An apparatus for the production of low pressure gaseous oxygen includes a heat exchanger and a system of columns comprised of an auxiliary column, a higher pressure column and a lower pressure column. The LP column and the HP column are thermally integrated via a top reboiler/condenser disposed on top of the HP column. The system of columns is configured to separate a cooled air stream into oxygen and nitrogen. The auxiliary column comprises a distillation section and a first and second reboiler. One of the reboilers is driven by the cooled air stream and the other reboiler is driven by a pressurized nitrogen stream. The first and second reboilers boil their fluids at the same pressure as the auxiliary column.

An air separation device for distilling air at a low temperature, includes a high-pressure column to separate high-pressure raw material air into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air; a low-pressure column to separate the high-pressure oxygen-enriched liquefied air into low-pressure nitrogen gas, low-pressure liquefied oxygen, and argon-enriched liquefied oxygen; an argon column to separate the argon-enriched liquefied oxygen having a pressure higher than the pressure into argon gas and medium-pressure liquefied oxygen; first and second indirect heat-exchangers; first and second gas-liquid separation chambers; a first/second passage which communicates the gas/liquid phase of the low-pressure column and the gas phase of the second gas-liquid separation chamber; and a first/second opening/closing mechanism located on the first/second passage.

A method for the production of low pressure gaseous oxygen includes providing a system of distillation columns and a heat exchanger, wherein the system of columns comprises a lower pressure column, a higher pressure column, an auxiliary column, the auxiliary column having a distillation section, a first reboiler, and a second reboiler, wherein the LP column and the HP column are thermally integrated via a top reboiler/condenser disposed on top of the HP column. A cooled air stream is rectified within the system of columns such that the auxiliary column produces a cold oxygen fluid that is then warmed in the heat exchanger to produce a low pressure oxygen product. The cooled air stream provides reboiling duty for the first reboiler prior to rectification within the system of columns, and a compressed nitrogen stream received from a cold end of the heat exchanger provides reboiling duty for the second reboiler.

A system and method serve generate oxygen by low-temperature air separation in a distillation column system having a high-pressure column and a low-pressure column, a main condenser which is constructed as a condenser-evaporator, and an auxiliary column. A gaseous oxygen-containing fraction is introduced into the auxiliary column. A nitrogen-containing liquid stream from the high-pressure column, the main condenser or the low-pressure column is applied as reflux to the top of the auxiliary column. An argon-rich stream from an intermediate site of the low-pressure column is introduced into an argon removal column that has an argon removal column top condenser. The low-pressure column is arranged beside the high-pressure column, the main condenser is arranged over the high-pressure column, the auxiliary column is arranged over the main condenser, the argon removal column is arranged over the auxiliary column and the argon removal column top condenser is arranged over the argon removal column.

The plant is used for producing oxygen by cryogenic air separation. The plant has a high-pressure column, a low-pressure column and a main condenser. An argon-elimination column is in fluid connection with an intermediate point of the low-pressure column and is connected to an argon-elimination column head condenser. An auxiliary column has a sump region, into which gas is introduced from the argon-elimination column head condenser. The head of the auxiliary column is connected to a return flow liquid line, in order to introduce a liquid stream from the high-pressure column or the head condenser. The liquid stream has an oxygen content which is at least equal to that of air. At least one part of the crude liquid oxygen from the sump of the high-pressure column is fed to the auxiliary column at a first intermediate point.

A method and apparatus for producing compressed nitrogen and liquid nitrogen. A separation system has a high-pressure column, a low-pressure column with a top condenser and a main condenser. Air is compressed in an air compressor, purified, cooled in a heat exchanger and introduced into the high-pressure column. A first part of the gaseous top nitrogen from the low-pressure column becomes compressed nitrogen product. A second part of the gaseous top nitrogen is condensed in the condensing space of the top condenser and vapour is drawn off as a residual gas stream. The vapor is expanded in a first expansion machine. A second compressed nitrogen stream from the top of the high-pressure column is expanded in a second expansion machine and then drawn off as compressed nitrogen product. A part of the nitrogen condensed in the top condenser is drawn off as liquid nitrogen product.

An apparatus for the production of low pressure gaseous oxygen includes a heat exchanger and a system of columns comprised of an auxiliary column, a higher pressure column and a lower pressure column. The LP column and the HP column are thermally integrated via a top reboiler/condenser disposed on top of the HP column. The system of columns is configured to separate a cooled air stream into oxygen and nitrogen. The auxiliary column comprises a distillation section and a first and second reboiler. One of the reboilers is driven by the cooled air stream and the other reboiler is driven by a pressurized nitrogen stream. The first and second reboilers boil their fluids at the same pressure as the auxiliary column.

A method for the production of low pressure gaseous oxygen includes providing a system of distillation columns and a heat exchanger, wherein the system of columns comprises a lower pressure column, a higher pressure column, an auxiliary column, the auxiliary column having a distillation section, a first reboiler, and a second reboiler, wherein the LP column and the HP column are thermally integrated via a top reboiler/condenser disposed on top of the HP column. A cooled air stream is rectified within the system of columns such that the auxiliary column produces a cold oxygen fluid that is then warmed in the heat exchanger to produce a low pressure oxygen product. The cooled air stream provides reboiling duty for the first reboiler prior to rectification within the system of columns, and a compressed nitrogen stream received from a cold end of the heat exchanger provides reboiling duty for the second reboiler.