Patents by Inventor Vijayaraghavan S. Chakravarthy
Vijayaraghavan S. Chakravarthy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10295254Abstract: A system and method for recovery of rare gases such as neon, helium, xenon, and krypton in an air separation unit is provided. The rare gas recovery system comprises a non-condensable stripping column linked in a heat transfer relationship with a xenon-krypton column via an auxiliary condenser-reboiler. The non-condensable stripping column produces a rare gas containing overhead that is directed to the auxiliary condenser-reboiler where most of the neon is captured in a non-condensable vent stream that is further processed to produce a crude neon vapor stream that contains greater than about 50% mole fraction of neon with the overall neon recovery exceeding 95%. The xenon-krypton column further receives two streams of liquid oxygen from the lower pressure column and the rare gas containing overhead from the non-condensable stripping column and produces a crude xenon and krypton liquid stream and an oxygen-rich overhead.Type: GrantFiled: September 5, 2017Date of Patent: May 21, 2019Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Vijayaraghavan S. Chakravarthy, Hanfei Tuo, Maulik R. Shelat, James R. Dray, Nick J. Degenstein
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Patent number: 10247471Abstract: An argon reflux condensation system and method in which a plurality of once-through condensers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the air separation plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Prior to flowing into the once-through condensers, the partially vaporized crude oxygen stream enters a phase separator which separates the crude oxygen vapor from the crude liquid oxygen.Type: GrantFiled: July 11, 2018Date of Patent: April 2, 2019Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: James R. Handley, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy, Maulik R. Shelat, Steven R. Falta
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Publication number: 20190072326Abstract: A system and method for recovery of rare gases such as neon, helium, xenon, and krypton in an air separation unit is provided. The rare gas recovery system comprises a non-condensable stripping column linked in a heat transfer relationship with a xenon-krypton column via an auxiliary condenser-reboiler. The non-condensable stripping column produces a rare gas containing overhead that is directed to the auxiliary condenser-reboiler where most of the neon is captured in a non-condensable vent stream that is further processed to produce a crude neon vapor stream that contains greater than about 50% mole fraction of neon with the overall neon recovery exceeding 95%. The xenon-krypton column further receives two streams of liquid oxygen from the lower pressure column and the rare gas containing overhead from the non-condensable stripping column and produces a crude xenon and krypton liquid stream and an oxygen-rich overhead.Type: ApplicationFiled: September 5, 2017Publication date: March 7, 2019Inventors: Vijayaraghavan S. Chakravarthy, Hanfei Tuo, Maulik R. Shelat, James R. Dray, Nick J. Degenstein
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Patent number: 10190819Abstract: An argon reflux condensation system and method in which a plurality of once-through heat exchangers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Feed stream flow rate to the argon column is controlled in response to air flow rate to the plant and product flow rate is controlled in response to the feed stream flow rate to the argon column.Type: GrantFiled: July 11, 2018Date of Patent: January 29, 2019Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Steven R. Falta, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy, Maulik R. Shelat
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Publication number: 20180328655Abstract: An argon reflux condensation system and method in which a plurality of once-through condensers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the air separation plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Prior to flowing into the once-through condensers, the partially vaporized crude oxygen stream enters a phase separator which separates the crude oxygen vapor from the crude liquid oxygen.Type: ApplicationFiled: July 11, 2018Publication date: November 15, 2018Inventors: James R. Handley, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy, Maulik R. Shelat, Steven R. Falta
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Publication number: 20180320962Abstract: An argon reflux condensation system and method in which a plurality of once-through heat exchangers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Feed stream flow rate to the argon column is controlled in response to air flow rate to the plant and product flow rate is controlled in response to the feed stream flow rate to the argon column.Type: ApplicationFiled: July 11, 2018Publication date: November 8, 2018Inventors: Steven R. Falta, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy, Maulik R. Shelat
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Patent number: 10082333Abstract: An argon reflux condensation system and method in which a plurality of once-through condensers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the air separation plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Prior to flowing into the once-through condensers, the partially vaporized crude oxygen stream enters a phase separator which separates the crude oxygen vapor from the crude liquid oxygen.Type: GrantFiled: June 30, 2015Date of Patent: September 25, 2018Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: James R. Handley, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy, Maulik R. Shelat, Steven R. Falta
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Patent number: 10060673Abstract: An argon reflux condensation system and method in which a plurality of once-through heat exchangers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Feed stream flow rate to the argon column is controlled in response to air flow rate to the plant and product flow rate is controlled in response to the feed stream flow rate to the argon column.Type: GrantFiled: June 30, 2015Date of Patent: August 28, 2018Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Steven R. Falta, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy
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Patent number: 10048004Abstract: A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.Type: GrantFiled: October 5, 2016Date of Patent: August 14, 2018Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Maulik R. Shelat, Vijayaraghavan S. Chakravarthy, Sang Muk Kwark
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Patent number: 10012439Abstract: A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.Type: GrantFiled: October 5, 2016Date of Patent: July 3, 2018Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Maulik R. Shelat, Vijayaraghavan S. Chakravarthy, Sang Muk Kwark
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Patent number: 9920988Abstract: A method and main heat exchange system for use in a cryogenic air separation plant in which down-flow and thermosiphon heat exchangers are employed to partially vaporize an oxygen-rich liquid produced in a lower pressure column and to condense the nitrogen-rich vapor in a higher pressure column. A greater proportion of the oxygen-rich liquid can be partially vaporized in the down-flow heat exchangers than in the thermosiphon heat exchangers and the nitrogen-rich vapor condensed in the thermosiphon heat exchangers can have a higher oxygen content than the nitrogen-rich vapor condensed in the down-flow heat exchangers. This allows the higher pressure column to operate at a lower pressure than would otherwise be possible. A central conduit can extend from the higher pressure column into the lower pressure column to introduce the nitrogen-rich vapor into at least the down-flow heat exchangers for purposes of reducing pressure drop and column height.Type: GrantFiled: August 22, 2016Date of Patent: March 20, 2018Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Vijayaraghavan S. Chakravarthy, Michael J. Lockett, Dante P. Bonaquist, Maulik R. Shelat, Karl K. Kibler
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Publication number: 20170023298Abstract: A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.Type: ApplicationFiled: October 5, 2016Publication date: January 26, 2017Inventors: Maulik R. Shelat, Vijayaraghavan S. Chakravarthy, Sang Muk Kwark
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Publication number: 20170023297Abstract: A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.Type: ApplicationFiled: October 5, 2016Publication date: January 26, 2017Inventors: Maulik R. Shelat, Vijayaraghavan S. Chakravarthy, Sang Muk Kwark
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Publication number: 20160356546Abstract: A method and main heat exchange system for use in a cryogenic air separation plant in which down-flow and thermosiphon heat exchangers are employed to partially vaporize an oxygen-rich liquid produced in a lower pressure column and to condense the nitrogen-rich vapor in a higher pressure column. A greater proportion of the oxygen-rich liquid can be partially vaporized in the down-flow heat exchangers than in the thermosiphon heat exchangers and the nitrogen-rich vapor condensed in the thermosiphon heat exchangers can have a higher oxygen content than the nitrogen-rich vapor condensed in the down-flow heat exchangers. This allows the higher pressure column to operate at a lower pressure than would otherwise be possible. A central conduit can extend from the higher pressure column into the lower pressure column to introduce the nitrogen-rich vapor into at least the down-flow heat exchangers for purposes of reducing pressure drop and column height.Type: ApplicationFiled: August 22, 2016Publication date: December 8, 2016Inventors: Vijayaraghavan S. Chakravarthy, Michael J. Lockett, Dante P. Bonaquist, Maulik R. Shelat, Karl K. Kibler
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Patent number: 9488408Abstract: A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.Type: GrantFiled: January 29, 2014Date of Patent: November 8, 2016Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Maulik R. Shelat, Vijayaraghavan S. Chakravarthy, Sang Muk Kwark
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Patent number: 9476641Abstract: A condenser reboiler system located within a bottom region of a low pressure column of a double column arrangement that is used in an air separation system to separate air. The condenser reboiler system incorporates first and second heat exchangers of the down-flow type that are situated in a side-by-side relationship and with the first heat exchanger being shorter than the second heat exchanger so that the first heat exchanger will remain functional after a shut-down of the air separation system when the second heat exchanger(s) are not capable of operating due to liquid dumping into a sump region of the low pressure column. The side-by-side relationship allows the column to be fabricated without excessive height.Type: GrantFiled: September 28, 2007Date of Patent: October 25, 2016Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Vijayaraghavan S. Chakravarthy, John Henri Royal
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Patent number: 9453674Abstract: A method and main heat exchange system for use in a cryogenic air separation plant in which down-flow and thermosiphon heat exchangers are employed to partially vaporize an oxygen-rich liquid produced in a lower pressure column and to condense the nitrogen-rich vapor in a higher pressure column. A greater proportion of the oxygen-rich liquid can be partially vaporized in the down-flow heat exchangers than in the thermosiphon heat exchangers and the nitrogen-rich vapor condensed in the thermosiphon heat exchangers can have a higher oxygen content than the nitrogen-rich vapor condensed in the down-flow heat exchangers. This allows the higher pressure column to operate at a lower pressure than would otherwise be possible. A central conduit can extend from the higher pressure column into the lower pressure column to introduce the nitrogen-rich vapor into at least the down-flow heat exchangers for purposes of reducing pressure drop and column height.Type: GrantFiled: June 5, 2014Date of Patent: September 27, 2016Assignee: PRAXAIR TECHNOLOGY, INC.Inventors: Vijayaraghavan S. Chakravarthy, Michael J. Lockett, Dante P. Bonaquist, Maulik R. Shelat, Karl K. Kibler
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Publication number: 20160003538Abstract: An argon reflux condensation system and method in which a plurality of once-through heat exchangers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Feed stream flow rate to the argon column is controlled in response to air flow rate to the plant and product flow rate is controlled in response to the feed stream flow rate to the argon column.Type: ApplicationFiled: June 30, 2015Publication date: January 7, 2016Inventors: Steven R. Falta, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy
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Publication number: 20160003539Abstract: An argon reflux condensation system and method in which a plurality of once-through condensers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the air separation plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Prior to flowing into the once-through condensers, the partially vaporized crude oxygen stream enters a phase separator which separates the crude oxygen vapor from the crude liquid oxygen.Type: ApplicationFiled: June 30, 2015Publication date: January 7, 2016Inventors: James R. Handley, Brian S. Powell, Henry E. Howard, Vijayaraghavan S. Chakravarthy, Maulik R. Shelat, Steven R. Falta
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Publication number: 20150211789Abstract: A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.Type: ApplicationFiled: January 29, 2014Publication date: July 30, 2015Inventors: Maulik R. Shelat, Vijayaraghavan S. Chakravarthy, Sang Muk Kwark