Falling film evaporation of single component liquids

Abstract

Heat transfer coefficients for evaporation of single-component liquids in falling films were experimentally measured over an extended range of parameters. By using two different fluids (propylene glycol and water), over a range of absolute pressures, it was possible to extend the existing data base by an order of magnitude in Prandtl numbers. These new data indicate that existing models and correlations were inadequate for fluids with Prandtl numbers greater than five. New models were developed for both the wavy laminar and the turbulent regimes. An exponential interpolation paradigm between the regimes enabled prediction of the evaporative heat transfer coefficient over the entire range of Reynolds and Prandtl numbers with an average deviation of less than 10% from the experimental data, © 1998 Elsevier Science Ltd. All rights reserved.