A distillation column is constituted by a cylindrical shell which contains mass and heat transfer elements and which is closed at one end by a cap and at the other end by a domed bottom and a cylindrical skirt that has the same diameter as the cylindrical shell, is aligned coaxially with the cylindrical shell and is fixed to one end of the cylindrical shell so as to surround the domed bottom, forming a space between the bottom, the walls of the skirt and a base, the skirt comprising at least one opening to allow the passage of a flushing gas.

An air separation apparatus is provided, including an air separation unit including a low-pressure column, a mixing column, and a pure nitrogen column, wherein the low-pressure column has a first nominal diameter, the pure nitrogen column has a second nominal diameter which is smaller than the first nominal diameter, wherein the mixing column has an open cylindrical shape, with the inner diameter nominally greater than the second nominal diameter, with the pure nitrogen column located within the mixing column interior.

Plant for the production of argon by cryogenic distillation, comprising an argon separation column, means for sending a gas containing argon and oxygen to the argon separation column, means for extracting a fluid enriched in argon at the top of the argon separation column, means for extracting a liquid enriched in oxygen at the bottom of the argon separation column and at least two storage tanks, positioned one above the other, each storage tank being connected to two different intermediate levels of the argon separation column by two pipes, the two storage tanks being contiguous.

Xenon and/or krypton is separated from a liquid oxygen stream comprising oxygen and xenon and/or krypton in a process comprising providing at least a portion of the liquid oxygen stream as a reflux liquid to the top of a rare gas recovery column operated at a pressure of between 5 to 25 bara, vaporizing a reboiler liquid in the reboiling zone in the bottom of the rare gas recovery column to produce a mixture of a rising vapor and a xenon and/or krypton-enriched liquid stream; and contacting the rising vapor with the reflux liquid in at least one distillation zone of the column to effect stripping xenon and/or krypton from the rising vapor to the reflux liquid. The process provides a recovery of xenon of greater than 90% and a krypton recovery of 15% to 90%.

An apparatus for the separation or liquefaction of a gas at cryogenic temperatures which comprises an isolated chamber comprises at least one front distillation column operating at cryogenic temperatures and also a pipe for transferring fluid coming from or going to the column, the pipe having a diameter D comprising a bend for changing the direction of flow of the fluid, with profiled deflector vanes placed inside the bend, with their concavity towards the centre of the bend forming a plurality of ducts.

Xenon and/or krypton is separated from a liquid oxygen stream comprising oxygen and xenon and/or krypton in a process comprising providing at least a portion of the liquid oxygen stream as a reflux liquid to the top of a rare gas recovery column operated at a pressure of between 5 to 25 bara, vaporizing a reboiler liquid in the reboiling zone in the bottom of the rare gas recovery column to produce a mixture of a rising vapor and a xenon and/or krypton-enriched liquid stream; and contacting the rising vapor with the reflux liquid in at least one distillation zone of the column to effect stripping xenon and/or krypton from the rising vapor to the reflux liquid. The process provides a recovery of xenon of greater than 90% and a krypton recovery of 15% to 90%.

An apparatus for the separation or liquefaction of a gas at cryogenic temperatures which comprises an isolated chamber comprises at least one front distillation column operating at cryogenic temperatures and also a pipe for transferring fluid coming from or going to the column, the pipe having a diameter D comprising a bend for changing the direction of flow of the fluid, with profiled deflector vanes placed inside the bend, with their concavity towards the centre of the bend forming a plurality of ducts.

An apparatus for distillation at cryogenic temperatures can include a cold box module comprising framing and having an upper module section and a lower module section, wherein the upper module comprises a roof; an upper column section disposed within the upper module section; a lower column section disposed within the lower module section; a plurality of support saddles attached to the upper and lower module sections that are configured to provide structural support for the upper and lower column sections when the upper and lower column sections are in a horizontal position during transportation; and means for limiting longitudinal movement of the lower column section when the lower module section is in a horizontal position during transport, wherein the means for limiting longitudinal movement are connected to the lower column section and the lower module section.

An annular divided wall column for the cryogenic rectification of air or constituents of air is provided. The annular divided wall column includes a first annular column wall and a second annular column wall disposed within the first annular column wall to define an annulus column region and an interior core column region. The present annular divided wall column further includes structured packing elements disposed within at least the annulus column region as well as a ring-shaped cantilevered collector; and a ring-shaped distributor disposed in the annulus column region above or below the plurality of structured packing elements. The thermal expansion and contraction of the second annular column wall in a radial direction and in an axial direction is independent of the thermal expansion and contraction of the first annular column wall in the radial and axial directions.

An annular divided wall column is provided. The annular divided wall column includes a first annular column wall and a second annular column wall disposed within the first annular column wall and radially spaced therefrom to define an annulus column region as the space between the first annular column wall and the second annular column wall. An interior core column region is also defined by the interior space of the second annular column wall. The present annular divided wall column further includes a plurality of packing elements, disposed within the interior core column region within the annulus column region having different surface area densities and optionally, also have different geometries.