Caf

Q FPL AB CAF

where

CAF = 0.3048 CAF0 SF

CB is the operating C-factor based on the bubbling area, m/s; Q is the liquid flow rate, m3/s; AB is the bubbling area, m2; FPL is the flow path length, m, i.e., the horizontal distance between the inlet downcomer and the outlet weir. The flow path length becomes shorter as the number of passes increases. CAF0 and CAF are the flood C-factors. CAF0 is obtained from Fig. 14-30 in English units (ft/s). Equation (14-88) converts CAF0 to the metric CAF (m/s), and corrects it by using a system factor SF. Values of SF are given in Table 14-9.

The Fair correlation [Pet/Chem Eng. 33(10), 45 (September 1961)] for decades has been the standard of the industry for entrainment flood prediction. It uses a plot (Fig. 14-31) of surface-tension-corrected Souders and Brown flood factor CSB against the dimension-less flow parameter shown in Fig. 14-31. The flow parameter represents a ratio of liquid to vapor kinetic energies:

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