Heat exchanger with helical baffles

Abstract

A heat exchanger includes a shell with a longitudinal axis and helical baffles inside the shell, arranged along the longitudinal axis in an alternating pattern of first baffle followed by second baffles. Each helical baffle includes first and second holes that receive tubes. The second holes have a larger diameter than the first holes, or there is a clearance between the second holes and the tubes that is greater than the clearance between the first holes and the tubes. This intentionally induces an increased leakage current in the spaces between the second holes and the tubes. This increased leakage current maintains a relatively constant rate of heat transfer while reducing the pressure drop, resulting in a better heat transfer-to-pressure-drop ratio for the heat exchanger.