Abstract
Liquid holdup and interfacial area were measured in columns packed with 1/2 and 1 in. ceramic spheres for upward cocurrent-flow mode, where the ratio of packing to column diameter, dp/dT, is 0.085, 0.128 and 0.169.
The empirical equations of liquid holdup Φl for void fraction e are given as follows:
Φl/ε=κRehiRe-jg
where κ=1.8, h=0.03, j=0.28 for Rel<695Re-0.5g and κ=0.72, h=0.17, j=0.21 for Rel>695Reg-0.5.
The empirical equations for interfacial area ap are also presented as follows:
apdp/(1-Φl/ε)=αRemlReno(dp/dT)-t
where the values of α, m, n and t are 16, 0.05, -0.4 and 0 for bubble (1), 2.2, 0.05, -0.2 and 0.5 for churn, 0.24. 0.27, 0 and 0.7 for pseudospray, 0.26, 2/3, -1/4 and 0.4 for bubble (11), 1.0×10-2, 2/3, 0 and 1.4 for pseudopulse and 2.9×10-4, 2/3, 0.2 and 2.5 for pulse flow, respectively. The equation for respective hydrodynamic flow boundary was found by combining two of these.
The predicted mass-transfer coefficients for liquid phase given by the simple equation for downward flow mode agree with the literature data in a wide range of gas and liquid flow rates.
