Toward Electrical Capacitance Tomography of Water-Dominated Multiphase Vertical Flows

Abstract

Imaging of multiphase flows holding water as continuous phase (i.e., water-dominated flows) is very challenging for conventional electrical capacitance tomography (ECT) due to the high permittivity of water. In this paper, we introduce a new approach, based on the multi-frequency excitation of ECT sensors, for imaging and real-time monitoring of water-dominated columnar or slug vertical flows. The proposed method exploits differences between measurements obtained at distinct frequencies caused by the Maxwell–Wagner–Sillars effect, which is present in multiphase flows with at least one conducting phase. To illustrate this new approach, several numerical simulations are carried out for two-phase and three-phase mixtures containing air, methylamine, and/or oil as dispersed phases and with water as the continuous phase. Experimental results are also provided to validate the findings.