Transport of Ultra-Fine Particles in Suspension through Structured Porous Media
Date
2014-09-15
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Abstract
Transport of suspensions of ultrafine and colloidal particles through porous structures is a common occurrence. Commercial filters are examples of media usually consisting of randomly-oriented fibers in layers to capture large particles. Aquifers, fixed-bed catalytic reactors and hydrocarbon reservoirs are granular formations with high spatial interconnectivity that allow small particles to be carried with the percolating fluid. Often, of interest is how far the particles would penetrate into the structure on advective streams. Experiments were conducted to record the paths of nanoparticles in dilute suspensions through micromodels of porous media. The particles are primarily propelled by hydrodynamic forces through regular arrays of cylindrical posts arranged between two closely-spaced flat surfaces. The setup consisted of the test cell, an inverted microscope, a high speed camera, a data processor, a precise actuating syringe pump, and spherical silica particles (0.2, 0.5 and 1.5 µm diameter) that encapsulated a fluorescent dye. The particle trajectories deviated from the streamlines for particle-free fluids through the domain, and the slip condition was prevalent in an environment in which the fluid velocity field and the particle motion affected each other. The trajectories show evidence of Brownian motion more significantly for the smaller particles that were also dispersed faster through the less porous media. Suspensions were dispersed in the Hele-Shaw section primarily by advection, and the extent was directly correlated to the flow rates and inversely correlated to the particle diameter, the solid volume fraction and the concentration. Axial dispersion was slower in the micro-models than in the Hele-Shaw cell.
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Engineering--Chemical
Citation
Sajjadiani, S. (2014). Transport of Ultra-Fine Particles in Suspension through Structured Porous Media (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28518