Page 168 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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3,2.1.2. Performance characteristics of random packings
As already mentioned in Chapter 2, the investigations on the
performance characteristics are carried out in two types of installations, one for
obtaining of experimental data necessary for determination of constants in the
equations for calculation of the columns, and another for investigation of
rectification to obtain first of all the values of HTUand HETP. The latter can be
used for design of industrial rectification columns, and also for comparison of
the efficiency of different packings. Of course in the second type of
installations, data for holdup, pressure drop, and loading and flooding point can
be obtained. That is why for easier comparison, it is expedient to consider
separately the performance characteristics of the packings obtained in every
type of experimental installation.

3.2.1.2.1. Performance characteristics of random packings obtained in cold
experimental installations

3.2.1.2.1.1. Pressure drop

3.2,1.2.1.1.1. Experimental data
Investigations on the pressure drop of random packings are carried out
by Mach [21], Zhavoronkov [20, 22], Kafarov and Bliachman [23], Glaser [24],
Schrader [25], Brauer [26], Teutsch [27], Leva [28, 29], Kast [30], Reichelt
[31], Kolev [B] s Billet [177] and others.
Data for the pressure drop of some highly effective packings versus the
gas capacity factor are presented in Fig. 10 and Figs, 1A to 9A in the appendix
of this chapter. The investigations are carried out [18] in a column with a 470
mm diameter with system air- water. The geometrical characteristics of the
packings are presented in Table 2. Data for some performance characteristics of
other highly effective random packings are also presented there.
From the figures it is seen that the increase of the packing size leads to
a significant reduction of its pressure drop.
In Fig, 11, taken from Schultes [321], the history of development of the
random packings after the time of Gay-Lussac is presented schematically.
Nevertheless that the classification of packing generations is offered by
Schultes [321], the author of the Raschig Super-Ring marked by him as a forth
generation packing, this classification corresponds very well not only to the
time of development but also to the real advantages of the best variants of Ms
packing. This can be seen later from the comparison of this packing with other
highly effective ones.