Page 307 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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Fig. 64 AP/NTUG VS.

The date in Fig 64 show that the best of all compared packings is the
honeycomb packing Nr 12. It is made of polypropylene treated with sand for
increasing its wettability. The ceramic packing Nr 10, also investigated by us,
[144], has about 8 times higher pressure drop because of smaller free cross-
section and smaller height of the elements. The packing of Kolar (Nr. 11) which
consists of parallel vertical plates of expanded metal (see Fig. 91) has very low
pressure drop, about the same as that for Nr 12. The Impulse Packing (packing
Nr 1) has the greatest pressure drop. It is an arranged packing of single
elements, each of them consisting of two truncated pyramids with a common
small base (Fig. 49) Thus, the packing cross-section significantly changes two
times in vertical direction for each element, which leads to strong increasing of
the pressure drop. The comparison shows that by constructing packings with
vertical walls, it is possible not only to reduce the pressure drop, but also to
reduce the pressure drop per one mass transfer unit which is especially
important.