Prof. Dr. Ian Wilson takes part in the Paste, Particle and Polymer Processing Group (in association with Sarah Rough and Bart Hallmark), and continues the activity started by John Bridgwater and Malcom Mackley. Their activities focus around fundamental studies, process modelling, product design and rheology, e.g. investigations of phenomena, such as wall slip, liquid phase migration, agglomeration and spheronisation, developing models of paste forming processes, such as rolling/calendering or screen extrusion and relating function, processing and formulation to deliver particular product properties. Ongoing projects include the extrusion of tungsten carbide pastes (with Sarah Rough) to understand monitor micro-structural development and defect formation, the rheology of bubbly liquids (aka cake batters and foamed cement, with Bart Hallmark), and extrusion-spheronisation of pharmaceutical materials (with Sarah Rough).
Fouling and Cleaning Mechanisms
A whole class of unwanted micro-structured materials can be found as fouling deposits on heat transfer surfaces, in distribution systems and other equipment. Fouling is a common (and expensive) operating problem in many processes, particularly the food industry, where the deposits formed can act as harbours for other problem species (e.g. bacteria ). This work relates to long-standing efforts in heat transfer and approaches the problem at three related scales: fundamental studies of deposit formation and removal (with particular focus on deposit structure and modelling), design, control and operation of individual heat exchanger units, both in production and during cleaning (e.g. for aspectic processing) and design and operation of large heat transfer networks, such as are used in energy intensive processes.
Recent work has looked at water scaling on copper surfaces (with Stuart Clarke) and novel, non-disruptive, in-situ methods for studying the growth or removal of soft layers in conjunction with John Chew (University of Bath). The soft layers include biofilms and protein matrices undergoing swelling for controlled release. Their interest in cleaning in the food sector has expanded into studies of the flow behaviour of liquid jets impinging on vertical walls and their cleaning behaviour. This work (in conjunction with John Davidson) features collaborations with TU Braunschweig, TU Dresden and DAMTP in Cambridge.
The paper by Ishiyama et al. in Heat Transfer Engineering (2014) brought the strands of soft-solids and fouling together in a unified framework for managing fouling and cleaning cycles, where deposit ageing (converting deposit from a soft solid to a hard material) is a key factor. The Matlab code for this work is available from Dr Edward Ishiyama. Ian was awarded an ScD by the University of Cambridge for his work in this field in 2013.
Other Professional Activities
Ian is the Editor-in-Chief (Food) of the IChemE journal Food & Bioproducts Processing, IChemE University Accreditation Assessor, IChemE Food & Drink Subject Interest Group and member of the EHEDG Working Group Tank Cleaning Systems.