Flooding reduction on a tubular heat exchanger

摘要

An asymmetrical, or non-uniform arrangement of heat exchanging tubes in a second stage heat exchanger of an integrated flue gas treatment system provides improved flow characteristics and reduces or eliminates flooding caused by the counter-flow of upwardly rising flue gases and downwardly falling reagent and condensate through the heat exchanging tubes. The non-uniform spacing produces a non-uniform velocity profile with at least one low velocity region in each row, allowing reagent and condensate to drain downward at said low velocity region, thereby preventing high gas phase pressure drop caused by the onset of flooding. Embodiments are provided in which one of every six tubes are removed from each row in a uniform array of tubes, or one of every four tubes are removed from each row in a uniform array of tubes. Other asymmetrical, or non-uniform spacings are possible.