For over two decades, LOOP (French acronym for Process Observation and Optimization Laboratory) researchers have been working at developing and/or improving specific sensors for flotation columns and their use for automatic control of this process. Several papers have already been published for the mineral processing industrial and scientific community in peer-reviewed journals and conference p...

Collisions of bubble jets have been experimentally studied in normal gravity conditions. The experimental setup, designed for a future use in a low gravity environment, allows the control of the impact angle between jets, bubble size and velocity. Individual bubble properties and the whole jet structure are analyzed from the images recorded. We present results on the role played by the impact a...

We study the dynamical behavior of a large bubble embedded in the plug flow of an ordered two-dimensional foam. At a critical velocity, the foam structure becomes instable and the large bubble migrates through the foam faster than the mean flow. This size segregation is due to viscous effects and happens only for flow velocities larger than a given threshold. We present analytical and numerical...

In present paper, dynamic behavior and control of a fluidized bed reactor for polyethylene production has been considered. A double active sites model for Ziegler-Natta catalysts is used for simulation of polymerization reaction. Hydrodynamic behavior of the bed is modeled using a two phase model including bubble and emulsion phases in which bubble phase has plug flow pattern with different...

Compressible large-eddy simulations of turbulent flow over a wall-mounted hump with active flow control are performedand comparedwithprevious experiments. Theflow is characterizedby the unsteady separationbefore the steep trailing edge, which naturally reattaches downstream of the hump to form an unsteady turbulent separation bubble. The lowMachnumber large-eddy simulation demonstrated a goodpr...

We report on a lithographic mode of electrochemically triggered free radical polymerization. The polymerization is initiated by the reduction of an electrochemically active initiator. Hydrogel patterns can be written by employing a small insulated counter electrode. The investigations show that the "pen" actually is a small oxygen bubble between the counter electrode and the sample surface. The...

The breakup of a millimetre size buoyantly rising bubble encountering a horizontal plane turbulent jet is experimentally investigated using high-speed shadowgraphy and acoustic techniques. The bubble diameter to jet height ratio is 0.75 and the jet height based Reynolds number is 4000. The high-speed imaging was recorded at 7 kHz simultaneous with hydrophone output at 100 kHz. Bubble breakup ev...

We analyze the stability of small bubbles in a closed system with fixed volume, temperature, and number of molecules. We show that there exists a minimum stable size of a bubble. Thus there exists a range of densities where no stable bubbles are allowed and the system has a homogeneous density which is lower than the coexistence density of the liquid. This becomes possible due to the finite liq...