3D-ECT Velocimetry for Flow Structure Quantification of GasLiquid-Solid Fluidized Beds

The electrical capacitance tomography (ECT) velocimetry techniques, namely tomography tracking velocimetry (TTV) and tomography image velocimetry (TIV) are proposed in this study to quantify the flow structure of gas-liquid-solid fluidized beds based on the ECT images. The tomography images of the bubbles in the three-phase system are obtained from image reconstruction using the neural network multi-criteria optimization image reconstruction technique (NN-MOIRT), developed earlier by the authors. The TTV is based on an auto-correlation of tomography images in a single plane sensor to track the three-dimensional position of a bubble swarm. The TIV is based on a cross-correlation of tomography images in two plane sensors to calculate the three-dimensional velocity components of the bubble swarm. The bubble spiral motions, the fluctuations of the three-dimensional bubble swarm velocity components and fluxes in threedimensional space are discussed along with the effect of gas superficial velocity, the presence of solid particles and the column height.