Abstract: A cryogenic rotary pump for pressurizing a flow of a cryogenic liquid and for dividing the flow into a first lower pressure and a second higher pressure stream has a series of pumping chambers. A single rotary drive shaft carries a rotary inducer located in the chamber, a first impeller in the chamber, and a second impeller in the chamber. A liquid receiving chamber is located intermediate the pumping chambers. A first outlet from the pump for the first lower pressure stream is contiguous to the chamber and a second outlet is provided for the second higher pressure stream. The pump may serve to pressurize a flow of unboiled liquid oxygen from a sump of a lower pressure column of a double column also having a higher pressure column.

Abstract: The present invention relates to processes and installations for the production of oxygen and nitrogen by cryogenic distillation. The cost of oxygen and nitrogen production is reduced by providing an improved high pressure process.

Abstract: Air is distilled in a single column (8) installed on a boat, and from here an oxygen-enriched liquid flow is drawn-off. This flow is pressurized by a pump (9) and vaporized by heat exchange with air or nitrogen. The oxygen (105) is used for the partial oxidation of a flow (101) containing hydrocarbons, for example natural gas.

Abstract: A method and apparatus for separating out is used to produce an oxygen product in which an air stream after having been compressed and purified is introduced into a bottom reblower located in a bottom region of the distillation column to produce boil up in such distillation column. The resultant air stream liquefies to produce a liquid air stream. The liquid air stream after having been valve expanded is stripped within the distillation column to produce a column bottoms which can be extracted as a product stream that is vaporized within a main heat exchanger. Product stream can be pressurized by being pumped to atmospheric a pressure hence liquefying a further compressed air stream to produce further liquid air is also stripped within the distillation column. The distillation column operates at near atmospheric pressures that is pressures between 1 and 1.3 bar absolute. Refrigeration is introduced into the plant by injecting liquid preferably liquid oxygen into a bottom region of the distillation column.

Abstract: There are included a fractionating tower for liquefying and separating the compressed air cooled by heat exchangers to an ultralow temperature, a liquid oxygen takeout path for guiding the liquid oxygen in the above-mentioned fractionating tower to the above-mentioned heat exchangers to gasify so as to become a gasified oxygen, and a product oxygen gas takeout path which extends from the front end of the above-mentioned liquid oxygen takeout path and increases the temperature of the above-mentioned gasified oxygen so as to obtain a product oxygen gas, the above-mentioned liquid oxygen takeout path being provided with an oxygen gas pressurizing pump, and the above-mentioned product oxygen gas takeout path on the side upstream the above-mentioned heat exchangers being provided with an expansion turbine.

Abstract: A cryogenic air separation system employing a double column wherein lower pressure column bottom liquid is pressurized in a single cryogenic liquid pump to provide driving fluid for the main condenser and to provide product elevated pressure oxygen.

Abstract: A plant which, when used to produce pressurized oxygen gas, includes a switch, e.g. a liquid oxygen/liquid air switch, for meeting relatively long-term peak demand as well as short-term, high-amplitude peak demand, and a circuit (13,30) for compressing oxygen to a pressure higher than the production pressure. This circuit leads to a buffer (15) at least partially meeting short-term, high-amplitude peak demand.

Abstract: The air coming from a blowing turbine (13) and intended for the low-pressure column of a double column (2) is cooled by indirect heat exchange with a liquid (15, 20). This liquid is a purge stream from a condenser (5, 6) of the system.

Abstract: A process and a system for the low-temperature separation of air by rectification is provided. A liquid fraction is obtained in a rectifying system, stored in a tank and at least a portion of the liquid fraction taken out of the tank and brought to an increased pressure. During normal operation, the liquid fraction, which was brought to an increased pressure, is heated in a preheat exchanger and evaporated in the main heat exchanger. During an operating disturbance, at least a portion of the liquid product is removed from the tank, evaporated and used for an emergency supply.

Abstract: Feed air is fed to a rectifying system (14, 15) for low-temperature separation, from which a liquid fraction (31, 32) is taken off and introduced into a first reservoir tank (33). The pressure of a variable rate of the liquid fraction (34) is increased (35). The liquid fraction (36) is evaporated under the elevated pressure by indirect heat exchange (12) and obtained as a gaseous pressurized product (37). A heat-transport medium circulates in a refrigeration cycle which has a cycle compressor (41, 42). A first partial stream (45) of the heat-transport medium (44) compressed in the cycle compressor (41, 42) is fed to the indirect heat exchange (12) to evaporate the liquid fraction (36) and is liquefied, at least in part, in the course of this. A second partial stream (59) of the heat-transport medium (44) compressed in the cycle compressor (41, 42) is expanded (43) so as to perform work. Liquefied heat-transport medium (45, 48) is buffered in a second reservoir tank (49).

Abstract: A cryogenic rectification system wherein low purity oxygen is recovered from a side column or the lower pressure column of a double column while a portion of the low purity oxygen is fed to an auxiliary column driven by fluid having a high nitrogen concentration wherein high purity oxygen is produced.

Abstract: A cryogenic rectification system wherein a product boiler is incorporated into the primary heat exchanger without encountering boiling to dryness problems wherein liquid from the cryogenic rectification plant is processed in a phase separator upstream of the product boiler, and fluid from the product boiler is passed into the phase separator prior to recovery.

Abstract: Air is separated into oxygen and nitrogen in a double rectification column comprising a higher pressure rectification column and a lower pressure rectification column. Liquid nitrogen reflux for the separation is provided by condensing nitrogen vapor taken from the column in a condenser-reboiler. Additional separation is performed in an intermediate pressure rectification column. A first stream of argon-enriched vapor is withdrawn from an intermediate region of the lower pressure rectification column and has an argon fraction separated from it in a first side rectification column. A second stream of argon-enriched vapor is similarly withdrawn and is separated in a second side rectification column which provides vapor to heat a reboiler associated with the intermediate pressure rectification column. Alternatively a stream of oxygen vapor can be so employed instead of the second argon-enriched vapor stream.

Abstract: A cryogenic rectification system for the separation of feed air wherein at least some of the feed air is liquefied upstream of the separation columns, all of the liquefied feed air is introduced into a higher pressure column, and then a portion of this liquefied feed air is withdrawn from the higher pressure column and in serial fashion introduced into a lower pressure column.

Abstract: A cryogenic rectification system for producing lower purity oxygen comprising a double column with a third column reboiled by feed air at an intermediate level and, optionally, in a staged manner at the bottom level.

Abstract: Air is separated in an arrangement of rectification columns including a double rectification column for separating oxygen and nitrogen from the air. The double rectification column comprises a higher pressure rectification column and a lower pressure rectification column. There is in addition a side rectification column for separating argon from a stream of argon-enriched oxygen/vapour withdrawn from the lower pressure rectification column. An intermediate pressure rectification column is employed to separate further nitrogen (oxygen-depleted vapour) from the air. An upward flow of vapour through the intermediate pressure rectification column is created by operation of a reboiler to boil liquid in the bottom of the column. In addition a flow of vaporised air is introduced into an intermediate mass transfer region of the column.

Abstract: A process is set forth for the cryogenic distillation of an air feed to produce at least two oxygen-rich gaseous streams having different oxygen purities. The process uses a mixing column system in addition to a distillation column system. A key to the process is that at least two oxygen-rich liquid streams having different oxygen purities are transferred from the distillation column system to the mixing column system in order to produce the oxygen-rich gaseous streams.

Abstract: Air is separated in an arrangement of rectification columns comprising a double rectification column having a higher pressure column and a lower pressure rectification column, an intermediate pressure rectification column, and a side rectification column communicating with the lower pressure column. The side rectification column is provided with a condenser and the intermediate pressure rectification column with a reboiler and a further condenser. A stream of oxygen-enriched liquid is withdrawn from the bottom of the higher pressure column through an outlet and is separated in the intermediate pressure rectification column. The reboiler is heated by a stream typically withdrawn from the side rectification column through an outlet thereof. The condensers of the side rectification column and the intermediate column are cooled by streams having different oxygen mole fractions.

Abstract: Air is separated in an arrangement of rectification columns comprising a double rectification column (which has a higher pressure column and a lower pressure column), an intermediate pressure rectification column and a side rectification column communicating with the lower pressure column. The side rectification column is provided with a condenser and the intermediate pressure rectification column with a reboiler and a condenser. A stream of oxygen-enriched liquid and a stream of liquid air are withdrawn from the higher pressure column through outlets and are separated in the intermediate pressure rectification column. The reboiler is heated by a stream typically withdrawn from the side rectification column through an outlet. A stream of liquid is withdrawn through an outlet at the bottom of the intermediate pressure rectification column is used to cool the condenser and is separated in the lower pressure rectification column.

Abstract: An improved efficiency system for producing low purity oxygen by rectification of air employs a high pressure column and a low pressure column and includes the steps of: turboexpanding a flow of nitrogen-rich gas from the high pressure column to provide a cooled nitrogen-rich gas flow; condensing the cooled nitrogen-rich gas flow to a nitrogen-rich liquid against a flow of a vaporizing oxygen-rich liquid flow taken from the low pressure column; passing the nitrogen-rich liquid as a reflux flow to the low pressure column; returning the vaporizing oxygen liquid to the low pressure column; and employing energy derived from the turboexpanding step to compress feed air.

Abstract: A single column cryogenic rectification system for producing lower purity oxygen wherein a major portion of the feed air is partially condensed in the column reboiler, the resulting vapor turboexpanded and then successively condensed in one or more vertically oriented stages within the column to enhance the generation of upflow vapor and reflux liquid for the column.

Abstract: Air is separated in an arrangement of rectification columns comprising a double rectification column (which has a higher pressure column and a lower pressure column), an intermediate pressure rectification column, and a side rectification column communicating with the lower pressure column. The side rectification column is provided with a condenser, and the intermediate pressure rectification column with a reboiler and a further condenser. A stream of oxygen-enriched liquid is withdrawn from the bottom of the higher pressure column through an outlet and is separated in the intermediate pressure rectification column. The reboiler is heated by a stream typically withdrawn from the side rectification column through an outlet. A stream of liquid is withdrawn from the bottom of the intermediate pressure rectification column, is employed to cool the further condenser of the intermediate pressure rectification column, and is partially vaporised therein.

Abstract: A cryogenic air separation system wherein higher pressure column kettle liquid is divided into a portion introduced directly into the lower pressure and a portion which is substantially completely vaporized to drive an argon column top condenser, enabling the vaporization of elevated pressure liquid oxygen against feed air while maximizing argon recovery.

Abstract: A method and apparatus for making gaseous oxygen at a delivery pressure in a single column oxygen generator. In accordance with the method and apparatus, a column bottoms stream composed of the product is pumped to the delivery pressure and then vaporized. A liquid coolant stream used in condensing reflux is recompressed by a recycle compressor and then recycled back into the bottom of the column. Such recycled stream has a higher nitrogen content than the column bottoms. Part of the nitrogen tower overhead, not used in forming the reflux, is turbo-expanded by a turbo-expander coupled to the recycle compressor.

Abstract: The present invention relates to an air liquefaction separation apparatus whose power cost is reduced. A low-pressure column of a double rectification column has a cleaning section at a lower position, and a liquid oxygen is partly withdrawn from the space above the cleaning section so as to supply it to a main condenser-evaporator. The liquid oxygen supplied to the main condenser-evaporator is subjected to heat exchange with a nitrogen gas separated at the head of a high-pressure column to be gasified into an oxygen gas. This oxygen gas is introduced to the space under the cleaning section. Hydrocarbons contained in the oxygen gas ascending through the cleaning section are removed by the rest of the liquid oxygen descending through the cleaning section to provide a clean oxygen gas. The liquid oxygen passed through the cleaning section is withdrawn from the low-pressure column.

Abstract: A cryogenic air separation system wherein feed air is compressed in a multistage primary air compressor, a first part is turboexpanded and fed into a cryogenic air separation plant, and a second part is turboexpanded and at least a portion of the turboexpanded second part is recycled to the primary air compressor at an interstage position.

Abstract: The method and the apparatus are used to obtain oxygen and nitrogen at superatmospheric pressure by low-temperature separation of air in a rectification column system. Compressed and purified feed air (1, 3) is introduced into a pressure column (4). Liquids (5, 8) from the lower region and, respectively, from the upper or middle region of the pressure column (4) are fed into the low-pressure column (7). A third liquid fraction (17) from the lower region of the low-pressure column (7) is evaporated in indirect heat exchange (12) with condensing vapour (11) from the upper region of the pressure column (4), at least a portion of the vapour (22, 24, 26, 27) obtained in the process being introduced into the low-pressure column (7). Condensate (13) is fed into the pressure column (4); A pressurized nitrogen fraction (10, 14, 15) is extracted as product from the upper region of the pressure column (4).

Abstract: A process is set forth for the cryogenic distillation of an air feed to produce an oxygen product, particularly an oxygen product at moderate purity (80-99%, preferably 85-95%). The process uses an auxiliary low pressure column in addition to the conventional high pressure column and low pressure column. The auxiliary low pressure column, which is preferably operated at the same pressure as the main low pressure column and which is heat integrated with the top of the high pressure column by means of its bottom reboiler/condenser, pretreats the crude liquid oxygen from the bottom of the high pressure column. The resulting overhead vapor stream and bottom stream are subsequently fed to the main low pressure column. Preferably, the bottom stream is fed to the main low pressure column in a state which is at least partially vapor.

Abstract: Compressed, purified, vaporous air and liquid air streams are introduced into a higher pressure rectification column. A stream of oxygen-enriched liquid flows from an outlet of the higher pressure rectification column via a reboiler and an expansion valve into a vessel. The oxygen-enriched liquid is partially vaporised in a boiler located in the vessel. The residual liquid flows from the vessel and a condenser to a lower pressure rectification column in which oxygen and nitrogen products are separated. A stream of vapour flows from the boiler through an outlet from the vessel to a pipeline which leads the air back for compression with incoming air. A greater yield of oxygen, and, if separated, argon is made possible by this recycle.

Abstract: Air is separated in a higher pressure rectification column into a bottom fraction of oxygen-enriched liquid air and a top fraction of nitrogen. The column has a first inlet for a first vaporous air stream at a first pressure communicating with an expansion turbine. A first condenser-reboiler for condensing a second vaporous air stream at a second pressure greater than the first pressure has an inlet communicating with a compressor. The condensate flows through an expansion valve into the higher pressure rectification column. A stream of oxygen-enriched liquid is withdrawn from the bottom of the column and is introduced into a lower pressure rectification column in which an impure oxygen fraction is separated. A second condenser-reboiler places the top of the higher pressure rectification column in heat exchange relationship with an intermediate region of the column. Reboil for the bottom of the column is provided by the first condenser-reboiler. An impure oxygen product is withdrawn from the column.

Abstract: A stream of precooled and purified air is introduced into a double rectification column comprising a higher pressure rectification column and a lower pressure rectification column and is separated therein into an oxygen-rich fraction and a nitrogen-rich fraction. A stream of argon-enriched oxygen vapor flows from an outlet of the lower pressure rectification column into a side column in which argon is separated therefrom. An oxygen-enriched liquid air stream is taken from an outlet at the bottom of the higher pressure rectification column. A vaporous oxygen-enriched air stream is introduced into the lower pressure rectification column through an inlet above the outlet. At least part of the oxygen-enriched liquid is separated in a further or intermediate pressure rectification column provided with a reboiler, thereby forming a vapor depleted of oxygen and a liquid air stream further enriched in oxygen.

Abstract: In a process for the production of gas under pressure by cryogenic distillation, the gas is produced by vaporizing (or pseudo-vaporizing) a liquid drawn off from a distillation column. In order to supply additional gas under pressure, a flow of a gas coming from an external source is at least partially liquefied, and the liquid thus formed is added to the liquid drawn off from the column before or after an optional pressurization step.

Abstract: A cryogenic rectification system having high recovery of both higher purity and lower purity oxygen which employs a side column having a bottom reboiler wherein feed air is partially condensed and the feed air vapor remaining after the partial condensation is turboexpanded prior to rectification.

Abstract: A double column cryogenic rectification system for producing low purity oxygen and high purity nitrogen, preferably at elevated pressure, wherein nitrogen-rich vapor from the higher pressure column is turboexpanded and condensed against lower pressure column intermediate liquid prior to being passed into the lower pressure column.

Abstract: A cryogenic rectification system wherein liquid oxygen from a cryogenic air separation plant is pressurized and then vaporized in a high pressure liquefier producing product high pressure oxygen gas and generating liquid nitrogen for enhanced liquid product production.

Abstract: The process and the device are used for low-temperature separation of air. A first split stream of compressed and purified air is cooled, fed to a main rectifying system and separated there into liquid oxygen and gaseous nitrogen. A liquid product fraction (for example, oxygen and/or nitrogen) is vaporized in indirect heat exchange with a second split stream of compressed and purified air. The second split stream condenses during indirect heat exchange at least partially. At least a portion of the second split stream, downstream from indirect heat exchange with the liquid product fraction, is used as cooling medium for top cooling of a crude argon column downstream from the main rectifying system. The second split stream makes available all or essentially all the cold needed for liquefaction of crude argon.

Abstract: A method for the control of the operation of an installation for the separation of air by cryogenic distillation comprising a double distillation column wherein the top of a medium pressure column and the base of a low pressure column are thermally interconnected by a vaporizer-condenser supplied with liquid oxygen from a bath of liquid oxygen in the base of the low pressure column. Liquid oxygen from the bath is continuously tested to detect the content of nitrous oxide in the bath, and upon the detection of a fall in the nitrous oxide content of the bath when the installation is operating under equilibrium conditions, the flow of liquid oxygen to the vaporizer-condenser is increased to raise the detected nitrous oxide content of the bath. But when the detected nitrous oxide level falls, then either a liquid oxygen purge line is opened farther, or else the operating time or pressure of switching adsorbers in the air supply is changed.

Abstract: A cryogenic rectification system for producing lower purity gaseous oxygen and high purity oxygen employing a double column and an auxiliary column which upgrades lower pressure column bottom liquid or processes higher pressure column kettle liquid.

Abstract: Process for the production of oxygen by cryogenic distillation of a supply mixture containing oxygen and nitrogen in a double column (5) comprising a medium pressure column (6) and a low pressure column (7), in which there is partially condensed at least one fraction of the supply mixture in a condenser (8) by vaporization of liquid oxygen from the base of the low pressure column (7), said partially condensed mixture is sent to the medium pressure column (6), all the oxygen destined to form the gaseous production being withdrawn in liquid phase from the base of the low pressure column (7), and brought to its utilization pressure.

Abstract: An air boiling dual column cryogenic rectification system for producing lower purity oxygen wherein a portion of the feed air is used to reboil the lower pressure column and then is partially condensed in a vertically oriented stage within the lower pressure column before undergoing rectification.

Abstract: A first flow of air is compressed in a first air compressor associated with a gas turbine and is purified in an adsorptive purification unit which separates water vapour and carbon dioxide from the air. The purified first flow of air is further compressed to a pressure at least 5 bar higher than that at which it is purified in a second air compressor whose outlet pressure is independent of fluctuations in the power output of the gas turbine, is cooled in a main heat exchanger, is passed through an expansion valve, and is introduced into a higher pressure rectification column. A second flow of air is compressed in a third air compressor which is independent of the gas turbine. The compressed second flow of air is purified in an adsorptive purification unit by the separation of water vapour and carbon dioxide therefrom. The purified second flow of air is cooled in the main heat exchanger and is introduced into the higher pressure rectification column.

Abstract: A cryogenic rectification system which can operate at elevated pressure without encountering a severe separation efficiency burden wherein additional column reflux is generated by an indigenous nitrogen heat pump circuit.

Abstract: An air separation process of the "pumped" type, in which liquid oxygen is removed from a double distillation column and is pumped to a higher production pressure and then vaporized under that pressure. The incoming air is divided into several streams. A first stream is compressed to the medium pressure, cooled and sent to the double distillation column (7). A second stream is compressed above about 25 bars, but below its condensation pressure during vaporization of the liquid oxygen under pressure, then cooled to an intermediate temperature, at which a portion of the air continues its cooling and is liquified (in 20A), then expanded (in 21A) and sent to the double column, while the rest is work expanded (in 4). Use in large size installations for the production of oxygen.

Abstract: Process and installation for the production of gaseous oxygen under pressure by cryogenic distillation of air in a double column (5) comprising a medium pressure column (6) and a low pressure column (7). Rich liquid from the medium pressure column is divided into first and second liquid fractions which are sent to different levels in the low pressure column (7). These different levels are both below the level of withdrawal of impure nitrogen from the low pressure column (7). A fluid enriched in argon is withdrawn from the low pressure column (7) and distilled in an argon column (16). Liquid enriched in oxygen is withdrawn from a lower portion of the low pressure column (7). The two fractions of rich liquid are cooled to different temperatures before being sent to the low pressure column (7). A portion of the supply air is blown into an intermediate level of the low pressure column (7) and the levels of injection of the rich liquid are not below this intermediate level.

Abstract: Air is compressed in a compressor, cooled in a main heat exchanger, partially condensed in a reboiler-condenser, introduced into a higher pressure rectifier, and separated therein into nitrogen and oxygen-enriched liquid. Resulting nitrogen is condensed in further reboiler-condensers. One part of the condensate is used as reflux in the higher pressure rectifier and another part as reflux in a lower pressure rectifier. A stream of oxygen-enriched liquid is withdrawn from the high pressure rectifier and sent to an intermediate pressure rectifier which is reboiled by one of the further reboiler-condensers and in which further nitrogen is separated. A stream of liquid further enriched in oxygen is withdrawn from the bottom of the intermediate pressure rectifier and is separated in the lower pressure rectifier and impure and pure oxygen products are withdrawn respectively therefrom.

Abstract: Cooled and purified air is introduced into a higher pressure rectification column and separated into oxygen-enriched liquid and nitrogen vapor. A stream of the oxygen-enriched liquid is flashed through a pressure reducing valve to form a mixture of liquid further enriched in oxygen and vapor depleted of oxygen. The liquid is reboiled by reboiler. A stream of the further enriched liquid is reboiled in condenser and is introduced into a lower pressure rectification column for separation into oxygen and nitrogen products. Reflux for the columns and is formed by condensing in condenser nitrogen vapor separated in the higher pressure rectification column. A reboiler provides an upward flow of vapor through the column. The condenser and reboiler take the form of a single heat exchanger. The reboiler is located in a phase separator, the reboiler is located in a rectification column containing liquid-vapor contact devices above the level at which fluid issuing from the valve is introduced.

Abstract: Air is introduced through an inlet into a higher pressure rectification column. A stream of oxygen-enriched liquid is withdrawn through an outlet from the higher pressure rectification column. A part of this stream is introduced into a low pressure rectification column through an inlet. The stream is separated in the column low pressure rectification into oxygen and nitrogen. In addition, an argon-enriched vapor stream is withdrawn from the low pressure rectification column through an outlet, and is at least partially condensed in a reboiler-condenser which reboils oxygen separated in an argon column. One part of the resulting at least partially condensed argon-enriched oxygen stream is reduced in pressure by passage through a valve and is introduced through an inlet into an intermediate mass exchange region of the argon column in which it is separated into argon and oxygen.

Abstract: Air is distilled in a distillation apparatus (13) associated with a heat exchange line (11) in which is circulated a heat transfer fluid under high pressure. A storage (20, 23) is supplied, at least intermittently, with gas in liquid phase; and gas in liquid phase withdrawn from the storage is raised to a vaporization pressure, and vaporized under this pressure in the heat exchange line (11). The supply of liquefied gas to the storage can be from the distillation apparatus (13) and/or from an external source such as a tank truck (29, 34). It is useful particularly for the supply of oxygen, nitrogen and argon under pressure to installations for the production of stainless steel such as electric arc furnaces.

Abstract: A cryogenic rectification system for producing elevated pressure gaseous oxygen wherein pressurized liquid oxygen is vaporized against pressurized working fluid which is then turboexpanded to form a dual phase stream having both vapor and liquid fractions.

Abstract: A stream of air is compressed in compressor and has water vapor and carbon dioxide removed therefrom in purification unit. A part of the resulting purified air is cooled by passage through heat exchanger and is employed to heat an intermediate reboiler in a lower pressure rectification column. The air flow from the reboiler passes into a higher pressure rectification column which supplies a stream of oxygen-enriched liquid air for separation in the lower pressure rectification column. Liquid nitrogen reflux for the higher pressure column is provided by taking nitrogen vapor from this column through an outlet and condensing it in another intermediate reboiler located above the reboiler in the lower pressure rectification column. The condensed nitrogen is returned to the top of the column.