At the bottom of our oceans, kilometers below the sea surface, large amounts of metal-rich deposits are found. For the European Union these deposits are seen more and more as an alternative for terrestrial resources.
Mining these resources requires excavation of the deposit at the seafloor, the transport of the deposit from the seafloor to the sea surface and the processing of the material. One of the technological challenges in deep sea mining is the vertical hydraulic transport of the material from the seafloor to the sea surface. Flow assurance is vital to the entire mining operation, since termination of the transport process by for instance blockage of the riser would be a showstopper for the entire operation.
How to model long distance transport? What about flow stability? Can solid plugs develop? How much pressure is needed to overcome a blocked riser? And how to design for flow assurance? Answering these questions is not trivial, and as a technology provider for the maritime industry IHC invests in the development of knowledge and technology for deep sea mining.
My PhD study, which was completed in February 2016, was part of IHC’s knowledge development program for deep sea mining. The work comprises both experimental research and numerical modelling. The experiments aim at an increased understanding of the vertical transport of especially coarse and irregularly shaped particles. They support the numerical model, which is used for detailed internal flow analysis.
The PhD thesis can be downloaded at http://dx.doi.org/10.4233/uuid:2e493b95-486a-4c2f-a8ae-749990b06a5e