CS-14 Shellside Condensation of Plain and Low-Finned Tubes in Horizontal Cross Flow

Z. H. Yang

After conducting downflow condensation experiments and discovering that our retention penalties resulted in underprediction of the performance of low-finned tubes, HTRI initiated the second phase of shellside condensation horizontal crossflow research. Because vertical baffled cut horizontal condensers are among the most common in chemical plants and petroleum refineries, we sought to determine if our findings in downflow condensation also applied to horizontal flow.

New experimental data confirm that the effect of condensate retention on low-finned tubes in horizontal cross flow is less than that in vertical downflow, especially for condensation in the transition and gravity-controlled flow regimes. Predictions show that the current vertical crossflow method underpredicts heat transfer coefficients for horizontal cross flow by about 5 - 15 percent for pure component fluids and by about 10 - 25 percent for mixtures. Based on the new data, we developed improvements for the condensate film coefficient and the condensate flooding retention factor in the HTRI Resistance Proration Method (RPM) and the previously modified Rose-Briggs Method. Comparisons show that the improved RPM and Rose-Briggs Method provide a high level of accuracy for designing and rating shellside horizontal crossflow condensers.