Condensation of vapors of immiscible binary liquids on horizontal copper and polytetrafluoroethylene-coated copper tubes

Heat transfer data are reported for the condensation of pure organic vapors and their eutectic mixtures with water on both horizontal one inch diameter copper and polytetrafluoroethylene-coated copper tubes at atmospheric pressure. With the pure vapors heat transfer is reduced by the coating, this reduction being enhanced when condensing cyclohexane, attributable to an absorption effect. For the eutectic mixtures, except for carbon tetrachloride, heat transfer is not reduced by the coating and is substantially increased for the cyclohexane-water system. An explanation is afforded in terms of buoyancy-surface force interaction.