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Advanced Imaging & Measurement for Multiphase Flows

Case 2. Periodical flows

Extends of EIT to the periodical oscillated two-phase flow in an oscillatory baffled reactor (OBR) were challenged (Figure 4). This is enabled through deployment of the third generation of ERT systems operating at ultra-fast speed (exceeding 1000 frames per second) and periodical sampling. Periodical concentration distributions caused by strokes of the OBR piston have been visualized using a 3D interpolation method (Figure 5), which revealed the effect of the oscillatory frequency being a larger impact on the mixing performance compared to the oscillatory amplitude. It was known that the conventional cross-correlation method is not able to extract dynamics of periodical flows. With a periodical sampling method developed in the study, pulsation velocity profiles were successfully extracted (Figure 6).

Figure 4: An oscillatory baffled reactor fitted with EIT sensors [2].

 

Figure 5: Concentration distribution in OBR [2].

 

Figure 6: Extracted oil flow velocity profiles in OBR with different sampling lengths

Author Information: Mi Wang, Institute of Particle Science and Engineering, School of Process, Environmental and Materials Engineering, Email: m.wang@leeds.ac.uk

References:
1. Li, H., Wang, M., Wu, Y. and Lucas, G. (2009) “Volume flow rate measurement in vertical oil-in-water pipe flow using electrical impedance tomography and a local probe”, MultScienTechn, 21(i1-2.70), 81-93.
2. Issa, M., Li, H., Schlaberg, H.I., Wang, M. and Williams, R.A. (2009) “Velocity measurements of multi-phase unsteady flow in oscillatory baffled reactor using electrical resistance tomography”, in Proceedings of 3rd International Workshop on Process Tomography (IWPT-3), Tokyo, Japan.
3. Ramskill, N.P. and Wang, M. (2010) “Measurement and Recognition of Gas-Liquid Multiphase Horizontal Flow Regimes using Electrical Resistance Tomography”, in Proceedings of 6th World Congress on Industrial Process Tomography, Beijing.