Page 247 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

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presented two equations. After small transformations to obtain more convenient
form, proposed by Ramm [128], the equations are as follows:

for random and arranged rings

1
Sh G= 0.715 f Re^Sc ^; (136)
(1-e)

for saddles

f m /3
Sh G= 0,715 Re* S4 . (137)
(1-e)

The coefficient Ff, called coefficient of form, is defined as a ratio of the surface
area of an equivalent sphere with the volume of the packing element to the
surface area of that element. Taking into account that the diameter do of the
equivalent sphere is given by the ratio:

(138)

it is easy to obtain the equation:

3
2 3
F = <k = H = (36x?"v!" = 4.83V /
a s a s a s

is the volume of the equivalent packing element;

a s = surface area of a single element;
3
N- number of packing elements per m .