Hydrodynamics of a cocurrent downflow of gas and foaming liquid through the packed bed. Part II. Liquid holdup and gas pressure drop

In the present study the results of experiments have been presented whose aim was to determine the values of liquid holdup as well as gas pressure drop through the packing for systems foaming under the pulse flow regime. On the basis of 245 experimental points for the pulse flow regime the verification of the models describing the hydrodynamics of the system has been performed. Attention was focused on the models of Benkrid et al. (Chem. Eng. Sci. 52 (1997) 4021), Pina et al. (AIChE J. 47 (2001) 19) and Fourar et al. (Chem. Eng. Sci. 56 (2001) 5987). It has been concluded that none of the models analysed describes the hydrodynamics of the foaming systems with enough accuracy. Next, based on our own data-base the verification has been carried out of parameters of Benkrid et al. (Chem. Eng. Sci. 52 (1997) 4021) (‘drift flux’ model for L and boundary layer model for ΔP/H) and Pina et al. (AIChE J. 47 (2001) 19) models as well as the estimation of the values of F*α-functions of Fourar et al. (Chem. Eng. Sci. 56 (2001) 5987) model. Using as the criterion the accuracy of estimation of the values of (ΔP/H) the best results have been obtained by applying Fourar et al. (Chem. Eng. Sci. 56 (2001) 5987) model (for the Ergun constants determined experimentally). The introduction of the estimated F*α-functions into the equations of the model (Eqs. 11 and 12) makes it possible to estimate the liquid holdup with the average absolute relative error not exceeding 9.8% and the pressure drop with an error less than 26%.