Flooding in vertical tubes

Therefore, for flooding in vertical tubes for a range of these conditions, the tube f.D. must be greater than 0.26 in. generally, the recommendation is to use 0.5-1.0-in. f.D. tubes, approximately, to move far enough away from the critical condition. 

Design equations are given in Volume 6, Chapter 12, for condensation both inside and outside horizontal and vertical tubes, and the importance of avoiding flooding in vertical tubes is stressed. 

When the vapour flows up the tube, which will be the usual arrangement for a reflux condenser, care must be taken to ensure that the tubes do not flood. Several correlations have been published for the prediction of flooding in vertical tubes, see Perry et al. (1997). One of the simplest to apply, which is suitable for use in the design of condensers handling low-viscosity condensates, is the criterion given by Hewitt and Hall-Taylor (1970) see also Butterworth (1977). Flooding should not occur if the following condition is satisfied ... 

Lacy, C. E., A. E. Dukler, 1994, Flooding in Vertical Tubes—I Experimental Studies of the Entrance Region, Int. J. Multiphase Flow 20 219-233 Flooding in Vertical Tubes—II A Film Model for Entrance Region Flooding, Int. J. Multiphase Flow 20 235-247. (3)... 

Upper Limit Flooding in Vertical Tubes If, instead of a gas jet being injected into a liquid as in distillation, the liquid runs down the walls and the gas moves up the center of the tube, higher velocities can be achieved than shown by Eq. (14-168) or (14-203). This application is important in the design of vertical condensers. 

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