Doctoral Dissertations

Keywords and Phrases

Flow Regimes Identification; Gamma-ray Densitometry; Maldistribution; Optical Fiber Probe; 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.


Al-Dahhan, Muthanna H.

Committee Member(s)

Neogi, P. (Partho), 1951-
Smith, Joseph D.
Ludlow, Douglas K.
Usman, Shoaib


Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering


Missouri University of Science and Technology

Publication Date

Spring 2017

Journal article titles appearing in thesis/dissertation

  • Flow regime identification using on-line gamma-ray densitometry for trickle bed reactors (TBRs)
  • Novel measurement technique based on optical probe to measure local flow dynamics in packed bed reactors
  • Overall distribution identification and effect of inlet distributor on the phase holdup in a trickle bed reactor using gamma-ray densitometry (GRD)


xvi, 130 pages

Note about bibliography

Includes bibliographic references.


© 2017 Mohd Fitri Abdul Rahman, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11069

Electronic OCLC #