Before " the DEM track treatment " second method in this article introduced a method, but that method is only applicable to a certain number of particles within the reactor, the absence of new incoming particles. Later in MFiX forum asked about, to solve this problem. Specific methods, see:
https://mfix.netl.doe.gov/forum/t/how-to-plot-information-of-feeding-particle-in-paraview/1347