Page 287 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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Nakov [165] investigated the effective surface area of a polypropylene
2
honeycomb block packing with specific surface area 185.5 m /m , free volume
3 3
88.3 m /m , height of the blocks 31 mm, and diameter of the circle inscribed in
the orifice 18J-19.3 mm. The surface of the packing is preliminary treated with
sand to increase its wettability. The investigations are carried out using the
method of van Krevelen et al. [282]. The viscosity and the density varied from 1
3
to 8.3 mPa.s and from 1000 to 1260 kg/m . The experimental data are presented
in Fig. 58.

3
1Q- Pa.s
3
= 4.6x10 Pa.s
s
3- UL = 8.3x1 Q- Pa.s
1 2 3 4 6 6 7
Lx1 (P, m/s

Fig. 58, Influence of superficial liquid velocity on the ratio of the effective to the total surface
area of the PP packing at different values of the liquid phase viscosity.

The experimental data are described with the equation:

Re L
(189)
/6
i
a l.lxlO' Gal +O.7Re l
Both Rei and Gai are defined with a as a geometrical parameter of the packing.
The mean error of the equation is 11%.
Later Nakov [166] investigated the influence of the liquid viscosity on
the effective area of the honeycomb packings presented in Table 27.