| 摘要 |
In a cryogenic air separation plant, a reversing heat exchanger has switching passes 4 and 6 for an incoming air stream and a "waste" nitrogen stream, and a pass 8 for product nitrogen. As shown in the drawing, water vapour and carbon dioxide previously deposited in pass 6 are resublimed by the waste nitrogen stream. The resulting impurity laden nitrogen stream is compressed in compressor 10 and purified in membrane separator 18. The resultant purified nitrogen stream may be expanded in an expansion turbine 24. The yield of nitrogen from an air separation plant may thus be increased. If desired, the membrane separator 18 may be retro-fitted to a cryogenic air separation plant. <IMAGE> |
