Tubeside Condensation

Since the main condenser operates at a vacuum, any leakage is into the shell side of the main condenser. Tubeside or circulating water in leakage is detected by measuring the... 

The shape of the coohng and warming curves in coiled-tube heat exchangers is affected by the pressure drop in both the tube and shell-sides of the heat exchanger. This is particularly important for two-phase flows of multicomponent systems. For example, an increase in pressure drop on the shellside causes boiling to occur at a higher temperature, while an increase in pressure drop on the tubeside will cause condensation to occur at a lower temperature. The net result is both a decrease in the effective temperature difference between the two streams and a requirement for additional heat transfer area to compensate for these losses. 

Palen, J. W., G. Breber, and J. Taborek, 1977, Prediction of Flow Regimes in Horizontal Tubeside Condensation, 17th Natl. Heat Transfer Conf., AIChE/ASME, Salt Lake City, UT. (3)... 

Tube velocity >1 m/s for crude preheat exchangers, tube velocity is 1 to 2 m/s for overhead water condensers, tube velocity is 1 to 3.5 m/s. To minimize fouling, keep tubeside velocities 3 to... 

G. Breber, J. W. Palen, and J. Taborek, Prediction of Horizontal Tubeside Condensation of Pure Components Using Flow Regime Criteria, J. Heat Transfer, 102, pp. 471-476,1980. 

For horizontal tubeside condensers, no good methods are available for predicting heat transfer coefficients when appreciable subcooling of the condensate is required. A conservative approach is to calculate a superficial mass velocity assuming the condensate filis the entire tube and use the equations presented previousiy for a singie phase sensible heat transfer inside tubes... 

Equipment with tubeside condensation are more easily vented, provided condensate is not permitted to flood the heat transfer surface. Horizontal units may experience maldistribution or higher rates of condensing at the top of the unit than at the bottom of the unit. Multipass tube arrangements help to avoid this problem. Condensate loading in the tubes must not be so high as to prevent proper venting. This is discussed in Chapter 22. 

Tubeside condensing generally requires fewer components to be fabricated of more expensive materials of construction. 

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