摘要 |
<p>A unit capable of simultaneously producing nitrogen of ultra high purity and liquid oxygen of ultra high purity, is provided. The inside of a first rectification column 6 includes an upper rectifying part 12, an upper-stage middle rectifying part 13, a lower-stage middle rectifying part 14 and a lower rectifying part 15. To the upper part 11 above the upper rectifying part 12 is connected a nitrogen condenser 8. A second rectification column 7 includes an upper rectifying part 22 and a lower rectifying part 23, and has a reboiler 25 provided under its lower rectifying part 22. Ultra high purity liquid nitrogen is recovered from between the upper rectifying part 12 and upper-stage middle rectifying part 13 of the first rectification column 6, and ultra high purity liquid oxygen is recovered from below the lower rectifying part 23 of the second rectification column 7. <IMAGE></p> |