Prediction of Pressure Drop in Air-Water Two Phase Upflow Through Packed Bed
The resistance characteristics of air-water flow upward through packed bed have been studied experimentally. Experiments were conducted in transparent tube with 50mm inner diameter filled with glass spheres of which the diameters are 2, 5 and 8mm, respectively. Experimental results show that the pressure drop increases with the increasing of gas-liquid mass flow rate, and has a certain relationship with the flow pattern. The different particle diameter and porosity have great influence on pressure drop under the same flow condition. The applicability of several representative correlations for calculating the two-phase pressure drop and two new correlations were evaluated against 234 group experimental data. All compared correlations can be grouped into two, namely: (a) the separated flow model based on Lockhart & Matinelli method (b) the homogeneous model based on gas and liquid Reynolds number. The results show that: (1) the best agreement between measured and calculated values is obtained with the correlations based on separate flow model, but the predictive ability is reduced with the increasing of particle diameter. (2) the existing homogeneous model shows the considerable discrepancies with experiment values; however the modified homogeneous correlation by considering particle-to-column diameter ratio and porosity gives good agreement with experimental data.