| 摘要 |
A method of separating air comprising: (a) separating air by a low temp. rectification process having a cooling stage (20) for cooling compressed air to a temp. suitable for its rectification, a distillation stage (22) for distilling the air into fractions enriched in components of the air and process streams composed of the air and fractions of the air flowing between the cooling and distillation stages; (b) forming a product stream (24) enriched in one of the air fractions and discharging it from the process; (c) partially warming or cooling at least part of a process stream (28) to form a refrigerant stream; (d) turbo-expanding the refrigerant stream with the performance of work; (e) recovering refrigeration from the refrigerant stream (32) by fully warming the stream within the cooling stage; (f) after the refrigerant stream has fully warmed drawing the stream at subatmospheric pressure and building its pressure to at least atmospheric. Also claimed is an appts. for separating ng air comprising an incoming air stream (12) with a filter (14) main compressor (16) after-cooler (18) and prepurification unit (19), a main heat exchanger (20), an air separation unit (22), a turbo expander (30) and blower (34). |
