GB190216615A - Improvements in the Separation of Gases from their Mixtures, especially Oxygen and Nitrogen from Atmospheric Air and Apparatus therefor. - Google Patents

Abstract

16,615. LÚvy, R. J., and Helbronner, A. July 26. Oxygen; nitrogen.-The invention is described for separating oxygen and nitrogen from air, but is applicable for separating other gaseous mixtures into their constituents. A column a, protected from loss of cold, is divided by partitions b into say, twelve compartments 1 to 12. Each plate has an overflow pipe d<1>, or a valved outlet as shown to the lowest plate b<1>. Each plate, excepting b<1>, has a central opening with a tube c' covered by a hood g having a star-shaped flange with end projections resting upon the p'ate, which forces ascending gases to pass through the liquid in the tray. To start operations, liquid air is poured into the top compartment through an inlet P, and overflows so as to charge each compartment as high as its outlet. Dry compressed air is cooled as explained below, and is then led through tubes e, e', e<2>, e<3> to coils E, E<1>, E<2>, E<3>. The liquid air formed collects in the tube F, and is delivered to the top chamber 12. As it overflows from compartment to compartment, it meets ascending gases, the result being that as it flows downwards it takes up more and more oxygen from the ascending gases, at the same time giving up nitrogen thereto. When working properly, a gas exceedingly rich in nitrogen escapes through the outlet M, while practicallypure liquid oxygen collects in the lowest compartment, and is evaporated by the incoming air, so that pure oxygen gas leaves at N. The compartment 2 is deeper than the others, and is cut up into four small compartments by partitions of varying heights, the liquid overflowing from one to the other. The cold nitrogen gas and the cold oxygen gas pass through separate heat-exchangers to cool down the air to be afterwards separated, such air having been previously compressed and dried. The pressure employed is regulated so as just to keep the process working continuously, or, if desired, liquid air may be occasionally added at P to make up for unavoidable loss. The invention is not limited to the precise form of apparatus shown. The plates b may vary in form and number, and a second perforated plate may be arranged beneath each plate and the overflow tubes bent so as to deliver the liquid on to it. In the Provisional Specification the arrangement shown varies slightly, namely:-(1) filters are interposed in the tube F to separate out solid carbonic acid, (2) the pipe F passes downwards to the chamber 10, valves allowing the liquid air to pass as desired to the chambers 11 and 12, (3) the gaseous air is admitted to the two bottom compartments only, and (4) the previous compression of the air is as low as possible.