2. Film condensation of pure steam

When condensation occurs on a wall, a liquid film forms on the cooled surface. The thickness of the liquid film results from the interaction between the flow of liquid and steam, depending on the geometry of the solid surface. In industrial practice, the exchange surfaces used are often highly complex and do not lend themselves easily to theoretical analysis of the condensation phenomenon. Phenomena such as waves on the surface of the condensate film or droplet plucking and flooding further complicate the analysis.

Because of the complexity of the interactions between the vapor flow and the liquid film, average heat exchange coefficients are determined by tests carried out on specific fixtures, and correlations are established using dimensional analysis. A plethora of such empirical correlations developed for different geometries and fluids is available in the scientific...