ERT algorithms for quantitative concentration measurement of multiphase flows

A quantitative image reconstruction algorithm for electrical resistance tomography (ERT) has been developed to visualize multiphase flows, like slurry flows in pipes. Based on image reconstruction techniques from literature, a generalized iterative algorithm (GIA) has been derived to solve the ERT inverse problem. Performance of this algorithm has been studied for synthetic and experimental test cases representing rods and solid particle beds in a pipe. Quantitative images have been obtained for each test case and a suitable strategy for the image reconstruction has been identified. In particular, it was found that convergence of the GIA can be ensured using Landweber or Tikhonov iterations, an efficient forward problem solver and an appropriate relaxation factor. Finally, experimental calibration curve of concentration of solid particle beds in a horizontal pipe has been done using the GIA. Results show the capability of ERT to produce quantitative concentration measurements of multiphase flows.