Dissertation | Technische Universität Graz (link)
In the present work the design of the RDC extractor, a well-established apparatus in solvent extraction, has been fundamentally simplified and optimized in terms of separation efficiency, load capacity and applicability for extraction of bio-based raw materials. Based on the Rotating Disc Contactor (RDC), a novel design of internals was discovered in the interaction of CFD simulation with Ansys Fluent and experimental validation (Particle Image Velocimetry, DSD measurements, sedimentation, tracer, load and mass transfer experiments). Being a hydrodynamic hybrid of a RDC and a Taylor-Couette reactor, the novel apparatus, therefore named TCDC, promises a wide range of applicability apart from solvent extraction. Experimentally validated simulation series show optimized hydrodynamic operating parameters (axial mixing, drop size distribution, vorticity, etc.) when the stator rings are abandoned and their function is adopted by rotor disks with increased diameter. Mass transfer experiments showed improved separation efficiency over the RDC, the HTU-value was decreased by ~ 35% while the operating/flooding limits were simultaneously increased. The elimination of the stator rings simplifies manufacturing and operation as well as cleaning and maintenance. Empirical design rules from literature, still state-of-the-art for the geometric design of RDCs, have been updated, simplified and theoretically consolidated.