scholarly journals A new, optimized Doppler optical probe for phase detection, bubble velocity and size measurements: investigation of a bubble column operated in the heterogeneous regime

2021 ◽  
pp. 117359
Author(s):  
Anthony Lefebvre ◽  
Yann Mezui ◽  
Martin Obligado ◽  
Stéphane Gluck ◽  
Alain Cartellier
Keyword(s):  
Bubble Column ◽  
Optical Probe ◽  
Bubble Velocity ◽  
Phase Detection

Bubble velocity, size, and interfacial area measurements in a bubble column by four-point optical probe

AIChE Journal ◽  
2008 ◽  
Vol 54 (2) ◽  
pp. 350-363 ◽  
Author(s):  
Junli Xue ◽  
Muthanna Al-Dahhan ◽  
M. P. Dudukovic ◽  
R. F. Mudde
Keyword(s):  
Bubble Column ◽  
Interfacial Area ◽  
Optical Probe ◽  
Bubble Velocity

Development and Validation of an X-Ray Tomograph for Two-Phase Flows

2002 ◽  
Author(s):  
Eric Hervieu ◽  
Emmanuel Jouet ◽  
Laurent Desbat
Keyword(s):  
Bubble Column ◽  
Optical Probe ◽  
Reconstruction Algorithms ◽  
Two Phase Flows ◽  
Two Phase ◽  
Reconstruction Procedure ◽  
X Ray ◽  
Validation Procedure ◽  
Development And Validation ◽  
Uniform Regularization

This paper describes the development and validation of a high spatial resolution X-ray tomograph devoted to investigate air-water two-phase flows. The device hardware is mainly composed of a 60 keV X-ray source, a detector and an accurate mechanical bench. This paper concentrates on accuracy quantification and emphasis is given on the reconstruction procedure. It is well known that absorption gradients induce reconstruction artifacts when using standard algorithms based on uniform regularization. In the particular case of two-phase flows in pipes, this leads to a poor measurement accuracy in the vicinity of the walls. To overcome such effects, improved algorithms have been developed in this study, involving different spatially adaptative regularization methods. A first calibration performed on static phantoms clearly exhibits the benefit brought by such advanced reconstruction algorithms. A validation procedure has been carried out on an air-water bubble column, equipped with an optical probe which can be translated in order to explore the 80 mm × 80 mm square cross section. Comparisons of local void fraction measurements have been performed pixel by pixel, and demonstrate the accuracy improvement induced by the advanced reconstruction algorithms.

scholarly journals Measurement of two-dimensional bubble velocity by Using tri-fiber-optical Probe

2009 ◽  
Vol 147 ◽  
pp. 012028 ◽  
Author(s):  
Ruichang Yang ◽  
Rongchuan Zheng ◽  
Fanling Zhou ◽  
Ruolei Liu
Keyword(s):  
Optical Probe ◽  
Bubble Velocity ◽  
Two Dimensional ◽  
Fiber Optical

Hydrodynamical similarities between bubble column and bubbly pipe flow

2001 ◽  
Vol 437 ◽  
pp. 203-228 ◽  
Author(s):  
ROBERT F. MUDDE ◽  
TAKAYUKI SAITO
Keyword(s):  
Pipe Flow ◽  
Single Phase ◽  
Liquid Velocity ◽  
Bubble Column ◽  
Laser Doppler Anemometry ◽  
Bubbly Flow ◽  
Bubble Velocity ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Superficial Liquid Velocity

The hydrodynamical similarities between the bubbly flow in a bubble column and in a pipe with vertical upward liquid flow are investigated. The system concerns air/water bubbly flow in a vertical cylinder of 14.9 cm inner diameter. Measurements of the radial distribution of the liquid velocity, gas fraction and the bubble velocity and size are performed using laser Doppler anemometry for the liquid velocity and a four-point optical fibre probe for the gas fraction, bubble velocity and size. The averaged gas fraction was 5.2% for the bubble column (with a superficial liquid velocity of zero) and 5.5% for the bubbly pipe flow at a superficial liquid velocity of 0.175 m s−1. From a hydrodynamical point of view, the two modes of operation are very similar. It is found that in many respects the bubbly pipe flow is the superposition of the flow in the bubble column mode and single-phase flow at the same superficial liquid velocity.The radial gas fraction profiles are the same and the velocity profiles differ only by a constant offset: the superficial liquid velocity. This means that the well-known large-scale liquid circulation (in a time-averaged sense) of the bubble column is also present in the bubbly pipe flow. For the turbulence intensities it is found that the bubbly pipe flow is like the superposition of the bubble column and the single-phase flow at the superficial liquid velocity of the pipe flow, the former being at least an order of magnitude higher than the latter. The large vortical structures that have been found in the bubble columns are also present in the bubbly pipe flow case, partly explaining the much higher ‘turbulence’ levels observed.

Hydrodynamic Study of Bubbles in a Bubble Column Reactor Part II – Numerical Study

2015 ◽  
Vol 813-814 ◽  
pp. 1023-1027
Author(s):  
S. Arunkumar ◽  
V. Harshavardhan Reddy ◽  
T.M. Sreevathsav ◽  
M. Venkatesan
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Bubble Column ◽  
Numerical Study ◽  
Image Processing Technique ◽  
Bubble Velocity ◽  
Bubble Column Reactor ◽  
Hydrodynamic Characteristics ◽  
Flow Rates ◽  
Column Reactor

The present work deals with the use of CFD analysis and the validation of the experimental work carried out on the artificial splitting of an air bubble in a bubble column reactor. In Part I of this work, artificial splitting of bubble in a bubble column rector is experimentally studied by using a high speed camera. Image processing technique was used to identify bubble size and bubble velocity. In present work CFD simulations are carried out using ANSYS FLUENT software using Volume of Fluids (VOF) method. VOF is based on a surface tracking technique applied to a fixed Eulerian space. The phase fraction in physical quantities that can be used to distinguish the distribution of gas hold up in a bubble Column reactor. The numerical study of splitting of bubble into two bubbles of nearly equal size is considered. In the bubble column reactor, the liquid phase is stationary and gas flow rate in it is varied. The superficial gas flow rates are 10 lph, 15 lph, 20 lph and 25 lph. The characteristics of bubble after splitting which include its shape, size and velocity for various gas flow rates mentioned above are studied numerically and are compared with experimental results. These hydrodynamic characteristics play a pivotal role in the reactions occurring between the liquid and gas phases in the bubble column reactor.

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