| 摘要 |
<p>A procedure for separating air uses a two-column separator in which a fluid is transferred via a rising duct with a first pressure reducing valve from a first column operating at one pressure to a second one operating at a lower pressure. The procedure uses a two-column separator (1) in which a fluid is transferred via a rising duct (6, 9, 12, 34) with a first pressure reducing valve (7, 10, 13, 35) from a first column operating at one pressure to a second one (3) operating at a lower pressure. A lightening gas is expanded to an injection pressure and injected into the rising duct after the first pressure reducing valve, a flow of purified and cooled compressed air is sent to the first of the columns (2), and a fluid rich in nitrogen (16) and another rich in oxygen (15) are drawn from the second column (3). A second pressure reducing valve (22, 23, 25, 27) is opened only when pv is below 3000 Pa (p being the density of the rising fluid and v the speed at which is rises in the duct at the outlet from the first valve).</p> |
