Abstract
Interfacial areas and liquid-phase volumetric mass-transfer coefficients were measured from chemical absorption of oxygen into sulfite solution and from physical absorption of carbon dioxide into water, respectively, in the cases of one, two, three and seven strings of touching spheres, and in irrigated columns packed with spheres, Raschig rings and Berl saddles. The columns having seven strings of touching spheres used both open and closed configurations of spheres.
When the number of spheres per string is larger than 10 and the number of strings m is 3 and 7, the empirical equation of interfacial area at for sphere diameter dp is given in terms of liquid Reynolds number Ret(=4ρQl/mπdpμl) and the number of contact points of spheres per sphere q as follows:
atdp=4.8q-1.1Ret(0.27q0.25)t
The equation obtained by replacing at by ap/(1-ε) and Ret by Rep in the above equation is applicable to illustrate the data in irrigated columns packed with spheres, (1-ε) in solid fraction, with an accuracy of ±20%. Suppose q=4.2 for Raschig rings and q=2.8 for Berl saddles, the predicted values agree with the experimental data.
The Sherwood numbers are presented by the same relation for the cases of one, two, three and seven strings, where the number of touching spheres is larger than 10, as follows:
Sht=k*ltdp/DA=7.1Re1/3tSc1/2
The equation obtained by substituting k*lt by k*lp, 7.1 by 27φ(1-ε) and Ret by Rep represents the data for columns with a packing of surface shape factor φ.
