The effect of modifying the external surface of copper tubes used in a falling film fluid of a horizontal tube bundle

Abstract

This paper reports on an experimental investigation of a falling fluid coverage over plain and longitudinally enhanced horizontal copper tubes. Four different fluid distributors made out of Ø15 mm copper pipe were prepared by drilling a linear array of 11 holes along the tube length. Distributor (a) had an array of 4.5 mm holes, distributor (b) had 3.5 mm, distributor (c) had 2.5 mm, and distributor (d) had 1.5 mm. Holes of all distributors were drilled at the same center-to-center pitch of 8 mm. A horizontal tube bundle of four Ø15 mm copper tubes was also prepared. The study aimed to investigate the fluid coverage on the horizontal tubes using varied distributors at 25 mm and 45 mm height between the distributor and tube bundle. It was established that not only radial enhancement on tubes can improve the falling fluid film but also the longitudinally arranged enhancement can improve the fluid flowing around the horizontal tubes.