摘要 |
An air separation process of the "pumped" type, in which liquid oxygen is removed from a double distillation column and is pumped to a higher production pressure and then vaporized under that pressure. The incoming air is divided into several streams. A first stream is compressed to the medium pressure, cooled and sent to the double distillation column (7). A second stream is compressed above about 25 bars, but below its condensation pressure during vaporization of the liquid oxygen under pressure, then cooled to an intermediate temperature, at which a portion of the air continues its cooling and is liquified (in 20A), then expanded (in 21A) and sent to the double column, while the rest is work expanded (in 4). Use in large size installations for the production of oxygen.
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