US 11,933,540 B2
Dual column nitrogen producing air separation unit with split kettle reboil and integrated condenser-reboiler
Hanfei Tuo, East Amherst, NY (US); and Zhengrong Xu, East Amherst, NY (US)
Assigned to Praxair Technology, Inc., Danbury, CT (US)
Filed by Hanfei Tuo, East Amherst, NY (US); and Zhengrong Xu, East Amherst, NY (US)
Filed on Apr. 13, 2023, as Appl. No. 18/300,033.
Application 18/300,033 is a continuation of application No. 17/234,080, filed on Apr. 19, 2021, granted, now 11,674,750.
Claims priority of provisional application 63/034,433, filed on Jun. 4, 2020.
Prior Publication US 2023/0251033 A1, Aug. 10, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. F25J 3/02 (2006.01); F25J 3/04 (2006.01); F25J 1/00 (2006.01)
CPC F25J 3/04412 (2013.01) [F25J 3/0257 (2013.01); F25J 3/04012 (2013.01); F25J 3/04763 (2013.01); F25J 1/0012 (2013.01); F25J 2200/50 (2013.01); F25J 2210/40 (2013.01); F25J 2250/20 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An integrated condenser-reboiler arrangement for a distillation column system comprising:
a phase separator; and
a once-through condenser-reboiler disposed within the phase separator, the once-through condenser-reboiler having a top section, an intermediate location, and a bottom section;
a plurality of condensing passages configured to receive a gaseous stream from the distillation column system at the top section of the once-through condenser-reboiler and condense the gaseous stream traversing through the plurality of condensing passages via indirect heat exchange with a first kettle stream and a second kettle stream to yield a condensate that exits the bottom section of the once-through condenser-reboiler;
a first set of boiling passages configured to receive the first kettle stream from the distillation column system at the bottom section of the once-through condenser-reboiler and partially vaporize the first condensing stream via indirect heat exchange with the gaseous stream traversing through the cooling passages to yield a dual phase boil off stream, and wherein the dual phase boil off stream is released from the top section of the once-through condenser-reboiler into the phase separator;
a second set of boiling passages configured to receive the second condensing medium from the phase separator at an intermediate location on the once-through condenser-reboiler and vaporize or partially vaporize the second condensing medium to yield another boil off stream that exits the top section of the once-through condenser-reboiler and directed back to the distillation column system;
wherein the phase separator is configured to separate the dual phase boil off stream into the second condensing medium and a recycle vapor stream.