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Turbulence Measurement Techniques for Multiphase Flows in
Mechanical Flotation Cells
Weiguo Xie
Department of Chemical Engineering, University of Minnesota Duluth, USA
Eiman Amini
ORICA Limited, Brisbane, Australia
ABSTRACT: Turbulence is an important factor affecting flotation performance. It affects air dispersion, particle
suspension, bubble-particle collection interactions, and entrainment of fine particles. However, quantifying
turbulence in multiphase flows has always been an enormous scientific challenge. In this paper, many turbulence
measurement techniques will be reviewed and compared including Laser Doppler Anemometry (LDA), Particle
Image Velocimetry (PIV), Positron Emission Particle Tracking (PEPT), Constant Temperature Anemometer
(CTA), Piezoelectric Vibration Sensor (PVS), and Electrical Resistance Tomography (ERT). The turbulence
profile obtained from measurement techniques can lead to better process knowledge and control of multiphase
flows in mechanical flotation cells.
Keywords Turbulence Measurement Techniques Multiphase Flows, Mechanical Flotation Cells
INTRODUCTION
Turbulence was first introduced by William Thomson in
1887 (Schmitt, 2017). Despite its paramount importance in
our lives, turbulence remains “the most important unsolved
problem of classical physics” according to the American
Nobel Prize Laureate for Physics Richard Feynman (Eames
and Flor, 2011). Turbulence is an important factor affecting
flotation performance in mineral processing. It affects air
dispersion, particle suspension, bubble-particle collection
interactions, and entrainment of fine particles (Fallenius,
1987 Schubert, 1999 Nguyen &Schulze, 2004 Evans et
al., 2008). Quantification of turbulent flows requires the
measurement of the fluctuating transport properties (mass,
constituent’s phase, heat, momentum, and energy) at a
high spatial and temporal resolution. Measurements of the
transition to turbulence in multiphase flows have long been
problematic. The environment inside multiphase flows is
highly aggressive, abrasive, and opaque. Most of the tra-
ditional fluid measurement techniques cannot be applied
(Xie, et al., 2016). For example, the flotation cell is often
treated as a “black-box” because we can only see the froth
surface (e.g., in Figure 1), making it challenging to obtain
information about the underlying slurry.
In this paper, many turbulence measurement tech-
niques will be reviewed and compared. Some of the mea-
surement techniques that have been used for the study of
fluid characteristics are described below. Optical techniques
such as Laser Doppler Anemometry (Tiitinen, et al., 2003
Kyselaa et al., 2013) and Particle Image Velocimetry (Baldi,
et al., 2002 Darabi, et al., 2017) can produce accurate mea-
surements with high spatial and temporal resolution, but
Turbulence Measurement Techniques for Multiphase Flows in
Mechanical Flotation Cells
Weiguo Xie
Department of Chemical Engineering, University of Minnesota Duluth, USA
Eiman Amini
ORICA Limited, Brisbane, Australia
ABSTRACT: Turbulence is an important factor affecting flotation performance. It affects air dispersion, particle
suspension, bubble-particle collection interactions, and entrainment of fine particles. However, quantifying
turbulence in multiphase flows has always been an enormous scientific challenge. In this paper, many turbulence
measurement techniques will be reviewed and compared including Laser Doppler Anemometry (LDA), Particle
Image Velocimetry (PIV), Positron Emission Particle Tracking (PEPT), Constant Temperature Anemometer
(CTA), Piezoelectric Vibration Sensor (PVS), and Electrical Resistance Tomography (ERT). The turbulence
profile obtained from measurement techniques can lead to better process knowledge and control of multiphase
flows in mechanical flotation cells.
Keywords Turbulence Measurement Techniques Multiphase Flows, Mechanical Flotation Cells
INTRODUCTION
Turbulence was first introduced by William Thomson in
1887 (Schmitt, 2017). Despite its paramount importance in
our lives, turbulence remains “the most important unsolved
problem of classical physics” according to the American
Nobel Prize Laureate for Physics Richard Feynman (Eames
and Flor, 2011). Turbulence is an important factor affecting
flotation performance in mineral processing. It affects air
dispersion, particle suspension, bubble-particle collection
interactions, and entrainment of fine particles (Fallenius,
1987 Schubert, 1999 Nguyen &Schulze, 2004 Evans et
al., 2008). Quantification of turbulent flows requires the
measurement of the fluctuating transport properties (mass,
constituent’s phase, heat, momentum, and energy) at a
high spatial and temporal resolution. Measurements of the
transition to turbulence in multiphase flows have long been
problematic. The environment inside multiphase flows is
highly aggressive, abrasive, and opaque. Most of the tra-
ditional fluid measurement techniques cannot be applied
(Xie, et al., 2016). For example, the flotation cell is often
treated as a “black-box” because we can only see the froth
surface (e.g., in Figure 1), making it challenging to obtain
information about the underlying slurry.
In this paper, many turbulence measurement tech-
niques will be reviewed and compared. Some of the mea-
surement techniques that have been used for the study of
fluid characteristics are described below. Optical techniques
such as Laser Doppler Anemometry (Tiitinen, et al., 2003
Kyselaa et al., 2013) and Particle Image Velocimetry (Baldi,
et al., 2002 Darabi, et al., 2017) can produce accurate mea-
surements with high spatial and temporal resolution, but