Page 281 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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0J0+ 0.15; 0.60 ± 0.17 ; 0.5 ± 0.12; -0.6 ± 0.25.
The mean error of Eq.(180) is 22.3%, This precision is satisfactory
because AA is only a correction of AQ.
Fig. 54 illustrates the comparison of the experimental pressure drop of
wetted packings, either up to the loading point or above it, with the values
calculated by Eqs. (179) and (180).

1000

20
20 40 60 100 200 400 600 1000
,,, Pa/m

Fig. 54. Comparison of experimental data for wet packings pressure drop below and above the
loading point with results calculated by Eqs. (179) and (180) (see Table 26 for symbols).

Eqs. (178)-(180) can be used [163] to determine also the loading point.
It has been shown [34] that the loading point can be defined as a point at which
the term K>, in Eq. (46) becomes noticeably different from 1. Determined on the
base of a great number of experimental loading points, the value of Kt, appears
to be 1.03 [34,160].
The value of Kf, depends not only on experimental data but also on the
relations used to estimate A o and M in Eq. (46). In [34, 160], Eq. (259) -
Chapter 1 is used. In this equation the power at (1-A) is 3, while Eq. (46) is
derived from Eq. (178), where the power in the expression for the local pressure
drop is 6.8. In fact, the loading point is that at which the pressure drop