An Electrical-Impedance Tomography System for Collecting Validation-Quality Data from Gas-Solid Flows

P R Tortora1, S L Ceccio1, W W Schultz1, T J O’Hern2, J R Torczynski2, S M Trujillo2

1Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2121, USA,

ceccio@engin.umich.edu

2Engineering Sciences Center, Sandia National Laboratories, Albuquerque, NM, 87185-0834, USA, tjohern@sandia.gov

ABSTRACT

Several studies are performed to design an electrical-impedance tomography system for a gas-solid flow to collect data suitable for validating computational models. A two-electrode system is studied experimentally. The needed accuracy, spatial resolution and temporal resolution are addressed, and modeling and reconstruction are discussed. Bulk solid volume fractions measured by the two- electrode system and by gamma-densitometry tomography are in general agreement. Experiments with the two-electrode system also show that the Maxwell-Hewitt relation, used to convert the mixture impedance to solid volume fraction, must be applied carefully, paying attention to the identity of the dispersed and continuous phases. The design of a 16-electrode system is also described.

Keywords EIT, tomography, riser, Maxwell-Hewitt relation