Application of γ-ray Attenuation for Measurement of Gas Holdups and Flow Regime Transitions in Bubble Columns

Dragomir B. Bukur, James G. Daly, Snehal A. Patel

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

In this study a γ-ray densitometry was used to measure radial and axial volume fraction distributions in a 0.21 m diameter bubble column, and flow regime transitions in a 0.05 m and 0.21 m diameter bubble columns. Experiments were conducted with two- and three-phase systems (nitrogen-Fischer-Tropsch derived waxes-iron oxide or silica particles) in both batch and continuous modes of operation at 265 °C and ambient pressure. Average radial gas holdups in the large diameter column showed the existence of a maximum at the center of the column, in both two- and three-phase systems. The maximum was more pronounced at higher superficial gas velocities (churn-turbulent flow regime). The axial and average gas holdup measurements in two-phase systems were in good agreement with results obtained by a conventional method (pressure measurements along the column height). An independent treatment of all three phases did not yield satisfactory results, due to large impact of small experimental errors on calculated holdups. Alternative methods based on measured values of solids concentration in the slurry yielded satisfactory results. Instantaneous signals from the nuclear density gauges were used successfully to determine transitions from homogeneous flow regime to slug flow (small diameter column) or churn-turbulent flow regime (large diameter column) in two-phase systems.

Original languageEnglish
Pages (from-to)70-80
Number of pages11
JournalIndustrial and Engineering Chemistry Research
Volume35
Issue number1
Publication statusPublished - Jan 1996
Externally publishedYes

Fingerprint

Transition flow
Bubble columns
Turbulent flow
bubble
Gases
Gas fuel measurement
Waxes
Pressure measurement
Iron oxides
gas
Silicon Dioxide
Gages
Volume fraction
Nitrogen
Silica
turbulent flow
slug flow
Experiments
wax
iron oxide

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Environmental Science(all)
  • Polymers and Plastics
  • Engineering(all)

Cite this

Application of γ-ray Attenuation for Measurement of Gas Holdups and Flow Regime Transitions in Bubble Columns. / Bukur, Dragomir B.; Daly, James G.; Patel, Snehal A.

In: Industrial and Engineering Chemistry Research, Vol. 35, No. 1, 01.1996, p. 70-80.

Research output: Contribution to journalArticle

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