A system and method for argon production in an air separation plant facility or enclave having multiple cryogenic air separation units is provided. The present system and method include a centralized argon refining system disposed within one of the cryogenic air separation units and which is configured to include an argon superstaged or ultra-superstaged column arrangement having one or more argon columns and an argon condenser. Crude argon streams from one or more of the other cryogenic air separation units are directed to the argon superstaged or ultra-superstaged column arrangement of the centralized argon refining process.

The air separation system can include: a process control unit 201 for controlling components constituting the air separation system; an oxygen concentration estimating unit 202 for estimating, by calculation, the oxygen concentration of oxygen-enriched liquid that accumulates in a column bottom portion of the higher-pressure column; a flow rate estimating unit for estimating, by calculation, the flow rate of oxygen-enriched liquid that has been discharged from the column bottom portion of the higher-pressure column and that is to be introduced into a distillation portion of the lower-pressure column; and a target temperature calculating unit for calculating a target temperature of an argon extraction portion on the basis of the flow rate of feed air that has passed through at least a portion of the main heat exchanger 1 and that is to be sent to an expansion turbine, the oxygen concentration of the oxygen-enriched liquid, and the flow rate of the oxygen-enriched liquid.

A process for cryogenic separation of air using an air separation plant configured as a high air pressure air separation plant is provided, wherein of the air initially compressed several partial air streams are formed which are at least in part further compressed, cooled in a main heat exchanger and expanded before being introduced into the column system. The partial air streams include a first partial air stream and a second partial air stream whose air is compressed in parallel in a first warm booster and a second warm booster and thereafter expanded in a first expander and a second expander mechanically coupled to the first booster and to the second booster, respectively. A corresponding air separation plant is also part of the present invention.

A liquefier device which may be a retrofit to an air separation plant or utilized as part of a new design. The flow needed for the liquefier comes from an air separation plant running in a maxim oxygen state, in a stable mode. The three gas flows are low pressure oxygen, low pressure nitrogen, and higher pressure nitrogen. All of the flows are found on the side of the main heat exchanger with a temperature of about 37 degrees Fahrenheit. All of the gasses put into the liquefier come out as a subcooled liquid, for storage or return to the air separation plant. This new liquefier does not include a front end electrical compressor, and will take a self produced liquid nitrogen, pump it up to a runnable 420 psig pressure, and with the use of turbines, condensers, flash pots, and multi pass heat exchangers. The liquefier will make liquid from a planned amount of any pure gas oxygen or nitrogen an air separation plant can produce.

A distillation column system and a plant are for production of oxygen by cryogenic fractionation of air. The distillation column system has a high-pressure column and a low-pressure column, a main condenser, and an argon column with an argon column top condenser. The low-pressure column comprises an upper mass transfer region, a lower mass transfer region and a middle mass transfer region. The argon column top condenser is arranged within the low-pressure column between the upper and middle mass transfer regions and is configured as a forced-flow evaporator.

In a method for regulating a device for separating air by cryogenic distillation, during the change from a low-flow mode to a high-flow mode, two flow rates of reflux sent to the low-pressure column of a double column are increased more rapidly than the flow rate of gaseous air sent to the medium-pressure column of the double column in order to ensure the stability of the oxygen content in the argon bulge of the low-pressure column during the mode change.

A method and device to variably obtain argon by means of low-temperature separation. Feed air is cooled in a main heat exchanger and then conducted into a distillation column system with a high-pressure column and a low-pressure column. Argon is obtained using a crud argon column and a purified argon column. A purified liquid argon product flow is generated from an argon-enriched flow from the low-pressure column. In a first operating mode, a first quantity of purified argon product is discharged, and in a second operating mode, a reduced quantity of purified argon product is discharged. In the second operating mode, a gaseous argon return flow is drawn from the crude argon column or the purified argon column and heated in a separate passage of the main heat exchanger.

A method and apparatus for separating air in which an oxygen-rich liquid stream is pumped and then heated within a heat exchanger to produce an oxygen product through indirect heat exchange with first and second boosted pressure air streams. The first boosted pressure air stream is cold compressed at an intermediate temperature of the heat exchanger, reintroduced into the heat exchanger at a warmer temperature and then fully cooled and liquefied. The second boosted pressure air stream, after having been partially cooled, is expanded to produce an exhaust stream that is in turn introduced into a lower pressure column producing the oxygen-rich liquid. The second boosted pressure air stream is partially cooled to a temperature no greater than the intermediate temperature at which the cold compression occurs so that both the first and second boosted pressure air streams are able to take part in the heating of the oxygen-rich stream.

A method for separating air by cryogenic distillation in a system of columns comprising a first column and a second column operating at a lower pressure than the first column, comprising the steps of compressing all of the feed air in a first compressor to a first output pressure of at least 1 bar greater than the pressure of the first column, sending a first portion of the air under the first output pressure to the second compressor, and compressing the air to a second output pressure, cooling and condensing at least a portion of the air under the second output pressure in a heat exchanger, withdrawal of a liquid from a column of the system of columns, pressurising the liquid and evaporating the liquid by heat exchange in the heat exchanger, and pressure reduction of a portion of the compressed air to a second output pressure, at least partially evaporating said air in the heat exchanger, optionally additional heating of said air in the heat exchanger, and sending at least a portion of this air to the second compressor.

An air separation plant for obtaining product containing argon by low temperature separation of compressed, cooled feed air. The air separation plant comprises a high-pressure column, a multi-part low-pressure column having a base segment and a head segment and a multi-part crude argon column having a base segment and a head segment. An oxygen-enriched flow is obtained from part of the feed air in the high pressure column, an argon-enriched flow is obtained from part of the oxygen-enriched flow in the low-pressure column, and an argon-rich flow is obtained from part of the argon-enriched flow in the crude argon column. Liquid flow is transferred from a lower region of the head segment of the low-pressure column and from a lower region of the base segment of the crude argon column into an upper region of the base segment of the low-pressure column.