MULTI-ZONE BOILING PROCESS AND APPARATUS

摘要

The invention relates to a process and apparatus for boiling flowing liquids such as liquefied gases in a heat exchanger in which a circulating flow is occurring, such as in reboiler-condensers in air separation and similar cryogenic plants or other applications where a high efficiency for boiling heat transfer is beneficial. The important feature of the process and apparatus is the use of two sequential heat transfer zones having different pressure drop and heat transfer characteristics in the same boiling channel, the first zone having an overall high-convective-heat-transfer characteristic and an overall higher pressure drop characteristic and comprising a plurality of sub-zones, each sub-zone sequentially having a lower pressure drop than the previous sub-zone and the second zone having a lower pressure drop and an enhanced nucleate boiling heat transfer characteristic.