Triple Column Patents (Class 62/900)
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Patent number: 6651460Abstract: Oxygen-containing gas comprising no more than about 50 mol % oxygen is fed (150) to an auxiliary separation column (40) in a multiple column cryogenic air distillation system comprising at least a higher pressure (“HP”) column (10) and a lower pressure (“LP”) column (30) for separation into nitrogen-rich overhead vapor and oxygen-rich liquid. Oxygen-rich liquid is fed (154) from the auxiliary column (40) to an intermediate location in the LP column (30). The auxiliary column (40) is refluxed with a liquid stream from or derived from the HP column (10). One advantage of the invention is that the diameter of the upper sections (II, III) of the LP column (30) need no longer be larger than the diameter of the rest of the column system thereby increasing the capacity of the column system (under the constraint of a defined maximum column section diameter).Type: GrantFiled: October 29, 2002Date of Patent: November 25, 2003Assignee: Air Products and Chemicals, Inc.Inventor: Declan P. O'Connor
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Patent number: 6622520Abstract: A cryogenic rectification system for producing low purity oxygen from an auxiliary column to a double column system and which can also effectively produce nitrogen gas product and/or one or more liquid products wherein the lower pressure column of the double column system is reboiled in part by turboexpanded shelf vapor which is condensed in an intermediate reboiler and preferably subcooled prior to passage into the lower pressure column.Type: GrantFiled: December 11, 2002Date of Patent: September 23, 2003Assignee: Praxair Technology, Inc.Inventors: Neil Mark Prosser, Minish Mahendra Shah
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Patent number: 6564581Abstract: The process and the apparatus are used to obtain argon using a three-column system for the fractionation of air, which has a high-pressure column (11), a low-pressure column (13) and a medium-pressure column (12). A first charge air stream (10, 64) is introduced into the high-pressure column (11), where it is separated into a first oxygen-enriched liquid and a first nitrogen top gas. A first oxygen-enriched fraction (23, 24, 26) from the high-pressure column (11) is introduced into the medium-pressure column (12), where it is separated into a second oxygen-enriched liquid and a second nitrogen top gas. A second oxygen-enriched fraction (33, 35), from the high-pressure column and/or from the medium-pressure column (12), is introduced into the low-pressure column (13), where it is separated into a third oxygen-enriched liquid and a third nitrogen top gas.Type: GrantFiled: March 21, 2002Date of Patent: May 20, 2003Assignee: Linde AktiengesellschaftInventor: Gerhard Pompl
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Patent number: 6536234Abstract: A three column cryogenic rectification system for producing at least one of oxygen and nitrogen employing a medium pressure column which is operating at a pressure between the operating pressures of the higher and lower pressure columns, and which receives an air feed which is at a lower pressure than the air feed to the higher pressure column. The medium pressure column processes oxygen-enriched liquid from the higher pressure column and is reboiled by a fluid taken from below the top of the higher pressure column.Type: GrantFiled: February 5, 2002Date of Patent: March 25, 2003Assignee: Praxair Technology, Inc.Inventor: Minish Mahendra Shah
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Patent number: 6272883Abstract: A plant for separation of a gas mixture comprises at least two columns which are of the same length. The tops of two of the columns are at the same height.Type: GrantFiled: January 12, 2001Date of Patent: August 14, 2001Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Olivier Bruder, Bernard Darredeau, Jean-Yves Lehman
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Patent number: 6257019Abstract: Nitrogen is produced by separation of it from air. Nitrogen so separated is condensed. Most or all of the nitrogen is separated by rectification. At least some of the condensed nitrogen is employed as reflux in the rectification. The nitrogen is both separated and condensed at three or more different pressures.Type: GrantFiled: November 24, 1998Date of Patent: July 10, 2001Assignee: The BOC Group plcInventors: John Douglas Oakey, Paul Higginbotham
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Patent number: 6196024Abstract: Process for separating air by cryogenic distillation and apparatus including a high pressure column, an intermediate pressure column, a low pressure column having a bottom reboiler and an argon column having a top condenser, a conduit for sending air to the high pressure column, a conduit for sending at least part of a first oxygen enriched liquid from the high pressure column to the intermediate pressure column, a conduit for sending a second oxygen enriched fluid from the bottom of the intermediate pressure column to the low pressure column, a conduit for sending a second nitrogen enriched fluid from the top of the intermediate pressure column to the low pressure column or to a top condenser of the argon column, a conduit for sending a heating gas to the bottom reboiler of the low pressure column, a conduit for removing a third oxygen enriched fluid from the low pressure column, a conduit for sending a nitrogen enriched liquid from the high pressure column to the low pressure column, a conduit for sending aType: GrantFiled: May 25, 1999Date of Patent: March 6, 2001Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventor: Bao Ha
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Patent number: 6185960Abstract: In a process for the production of a pressurized gaseous product by low-temperature separation of air, which is at times done in a gas operation and at times in a combined operation, whereby in the gas operation and in the combined operation (a) purified charging air is cooled under pressure, partially liquefied, and subjected to rectification to produce gaseous and liquid fractions, (b) extremely cold liquid of at least one of the liquid fractions from the rectification is evaporated under elevated pressure by indirect heat exchange with feed air, heated, and obtained as a pressurized gaseous product, whereby in combined operation, (c) the cold that is required for this purpose is generated in an air-refrigeration cycle, by air being compressed in the refrigeration cycle and work expanded, in which case heat is removed from the air, and the actively depressurized air that is partially in countercurrent is heated again with the charging air that is to be cooled and then repressurized, (d) extremely cold liquiType: GrantFiled: April 8, 1999Date of Patent: February 13, 2001Assignee: Linde AktiengesellschaftInventor: Jürgen Voit
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Patent number: 6182470Abstract: In this air distillation plant (1) comprising a double column and a mixing column (5), the medium-pressure column (2), the low-pressure column (3) and the mixing column (5) are placed one on top of another, forming a single erected structure. Application to the supply of impure oxygen for the iron and steel industry.Type: GrantFiled: April 30, 1999Date of Patent: February 6, 2001Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventor: Alain Guillard
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Patent number: 5934104Abstract: The present invention is an improvement to a nitrogen generator enabling the process to efficiently coproduce oxygen with low recovery, typically less than 70% and preferably less than 55%, in addition to the primary product, nitrogen. In the nitrogen generator process, air is distilled in a distillation column system having a higher pressure column and a lower pressure column. The feed air is compressed, treated to remove water and carbon dioxide, cooled to near its dew point and fed to the higher pressure column of the distillation column system. The nitrogen product is produced by removing an overhead vapor stream from at least one of the columns of the distillation column system. At least one oxygen-enriched stream is removed from the lower pressure column.Type: GrantFiled: June 2, 1998Date of Patent: August 10, 1999Assignee: Air Products and Chemicals, Inc.Inventors: Zbigniew Tadeusz Fidkowski, Donn Michael Herron, Jeffrey Alan Hopkins
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Patent number: 5921107Abstract: A method for producing a small amount of oxygen, related to a nitrogen generator unit, is provided. In a nitrogen rectification column which cools down and liquefies feed air after moisture and carbon dioxide contained therein are removed, thereby producing nitrogen, oxygen-rich liquid air is used as a cold source for a nitrogen condenser and the thus-obtained oxygen-rich air is then used as a heating source for a reboiler in an oxygen rectification column.Type: GrantFiled: November 22, 1996Date of Patent: July 13, 1999Assignee: Teisan Kabushiki KaishaInventor: Takao Yamamoto
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Patent number: 5881570Abstract: A cryogenic rectification plant comprising a double column and a side column having a bottom reboiler wherein feed air is passed into the double column by way of the bottom reboiler and an auxiliary compressor is connected in parallel with the feed air line.Type: GrantFiled: April 6, 1998Date of Patent: March 16, 1999Assignee: Praxair Technology, Inc.Inventors: Raymond Francis Drnevich, Ravindra Fulchand Pahade, Minish Mahendra Shah
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Patent number: 5730004Abstract: The process and apparatus are based on a triple-column system, having at least a high-pressure column (7), a medium-pressure column (8) and a low-pressure column (9). Feed air (1) is compressed to a first pressure (2). A first partial stream (101, 103, 104) of the resultant air feed (3) is sent into high-pressure column (7) after it has been compressed to a second pressure (5, 102), which is at least equal to the operating pressure of the high-pressure column (7). A second partial stream (201, 202) of the compressed air feed (3) is fed into the medium-pressure column (8). A third partial stream (301, 303, 304) of the compressed air feed (3) is engine-expanded (305) and then fed (306) into the low-pressure column (9). Fractions (18; 26) from the high-pressure column (7) and the medium-pressure column (8) are introduced at least partially into low-pressure column (19, 20; 28, 29). Nitrogen-enriched top fractions (10; 21) from high-pressure column (7) and medium-pressure column (8) are condensed (11; 22).Type: GrantFiled: October 10, 1996Date of Patent: March 24, 1998Assignee: Linde AktiengesellschaftInventor: Jurgen Voit
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Patent number: 5715706Abstract: Cooled and purified air is introduced into a higher pressure rectification column and separated into oxygen-enriched liquid and nitrogen vapour. 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 vapour 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 vapour separated in the higher pressure rectification column. A reboiler provides an upward flow of vapour 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-vapour contact devices above the level at which fluid issuing from the valve is introduced.Type: GrantFiled: August 29, 1996Date of Patent: February 10, 1998Assignee: The BOC Group plcInventor: Thomas Rathbone
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Patent number: 5682764Abstract: A cryogenic process for producing impure oxygen and/or substantially pure nitrogen utilizes a classic double column arrangement and an additional third column operating at a medium pressure, i.e. between the pressure of the higher pressure stage and the lower pressure stage of the double column system. A portion of the feed air is separated in the stages of the double column system, and another portion of the feed air is distilled in the medium pressure stage. Crude liquid oxygen from the higher pressure stage and/or the medium pressure stage is reduced in pressure and boiled in a reboiler/condenser at the top of the medium pressure column. The vaporized crude liquid oxygen from the top reboiler/condenser of the medium pressure column is subsequently introduced as a vapor feed to the lower pressure stage, which reduces irreversibilities of separation in the lower pressure stage.Type: GrantFiled: October 25, 1996Date of Patent: November 4, 1997Assignee: Air Products and Chemicals, Inc.Inventors: Rakesh Agrawal, Zbigniew Tadeusz Fidkowski
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Patent number: 5664438Abstract: A cryogenic rectification system for producing low purity oxygen and high purity nitrogen, preferably at elevated pressure, wherein nitrogen-rich vapor from a higher pressure column is turboexpanded and condensed against lower pressure column intermediate liquid prior to being passed into the lower pressure column and low purity oxygen is produced in an auxiliary side column driven by fluid from the higher pressure column.Type: GrantFiled: August 13, 1996Date of Patent: September 9, 1997Assignee: Praxair Technology, Inc.Inventors: Dante Patrick Bonaquist, Susan Marie Sattan
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Patent number: 5644933Abstract: A stream of compressed air is purified in a unit by removal of carbon dioxide and water vapour. The air is cooled by passage through a heat exchanger to a temperature suitable for its rectification. The air is separated in a higher pressure rectifier into oxygen-enriched liquid and nitrogen vapour. A stream of the oxygen-enriched liquid is reduced in pressure and introduced into a phase separator provided with a reboiler with the result that further separation takes place and a liquid further enriched in oxygen and an intermediate vapour are formed. A stream of the further-enriched liquid is separated into oxygen and nitrogen in a lower pressure rectifier. A stream of the intermediate vapour is condensed in a condenser and is introduced into the lower pressure rectifier.Type: GrantFiled: January 3, 1996Date of Patent: July 8, 1997Assignee: The BOC Group plcInventor: Thomas Rathbone
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Patent number: 5582035Abstract: 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.Type: GrantFiled: September 25, 1995Date of Patent: December 10, 1996Assignee: The BOC Group plcInventors: Thomas Rathbone, John T. Lavin, David Stuart
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Patent number: 5582032Abstract: A process for producing an ultra-high purity fluid product comprising the steps of collecting in the lower portion of a cryogenic fractionation zone an ultra-high purity fluid product; providing reboil to said fractionation zone by condensing a portion of a lesser purity composition of the same fluid product by indirect heat exchange in a first reboiler; and vaporizing said portion of said lesser purity composition by indirect heat exchange with a warmer stream of an impure fluid.Type: GrantFiled: August 11, 1995Date of Patent: December 10, 1996Assignee: Liquid Air Engineering CorporationInventors: James T. Shelton, deceased, Bao Ha