Micro- and macromixing studies in two- and three-phase (gas-solid-liquid) stirred chemical reactors

Hofinger, Julia (2013). Micro- and macromixing studies in two- and three-phase (gas-solid-liquid) stirred chemical reactors. University of Birmingham. Ph.D.

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Abstract

The iodide/iodate reaction scheme was used to study the effect of gas sparging and/or solid particles on micromixing in a stirred vessel. A literature review illustrated the need for focused work on this matter and gave valuable ideas for the experiments. For this, the experimental method was first validated for using the added gaseous and solid phases air and glass beads, respectively. The experiments covered a range of conditions for micromixing in single-phase, for validation, in gas-liquid, solid-liquid and gas-solid-liquid systems: power inputs up to 1.94 W/kg, gas sparge rates up to 1.5 vvm and up to 11.63 wt.% solids with diameters from 150 to 1125 μm. For comparison, the power inputs from the impeller were kept constant when affected by the added phase(s). In order to allow better quantification of the experimental data, variations of the Incorporation model were evaluated for taking recent suggestions for the reaction scheme into consideration. The second dissociation of sulphuric acid was included in the model and different kinetic rate laws from the literature on the Dushman reaction were implemented. These variations allowed order-of-magnitude estimates and further comparisons of local specific energy dissipation rates.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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