X-ray and neutron radiography of optically opaque fluid flows: experiments with particle-laden liquid metals and liquid foams


X-ray and neutron radiography of optically opaque fluid flows: experiments with particle-laden liquid metals and liquid foams

Lappan, T.

Multi-phase flows of small solid particles and gas bubbles in optically opaque fluids play a key role in both mineral and metallurgical processing, which use the principle of froth flotation and bubble flotation, respectively. To gain visual insight into such particle-laden multi-phase flows, this dissertation investigates the application of radiographic techniques, employing both X-rays and neutron radiation. Lab-scale experiments are performed with model particles in liquid foams and liquid metals, focussing on the time-resolved measurement of the particles’ motion in the multi-phase flows, aiming for a sufficient contrast-to-noise ratio in the X-ray or neutron image sequences.

The model experiments in this dissertation demonstrate the capabilities of X-ray and neutron radiography to image multi-phase flow in particle-laden and optically opaque fluids, especially to measure the motions of small particles with high spatial and temporal resolution. X-ray radiography enables to track custom-tailored tracer particles acting as tools for experimental investigations of flow phenomena in three-dimensional liquid foams. Both radiographic techniques supplement each other for imaging measurements of multi-phase flows with gas bubbles and solid particles in liquid metals. However, to visualise smallest model particles in liquid metal flows, neutron radiography proves to be the more promising technique compared to X-ray radiography. All in all, this dissertation contributes to paving the way for systematic radiographic measurements and further studies of particle-laden flows in optically opaque fluids.

Keywords: X-ray radiography; neutron radiography; liquid metal; liquid foam; flotation

  • Doctoral thesis
    TU Dresden, 2021
    Mentor: Dr. Sven Eckert, Dr. Sascha Heitkam, Prof. Kerstin Eckert

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Publ.-Id: 32539