Publication B: Neighborhood Relationships of Widely Distributed and Irregularly Shaped Particles in Partially Dewatered Filter Cakes
https://opara.zih.tu-dresden.de/xmlui/handle/123456789/1943
A more thorough understanding of the properties of bulk material structures in solid–liquid
separation processes is essential to understand better and optimize industrially established
processes, such as cake filtration, whose process outcome is mainly dependent on the properties
of the bulk material structure. Here, changes of bulk properties like porosity and permeability
can originate from local variations in particle size, especially for non-spherical
particles. In this study, we mix self-similar fractions of crushed, irregularly shaped Al2O3
particles (20 to 90 μm and 55 to 300 μm) to bimodal distributions. These mixtures vary in
volume fraction of fines (0, 20, 30, 40, 50, 60 and 100 vol.%). The self-similarity of both
systems serves the improved parameter correlation in the case of multimodal distributed
particle systems. We use nondestructive 3D X-ray microscopy to capture the filter cake
microstructure directly after mechanical dewatering, whereby we give particular attention
to packing structure and particle–particle relationships (porosity, coordination number,
particle size and corresponding hydraulic isolated liquid areas). Our results reveal widely
varying distributions of local porosity and particle contact points. An average coordination
number (here 5.84 to 6.04) is no longer a sufficient measure to describe the significant bulk
porosity variation (in our case, 40 and 49%). Therefore, the explanation of the correlation
is provided on a discrete particle level. While individual particles < 90 μm had only
two or three contacts, others > 100 μm took up to 25. Due to this higher local coordination
number, the liquid load of corresponding particles (liquid volume/particle volume) after
mechanical dewatering increases from 0.48 to 1.47.2024-03-29T13:01:22ZX-ray tomography scans of filter cakes (feed slurry: variation in fraction of fines)
https://opara.zih.tu-dresden.de/xmlui/handle/123456789/1963
X-ray tomography scans of filter cakes (feed slurry: variation in fraction of fines)
Löwer, Erik
X-ray tomography scans of partially dewatered filter cakes with variation of fine particles within the feed slurry. The mixture composition varies by addition of fines by 0, 20, 30, 40, 50, 60 and 100 vol.-%. The initial slurry contains Al2O3 particles suspended in a potassium iodide-glycerol solution and separated by cake-forming filtration. All filtration experiments took place in an in-situ apparatus inside the Zeiss Xradia 510 X-ray microscope.
see note parameter.png in each measurement file for further measurement and reconstruction parameters
2021-01-01T00:00:00Z