| 摘要 |
<p>PURPOSE: To efficiently generate a liquid product by providing high- and low-pressure distillation columns so that heat can be transferred, by producing a nitrogen product in the low-pressure distillation column for separating it from air, and by combining the partial warming of the nitrogen product with each process of expansion and freezing. CONSTITUTION: Compressed air where CO2 and other constituents are eliminated is sent to a main heat exchanger 900 by a pipeline 101, is cooled to temperature close to the dew point, is sent to a high-pressure column 902, and is rectified to a high- pressure nitrogen overhead and high-oxygen residual liquid. One part of the high- pressure nitrogen overhead is eliminated by a pipeline 120, is brought into contact with boiling liquid oxygen by a reboiler/condenser 912, is condensed, and is separated into two parts. Then, one part is returned to the upper part of the high-pressure distillation column 902 as liquid reflux, and the remaining part is eliminated by a pipeline 135, is subjected to warming by the main heat exchanger 900, and is taken out as a high-pressure nitrogen product. The high-oxygen residual liquid is excessively cooled, is flushed, is sent to a low-pressure distillation column 904, and is distilled to the low-pressure nitrogen overhead and liquid oxygen residual liquid.</p> |
