Page 257 - Packed bed columns for absorption, desorption, rectification and direct heat transfer

247

owing to not abiding the n theorem, Chapter 1 (1.3.2.). In Eq. (153) these are
the diffusivity and the viscosity. It was already mentioned that according to the
mass transfer theory and the experimental data of Sherwood [137], the power at
Di is 0.5 which is accepted practically in all equations for calculation of K L. The
influence of the viscosity after different equations for calculating the liquid-side
controlled mass transfer is presented in Fig. 39.
As a measure for the influence of the viscosity, the ratio
\0.S
D
L L2S°C
j g use( j jj er e 25°C means the temperature at
which the respective data are obtained. From the comparison it is to be seen that
the effect of the viscosity is taken into account by equation (153).
Mangers and Ponter [221] collected some of the literature date for the
exponents at the physical values in the equations for calculating the liquid-side
controlled mass transfer coefficient after different investigators (Table 22).

1.5 1
».
\ • - Sherwood [137]
1.4 \ \\ o - Vivian [142]
\ 1 - Shulman [48]
2 - Yoshida [50]
V
1.3 - SBmeltausr [83]
\
-Eq.[153)
1.2 \i\ 5 - Kasatkin[132]
S - Onda [135]
X 7 - Reichelt [51]
1.1 - Kling
_ i
21
1.0
8.
1 0.9 ^10
""11
SB
0.8
9- Norman [53] \
0.7 10- Davdson[54] 4
ii - Sherwood [137]
\ ;
0.6 2 - Mite [55] * w
3-Onda [141]
** ,
0.5
0.6 0.8 1.0 1.2 1.4 1.6
/j, Lx1(P, Pas

Fig. 39. Influence of the viscosity after different equations for calculating the mass transfer
coefficient for liquid-side controlled process and after some experimental data.