| 摘要 |
PURPOSE: To ensure improvement of flexibility of an operation and reduction of necessity of heat pumping work, by forming reboiling to a low pressure fractionating column and a reflux to high and low fractionating columns by operating a heat pump cycle. CONSTITUTION: A heat pumping cycle is constructed with taking-out of a nitrogen vapor stream from a fractionating column 6 through an outlet 32, heating of the stream in a heat exchanger 2, compression of the stream in a compressor 34, temperature relowering of the same in the heat exchanger 2, condensation of the same in a reboiler 26, reintroduction from an inlet 24 to the column 6, and a phase change due to homogeneous exchange with an ascending vapor stream in the column 4. In this cycle, there is actually existent a heat flow up to relatively high temperature at a bottom of the column 6 where the reboiler 26 is disposed from low temperature at a top of the column 6. The amount of nitrogen flowing through the heat pump cycle can be selected such that a liquid/vapor ratio at both columns 4, 6 is optimum. Further, being different from an ordinary double column operation pressures in both fractionating columns 4, 6 can be set independent of each other.
|
