Abstract: The present invention relates to a boiling process in a downflow heat exchanger and the heat exchanger itself with liquid distribution enhancing features which improve performance and allow safe and efficient operation. Performance enhancing features include a partially flooded hardway distribution region with a liquid volume fraction greater than about 0.25 and preferably greater than 0.5, adjusting the heat transfer surface area to maintain a liquid film Reynolds number above 20 and, preferably, above 50 yet less than 1000, preferably less than 300, for at least 75% of the reboiler surface, and, optionally, intermediate feeding of liquid at various intervals along the length of the heat exchanger to obtain more uniform values of liquid film Reynolds numbers and intermediate redistribution.

Abstract: The present invention relates to a process to produce large quantities of pure nitrogen and small amounts of high purity oxygen co-product which utilizes a modified single distillation column nitrogen generator. The modification is the addition of a small second column which purifies a portion of the oxygen enriched liquid from the nitrogen generator overhead condenser. Reboiling for the second column is provided by condensing part of the nitrogen overhead from the nitrogen generator. This condensed nitrogen is used as reflux in the nitrogen generator.