RB3-5 Falling Film Evaporators - Areas of Application and Recommendations for Future Research

J. W. Palen

This Research Brief describes some of the areas of process heat transfer in which falling film evaporators should give performance far superior to that of other types of reboilers or vaporizers. A brief literature survey is given, and a first attempt is made to calculate heat transfer incrementally along the tube from basic principles and existing correlations. A comparison of these calculations for a falling film evaporator is made with results from the HTRI RTF-2 Computer Program for a vertical thermosiphon reboiler for two cases. Calculated temperature and composition gradients are shown for a third case. Additional research is required to better define the effect of mass transfer and the effect of nucleate boiling on heat transfer.