Online monitoring of gas-solid two-phase flow using projected CG method in ECT image reconstruction

► The solution space is projected into the Krylov subspace and the inverse problem is solved by the CG method in Krylov subspace. ► The results show that the projected CG method improves the quality of reconstructed images and reduces computation time in gas-solid two-phase flows. ►Key flow parameters in pneumatic conveying can be estimated with better accuracy according to the gray level values of the images reconstructed with the projected CG method.