| 摘要 |
<p>968,019. Cold separation of gas mixtures. A. HARMENS. Aug. 19, 1963, No. 32706/63 Heading F4P. Product nitrogen-lean gas is obtained from a nitrogen-rich feed gas mixture, e.g. natural hydrocarbon gas by liquefying the latter in a pass 17 of the reboiler 18 of a separating column 27 to which the liquid is fed through a duct 20, 26, withdrawing nitrogen - lean liquid from the base of column 27 through ducts 28, 30, cooling it in the warm side 21 of an aftercooler 22, reducing its pressure at a valve 32, vaporizing the so-cooled and expanded liquid in a heat exchanger 35 serving to condense nitrogen rich top gas of column 27 and withdrawing the nitrogen-lean gas through a duct 37 and discharging it as product through a duct 40. A portion of the condensed top gas is returned through a duct 44 as reflux whilst the remainder is expanded at a valve 45 into a separator 47 from which nitrogen gas is withdrawn through ducts 53, 54 and from which liquid nitrogen is expanded to ambient pressure at a valve 49 and passed to a storage tank 51. The after-cooler 22 also serves to cool the liquefied feed gas prior to its expansion at a valve 25 and entry into the column 27 and the after-cooler is cooled by an external refrigerant, e.g. liquefied natural gas admitted through at duct 55 and expansion valve 56. The resulting refrigerant vapour is added to product nitrogenlean gas in duct 37 whilst the residual liquid refrigerant is forced by a pump 59 into the product duct 40 after having cooled the feed gas mixture in an exchanger 12.</p> |
