(268d) Condensation of Organic Vapors on Finned Tubes

The heat transfer coefficients of condensing organic vapors on horizontal/vertical tubes are much lower than that of condensing steam. Literature shows increasing condensation rates on finned tubes. Experiments were conducted with organic vapors condensing on a fabricated aluminum finned tube. The test condenser was an aluminum tube 300mm long, 24 mm OD and 21mm ID on which four longitudinal fins (10mm height and 1.2 mm thickness) were attached at equal angle circumferentially. Condensation of water, methanol, carbon tetrachloride and n-Hexane were carried at near atmospheric pressure on horizontal orientation of condenser. The details of experimental setup, measurements and instrumentation would be given. A preliminary data analysis indicated that the Nusselt analysis is not satisfactory in explaining the data. A video graphic study was carried out to check the nature of condensation. It was found that the condensation of organic vapors occurred in mixed mode i.e., both film wise and drop wise. Further data are being obtained and the data analysis would include:

?vapor entry velocity effect on the heat transfer coefficient ?Effect of coolant thermal resistance variation along the condenser ?Contribution of drop wise condensation to overall heat transfer rate.