Investigation of local velocities and phase holdups, and flow regimes and maldistribution identification in a trickle bed reactor
"Trickle bed reactors are packed beds of catalyst on which gas and liquid reactants flow concurrently downward. In this work, the experimental work was carried out in 0.14 m diameter Plexiglas column using air-water system flowing over a packed bed of 3 mm glass bead particles. The local liquid and gas velocities, phase saturation and their time series have been investigated for the first time by developing, validating, and implementing a new two-tip optical fiber probe technique. It was found the radially and axially the liquid and gas velocities and their saturation vary and they also vary with times. In various locations, due to non-uniform distribution of the flowing phases, there are windows of time where the gas phase does not pass through that location where the optical fiber probe was put at. The non-invasive gamma-ray densitometry (GRD) technique has been implemented for the first time in trickle bed reactor as in online monitoring technique to identify flow regime, gross maldistribution and liquid distribution. The GRD technique was able to identify trickle and pulse flow regime and their transition. The findings have been consistent with what have been reported in the literature. The measurement of these techniques was conducted at various axial and radial positions with the superficial liquid velocity varies in the range 0.004 - 0.016 m/s and the superficial gas velocity varies in the range of 0.03-0.27 m/s covering trickling and pulsing flow regime. The results obtained confirm that these techniques can be used with fidelity for measurements and the studies mentioned above and can be employed in various sizes of reactor operated at industrial conditions including harsh conditions of corrosion materials, high pressure, and high temperatures"--Abstract, page iv.
Flow Regimes Identification, Gamma-ray Densitometry, Maldistribution, Optical Fiber Probe, Trickle Bed Reactor, Chemical Engineering
Missouri University of Science and Technology
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