Integral analysis of condensation in a paper drum with a scraper

An integral analysis is made for laminar film condensation in a rotating paper drum with a scraper. The analysis includes the nonlinear inertial terms in the equation of motion, with the interface shear stress being considered. The results of numerical solutions show that the inertial terms cannot be neglected except in the cases of a very thin condensate film or a very large Froude number, that the condensation heat transfer will be, to some extent, enhanced by the inertial effect, and that the vapor shear at the vapor-liquid interface proves to be negligible. Distributions of the interface velocity and film thickness as well as heat transfer results are obtained and discussed. Included also in this paper is the investigation for transition of the condensate flow from steady state to unsteady one. Received on 6 December 1996