ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals, University of Newcastle, Callaghan, NSW Australia
Title of the talk:
Geometry Matters – How Inclination Shifts the Drift Flux and the Process
Kevin Galvin is the inventor of the RefluxTM Classifier, a novel fluidized bed used in gravity separation of fine particles. With over 240 installations around the world, the technology has been used to beneficiate iron ore, mineral sands, potash, chromite, spodumene, manganese and other base metal oxides. New innovative systems incorporating gas bubbles are emerging including the Reflux Flotation Cell and CoarseAIR through collaboration with FLSmidth. Kevin Galvin obtained his PhD from Imperial College and is a Laureate Professor at the University of Newcastle, Australia. He is a Fellow of the Australian Academy of Science and Australian Academy of Technology and Engineering and previous recipient of numerous awards including the Antoine Gaudin Award in mineral processing. He is Director of the ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals.
Institute of Multiphase Flows, Hamburg University of Technology, Hamburg, Germany
Title of the talk:
The Journey of Reacting Species through Multiphase Reactors: From Eulerian to Lagrangian View
For the design and operation of multiphase reactors, temporally and spatially averaged data from an Eulerian perspective are generally used, such as dispersion coefficients, residence time distributions or energy dissipation rates. With this assumption of a homogeneous mixed system, inhomogeneities, as they usually occur in multiphase reactors, are not captured. Nevertheless, these inhomogeneities are important from the point of view of a reacting species, such as a catalytic particle or a cell, as they are ex-posed to changing conditions in such inhomogeneities on their trajectory through the reactor, such as changing temperatures, concentrations, or shear stresses. New experimental methods with 4D Particle Tracking Velocimetry or Lagrangian Sensor Particles as well as new analytical methods with Lagrangian Coherent Structure Analysis or Mean Age Theory open up new possibilities to track reactive species in multiphase reactors on their individual paths. This Lagrangian perspective allows deep insights into reactor performance and the possibilities and limits of scaling up. In the lecture, the new possibilities will be presented, compared and discussed with regard to their use in chemical, biochemical and pharmaceutical applications.
Bernal Chair Professor of Process Engineering at Bernal Institute
University of Limerick, Ireland
Title of the talk:
Hydrodynamic cavitation for intensifying multiphase processes:
State of the art, challenges, and path forward
Multiphase processes are used in a wide range of applications and are of great economic and ecological importance. Hydrodynamic cavitation is a phenomenon of formation, growth and collapse of vapour filled cavities that generates highly localised extreme conditions (temperatures > 103 K, pressures > 102 MPa, energy dissipation rates > 107 m2/s3, and highly oxidising radicals). Harnessing such localised extreme conditions hold tremendous promise for intensifying a wide range of multiphase processes and thereby enhancing resource efficiency and facilitating decarbonisation throughout the value chain and across the economy. In recent years, hydrodynamic cavitation has been used for intensifying wastewater treatment, ozonation, microbial disinfection, descaling, desulphurisation of fuels, biomass pre-treatment, biodiesel synthesis, food and beverage production, multiphase reactions, crystallisation, and many other applications. Despite the intense research and several start-up companies, the full potential of hydrodynamic cavitation is not yet realised. One of the key reasons for this is inadequate understanding of inception as well as resulting physico-chemical effects of cavitation. Systematic methodology for designing hydrodynamic cavitation devices and generalised framework for development, scale-up and optimisation of hydrodynamic cavitation processes is still not adequately established. In this talk, I will critically review the state of the art on applications of hydrodynamic cavitation including types and performance of different cavitation devices. In addition, the current state of fundamental understanding of complex physico-chemical processes occurring in hydrodynamic cavitation will be reviewed. This will include the inception of cavitation, collapsing cavities, media properties like viscosity, dissolved gases, presence of dispersed phase particles, operating parameters (temperature, pH, concentrations) as well as device design and scale. Various prevailing approaches for modelling of hydrodynamic cavitation including empirical, phenomenological, and multi-scale models will be discussed in light of personal experience of their application. Key challenges and potential ways of overcoming these challenges will be highlighted. At the end, some thoughts on the path forward and prospects will be shared. I believe that hydrodynamic cavitation has a great potential to beneficially impact resource efficiency, new products, and decarbonisation across many sectors. I hope that the talk will stimulate further research on hydrodynamic cavitation and facilitate wider applications of hydrodynamic cavitation to realise its true potential.