| 摘要 |
<p>The present invention is intended to provide a nitrous oxide producing method and unit which can produce nitrous oxide of ultra-high purity at a higher recovery. According to the present invention, a feed gas (2) comprising nitrous oxide and containing nitrogen, oxygen and water in a saturated state as impurities is compressed by compressor (4) and water in the compressed feed gas is removed by a drier (8), and then the feed gas is cooled down in a main heat exchanger (12) so as to form mixed gas-liquid nitrous oxide. Then, this mixed gas-liquid nitrous oxide is introduced into a rectification column (16), where it is rectified and separated through gas-liquid contact therein so that high purity liquefied nitrous oxide is reservoired in the bottom thereof. Nitrogen and oxygen in the high purity liquefied nitrous oxide are evaporated and stripped off by means of a boiler (18) making use of the mixed gas-liquid nitrous oxide as a heat source, whereby it can be purified to ultra-high purity liquefied nitrous oxide. <IMAGE></p> |
