Influence of liquid viscosity and surface tension on the gas-liquid mass transfer coefficient for solid foam packings in co-current two-phase flow

摘要

The gas-liquid mass transfer coefficient and other hydrodynamic parameters such as liquid holdup and frictional pressure drop are presented for gas and liquid moving in co-current upflow and downfiow through solid foam packings of 10 and of 40 pores per linear inch(ppi).The effect of increasing the liquid viscosity on the mass transfer coefficient in co-current upflow is quantified and correlated to the frictional pressure drop,a measure of the frictional energy dissipation:k_La_(GL)epsilon_L(Sc_L/Sc_(water))~(0.69)=2.05 X 10~(-4)P_f~(0.8)(m_L~3 m_p~(-3)s~(-1)).The gas-liquid mass transfer coefficient in co-current downfiow is correlated to the liquid velocity and the Schmidt number using the correlation proposed by Sherwood and Holloway[Sherwood,T.and Holloway,E,1940,Performance of packed towers-liquid film data for several packings,Transactions of the American Institute of Chemical Engineers 36:39-70]:k_L a_(GL)epsilon_L D_L~(-1)=3.7(u_(L rho L mu_L)~(-1))~(1.16)(Sc_L)~(0.5)(m_L m_p~(-3)).The results for the gas-liquid mass transfer coefficient in co-current upflow were correlated with a similar equation,where the influence of the gas velocity is included,similar to the correlations for packed beds of spherical particles proposed in Fukushima and Kusaka[Fukushima,S.and Kusaka,K.,1979,Gas-liquid mass transfer and hydrodynamic flow region in packed columns with cocurrent upward flow,Journal of Chemical Engineering of Japan 12(4):296-301]:k_L a_(GL)epsilon_L D_L~(-1)=311u_G~(0.44)(u_(L rho L mu_L~(-1))~(0.92)(Sc_L)~(0.5)(m_L m_p~(-3)).In this study the liquid Schmidt number dependency of the gas-liquid mass transfer coefficient points to the penetration theory describing the rate of mass transfer for gas-liquid flow through solid foam packings.