DEM runs are expensive. Do you require to have the flow resolved? If not switch off flow and run pure particles!/forum/discussion/comment/105915#Comment_105915

Thanks for replaying, actually, because of the periodic boundary condition, I solved the continuous phase as first with periodic boundary condition and specified air mass flow as of zero Kg/s, in another word I switch off the air flow and then I have run the DPM phase as next as pure particle, but it still very longs time Iteration. I really surprised, because algorithmically, it should not be a problem, the particle dynamics to simulate 300 particles on a CPU.nRegardsnn