Evaluation of multiphase flotation models in grid turbulence via Particle Image Velocimetry

A review of turbulence measurement techniques for flotation

“…Laakkonen et al (2005) employed PIV to simultaneously measure flow velocities, gas-liquid interfacial areas, local bubble size distributions and gas-holdups to validate computer simulations of agitated gas-liquid reactors. Brady et al (2006) compared experimental measurements of the motion of particles, bubbles and liquid in a three phase turbulent flow produce by a grid obtained using a Digital Particle Image Velocimetry (DPIV) system to that predicted using models published in the literature. The DPIV system proved capable of measuring with great precision and with a high temporal resolution (i.e.…”

Experimental quantification of turbulence and its applications in the study of multiphase flotation pulps

“…A PIV device consists of a CCD digital camera, a laser or a strobe designed to illuminate only the area to be photographed, an external trigger to manage the operation of the laser and exposure of the camera, the fluid, and the seeding particles. Figure 8: A schematic of a PIV system (Johnson, et al, 2014) As an example of application, Brady et al(2006) employed a Digital Particle Image Velocimeter (DPIV), with CMOS digital camera and Copper vapour pulsing laser, that can record with great accuracy and kHz temporal resolution, velocity vectors of all three phases, namely the fluid, the solid particles and the air bubbles, in homogeneous isotropic turbulence generated by cylindrical grids. Figure 9 shows two sample images just above the turbulence grid and the resulting velocity field produced by cross correlation.…”

“…Two sample images with 80μm solid particles and flow tracers (top row), and 1.2 mm bubbles and flow tracers (bottom row) separated by 0.001 s and corresponding velocity field from cross correlation as perBrady et al (2006).…”

“…A schematic of a PIV system(Johnson, et al, 2014) Two sample images with 80μm solid particles and flow tracers (top row), and 1.2 mm bubbles and flow tracers (bottom row) separated by 0.001 s and corresponding velocity field from cross correlation as perBrady et al (2006). a) Comparison of values in the plane z/T = 0.28 obtained byFentiman et al (1998) and PIV; b) Comparison of ′ values in the plane z/T = 0.18 obtained byFentiman et al (1998) and PIV.…”

Effect of cone angles on single-phase flow of a laboratory cyclonic-static micro-bubble flotation column: PIV measurement and CFD simulations

“…However, CFD models are still uncertain in complex geometry and need validation against experimental data. Particle image velocimetry (PIV) is often used for single-flow patterns and proper bubble size distribution which is an important factor in predicting gas-liquid flow [17][18][19]. Domestic research on FCSMC remains on single-phase (liquid) for the overall vessels and two-phase (gas-liquid) for part of the vessels level [20][21].…”