdrawn from the top of the column 74, and a part of it is returned to the column 70 and the rest is condensed in a condenser 97 with the resulting liquid being united with the liquid oxygen from the column 70. A liquid nitrogen stream 94 is returned from the bottom of the column 74 to near the top of the column 70 so as to reduce the requirements for external heat pumping duty for condenser 78 and thus reduce the specific power consumption of the plant in respect of the production of argon.</p> |
