Electrical Impedance Imaging of Paste During Extrusion

Robert M West1, Yong Wu1, David M Scott2, Gregg Sunshine2, Brian S Hoyle3, Jacek Kostuch4, Chris N McLeod5 and Richard A Williams1

1Centre for Particle and Colloid Engineering, School of Process, Environmental and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK

2DuPont Central Research and Development, Experimental Station, Wilmington, DE 19880-0304, USA

3Department of Electrical and Electronic Engineering, University of Leeds, Leeds, LS2 9JT, UK

4IMERYS, John Keay House, St Austell, Cornwall, PL 25 4DJ, UK 5School of Engineering, Oxford Brookes University, Oxford, OX3 0BP, UK Email: r.m.west@leeds.ac.uk

ABSTRACT

A case study is presented where electrical impedance tomography is used to image paste during extrusion. This indicates regions of high moisture where slip planes are formed making extrusion more efficient. A two-step Newton image reconstruction method is used with axi-symmetric regularization. This provides clear images of the paste that can be used to gauge extrudability of a paste formulation.

Keywords Electrical impedance tomography, Regularized iterative reconstruction, Paste, Extrusion