| 摘要 |
<p>Air is compressed in compressor 200, is reduced in temperature to its dew point by passage through successive heat exchangers 204, 206, 210 and 212 (water and carbon dioxide being removed therefrom in heat exchangers 204 and 206). The air is introduced into a first distillation column 216 through an inlet 218. It is separated into oxygen and nitrogen therein. Nitrogen vapour is withdrawn from the top of the column 216 through outlet 228, is warmed, is compressed in compressors 234 and 236, is cooled, is expanded in expansion turbine 238 and is then passed through a reboiler 220 to provide reboil for the column 216. A resulting liquid stream is passed through a throttling valve 244 and liquid nitrogen is collected in phase separator 230. Some of this liquid nitrogen is returned to the column 216 as reflux, while another part is used to provide product. Argon-enriched oxygen vapour is withdrawn from the column 216 through an outlet 260, and is separated to form argon product in a further distillation column 226 which is reboiled by vapour from the top of the column 216.</p> |
