CS-6 Shellside Condensation of Immiscible Mixtures on Horizontal Tube Bundles

K. Ishihara

Experimental data have been obtained for shellside condensation of steam/n-pentane and steam/n-pentane/p-xylene on horizontal tube bundles.

Data for plain tubes, tubes with 11 fins/in., and tubes with 19 fins/in. are reported. Condensing coefficients of a binary immiscible system depend strongly on the vapor-liquid equilibrium conditions of the mixture. Data indicate that the condensing coefficients under eutectic runs are higher than the coefficients of miscible mixtures. The condensing coefficients under noneutectic condensation are in the same range or slightly better than those of the miscible mixture condensation.

The vapor-phase coefficient for noneutectic runs is found to be the controlling coefficient and can be predicted by the existing correlation for miscible mixtures using mixture properties. The condensate film coefficient for eutectic runs is controlling but can be predicted well by use of mixture properties with the correlation for the condensate film coefficient. Use of a more sophisticated model for the film coefficients does not result in better prediction of the data. Use of homogenous mixture properties with the existing condensation heat transfer correlation for miscible mixtures is acceptable in practical design application if the proper profile is provided.