| 摘要 |
<p>PURPOSE:To promote high purity characteristics of product nitrogen by a method wherein a part of liquid nitrogen after component of low boiling point such as hydrogen and the like is fed out of a refining tower, component of low boiling point not refined and separated is removed under a gas-liquid separation and at the same time the separated liquid nitrogen is gasified. CONSTITUTION:Raw material air is supplied to a lower part refining tower 5 of a complex type refining tower, where gaseous nitrogen refined and separated is condensed and liquefied by a condensor 15. The condensed and liquefied liquid nitrogen is fed again into the top part of a single refining tower 5 as the returning liquid. In addition, a part of the returning liquid is fed out of the single refining tower 5, gasified and then product of nitrogen is manufactured. At this time, hydrogen and carbon monoxide contained in the raw material air are oxidized and at the same time the oxidized moisture content and carbon dioxide are removed. After this operation, the raw material air is supplied from a supplying passage P4 to a lower refining tower 5. Liquid nitrogen fed out of the discharging passage P13 is separated into gas and liquid by a gas-liquid separator 10, and the separated gas is discharged out of a discharging passage 31. In turn, the separated liquid nitrogen is gasified by a gasifying means 11.</p> |
