Patent GB-190220053-A (GB)
Title: Improvements in the Separation of Gases from their Mixtures, especially Oxygen and Nitrogen from Atmospheric Air and in Apparatus therefor.
Inventor: LEVY RENE JACQUES
Filed: 1902-09-13
Granted: 1903-09-10
Abstract: 20,053. LÚvy, R. J., and Helbronner, A. Sept. 13. Oxygen; nitrogen.-The invention is described for separating oxygen and nitrogen from liquefied air, but is applicable for separating other gaseous mixtures into their constituents. The apparatus consists of a column divided by a partition X into two chambers, the lower one being similar to that described in Specification No. 16,615, A.D. 1902. The gas given off in the lower part, consisting of a mixture rich in nitrogen, is re-liquefied, and again separated into oxygen and nitrogen in the upper part. More than two such successive separations may be made, the final separation only taking place under atmospheric pressure, the previous separations being effected at pressures which decrease from the first to the last. Horizontal trays D<1> to D<10> divide the column into any desired number of compartments, each having one or more passages E, covered with bells e having notched edges, for the upward passage of gas, an overflow pipe F for the downward passage of liquid, and annular division plates d to keep the liquid in circulation. Concentric tubes H, H<1> are provided for use as heat interchangers, and connecting pipes and valves are provided as shown, while the partitions, coils and valves in chambers D and A correspond to those described in No. 16,615, A.D. 1902, To start the process, the trays D' to D<8> are charged with liquid air through the valves R, R'. The cold dry air at the lowest adequate pressure is simultaneously introduced into the coils q, p, p<1>, p' which are immersed in liquid oxygen in the compartment A, and in liquids rich in oxygen in the trays D, D'. This air is liquefied in the coils, while a portion of the liquid oxygen in A is vaporized and escapes at O, and the liquid in the trays is partially vaporized, losing nitrogen more rapidly than oxygen, and the gases produced rise up the column. The liquefied air obtained passes through the tubes C, C<1>, and is delivered partly to the intermediate tube of the heat interchanger H, and partly to the tray D<8>, the valve G being manipulated as required. The liquid on the trays D<5> D<8> has the composition of ordinary air. The liquid air, cooled further in the interchanger H, passes through the tube V to the top tray D<5>, and thence flows downwards, becoming more and more rich in oxygen, while gas containing nitrogen passes upwards. In the tray D<3>, it receives an additional supply of liquid air rich in oxygen from the compartment A<1> by the tube M. The compartment A contains pure liquid oxygen, as described in the afore-mentioned Specification. The gas given off from the tray D<5> enters at V the interchanger H in which it gives up heat, and thence passes by the tube N to the interchanger H<1>, in which it receives heat, and thence passes by the tube T' to the coils q<1> in the compartment B', wherein it is re-liquefied. This liquid is then delivered by the tube T<3> to the top tray D', and flows downwards, becoming gradually richer in oxygen, while giving up its nitrogen. Practically pure nitrogen is given off the tray D', and after passing through the heat interchanger, escapes by the opening V<1> and may be collected. The liquid in the compartment B<1> overflows from space to space therein till it reaches the space on the extreme right, from which it is discharged by means of a float s<1> and valve S<1> into the compartment A'. When the level of the liquid rises considerably, the valve S<2> actuated by the float s<2> allows the compartments A<1> and D<5> to communicate with one another. The additional pressure due to this communication forces open the valve S<3>, allowing liquid to escape by the tube M to the tray D<3>. When the liquid level falls, the float s<2> closes communication between D<5> and A<1>, and opens that between the latter and B<1> so that both the latter become of the same pressure, namely that of the atmosphere, whereby the valve S<3> automatically closes again.