A concurrent gas-solid downflow system was investigated with the use of air, distilled water in 100 cm height, 3.4 cm inside diameter column packed with 0.475 ×0.403cm granular type active carbon.
Dynamic saturation, pressure-drop and contacting efficiency were measured in gas continuous regime with changing gas and liquid superficial velocities.
Based on the data of this experiment, the dynamic saturation and the pressuredrop were correlated by the following expressions, respectively.
$\omega_d = 97.8 (Re_L)^{0.542} (Ga^{\ast})^{-0.519}$
$LG = 56.1 \frac{(1.-\varepsilon_B(1.-\omega_s-\omega_d))^2} {\varepsilon_B^3(1.-\omega_s -\omega_d)^3}v_G+680. \frac{1.-\varepsilon_B(1.-\omega_s-\omega_d)} {\varepsilon_B^3(1.-\omega_s-\omega_d)^3}v^2_G$
The fraction of wetted area in internal catalyst (internal contacting efficiency) was unity over the whole range of gas and liquid superficial velocities studied.
The fraction of externally wetted area (external contacting efficiency) increased monotonically with liquid and gas superficial velocities.
The following correlation equation for the external contacting efficiency in terms of Reynolds number and modified Galileo number was obtained based on the data of this study,
$\eta_{CE} = 1.156\times10^{-4} Re_L^{0.340} (Ga^{\ast})^{0.284}$
