Mathematical Modelling of Flow Parameters in an Oscillatory Baffled Reactor through Electrical Impedance Tomography

G. Vilar1, R.A.Williams1, M.Wang1 and R.J.Tweedie2

1Institute of Particle Science & Engineering, Houldsworth Building, University of Leeds, Clarendon Road, Leeds, West Yorkshire, LS2 9JT, United Kingdom, Email: pre4gvu@leeds.ac.uk

2Malvern Instruments Ltd, Enigma Business Park, Grovewood Road, Malvern, Worcestershire, WR14 1XZ, United Kingdom

ABSTRACT

Tomographic measurement of the different impedance of the two-phase fluids in a chemical process is used to infer different variables (concentration, velocity profiles) to control an Oscillatory Baffled Reactor (OBR). In this paper, the development of a mathematical model of a water-in-oil/oil-in-water emulsion process through Electrical Impedance Tomography (EIT) measurement is presented.

The experimental work is carried out with an Oscillatory Baffled Reactor (OBR), whose main characteristic is that the process fluid has an oscillatory movement superimposed upon the fluid in the reactor. The main advantage of the OBR is that it makes it possible to perform better control of chemical reactions continuously, which previously were only possible in batch operation. For example, in the speciality chemicals industry, where stirred tank batch reactors are often employed which are inefficient and unsafe because of the large inventories of hazardous and/or volatile liquids.

The on-line measurement with the EIT sensor enables the mapping of the concentration of oil (dispersed phase) in the OBR. The application of cross correlation software to the data from the Tomography measurement allows the estimation of the transverse and axial velocity profiles. The main objective of the study is to obtain a mathematical model to relate the velocity parameters from the cross correlation with the experimental measurement together with the characteristic non dimensional parameters of the OBR. The understanding of these parameters enables improved operational control and instrumentation of the reactor, the mathematical prediction of the droplet size and distribution of the dispersed phase and the energy consumption in the OBR. These parameters have a great influence in the new industrial applications of the OBR.

Keywords Oscillatory baffled reactor, electrical impedance tomography