Characterization of slurry flow regime transitions by ERT

Slurry flows in a pipe have been visualized using electrical resistance tomography (ERT). Complementary to image reconstruction technique, a strategy based on the direct interpretation of the raw ERT measurements has been developed to analyze slurry flow regimes in a horizontal pipe. Experiments have been conducted using a lab-scale pipe loop equipped with a commercial ERT device. The images of slurry concentration have been reconstructed using an iterative Landweber method and compared to a direct linear back-projection (LBP) method available in the ERT software. The slurry concentration has been estimated and the homogeneity of the concentration distribution has been assessed directly from resistance measurements and a simple resistance model. It is shown that this procedure, combining the image reconstruction and the direct interpretation of ERT measurements, allows analyzing the slurry flow regimes and transitions for slurry concentrations up to 20% v/v and velocities up to 2.2 m/s.