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 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 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 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 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.

A method for compression of an incoming feed air stream using at least two variable speed compressor drive assemblies controlled in tandem is provided. The first variable speed drive assembly drives at least one compression stage in the lower pressure compressor unit driven while the second variable speed drive assembly drives higher pressure compression stage disposed either in the common air compression train or the split functional compression train of the air separation plant. The first and second variable speed drive assemblies are preferably high speed, variable speed electric motor assemblies each having a motor body, a motor housing, and a motor shaft with one or more impellers directly and rigidly coupled to the motor shaft via a sacrificial rigid shaft coupling.

A method for compression of an incoming feed air stream using at least two variable speed compressor drive assemblies controlled in tandem is provided. The first variable speed drive assembly drives at least one compression stage in the lower pressure compressor unit driven while the second variable speed drive assembly drives higher pressure compression stage disposed either in the common air compression train or the split functional compression train of the air separation plant. The first and second variable speed drive assemblies are preferably high speed, variable speed electric motor assemblies each having a motor body, a motor housing, and a motor shaft with one or more impellers directly and rigidly coupled to the motor shaft via a sacrificial rigid shaft coupling.

A method for compression of an incoming feed air stream using at least two variable speed compressor drive assemblies controlled in tandem is provided. The first variable speed drive assembly drives at least one compression stage in the lower pressure compressor unit driven while the second variable speed drive assembly drives higher pressure compression stage disposed either in the common air compression train or the split functional compression train of the air separation plant. The first and second variable speed drive assemblies are preferably high speed, variable speed electric motor assemblies each having a motor body, a motor housing, and a motor shaft with one or more impellers directly and rigidly coupled to the motor shaft via a sacrificial rigid shaft coupling.

A system and method for improving the performance of an oxygen, nitrogen, and argon producing air separation unit configured to produce a gaseous nitrogen product stream is provided. By recycling the argon condenser boil-off vapor stream to the main air compression train, the argon recovery and oxygen recovery while maintaining the production level of a medium or high pressure gaseous nitrogen product stream. In addition, some operational cost savings in terms of lower power costs can also be realized compared to some prior art oxygen, nitrogen, and argon producing air separation units.

Enhancements to a dual column, nitrogen producing cryogenic air separation unit are provided. Such enhancements include an improved air separation cycle that uses multiple condenser-reboilers and recycles a portion of the vapor from one or more of the condenser-reboilers to the incoming feed stream and or the compressed purified air streams to yield improvements in such dual column, nitrogen producing cryogenic air separation units. The multiple condenser-reboilers preferably include an integrated condenser-reboiler arrangement comprising a heat exchanger having a set of nitrogen condensing passages, a first set and second set of boiling passages, and a phase separator.