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3.2.1.2.1.4.2. Equation for calculation of wetted and effective surface areas
For determination of the wetted surface area the following equation is
suggested [83, 84]:
i L m
^ = l-K Ie- (93)
a
where:
m = bRef (94)
The experimental constants in this equation are as follows:
Lp L Z b P
Rings 15-35 mm [85] 0.028-8.3 1.02 0.16 0.4
Rings 15 mm [86] 0.17-5.5 1.0 0,167 0.415
Saddles 15 mm [86] 0.17-5.5 1.0 0,089 0.7
It is not correct from the similarity theory point of view to use
Re L instead of L, without changing the viscosity, for obtaining of these
experimental constants. The Buckingham theorem requires in this case 4
dimensionless values, but not only two.
Hikita and Kataoka [69] based on their own experimental data obtained
with paper Raschig rings, using the colour method described in 2.1.2.5.1,
proposed the equation:
( f() (95)
L
a
where m = ^
The mass liquid superficial velocity L.p L for obtaining of this equation
2 1
is changing from 0.14 to 5.6 kg m' s .
Using data from different investigators, Bolshakov and Grinevieh [98]
obtained the equation:
