H.F.Svendsen1; 罗和安2; K.W.Hjarbo3; H.A.Jakobsen4
H.F.Svendsen1; Luo He an2; K.W.Hjarbo3; H.A.Jakobsen4
摘要: Using a five point conductivity technique local values of bubble size, bubble velocity and gas fraction have been experimentally determined in a 288 mmID and 4.3 m high bubble column as a function of axial and radial position for the air/
water and CO2/N2/aqueous MDEA systems.The experimental results are compared with predictions from a fundamental two-fluid
model.The implementation of a non-steady lateral drag term in the two-fluid model has beenshown.In addition to improving the
physical realism of the model, it is found to give slight improvements in the predictions of the distributions of local
bubble size. Predictions of bubble sizeare found in reasonable agreement with experimental values in the heterogeous flow
regime, whereas they arestill found to be unreliable at low gas velocities.Local void predictions are found in reasonable
agreementwith experimental values, but deviations occur in thehomogeneous flow regime towards the wall.This is attributed to
deficiencies in the simplified bubble size model, suggesting improvements of that .It is shown how the Sauter mean diameter
as a measure for bubble size is a more sensitive parameter to the radial bubble structure variations in a bubble column than
the number averaged diameter. An equation for the calculation of local volumetric gas flow rates, based on conductivityprobe
data, has been developed and is shown to give improved predictions compared to previous methods in theheterogeneous regime.