This work examined the mass transfer efficiency of a rotating packed bed with various radii of the packed bed. Experimental results showed that k L a increased with decreasing volume of the packed bed. This may contribute to the significant end effects as the volume of the packed bed is reduced. A correlation which takes end effects into consideration for k L a in a rotating packed bed was proposed and is valid for different sizes of the rotating packed bed and for viscous Newtonian and non-Newtonian liquid systems. In addition, it was also found that the correlation could reasonably estimate most of the k L a data in the Higee literature.

This work investigated the mass transfer of a rotating packed bed (RPB) with emphasis on the effects of the packing's size, shape, material, and surface property. Experimental results show that there is no obvious relationship between a t and k L a. Among the various shapes of the packings, the mass transfer coefficients of Raschig rings and Intalox saddles are lower than those of the others, while the k L a of the wire meshes is the highest. As to materials, the mass transfer coefficients are similar for acrylic, glass, ceramic, and stainless steel beads. Besides, the k L a values of the hydrophobically treated packings are 8−27% lower than those of the original glass and ceramic packings. A modified correlation of k L a, which includes the effects of various packings, is proposed based on our RPB experimental results. Further, this correlation can also reasonably estimate most of the k L a data in the Higee literature.

A Higee absorption process was developed to remove VOCs (volatile organic compounds) from air into an aqueous phase under a centrifugal field. The experimental results showed that the overall volumetric gas-phase mass-transfer coefficient (K G a) increased as a function of the gas Grashof number (Gr G ) to the power of 0.18. In analyzing k G and a individually, it was found that the enhancement of mass transfer by the centrifugal force can mainly be attributed to an increase in the effective gas-liquid interfacial area. The values of k G lie in a range similar to that for conventional packed beds.

A theoretical analysis was developed to predict the apparent viscosity of a non-Newtonian fluid in a rotating packed bed. It is based on laminar liquid film flow on a rotating disk with the assumption of the randomly inclined surfaces in the rotating packed bed. In addition, experiments of deoxygenation were performed in glycerol solutions and CMC solutions, which are Newtonian and shear-thinning fluids, respectively. It is shown that mass transfer coefficients decreased with increasing viscosity, while the centrifugal force still revealed effective in enhancing mass transfer in viscous media. A correlation for mass transfer coefficient was proposed and valid for both the Newtonian and non-Newtonian fluids. Compared with a packed column, the influence of mass transfer coefficients by liquid viscosity was less in a rotating packed bed.