Results and discussions
In the cross-flow moving bed, gas phases exert forces on particles from gas upstream to gas downstream. The cavity appears at the upstream of the Johnson net, wherein no particles; the pinning occurs in the downstream of the bed, wherein particle stop moving downward; the air lock is seen near the feed tube, when particles cannot feed into bed. In particular, the theoretical equation of pinning and cavity are summarized or derived in Appendix . Considering the differences between the rectangular and radial beds, the abnormal phenomena are analyzed respectively in this paper.