US 12,247,783 B2
Integrated nitrogen liquefier for a nitrogen and argon producing cryogenic air separation unit
Brian R. Kromer, Buffalo, NY (US); Neil M. Prosser, Lockport, NY (US); Jeremy M. Cabral, Clarence Center, NY (US); and James R. Handley, East Amherst, NY (US)
Assigned to LINDE GmbH, Pullach (DE)
Filed by Brian R. Kromer, Buffalo, NY (US); Neil M. Prosser, Lockport, NY (US); Jeremy M. Cabral, Clarence Center, NY (US); and James R. Handley, East Amherst, NY (US)
Filed on Mar. 8, 2023, as Appl. No. 18/180,211.
Application 18/180,211 is a division of application No. 17/241,218, filed on Apr. 27, 2021, granted, now 11,629,913.
Claims priority of provisional application 63/025,358, filed on May 15, 2020.
Prior Publication US 2023/0221069 A1, Jul. 13, 2023
Int. Cl. F25J 3/04 (2006.01)
CPC F25J 3/04412 (2013.01) [F25J 3/04084 (2013.01); F25J 3/0409 (2013.01); F25J 3/04096 (2013.01); F25J 3/04181 (2013.01); F25J 3/04187 (2013.01); F25J 3/04212 (2013.01); F25J 3/04357 (2013.01); F25J 3/04393 (2013.01); F25J 3/04496 (2013.01); F25J 3/04672 (2013.01); F25J 3/04036 (2013.01); F25J 2200/34 (2013.01); F25J 2205/60 (2013.01); F25J 2210/42 (2013.01); F25J 2230/52 (2013.01); F25J 2235/42 (2013.01); F25J 2245/42 (2013.01); F25J 2245/50 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A nitrogen liquefier configured to be integrated with an argon and nitrogen producing cryogenic air separation unit, the nitrogen liquefier comprising:
a gaseous nitrogen product stream produced from the cryogenic air separation unit and a gaseous nitrogen feed stream comprising between 1% and 10% of the gaseous nitrogen product stream by volume;
a nitrogen feed compressor configured to receive the gaseous nitrogen feed stream via a flow control valve disposed upstream of the nitrogen feed compressor and compress the gaseous nitrogen feed stream;
a nitrogen recycle compressor configured to receive the compressed gaseous nitrogen feed stream from the nitrogen feed compressor or receive the gaseous nitrogen feed stream via a bypass valve and further compress the received stream to produce a further compressed warm nitrogen stream;
a warm booster compressor disposed downstream of the nitrogen recycle compressor and configured to still further compress a first portion of the further compressed warm nitrogen stream to produce a further compressed nitrogen stream;
a cold booster compressor configured to still further compress the further compressed nitrogen stream to produce a primary nitrogen liquefaction stream;
a booster loaded warm turbine operatively coupled to the warm booster compressor and configured to expand a second portion of the further compressed warm nitrogen stream to produce a recycle stream;
a booster loaded cold turbine operatively coupled to the cold booster compressor and configured to expand a recycle portion of the primary nitrogen liquefaction stream and produce a cold recycle stream;
a heat exchanger configured to cool the primary nitrogen liquefaction stream via indirect heat exchange with the recycle stream and cold recycle stream to produce a liquid nitrogen product stream;
wherein the recycle stream and cold recycle stream are recycled back to the nitrogen recycle compressor after exiting the heat exchanger;
wherein the nitrogen liquefier is configured to operate in a nil liquid nitrogen mode wherein the flow control valve and the bypass valve are oriented in a closed position such that no portion of the gaseous nitrogen product stream is diverted to the nitrogen liquefier and no liquid nitrogen product stream is produced in the nitrogen liquefier;
wherein the nitrogen liquefier is configured to operate in a low liquid nitrogen mode wherein the flow control valve is oriented in a closed position and the bypass valve is oriented in an open position such that a portion of the gaseous nitrogen product stream is diverted as the gaseous nitrogen feed stream to the nitrogen recycle compressor and bypasses the nitrogen feed compressor; and
wherein the nitrogen liquefier is configured to operate in a high liquid nitrogen mode wherein the flow control valve is oriented in an open position and the bypass valve is oriented in a closed position such that a portion of the gaseous nitrogen product stream is diverted as the gaseous nitrogen feed stream to the nitrogen feed compressor.