Abstract:
A differential pressure sensor and an A/D converter with high frequency were employed to collect
transient pressure drop data in a fixedbed bubblecolumn reactor. Methods were established to identify the flow
patterns in the reactor. The ECT(electrical capacitance tomography)system was employed to investigate transient
characteristics of gas holdup in different flow regimes. The waveforms,probability density distributions and power
spectrum density distributions of pressure drops are significantly different in various flow regimes. So do
transient gas holdups. The bed pressure drop gradient increases with the increase of gas and liquid flow rates.
Comparison between experimental data and estimation shows that the revised Larachi's relationship and Khan and
Varma's relationship can be used to predict frictional pressure drops in fixedbed bubblecolumn reactors of
medium diameter(280 mm) with an averaged deviation of 18.0% and 14.5%, respectively.